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New Orleans Local Weather thread - dkmac - 10-20-2009 06:56 AM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
431 AM CDT TUE OCT 20 2009

.DISCUSSION...
ANOTHER QUIET AND VERY PLEASANT DAY IS ON TAP FOR THE FORECAST
AREA TODAY BEFORE CONDITIONS BEGIN TO DETERIORATE AS THE NEXT
SYSTEM APPROACHES. FLAT UPPER RIDGING OVER THE GULF COAST REGION
WILL SHIFT EAST TONIGHT AS THE UPPER TROUGH CURRENTLY OVER THE
WESTERN U.S. ADVANCES INTO THE SOUTHERN AND CENTRAL ROCKIES. AT THE
SURFACE...HIGH PRESSURE OVER THE SOUTHEAST WILL CONTINUE TO SHIFT
EASTWARD ALLOWING LOW LEVEL EASTERLY FLOW TO BECOME MORE SOUTHEAST
WITH TIME. AS THE FLOW BECOME MORE SOUTHERLY IN ADVANCE OF THE
UPPER TROUGH MOVING INTO THE PLAINS ON WEDNESDAY...MOISTURE WILL
INCREASE AND DEEPEN ACROSS THE REGION. A FEW SHOWERS MAY BE IN THE
OFFING ON WEDNESDAY...PARTICULARLY ACROSS THE COASTAL WATERS AND
WESTERN SECTIONS OF THE FORECAST AREA AS MOISTURE ADVECTION
INCREASES. MOST OF THE RAIN...HOWEVER...WILL HOLD OFF UNTIL LATE
WEDNESDAY AND ESPECIALLY THURSDAY INTO FRIDAY AS THE UPPER TROUGH
ADVANCES EASTWARD WITH AN ASSOCIATED COLD FRONT PUSHING ACROSS THE
AREA LATE THURSDAY NIGHT AND FRIDAY. IT APPEARS THAT THERE WILL BE
PLENTY OF MOISTURE FOR THIS SYSTEM TO WORK WITH AS THE MOISTURE
FROM THE REMNANTS OF HURRICANE RICK IN THE PACIFIC WILL LIKELY BE
DRAWN INTO THIS SYSTEM. THE BEST CHANCE FOR RAIN WILL BE THURSDAY
AFTERNOON THROUGH FRIDAY MORNING...WITH THE RAIN THEN GRADUALLY
ENDING FROM WEST TO EAST FRIDAY AFTERNOON AND FRIDAY EVENING.
WHILE MOISTURE WILL BE PLENTIFUL...OVERALL INSTABILITY AND CAPE
WILL BE BE MODEST. AS A RESULT...WIDESPREAD SEVERE WEATHER IS NOT
EXPECTED WITH THIS SYSTEM ALTHOUGH A FEW STRONG STORMS CANNOT BE
RULES OUT AS MODELS DO FORECAST STRENGTHENING WIND FIELDS WITH
SOME SHEAR THAT WOULD BE CONDUCIVE TO PROMOTING SOME STRONGER
THUNDERSTORMS.

AFTER THIS SYSTEM PUSHES TO THE EAST...DRIER AND SOMEWHAT COOLER
CONDITIONS WILL RETURN FOR THE WEEKEND. AT THIS TIME...A DRY
FORECAST WILL BE INDICATED FOR THE PERIOD SUNDAY INTO EARLY NEXT
WEEK AS GENERALLY INDICATED BY THE GFS. THE ECMWF IS NOT AS
OPTIMISTIC AND PAINTS A WETTER SCENARIO WITH A SHORT WAVE TROUGH
SWINGING ACROSS THE GULF COAST REGION AND LOWER MISSISSIPPI VALLEY
GENERATING SOME PRECIPITATION. 11

&&

.AVIATION...
VFR THROUGH FORECAST PERIOD FOR ALL TERMINALS. MOISTURE FIELDS
INDICATE WE WILL BE A LITTLE MORE PRONE TO CUMULUS DEVELOPMENT BY
MID DAY...WITH CLOUDS PROBABLY AROUND 4K FEET...LIKELY NOT TO
BE ENOUGH FOR WIDESPREAD CEILINGS BEFORE 00Z. WINDS GENERALLY NEAR
OR BELOW 10 KNOTS THROUGH THE PERIOD WITH AN EASTERLY COMPONENT.
LITTLE MORE FOG ACROSS THE AREA TONIGHT AS MOISTURE BEGINS TO MOVE
IN. MOSTLY 1SM WITH A LOWER VALUE POSSIBLE AT MCB BY MORNING. 17

&&

.MARINE...
WINDS WILL LIKELY INCREASE TO THE EXERCISE CAUTION RANGE OVER
THE COASTAL WATERS THIS EVENING AND LINGER INTO THURSDAY. SEAS WILL
REACT ACCORDINGLY...POSSIBLY REACHING AROUND 7 FEET THURSDAY FOR THE
OUTER WATERS. THERE MAY BE ABOUT A 12 HOUR LULL IN EXERCISE
CAUTION CONDITIONS BEFORE WINDS INCREASE IN ADVANCE OF THE COLD
FRONT. THIS FRONTAL PASSAGE WILL AFFECT THE COASTAL WATERS
FRIDAY...WITH SMALL CRAFT ADVISORY CONDITIONS LIKELY FRIDAY THROUGH
EARLY SATURDAY NIGHT...BEFORE RELAXING. THIS EVENT WILL NOT BE AS
STRONG AS THE ONE THIS PAST WEEKEND...BUT STILL DANGEROUS FOR
MARINERS WITH SMALL CRAFT. 17

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 75 53 78 66 / 0 0 20 40
BTR 76 56 80 67 / 0 0 20 40
MSY 76 61 79 69 / 0 10 20 30
GPT 74 57 77 67 / 0 0 20 30


New Orleans Local Weather thread - dkmac - 10-21-2009 04:38 AM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
410 AM CDT WED OCT 21 2009

.SHORT TERM...HIGH PRESSURE AT THE SFC CONTINUES TO EXIT TO THE ENE
AND THIS IS LEADING TO INCREASING SE LL FLOW. DEWPOINTS HAVE
CONTINUED TO RISE THROUGH THE NIGHT AND THIS WILL BE THE CASE TODAY
AS WELL. AT 7Z THE UPPER LOW WAS OVER THE FOUR CORNERS REGION WHILE
CYCLOGENESIS IS OCCURRING ACROSS W TX.

TODAY SHOULD BEGIN RATHER BENIGN BUT AS THE DAY WEARS ON WEAK
ISENTROPIC LIFT/WAA SHRA WILL BEGIN TO DEVELOP ACROSS THE LA COAST.
THESE SHRA SHOULD SPREAD N THROUGH THE LATE AFTN AND INTO THE EVN
HRS. MOISTURE WILL INCREASE ALL DAY LONG AND OVERNIGHT THROUGHOUT
THE ENTIRE COLUMN. LL FLOW WILL PROGRESSIVELY BECOME MORE SRLY
THROUGH THE DAY WHILE SWRLY MID LVL FLOW WILL TRANSPORT MOISTURE
FROM TS RICK ACROSS OLD MEXICO AND INTO THE AREA. BY TOMORROW
MORNING PWS ARE EXPECTED TO BE ALL THE WAY BACK TO NEAR 2"(AT 00Z
LAST NIGHT WE WERE SITTING AT LESS THAN THREE QUARTERS OF AN INCH).
THIS WILL SET THE STAGE FOR A WET 24 TO 36 HRS THU AND POSSIBLY WELL
INTO FRI.

TONIGHT THROUGH FRI. THE 4 CORNERS UPPER LOW WILL LIFT OUT TO THE NE
WHILE DRIVING A COLD FRONT TWRDS THE LOWER MS VALLEY. THE FRONT WILL
BE SLOW TO MOVE THROUGH ESPECIALLY WITH THE POSSIBILITY OF A WEAK
WAVE DEVELOPING ALONG THE FRONT ACROSS THE NRN GULF LATE THU
NIGHT/EARLY FRI MORNING. THIS COULD LEAD TO A WET DAY AND A HALF
WITH WIDESPREAD RAINFALL TOTALS OF AROUND 2" AND LOCALLY HIGHER
AMOUNTS. SHRA AND EMBEDDED TSRA SHOULD START TO BECOME MORE NUMEROUS
AS THE DAY WEARS ON THU AND THE FRONT PUSHES CLOSER TO THE AREA. BY
LATE THU NIGHT RAIN MAY BECOME MORE FOCUSED ACROSS THE LA COAST
WHERE THE POSSIBILITY OF A SFC WAVE ALONG THE FRONT LOOKS TO TRACK.
THIS WAVE WILL MOVE UP THE FRONT THROUGH THE DAY FRI WITH THE FRONT
PUSHING INTO THE COASTAL WATERS BY MIDDAY FRI. RAIN WILL START TO
COME TO AN END LATE FRI MORNING BEGINNING IN THE NW AND BY FRI EVN
MOST OF THE RAIN SHOULD BE ALONG THE COAST AND IN THE COASTAL
WATERS. AGAIN THU THROUGH FRI MORNING LOOKS TO BE RATHER WET. PWS
WILL APPROACH 2" WHICH IS AROUND 200% OF NORMAL THIS TIME OF THE
YEAR. LL MOISTURE NOT QUITE AS IMPRESSIVE BUT H85 THETA E AIR SHOULD
INCREASE TO AROUND 337-338K JUST AHEAD OF THE FRONT. ADD IN THE SLOW
FORWARD MOTION OF THE FRONT ALONG WITH A SFC WAVE AND WE COULD SEE
A VERY EFFICIENT RAIN PRODUCING SYSTEM. LUCKILY WE HAVE BEEN ABLE TO
DRY OUT A LITTLE BUT THIS WILL ADD SOME RAIN TO THE HIGHER RIVERS
ESPECIALLY THE PEARL RIVER.

.LONG TERM...THE MEDIUM RANGE MDLS ARE FOR THE MOST PART IN FAIR
AGREEMENT BUT THERE IS THE GENERAL STRENGTH...TIMING...AND TRACK
ISSUES. BOTH THE ECMWF AND GFS KEEP THINGS SOMEWHAT ACTIVE NEXT WEEK
WITH MOSTLY SW FLOW ALOFT. THEY BOTH TRY TO SHOW A S/W COMING ACROSS
THE REGION SOMETIME MON...ECMWF FASTER/GFS SLOWER. RIGHT NOW
CONFIDENCE IS NOT TOO GREAT IN THE FCST FOR THE FIRST HALF OF NEXT
WEEK SINCE PREV MDLS RUNS WERE MOSTLY DRY IN THE EXTENDED AND NOW
NOT QUITE AS MUCH SO I AM BASICALLY GOING TO STICK WITH THE MEX GUI.

THIS WEEKEND WILL BE PLEASANT WITH A RETURN OF DRIER AND COOLER
CONDITIONS. FRONT WILL PUSH WELL INTO THE GULF AGAIN. THIS WILL
DRIVE ALL OF THE MOISTURE SOUTH OF OUR AREA WHILE COOLER AIR SHOULD
ALREADY BE IN PLACE BY SAT MORNING. SFC HIGH WILL DOMINATE THE AREA
THROUGH MUCH OF THE WEEKEND. COMBINE THIS WITH MOSTLY CLEAR SKIES
AND DRIER AIR SHOULD AND THIS WILL LEAD TO DECENT RAD COOLING
CONDITIONS. THAT SAID THIS IS NOT A REAL COLD AIRMASS COMPARED TO
WHAT WE SAW THIS PAST WEEKEND SO LOWS SHOULD ONLY FALL INTO THE
UPPER 40S TO MID 50S.

NEXT WEEK...BY SUN NIGHT THE BACK END OF THE OLD COLD FRONT WILL
START TO RETREAT BACK TO THE N ACROSS THE NWRN GULF AS THE SFC HIGH
PUSHES OFF TO THE ENE. THIS WILL ALLOW MOISTURE TO START TO INCREASE
ACROSS THE REGION ESPECIALLY AS WE MOVE FURTHER INTO THE WORK WEEK.
THERE ARE INDICATIONS OF A WEAK S/W MOVING THROUGH THE REGION
SOMETIME MON AS THE FLOW ALOFT BECOME MORE SWRLY AGAIN. THIS COULD
SPARK ISLTD TO SCT SHRA WITH THE GREATEST RISK FOR RAIN ACROSS THE
SERN HALF OF THE CWA. RAIN CHANCES WILL REMAIN IN THE 20% RANGE FOR
TUE AND WED AS MOISTURE CONTINUES TO SLOWLY INCREASE. WE WILL BE
UNDER SW FLOW WITH BROAD LIFT ACROSS THE ENTIRE REGION. ONE THING TO
NOTE...THE ECMWF IS HINTING AT THE POSSIBILITY OF A RATHER STRONG
SYSTEM MOVING THROUGH THE CNTRL CONUS LATE NEXT WEEK WITH THE
POSSIBILITY OF SVR WEATHER OCCURRING OVER THE REGION. THIS IS 8+
DAYS AWAY SO THIS COULD CHANGE SIGNIFICANTLY BUT IT IS WORTH KEEPING
AND EYE ON. /CAB/

&&

.AVIATION...
...PRELIMINARY 12Z AVIATION DISCUSSION...
VFR WILL CONTINUE AT ALL TERMINALS THROUGH THE DAY. WILL SEE UPPER
DECK MOVE INTO THE AREA TODAY BECOMING BKN-OVC200. LOWER CEILINGS
WILL BEGIN TO DEVELOP LATE TONIGHT AT ABOUT BKN070. SOME LIGHT RAIN
MAY ALSO BEGIN TO MOVE INTO THE WESTERN PERIPHERY BUT IS NOT
EXPECTED TO BE A PROBLEM THROUGH THE END OF THE TAF PERIOD 12Z.

EXPECTATIONS WERE TO SEE FOG THIS MORNING AS DEW PTS MOVED UP QUITE
A BIT THROUGH THE DAY YESTERDAY AND RADIATIONAL COOLING HAS BEEN
EVIDENT THROUGH THE NIGHT. THIS HAS NOT OCCURRED AND ALL GUIDANCE
PACKAGES SHOW THE SAME...LITTLE TO NO RESTRICTIONS. LOCAL MODEL RUNS
HAVE SHOWN THIS QUITE STRONGLY OVER THE LAST FEW DAYS. SO WILL NOT
SET ANY VIS RESTRICTIONS IN TAFS AT LEAST FOR THIS MORNING.

&&

.MARINE...
WINDS ARE NOW BEGINNING TO RESPOND TO AN INCREASING PRESSURE
GRADIENT OVER THE COASTAL WATERS...ESPECIALLY WEST OF THE MISS
RIVER. WINDS OF 20 TO 25 KNOTS SHOULD ENVELOPE THE ENTIRE AREA
WATERS TODAY AND ADVISORIES ARE IN PLACE. WINDS WEAKEN JUST A
BIT...BUT ENOUGH TO BRING IN CAUTION STATEMENTS AFTER MIDNIGHT
TONIGHT CAUSING THE ADVISORIES TO FALL FROM EAST TO WEST. AT
LEAST...CAUTION STATEMENTS WILL BE UP THROUGH THURSDAY NIGHT. A COLD
FRONT IS EXPECTED TO MOVE THROUGH FRIDAY CAUSING WINDS TO INCREASE
ONCE AGAIN TO ADVISORY STATUS.

THE OTHER HAZARD WILL BE STRONG AND SEVERE TS DEVELOPMENT. A STRONG
DISTURBANCE AND ASSOCIATED SFC LOW SHOULD DEVELOP ALONG THE COLD
FRONT THU NIGHT INTO FRI MORNING. THIS SHOULD PROVIDE SEVERAL AREAS OF
SEVERE TS OVER THE COASTAL WATERS. SOME OF THESE WILL EVEN MOVE INTO
THE NEAR SHORE WATERS AND ISLAND MARSH AREAS ALONG THE COAST. STRONG
HIGH PRESSURE WILL MOVE IN PROVIDING LESS VOLATILE WEATHER BY LATE
SUNDAY. RETURN FLOW WILL THEN BEGIN BY THE START OF THE WEEK AHEAD
OF ANOTHER COLD FRONT.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 73 64 75 63 / 20 40 100 80
BTR 76 66 78 63 / 40 60 100 80
MSY 79 69 81 69 / 40 50 90 90
GPT 75 67 77 68 / 30 30 90 80

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM...AND LAKE PONTCHARTRAIN AND
LAKE MAUREPAS.

SMALL CRAFT ADVISORY UNTIL 7 AM THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO
60 NM...AND COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM...AND LAKE PONTCHARTRAIN AND
LAKE MAUREPAS.

SMALL CRAFT ADVISORY UNTIL 7 AM THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO
60 NM...AND COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.


New Orleans Local Weather thread - ROLLTIDE - 10-21-2009 02:55 PM

Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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000
FXUS64 KLIX 211258
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
758 AM CDT WED OCT 21 2009

.UPDATE...
.SOUNDING DISCUSSION...

THE MOISTURE HAS BEGUN TO MOVE BACK INTO THE AREA DUE TO THE
SOUTHERLY FLOW IN THE LOW LEVELS. A SIGNIFICANT AMOUNT OF DRY AIR
IS PRESENT FROM ABOUT 850 MB TO 375 MB...PRECIPITABLE WATER VALUE
OF 0.93 INCHES. WINDS ARE OUT OF THE SOUTHEAST UP TO 500 MB AND
OUT OF THE NORTHWEST ALOFT.

&&

.PREV DISCUSSION... /ISSUED 410 AM CDT WED OCT 21 2009/

SHORT TERM...HIGH PRESSURE AT THE SFC CONTINUES TO EXIT TO THE ENE
AND THIS IS LEADING TO INCREASING SE LL FLOW. DEWPOINTS HAVE
CONTINUED TO RISE THROUGH THE NIGHT AND THIS WILL BE THE CASE TODAY
AS WELL. AT 7Z THE UPPER LOW WAS OVER THE FOUR CORNERS REGION WHILE
CYCLOGENESIS IS OCCURRING ACROSS W TX.

TODAY SHOULD BEGIN RATHER BENIGN BUT AS THE DAY WEARS ON WEAK
ISENTROPIC LIFT/WAA SHRA WILL BEGIN TO DEVELOP ACROSS THE LA COAST.
THESE SHRA SHOULD SPREAD N THROUGH THE LATE AFTN AND INTO THE EVN
HRS. MOISTURE WILL INCREASE ALL DAY LONG AND OVERNIGHT THROUGHOUT
THE ENTIRE COLUMN. LL FLOW WILL PROGRESSIVELY BECOME MORE SRLY
THROUGH THE DAY WHILE SWRLY MID LVL FLOW WILL TRANSPORT MOISTURE
FROM TS RICK ACROSS OLD MEXICO AND INTO THE AREA. BY TOMORROW
MORNING PWS ARE EXPECTED TO BE ALL THE WAY BACK TO NEAR 2"(AT 00Z
LAST NIGHT WE WERE SITTING AT LESS THAN THREE QUARTERS OF AN INCH).
THIS WILL SET THE STAGE FOR A WET 24 TO 36 HRS THU AND POSSIBLY WELL
INTO FRI.

TONIGHT THROUGH FRI. THE 4 CORNERS UPPER LOW WILL LIFT OUT TO THE NE
WHILE DRIVING A COLD FRONT TWRDS THE LOWER MS VALLEY. THE FRONT WILL
BE SLOW TO MOVE THROUGH ESPECIALLY WITH THE POSSIBILITY OF A WEAK
WAVE DEVELOPING ALONG THE FRONT ACROSS THE NRN GULF LATE THU
NIGHT/EARLY FRI MORNING. THIS COULD LEAD TO A WET DAY AND A HALF
WITH WIDESPREAD RAINFALL TOTALS OF AROUND 2" AND LOCALLY HIGHER
AMOUNTS. SHRA AND EMBEDDED TSRA SHOULD START TO BECOME MORE NUMEROUS
AS THE DAY WEARS ON THU AND THE FRONT PUSHES CLOSER TO THE AREA. BY
LATE THU NIGHT RAIN MAY BECOME MORE FOCUSED ACROSS THE LA COAST
WHERE THE POSSIBILITY OF A SFC WAVE ALONG THE FRONT LOOKS TO TRACK.
THIS WAVE WILL MOVE UP THE FRONT THROUGH THE DAY FRI WITH THE FRONT
PUSHING INTO THE COASTAL WATERS BY MIDDAY FRI. RAIN WILL START TO
COME TO AN END LATE FRI MORNING BEGINNING IN THE NW AND BY FRI EVN
MOST OF THE RAIN SHOULD BE ALONG THE COAST AND IN THE COASTAL
WATERS. AGAIN THU THROUGH FRI MORNING LOOKS TO BE RATHER WET. PWS
WILL APPROACH 2" WHICH IS AROUND 200% OF NORMAL THIS TIME OF THE
YEAR. LL MOISTURE NOT QUITE AS IMPRESSIVE BUT H85 THETA E AIR SHOULD
INCREASE TO AROUND 337-338K JUST AHEAD OF THE FRONT. ADD IN THE SLOW
FORWARD MOTION OF THE FRONT ALONG WITH A SFC WAVE AND WE COULD SEE
A VERY EFFICIENT RAIN PRODUCING SYSTEM. LUCKILY WE HAVE BEEN ABLE TO
DRY OUT A LITTLE BUT THIS WILL ADD SOME RAIN TO THE HIGHER RIVERS
ESPECIALLY THE PEARL RIVER.

LONG TERM...THE MEDIUM RANGE MDLS ARE FOR THE MOST PART IN FAIR
AGREEMENT BUT THERE IS THE GENERAL STRENGTH...TIMING...AND TRACK
ISSUES. BOTH THE ECMWF AND GFS KEEP THINGS SOMEWHAT ACTIVE NEXT WEEK
WITH MOSTLY SW FLOW ALOFT. THEY BOTH TRY TO SHOW A S/W COMING ACROSS
THE REGION SOMETIME MON...ECMWF FASTER/GFS SLOWER. RIGHT NOW
CONFIDENCE IS NOT TOO GREAT IN THE FCST FOR THE FIRST HALF OF NEXT
WEEK SINCE PREV MDLS RUNS WERE MOSTLY DRY IN THE EXTENDED AND NOW
NOT QUITE AS MUCH SO I AM BASICALLY GOING TO STICK WITH THE MEX GUI.

THIS WEEKEND WILL BE PLEASANT WITH A RETURN OF DRIER AND COOLER
CONDITIONS. FRONT WILL PUSH WELL INTO THE GULF AGAIN. THIS WILL
DRIVE ALL OF THE MOISTURE SOUTH OF OUR AREA WHILE COOLER AIR SHOULD
ALREADY BE IN PLACE BY SAT MORNING. SFC HIGH WILL DOMINATE THE AREA
THROUGH MUCH OF THE WEEKEND. COMBINE THIS WITH MOSTLY CLEAR SKIES
AND DRIER AIR SHOULD AND THIS WILL LEAD TO DECENT RAD COOLING
CONDITIONS. THAT SAID THIS IS NOT A REAL COLD AIRMASS COMPARED TO
WHAT WE SAW THIS PAST WEEKEND SO LOWS SHOULD ONLY FALL INTO THE
UPPER 40S TO MID 50S.

NEXT WEEK...BY SUN NIGHT THE BACK END OF THE OLD COLD FRONT WILL
START TO RETREAT BACK TO THE N ACROSS THE NWRN GULF AS THE SFC HIGH
PUSHES OFF TO THE ENE. THIS WILL ALLOW MOISTURE TO START TO INCREASE
ACROSS THE REGION ESPECIALLY AS WE MOVE FURTHER INTO THE WORK WEEK.
THERE ARE INDICATIONS OF A WEAK S/W MOVING THROUGH THE REGION
SOMETIME MON AS THE FLOW ALOFT BECOME MORE SWRLY AGAIN. THIS COULD
SPARK ISLTD TO SCT SHRA WITH THE GREATEST RISK FOR RAIN ACROSS THE
SERN HALF OF THE CWA. RAIN CHANCES WILL REMAIN IN THE 20% RANGE FOR
TUE AND WED AS MOISTURE CONTINUES TO SLOWLY INCREASE. WE WILL BE
UNDER SW FLOW WITH BROAD LIFT ACROSS THE ENTIRE REGION. ONE THING TO
NOTE...THE ECMWF IS HINTING AT THE POSSIBILITY OF A RATHER STRONG
SYSTEM MOVING THROUGH THE CNTRL CONUS LATE NEXT WEEK WITH THE
POSSIBILITY OF SVR WEATHER OCCURRING OVER THE REGION. THIS IS 8+
DAYS AWAY SO THIS COULD CHANGE SIGNIFICANTLY BUT IT IS WORTH KEEPING
AND EYE ON. /CAB/

AVIATION...
..PRELIMINARY 12Z AVIATION DISCUSSION...
VFR WILL CONTINUE AT ALL TERMINALS THROUGH THE DAY. WILL SEE UPPER
DECK MOVE INTO THE AREA TODAY BECOMING BKN-OVC200. LOWER CEILINGS
WILL BEGIN TO DEVELOP LATE TONIGHT AT ABOUT BKN070. SOME LIGHT RAIN
MAY ALSO BEGIN TO MOVE INTO THE WESTERN PERIPHERY BUT IS NOT
EXPECTED TO BE A PROBLEM THROUGH THE END OF THE TAF PERIOD 12Z.

EXPECTATIONS WERE TO SEE FOG THIS MORNING AS DEW PTS MOVED UP QUITE
A BIT THROUGH THE DAY YESTERDAY AND RADIATIONAL COOLING HAS BEEN
EVIDENT THROUGH THE NIGHT. THIS HAS NOT OCCURRED AND ALL GUIDANCE
PACKAGES SHOW THE SAME...LITTLE TO NO RESTRICTIONS. LOCAL MODEL RUNS
HAVE SHOWN THIS QUITE STRONGLY OVER THE LAST FEW DAYS. SO WILL NOT
SET ANY VIS RESTRICTIONS IN TAFS AT LEAST FOR THIS MORNING.

MARINE...
WINDS ARE NOW BEGINNING TO RESPOND TO AN INCREASING PRESSURE
GRADIENT OVER THE COASTAL WATERS...ESPECIALLY WEST OF THE MISS
RIVER. WINDS OF 20 TO 25 KNOTS SHOULD ENVELOPE THE ENTIRE AREA
WATERS TODAY AND ADVISORIES ARE IN PLACE. WINDS WEAKEN JUST A
BIT...BUT ENOUGH TO BRING IN CAUTION STATEMENTS AFTER MIDNIGHT
TONIGHT CAUSING THE ADVISORIES TO FALL FROM EAST TO WEST. AT
LEAST...CAUTION STATEMENTS WILL BE UP THROUGH THURSDAY NIGHT. A COLD
FRONT IS EXPECTED TO MOVE THROUGH FRIDAY CAUSING WINDS TO INCREASE
ONCE AGAIN TO ADVISORY STATUS.

THE OTHER HAZARD WILL BE STRONG AND SEVERE TS DEVELOPMENT. A STRONG
DISTURBANCE AND ASSOCIATED SFC LOW SHOULD DEVELOP ALONG THE COLD
FRONT THU NIGHT INTO FRI MORNING. THIS SHOULD PROVIDE SEVERAL AREAS OF
SEVERE TS OVER THE COASTAL WATERS. SOME OF THESE WILL EVEN MOVE INTO
THE NEAR SHORE WATERS AND ISLAND MARSH AREAS ALONG THE COAST. STRONG
HIGH PRESSURE WILL MOVE IN PROVIDING LESS VOLATILE WEATHER BY LATE
SUNDAY. RETURN FLOW WILL THEN BEGIN BY THE START OF THE WEEK AHEAD
OF ANOTHER COLD FRONT.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 73 64 75 63 / 20 40 100 80
BTR 76 66 78 63 / 40 60 100 80
MSY 79 69 81 69 / 40 50 90 90
GPT 75 67 77 68 / 30 30 90 80

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT THURSDAY FOR GMZ530-555-575.

SMALL CRAFT ADVISORY UNTIL 7 AM CDT THURSDAY FOR GMZ550-570.

MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT THURSDAY FOR GMZ555-575.

SMALL CRAFT ADVISORY UNTIL 7 AM CDT THURSDAY FOR GMZ570.

&&

$$


New Orleans Local Weather thread - dkmac - 10-22-2009 05:44 AM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
534 AM CDT THU OCT 22 2009

.SHORT TERM...
THIS MORNING...PERSISTENT MODERATE TO STRONG SOUTHEAST WINDS AND
LARGE WAVES WILL CONTINUE TO PUSH WATER INTO COASTAL SECTIONS.
TIDE LEVELS CONTINUE TO RUN ABOUT A FOOT AND A HALF TO TWO FEET
ABOVE NORMAL...AND ARE EITHER NEAR OR JUST BEYOND THE HIGH
ASTRONOMICAL TIDE. HAN**** COUNTY EMA REPORTED COASTAL FLOODING OF
THE LOW LYING ROADWAYS IN THE LAKESHORE AREA. TIDES WILL REMAIN
ABOVE NORMAL THROUGH TONIGHT...BUT LEVELS SHOULD BE BELOW FLOOD BY
LATE MORNING OR EARLY AFTERNOON. HAVE CONVERTED THE COASTAL FLOOD
WATCH TO A COASTAL FLOOD ADVISORY THAT IS IN EFFECT UNTIL 1 PM
TODAY.

THE OTHER CONCERNS TODAY ARE SEVERE THUNDERSTORM POTENTIAL AND
HEAVY RAINFALL. VIGOROUS MID/UPPER TROUGH WILL MOVE EAST AND
NORTHEAST ACROSS THE PLAINS STATES TODAY WITH A SURFACE LOW MOVING
THOUGH THE ARK-LA-TEX REGION AND LOWER MISSISSIPPI VALLEY. THE
STORM SYSTEM WILL MOVE NORTHEAST TONIGHT AND DRAG A COLD FRONT
THROUGH MOST OF THE FORECAST AREA TONIGHT. GULF MOISTURE COMBINED
WITH PACIFIC MOISTURE FROM THE REMNANTS OF FORMER HURRICANE RICK
WILL INTERACT WITH THE STRONG DYNAMICS. THIS WILL PRODUCE
NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED TO SCATTERED
THUNDERSTORMS TODAY AS INSTABILITY INCREASES. THE MAIN INGREDIENTS
TO SUPPORT A SLIGHT RISK OF SEVERE THUNDERSTORMS ARE LOW LEVEL
SHEAR AND LOW LEVEL INSTABILITY DUE TO HIGH DEWPOINTS. THE
INHIBITING FACTOR IS WEAK MID LEVEL LAPSE RATES. THE MAIN THREATS
FROM ANY SEVERE STORMS ARE DAMAGING STRAIGHT LINE WINDS AND
ISOLATED TORNADOES AND WATERSPOUTS. WIDESPREAD FLOODING IS NOT A
CONCERN...HOWEVER...WIDESPREAD RAINFALL AMOUNTS OF 2 TO 3 INCHES
ARE EXPECTED OVER PORTIONS OF SOUTHWEST MISSISSIPPI AND PORTIONS
OF EAST CENTRAL AND SOUTHEAST LOUISIANA...INCLUDING THE BATON
ROUGE AREA THROUGH TONIGHT. FLASH FLOOD GUIDANCE VALUES ARE HIGH
ENOUGH TO HANDLE THE EXPECTED RAINFALL...HOWEVER LOCALLY HIGHER
AMOUNTS OF 3 TO 4 INCHES COULD PRODUCE SOME SIGNIFICANT PONDING
AND BRIEF FLOODING OF STREETS AND SMALL STREAMS.

THE COLD FRONT WILL MOVE OFFSHORE FRIDAY MORNING WHICH WILL DRY
THINGS OUT FAIRLY QUICKLY ON LAND. HAVE LOWERED THE RAIN CHANCES
FROM THE PREVIOUS FORECAST DUE THE SLIGHTLY FASTER MOVEMENT OF THE
FRONT. DRIER AND MILDER AIR WILL MOVE IN FRIDAY AFTERNOON
ACCOMPANIED BY CLEARING SKIES.

FRIDAY NIGHT WILL BE MOSTLY CLEAR AND COOLER.

.LONG TERM...
SURFACE HIGH PRESSURE WILL MAKE FOR A DRY AND PLEASANT WEEKEND.
NEXT WEEK...A FAST MOVING SHORTWAVE TROUGH WILL MOVE THROUGH THE
LOWER MISSISSIPPI VALLEY ON MONDAY. IT APPEARS MOISTURE WILL HAVE
A TOUGH TIME RETURNING NORTH...SO AM ONLY INCLUDING A SLIGHT
CHANCE OF SHOWERS. ANOTHER VIGOROUS HIGH AMPLITUDE UPPER TROUGH IS
EXPECTED TO DEVELOP OVER THE CENTRAL CONUS WEDNESDAY. THE ECMWF IS
FASTER MOVING THIS SYSTEM AND THE ASSOCIATED COLD FRONT EAST WITH
THE GFS SLOWER. WILL LIKELY HAVE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL DURING THIS TIME
FRAME...AND THIS WILL HAVE TO BE FINE TUNED AS IT GETS CLOSER.

22/TD
&&

.AVIATION...
...PRELIMINARY 12Z AVIATION DISCUSSION...
AS ISENTROPIC LIFT AIDS IN SATURATING THE AIRMASS...CEILINGS WILL
BEGIN TO LOWER WITH KMCB AND KBTR LIKELY SEEING MVFR CIGS BY MID
MORNING. ONCE CEILINGS BKN015 MOVE IN THEY SHOULD STAY WITH A FEW
TEMPO UP TO BKN050 THROUGH TONIGHT. SHOULD NOT SEE LARGE VISIBILITY
SWINGS UNTIL PRECIPITATION BECOMES HEAVIER LATER IN THE DAY OR
DURING THE EVENING. CONVECTIVE CHANCES WILL BEGIN TO INCREASE BY
EARLY TO MID AFTERNOON FROM THE NORTHWEST. COLD FRONTAL PASSAGE
SHOULD BE THROUGH ALL TERMINALS BY 13Z FRI.

&&

.MARINE...
WILL EXTEND MARINE ADVISORIES AND CAUTION STATEMENTS. ADVISORIES
WILL GO OUT TO MID FRI MORNING AS WINDS SHOULD STAY INSIDE OR AT THE
LOW END OF CRITERIA. CAUTION STATEMENTS WILL BE HEADLINED FOR TODAY
BUT WILL BE EXTENDED THROUGH TONIGHT DURING THE DAY SHIFT. STRONG
WINDS AND LONG FETCH IS BRINGING 7 TO 8 FOOT SEAS NEAR THE COAST.
THESE SEAS SHOULD CONTINUE THROUGH MID FRI MORNING AS THE COLD FRONT
MOVES THROUGH. ON THE BACK SIDE OF THE FRONT WINDS WILL SHIFT TO NW
AND SLOWLY INCREASE INTO FRI NIGHT BACK TO ADVISORY STATUS. WINDS
AND SEAS SHOULD SUBSIDE BY THE START OF THE WEEK. RETURN FLOW WILL
START UP AGAIN BY TUE AND THE NEXT SYSTEM IS DUE IN THE AREA AROUND
MID WEEK.

THE OTHER HAZARD TODAY AND TONIGHT WILL BE STRONG TO SEVERE TSTM
DEVELOPMENT. A STRONG DISTURBANCE AND ASSOCIATED SFC LOW SHOULD
DEVELOP ALONG THE COLD FRONT TODAY AND MOVE NORTH ALONG THE FRONT
TONIGHT. THIS SHOULD HELP PROVIDE SEVERAL AREAS OF SEVERE TS OVER
THE COASTAL WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 77 60 68 47 / 100 100 20 0
BTR 79 60 72 49 / 100 100 10 0
MSY 82 68 74 56 / 90 100 30 0
GPT 78 68 75 52 / 70 100 60 0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...COASTAL FLOOD ADVISORY UNTIL 1 PM THURSDAY FOR THE FOLLOWING
ZONES: LOWER JEFFERSON...LOWER LAFOURCHE...LOWER
PLAQUEMINES...LOWER ST. BERNARD...LOWER
TERREBONNE...ORLEANS...ST. TAMMANY...AND UPPER ST. BERNARD.

GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

SMALL CRAFT ADVISORY UNTIL 10 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF
THE MISSISSIPPI RIVER FROM 20 TO 60 NM...AND COASTAL WATERS
FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER OUT 20 NM.

MS...COASTAL FLOOD ADVISORY UNTIL 1 PM THURSDAY FOR THE FOLLOWING
ZONES: AND HAN****.

GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

SMALL CRAFT ADVISORY UNTIL 10 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF
THE MISSISSIPPI RIVER FROM 20 TO 60 NM...AND COASTAL WATERS
FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER OUT 20 NM.


New Orleans Local Weather thread - ROLLTIDE - 10-22-2009 09:28 PM

Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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000
FXUS64 KLIX 230109
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
809 PM CDT THU OCT 22 2009

.UPDATE...
...SOUNDING DISCUSSION...

NO PROBLEMS WITH THE FLIGHT THIS EVENING. A VERY MOIST ATMOSPHERE
IN PLACE AND A FAIR AMOUNT OF INSTABILITY WITH A PW OF 2.16 INCHES
AND AN LI -3.6. A GOOD AMOUNT OF SPEED SHEAR FROM THE SURFACE UP
TO THE LOWER LEVELS HELPING AID IN TORNADO THREATS. A VERY FAST STORM
MOTION OF 29 KNOTS ALLOWED FOR A VERY FAST MOVEMENT OF SHOWERS AND
STORMS.


&&

.PREV DISCUSSION... /ISSUED 456 PM CDT THU OCT 22 2009/

UPDATE...
CWF AND ZFP PRODUCTS UPDATED FOR TORNADO WATCH 773 IN EFFECT UNTIL
03Z...WATCH NUMBER 772 EXPIRES AT 00Z...SO WILL HAVE ANOTHER
UPDATE TO ZFP AT OR BEFORE THAT POINT. 35

PREV DISCUSSION... /ISSUED 348 PM CDT THU OCT 22 2009/

SHORT TERM...MAIN CONCERN IS SVR POTENTIAL FOR THE AREA FOR THE
REMAINDER OF THE AFTERNOON AND EVENING HRS. A TOR WATCH IS STILL IN
EFFECT THROUGH 7PM FOR AREAS WEST OF A LINE FROM HAMMOND TO
DONALDSONVILLE TO MORGAN CITY. SFC LOW CONTINUES TO TRACK TO THE NNE
THROUGH NWRN LA AND DEEPEN. THIS HAS CAUSED SFC PRESSURES TO FALL
ACROSS THE REGION AND TIGHTENING THE PRESSURE GRADIENT. UPPER LOW
CONTINUES TO MOVE TO THE NE THROUGH THE CNTRL PLAINS.

THIS AFTN AND THIS EVN...THIS IS THE MAIN TIME CONCERN. THE SFC LOW
WILL TRACK TO THE NNE TWRDS THE MID MS VALLEY AND DRIVE A COLD FRONT
INTO THE REGION LATE TONIGHT. WE ARE STILL EXPECTING A LINE OF SHRA
AND TSRA JUST AHEAD OF THE FRONT PROBABLY APPROACH THE BTR METRO
AROUND 21Z...THE N.O. METRO AROUND 23-00Z AND CNTRL MS COAST JUST
BEFORE 2Z. THE FRONT SHOULD BE NOT TOO FAR BEHIND THE LINE OF
CONVECTION AND LOOKS TO PUSH INTO THE COASTAL AREA BEFORE SUNRISE
AND PROBABLY THROUGH MUCH OF THE CWA A FEW HRS AFTER SUNRISE.

AS FOR SVR POTENTIAL THINGS DON`T LOOK THAT GREAT BUT THERE ARE
ENOUGH INGREDIENTS TO GET A FEW NASTY STORMS ACROSS THE REGION.
OVERALL INSTABILITY IS LACKING AND MID LVL LAPSE RATES ARE VERY
SHALLOW. THAT SAID THERE IS A LOT OF SHEAR AND THE LL ARE MOIST AND
MODERATELY UNSTABLE. THERE IS MORE THAN ENOUGH FORCING WITH 50 KTS
OF MID LVL FLOW TO KEEP CONVECTION GOING THROUGH THE AFTN AND
OVERNIGHT HRS. THE LINE WILL HAVE THE CAPABILITY OF PRODUCING STRONG
TO DAMAGING STRAIGHTLINE WINDS. AS OF 20Z THE LINE ACTUALLY APPEARS
TO BE WEAKENING AND THIS COULD BE DUE TO SLIGHTLY WARMER MID LVL
TEMPS...MOVING AWAY FROM THE ADDED FORCING FROM THE REMNANTS OF T.C.
RICK...OR WE MAY BE GETTING CUT OFF FROM THE CONVECTION OCCURRING IN
THE GULF. SO THE SVR THREAT MAY BE ON DECLINE NOW BUT THIS SYSTEM
HAS HAD A HISTORY OF PRODUCING DAMAGE AND TORNADOES SO WE ARE NOT
QUITE READY TO COMPLETELY WRITE THE SVR POTENTIAL OFF BUT IT DOES
LOOK LESS LIKELY NOW. THE BIGGEST CONCERN CONTINUES TO BE IF ANY
STORMS CAN DEVELOP AHEAD OF THE SQUALLINE AND BECOME LOW TOPPED
SUPERCELLS. THESE STORMS WILL HAVE MORE THAN ENOUGH GOING FOR THEM
TO ROTATE AND ALLOW FOR A TORNADO OR TWO TO DEVELOP. THE SVR THREAT
SHOULD REALLY COME TO AN END OVER MUCH OF THE CWA AFTER MIDNIGHT AS
THE SFC LOW CONTINUES TO LIFT OUT TO THE NNE.

AS FOR HEAVY RAIN POTENTIAL...INITIALLY THE LINE APPEARS TO BE
MOVING FAST ENOUGH LEADING TO LESS POTENTIAL FOR FLASH FLOODING BUT
WE ARE STILL EXPECTING WIDESPREAD 1-2" WITH LOCALLY HIGHER AMOUNTS.
ONE THING TO KEEP AN EYE ON IS IF THE FRONT SHOWS ANY POTENTIAL OF
HANGING UP ACROSS COASTAL MS AS THE SFC LOW PULLS TO THE NNE. THIS
COULD LEAD TO SOME POSSIBLE TRAINING OVER THAT AREA BUT LOOKING AT
WV THERE APPEARS TO BE MORE THAN ENOUGH OF A PUSH TO GET THE FRONT
ALL THE WAY THROUGH OUR CWA SHORTLY AFTER SUNRISE FRI.

TOMORROW THINGS WILL START TO DRY OUT AS THE FRONT PUSHES FURTHER TO
THE SOUTH AND EAST. THE COOLER AIR WILL LAG BACK A LITTLE AND WINDS
WILL START TO PICK UP SLIGHTLY BE LATE AFTERNOON WITH SOME GUSTS
POSSIBLY BETWEEN 20-25KTS. WINDS WILL BE STRONGER OVER THE COASTAL
WATERS FRI NIGHT. SKIES WILL CLEAR OUT AND TEMPS WILL BE BACK TO
ABOUT 5 DEGREES BELOW NORMAL.

THIS WEEKEND HIGH PRESSURE WILL DOMINATE THE AREA WITH CLEAR SKIES
AND COMFORTABLE TEMPS. SUN MRNG WILL BE THE COOLEST THIS WEEKEND
AS HIGH PRESSURE SHOULD BE DIRECTLY OVERHEAD AND WITH CLEAR SKIES
RAD COOLING CONDITIONS WILL BE OPTIMAL AND THIS SHOULD LEAD TO LOWS
IN THE LOWER 40S TO MID 50S ALONG THE LA COAST. /CAB/

LONG TERM...
LONG TERM...MDLS CONTINUE TO HAVE A HARD TIME WITH THE EXTENDED AND
WITH SVR WEATHER POSSIBLE TODAY I HAVE MADE NO CHANGES TO THE
EXTENDED. PREVIOUS LONG TERM DISCUSSION HAS BEEN APPENDED. /CAB/

NEXT WEEK...A FAST MOVING SHORTWAVE TROUGH WILL MOVE THROUGH THE
LOWER MISSISSIPPI VALLEY ON MONDAY. IT APPEARS MOISTURE WILL HAVE
A TOUGH TIME RETURNING NORTH...SO AM ONLY INCLUDING A SLIGHT CHANCE
OF SHOWERS. ANOTHER VIGOROUS HIGH AMPLITUDE UPPER TROUGH IS EXPECTED
TO DEVELOP OVER THE CENTRAL CONUS WEDNESDAY. THE ECMWF IS FASTER
MOVING THIS SYSTEM AND THE ASSOCIATED COLD FRONT EAST WITH THE GFS
SLOWER. WILL LIKELY HAVE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
WITH LOCALLY HEAVY RAINFALL DURING THIS TIME FRAME...AND THIS WILL
HAVE TO BE FINE TUNED AS IT GETS CLOSER. 22/TD

AVIATION...
STRONG SOUTHEAST FLOW HAS DEVELOPED ACROSS THE FORECAST AREA. WIND
GUSTS HAVE APPROACHED 25 KNOTS A FEW TIMES THIS MORNING. THE
STRONG GUSTY WINDS ARE ASSOCIATED WITH THE LEADING EDGE OF A
STRONG UPPER LEVEL TROUGH AND COLD FRONT THAT APPROACHING WESTERN
LOUISIANA AT THIS TIME. THERE IS A POSSIBILITY OF ISOLATED SEVERE
THUNDERSTORMS FORMING AHEAD OF AN ADVANCING LINE OF NUMEROUS
THUNDERSTORMS LATER THIS AFTERNOON AND EVENING. AT 20Z THE LINE OF
THUNDERSTORMS EXTENDED FROM WEST OF KESF AND KLFT SOUTH INTO THE
GULF OF MEXICO. THE LINE IS MOVING EAST AROUND 20 KNOTS. TIMES OF
GREATEST THUNDERSTORM RISK FOR KBTR ARE 21Z TO 02Z. KMCB AND KMSY FROM
23Z TO 04Z. KGPT FROM 01Z TO 06Z.

MARINE...
WILL CONTINUE SMALL CRAFT EXERCISE CAUTION FOR LAKE PONTCHARTRAIN
AND MAUREPAS AND SMALL CRAFT ADVISORY FOR COASTAL WATERS FOR TONIGHT
AS COLD FRONT AND UPPER LEVEL TROUGH APPROACHES THE AREA FROM THE
WEST. THE FRONT SHOULD MOVE THROUGH THE REGION LATE TONIGHT AND
EARLY FRIDAY MORNING. AS THE UPPER LEVEL LOW CONTINUES TO MOVE
TOWARDS THE NORTH AWAY FROM THE GULF COAST REGION...WINDS SHOULD
DIMINISH AND REMAIN IN THE 10 TO 15 KNOT RANGE. HIGH PRESSURE WILL
DOMINATE THE WEATHER THIS WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 57 68 47 72 / 90 10 10 0
BTR 57 70 48 71 / 70 10 10 0
MSY 65 74 55 71 / 100 10 10 10
GPT 65 74 50 71 / 100 20 10 10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 10 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF
THE MISSISSIPPI RIVER FROM 20 TO 60 NM...AND COASTAL WATERS
FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER OUT 20 NM.

SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

SMALL CRAFT ADVISORY UNTIL 10 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF
THE MISSISSIPPI RIVER FROM 20 TO 60 NM...AND COASTAL WATERS
FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER OUT 20 NM.

&&

$$


New Orleans Local Weather thread - dkmac - 10-23-2009 05:13 AM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
450 AM CDT FRI OCT 23 2009

.SHORT TERM...
COLD FRONT IS PUSHING THROUGH COASTAL SECTIONS AND WILL MOVE
THROUGH THE REMAINING LAND AREAS AND COASTAL WATERS DURING THE
EARLY TO MID MORNING HOURS. HAVE CONTINUED MENTION OF SHOWERS
ALONG AND AHEAD OF THE FRONT. SOME SPOTTY VERY LIGHT RAIN AND
DRIZZLE IS OCCURRING WELL BEHIND THE FRONT...BUT THIS WILL BE
BRIEF IN ADVANCE OF THE CLEARING LINE WHICH IS MAKING ITS WAY INTO
SOUTHWEST MISSISSIPPI AND ACROSS SOUTH CENTRAL LOUISIANA. CLEARING
SKIES WILL OCCUR OVER MOST OF THE FORECAST AREA TODAY...BUT THERE
COULD BE SOME PARTLY CLOUDY CONDITIONS ASSOCIATED WITH A SURGE OF
LOW CLOUDS MOVING ACROSS NORTHEAST TEXAS INTO FAR NORTHWEST
LOUISIANA. LOWER HUMIDITY IS ON THE WAY TODAY WITH DEWPOINTS
DROPPING INTO THE UPPER 40S TO MID 50S.

THE COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 8 AM. TIDE
GAGES SHOW THE WATER LEVELS WERE A BIT HIGHER ALONG THE HAN****
COUNTY COAST THAN LAST NIGHT...AND WATER WAS REPORTED ON SOME OF
THE USUAL LOW LYING ROADS AND STREETS MAINLY WEST OF WAVELAND
EARLIER THIS MORNING AND LATE LAST EVENING. THE COMBINATION OF
OFFSHORE WINDS BEHIND THE COLD FRONT AND FALLING ASTRONOMICAL
TIDES THIS MORNING WILL CAUSE THE WATER LEVELS TO DROP 2 TO 3 FEET
TODAY.

MOSTLY CLEAR SKIES AND COOL TEMPERATURES CAN BE EXPECTED TONIGHT.
THE SOUTHERN PORTION OF THE SHARP SHORTWAVE TROUGH WILL BE MOVING
THROUGH THE LOWER MISSISSIPPI VALLEY LATE TONIGHT AND SATURDAY
MORNING WITH SURFACE HIGH PRESSURE BUILDING RIGHT OVER THE
FORECAST AREA. THIS WILL BE A PERFECT WEEKEND TO BE OUTDOORS BUT
REMEMBER TO USE SUNSCREEN. THE COOLEST TEMPERATURES WILL BE
SATURDAY NIGHT WITH LOWS FALLING INTO THE 40S OVER MOST OF THE
AREA EXCEPT LOWER 50S NEAR THE SOUTH SHORE OF LAKE PONTCHARTRAIN
AND THE SOUTHEAST LOUISIANA COAST.

.LONG TERM...
SUNDAY WILL BE ANOTHER GORGEOUS DAY WITH HIGHS IN THE MID 70S.
ANOTHER VIGOROUS SHORTWAVE TROUGH IN THIS PROGRESSIVE PATTERN
WILL APPROACH AND MOVE THROUGH THE FORECAST AREA MONDAY AND MONDAY
NIGHT. MOISTURE WILL INCREASE DUE TO STRONG LIFTING MORE THAN
ADVECTION. HAVE RAISED THE POP SLIGHTLY OVER WESTERN SECTIONS TO
30 PERCENT FOR SHOWERS MONDAY AFTERNOON AND EVENING WITH A SLIGHT
CHANCE OF RAIN ELSEWHERE.

TUESDAY AND WEDNESDAY APPEAR TO BE TRENDING DRY AS A DEEP UPPER
TROUGH FORMS OVER THE WESTERN STATES. THE GFS AND ECMWF STILL
DIFFER ON THE TIMING OF THIS SYSTEM MOVING INTO THE SOUTHERN PLAINS
WITH THE 00Z GFS SHOWING THE SYSTEM BRINGING THE BEST CHANCE OF
SHOWERS AND THUNDERSTORMS TO OUR AREA THURSDAY THROUGH NEXT FRIDAY
MORNING AS THE UPPER TROUGH SWINGS THROUGH. THE 00Z ECMWF IS
SLOWER AND DOES NOT BRING THIS SYSTEM THROUGH UNTIL NEXT
SATURDAY...HALLOWEEN. IT IS STILL TOO EARLY TO HAVE CONFIDENCE IN
THE TIMING...SO WILL FINE TUNE THIS OVER THE NEXT FEW DAYS.

22/TD
&&

.AVIATION...
...12Z PRELIMINARY AVIATION DISCUSSION...

VERY DRY AIR IS SPREADING INTO WESTERN LOUISIANA EARLY THIS
MORNING...ALLOWING FOR A SHARP BOUNDARY BETWEEN SKC CONDITIONS AND A
LOW STRATUS DECK IN THE WAKE OF A COLD FRONT. THE FRONT SHOULD
CLEAR ALL OF THE TERMINALS PRIOR TO 12Z. SOME IFR CEILINGS WILL
PERSIST AT KMCB...KMSY...AND KGPT THROUGH 12-15Z...WITH RAPID
CLEARING EXPECTED AFTER 15Z. VFR CONDITIONS WILL THEN PERSIST
THROUGH THE OVERNIGHT HOURS. GOING BEYOND CEILING AND VISIBILITY
IMPACTS...WINDS WILL BE THE MAIN IMPACT FOR KMSY. STRONG COLD AIR
ADVECTION AND CONTINUED RELATIVELY WARM LAKE WATERS WILL ALLOW FOR
THERMAL MIXING OF BOUNDARY LAYER WINDS IN EXCESS OF 12 KNOTS DOWN TO
THE SURFACE. THESE STRONG WINDS WILL BE MOST PREVALENT AFTER 03Z
TONIGHT AND SHOULD LAST THROUGH 12Z. 32

&&

.MARINE...

A STRONG LOW LEVEL JET WILL CONTINUE TO KEEP STRONG SOUTHWESTERLY
WINDS AND HIGHS SEAS IN PLACE OVER THE COASTAL WATERS EAST OF THE
MISSISSIPPI RIVER. THESE WINDS WILL WEAKEN AFTER 15Z...AS THE COLD
FRONT SLIDES THROUGH. IN THE WAKE OF THE FRONT...WINDS WILL REMAIN
IN THE 15 TO 20 KNOT RANGE ACROSS ALL OF THE GULF COASTAL
WATERS...AS STRONG DRY AND COLD AIR ADVECTION TAKES HOLD. THIS
ADVECTION ACROSS THE WARM GULF WATERS WILL ALLOW FOR AMPLE THERMAL
MIXING WHICH WILL IN TURN ALLOW STRONG BOUNDARY LAYER WINDS TO
TRANSPORT DOWN TO THE SURFACE. THIS GRADIENT FLOW WILL INCREASE
OVERNIGHT...WITH EXERCISE CAUTION CONDITIONS EXPECTED NOT ONLY IN
THE GULF WATERS BUT ALSO THE TIDAL LAKES. AS THE HIGH BECOMES MORE
CENTERED OVER THE REGION...WINDS AND SEAS WILL DROP OFF A BIT SUNDAY
THROUGH MONDAY. A WEAK FAST MOVING UPPER LEVEL LOW AND ASSOCIATED
FRONT WILL SLIP THROUGH MONDAY NIGHT INTO TUESDAY. THIS SYSTEM DOES
NOT HAVE A STRONG HIGH ASSOCIATED WITH IT...AND DO NOT EXPECT MUCH
OF AN IMPACT OUTSIDE OF THUNDERSTORMS FROM THIS SYSTEM. OVERALL
LIGHT WINDS AND SEAS LESS THAN 4 FEET ARE EXPECTED IN THE COASTAL
WATERS EARLY NEXT WEEK. 32

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 68 47 69 43 / 0 0 0 0
BTR 70 48 70 45 / 0 0 0 0
MSY 73 56 69 52 / 10 0 0 0
GPT 74 50 70 47 / 20 0 0 0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

SMALL CRAFT ADVISORY UNTIL 10 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF
THE MISSISSIPPI RIVER FROM 20 TO 60 NM...AND COASTAL WATERS
FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER OUT 20 NM.

MS...COASTAL FLOOD ADVISORY UNTIL 8 AM FRIDAY FOR THE FOLLOWING
ZONES: HAN****...HARRISON...AND JACKSON.

GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM.

SMALL CRAFT ADVISORY UNTIL 10 AM FRIDAY FOR THE FOLLOWING ZONES:
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF
THE MISSISSIPPI RIVER FROM 20 TO 60 NM...AND COASTAL WATERS
FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER OUT 20 NM.


New Orleans Local Weather thread - dkmac - 10-24-2009 05:06 AM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
358 AM CDT SAT OCT 24 2009

.DISCUSSION..
LATEST SURFACE ANALYSIS SHOWED AT 1016MB HIGH OVER SOUTH AND
CENTRAL TEXAS WITH A RIDGE AXIS EAST TO FLORIDA PANHANDLE. UPPER AIR
ANALYSIS SHOWED THE TROUGH AXIS WISCONSIN TO EAST TEXAS. IN
ADDITION...A WAVE WAS NOTED IN THE NORTHWEST FLOW OVER THE
NORTHERN PLAINS. SURFACE HIGH IS EXPECTED TO SHIFT EAST OVER THE
FORECAST AREA TODAY AND OHIO VALLEY EARLY SUNDAY. RIDGE AXIS
SHOULD REMAIN ACROSS THE AREA TONIGHT. CALM WINDS AND CLEAR SKIES
WILL YIELD GOOD RADIATIONAL COOLING TONIGHT...PRODUCING THE
COOLEST NIGHT OF THIS PACKAGE. UPPER LEVEL FLOW QUICKLY BECOME
SOUTHWEST LATE SUNDAY. DEEP MOISTURE RETURN WILL BE LIMITED AS AIR
MASS OVER NORTHWEST AND CENTRAL REMAINS RELATIVELY DRY SUNDAY INTO
MONDAY. UPPER LEVEL WAVE IS EXPECTED TO DIVE EAST TO THE GREAT
LAKES BRINGING AN AXIS ACROSS THE FORECAST AREA LATE MONDAY INTO
EARLY TUESDAY AND PRODUCE A SLIGHT CHANCE OF RAIN. FOR THE LATTER
PART OF NEXT WEEK...ANOTHER SYSTEM IS EXPECTED TO DIVE SOUTHEAST
ACROSS WASHINGTON MONDAY TO THE MID MISSISSIPPI VALLEY BY
WEDNESDAY. THE DEEPENING TROUGH WILL PUSH AN AXIS AND SURFACE
FRONT THROUGH THE AREA THURSDAY/POSSIBLY FRIDAY...PRODUCING SHOWERS AND
THUNDERSTORMS. MID RANGE MODELS ARE NOT IN AGREEMENT TIMING OF
THIS SYSTEM. GFS HAS AGGRESSIVELY PUSH THE PASSAGE TO EARLY
THURSDAY WHILE ECMWF STALLS A FRONT ACROSS THE AREA NEXT WEEKEND.
WILL GO WITH A LITTLE CONSISTENCY WITH A PASSAGE OCCURRING LATE
THURSDAY INTO FRIDAY FOR NOW.

.AVIATION...
...PRELIMINARY 12Z AVIATION DISCUSSION...

A DEEP LAYER OF DRY AIR IN THE MID AND UPPER LEVELS AS INDICATED BY
THE 00Z SOUNDING WILL CONTINUE TO REMAIN OVER THE AREA THROUGH
SUNDAY MORNING. IN ADDITION...STRONG SUBSIDENCE IN THE WAKE OF AN
UPPER LEVEL TROUGH WILL TAKE HOLD OF THE REGION TODAY AND CONTINUE
INTO TONIGHT. VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH
THE FORECAST PERIOD. 32

&&

.MARINE...

SURFACE AND UPPER LEVEL RIDGING WILL CONTINUE TO BUILD OVER THE
REGION TODAY INTO TONIGHT...IN THE WAKE OF A STRONG UPPER LEVEL
TROUGH THAT PASSED THROUGH THE AREA YESTERDAY. OVERALL GRADIENT
FLOW HAS WEAKENED CONSIDERABLY TONIGHT...AND HAVE DECIDED TO DROP
THE SMALL CRAFT ADVISORIES FOR THE COASTAL WATERS. BOTH THE NAM AND
GFS SHOW THE RIDGING HOLDING FAST THROUGH MONDAY...WITH LIGHT
GRADIENT FLOW AND SEAS OF 3 FEET OR LESS EXPECTED. HEADING INTO
MONDAY NIGHT...THERE IS SOME DISAGREEMENT ON THE TIMING AND STRENGTH
OF THE NEXT SYSTEM. AT THIS TIME...HAVE LEANED TOWARD THE NAM
SOLUTION...AND SHOW A FAIRLY SHARP UPPER LEVEL TROUGH...AND A WEAK
SURFACE FRONT SLIDING THROUGH THE AREA. WINDS AND SEAS WILL
INCREASE IN THE WAKE OF THE WEAK FRONT...BUT ADVISORY CONDITIONS
WILL NOT BE MET ON TUESDAY. A WEAK RIDGE WILL SLIP THROUGH TUESDAY
INTO TUESDAY NIGHT...WITH EASTERLY AND SOUTHEASTERLY FLOW BECOMING
DOMINANT ON WEDNESDAY...AS THE GRADIENT BETWEEN THE SURFACE HIGH TO
THE EAST AND ANOTHER DEVELOPING LOW TO THE WEST INCREASES. WINDS
MAY CLIMB TO NEAR EXERCISE CAUTION WEDNESDAY NIGHT INTO THURSDAY DUE
TO THIS INCREASED GRADIENT. IN ADDITION...A FAIRLY LONG FETCH
ACROSS THE GULF WILL ALLOW SEAS INCREASE INTO EXERCISE CAUTION RANGE
BY THURSDAY. 32

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 67 40 75 46 / 0 0 10 10
BTR 68 44 75 50 / 0 0 10 10
MSY 69 52 75 56 / 0 0 10 10
GPT 68 46 73 49 / 0 0 10 10


New Orleans Local Weather thread - ROLLTIDE - 10-24-2009 02:10 PM

....


New Orleans Local Weather thread - dkmac - 10-24-2009 06:12 PM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
332 PM CDT SAT OCT 24 2009

...ACTIVE PATTERN SETTING UP FOR NEXT WEEK...

.SHORT TERM...ANOTHER QUIET DAY OR TWO BUT THINGS LOOK TO PICK UP
BY TUESDAY. HIGH PRESSURE IS SETTLING IN OVER THE AREA WITH CIRRUS
STREAMING NE ACROSS THE WRN AND NCTRL GULF AND ANOTHER BAND OF
CIRRUS SPILLING OVER THE SRN ROCKIES.

TONIGHT THROUGH MON...FORECAST CHALLENGE WILL GENERALLY BE TEMPS.
HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT BEFORE PULLING OFF
TO THE EAST TOMORROW. THIS WILL HELP KEEPS WINDS RATHER LIGHT. WE
WILL REMAIN DRY BUT DEWPOINTS THIS AFTN HAVE ONLY DROPPED INTO THE
LOWER TO MID 40S. ALSO WE COULD STILL SEE SOME CIRRUS TONIGHT BUT IT
LOOKS LIKE MOST SHOULD PUSH EAST WITH WHATEVER THAT IS LEFT RATHER
THIN SO OVERALL IT SHOULD TURN OUT TO BE MOSTLY CLEAR. GIVEN THESE
FEATURES RAD COOLING CONDITIONS SHOULD BE PRETTY GOOD AND LOWS IN
THE LOWER 40 ACROSS THE NORTH TO LOWER 50S ALONG THE LA COAST.
TOMORROW SLIGHTLY WARMER LL TEMPS BUT MORE SO SUNNY SKIES SHOULD
LEAD TO HIGHS BEING ABOUT 10 DEGREES WARMER. THE SFC HIGH WILL
CONTINUE TO PUSH EAST AND BY TOMORROW NIGHT SHOULD BE OVER THE
ATLANTIC COAST. A WEDGE HIGH PRESSURE WILL STILL PUSH SW DOWN ACROSS
THE CWA SO ANOTHER COOL NIGHT LOOKS TO BE IN STORE WITH THE COOLEST
TEMPS ACROSS OUR NERN 3RD. MON WILL BE THE DAY WHEN WE START TO
TRANSITION AS THE NEXT DISTURBANCE DROPS SOUTH TWRDS THE BIG BEND
REGION. THIS SHOULD INDUCE CYCLOGENESIS ALONG THE TX GULF COAST
CAUSING WINDS TO VEER BACK AROUND THE THE SOUTHEAST THEN SOUTH THE
DAY.

MON NIGHT THROUGH TUE NIGHT ...VERY INTERESTING FCST NOW. THE ECMWF
AND GFS HAVE COME INTO BETTER AGREEMENT NOW. BOTH SHOW THE BIG BEND
DISTURBANCE PULLING OUT TO THE EAST ACROSS CNTRL TX AND THEN LIFT IT
TO THE NE THROUGH THE LOWER MS VALLEY. THIS CAUSES THE SFC LOW TO
DEEPEN NICELY ACROSS THE NWRN GULF AND THEN DEEPEN FURTHER AS IT
MOVES INTO THE ARKLAMISS BY MIDDAY TUE. THE BIGGEST DIFFERENCE B/T
THE GFS AND ECMWF IS TIMING WHERE THE GFS IS ABOUT 6-12 HRS FASTER.
THE NAM ALSO SHOWS THIS BUT IS A TAD FASTER AND A LITTLE WEAKER WITH
THE SFC LOW. WITH ALL OF THIS SAID I HAVE HAD TO DRASTICALLY
INCREASE THE POPS ACROSS THE AREA MON NIGHT AND TUE. I HAVE NOT GONE
WITH LIKELY POPS YET BUT IF THE MDLS CONTINUE TO GO WITH THIS WE
WILL NEED TO INCREASE THESE. THE SFC LOW WILL CONTINUE TO PULL OUT
TO THE NE WITH RAIN COMING TO AN END EITHER TUE AFTN OR EVN.

NOW WITH THIS SETUP THE QUESTION OF WHETHER OR NOT WE WILL SEE SVR
WEATHER COMES UP. OVERALL INSTABILITY AND MOISTURE WILL BE LACKING
BUT WITH THE STRONG MID LVL DISTURBANCE BECOMING NEGATIVELY TITLED
AS IT LIFTS THROUGH THE LOWER MS VALLEY THERE WILL BE AMPLE FORCING
TO WORK WITH AND THIS SHOULD BE ABLE TO OVERCOME THE LACK OF
INSTABILITY. THAT SAID THE GFS IS INDICATING MLCAPE POSSIBLY UP TO
1000 J/KG ALONG THE COAST. IF THIS IS THE CASE THAT WOULD BE QUITE
SUFFICIENT GIVEN THE AMOUNT OF FORCING. THE KINEMATIC FIELD WILL BE
QUITE STRONG WITH A LL JET NEAR 50KTS AND A MID LVL PUNCH OF
POSSIBLY 70-80KTS AND WE MAY INITIALLY START OUT IN THE RRQ OF A
110KT JET. SHEAR WILL NOT BE AN ISSUE AND 0-1KM AND 0-3KM SRH COULD
APPROACH 300 AND 400 M2/S2 RESPECTIVELY. ALSO THE SYNOPTIC FEATURES
WILL ACTUALLY BE QUITE FAVORABLE WITH LOW SFC PRESSURE DUE TO THE
TRACK OF THE SFC LOW AND FAVORABLE MID LVL HGHTS. WITH ALL OF THIS
WE COULD HAVE ANOTHER ENVIRONMENT FAVORABLE FOR LOW TOPPED
SUPERCELLS AND WITH THE AMOUNT OF TURNING IN THE LL THESE STORMS
COULD BE PRONE TO PRODUCING TORS. NOW WITH ALL OF THE SAID IT
WOULDN`T TAKE MUCH TO KILL ANY SVR THREAT LIKE A LOT CONVECTION
FIRING SOUTH IN THE GULF CUTTING THINGS OFF FURTHER NORTH OR GIVEN
THE AMOUNT OF FORCING WE COULD JUST SEE NUMEROUS TO WIDESPREAD SHRA
AND EMBEDDED TSRA DEVELOP EVERYWHERE MAKING A MESS OF EVERYTHING.
AFTER SEEING WHAT HAPPENED EARLIER THIS WEEK JUST TO OUR WEST I AM
GOING TO BE A LITTLE MORE ON THE CAUTIOUS SIDE AND WE WILL ADD
STRONG TO SVR WORDING TO THE HWO FOR MON NIGHT AND TUE.

.LONG TERM...STILL A VERY LOW CONFIDENT FCST IN THE EXTENDED BUT NOW
THE MEDIUM RANGE MDLS ARE STARTING TO COME A LITTLE CLOSER TOGETHER.
THE ECMWF HAS BEEN THE MOST CONSISTENT DROPPING A DEEP SYSTEM INTO
THE SRN ROCKIES AND THEN SWINGING IT THROUGH THE PLAINS STATES LATE
NEXT WEEK. THE GFS HAS BEEN THE MORE PROGRESSIVE MDLS WITH AN OPEN
L/W TROUGH. NOW THE GFS IS STILL THE FASTER OF THE TWO BUT IT DOES
HAVE A MUCH DEEPER SYSTEM MOVING THROUGH THE CNTRL PLAINS. THERE NOW
IS ALSO SOME SUPPORT FOR A DEEP SYSTEM LATE NEXT WEEK FROM THE
GEFS/CANADIAN.

WED THROUGH FRI...WITH NO REAL COLD FRONT PUSHING THROUGH WITH TUE`S
SYSTEM WINDS WILL QUICKLY VEER BACK AROUND TO THE SOUTH AS ANOTHER
MUCH STRONG SYSTEM TAKES SHAPE. AS A MATTER OF FACT TUE`S SYSTEM
COULD END UP PRIMING THE ATMOSPHERE FOR THE MUCH STRONGER SYSTEM
EXPECTED LATE IN THE WORK WEEK. THERE IS STILL QUITE A BIT OF
UNCERTAINTY WITH THE TIMING AND STRENGTH BUT AT THIS MOMENT IT LOOKS
LIKE A A STRONG SYSTEM WILL DROP SOUTH INTO THE SRN ROCKIES WED
DEEPEN AND START TO PULL OUT TO THE EAST OVER THE CNTRL PLAINS. THIS
WILL DEVELOP A DEEP SFC LOW AND TRACK IT ACROSS THE CNTRL PLAINS AND
INTO THE MID/UPPER MS VALLEY. MOISTURE AND INSTABILITY WILL BE MUCH
HIGHER WITH THIS SYSTEM AND WITH AMPLE FORCING WE COULD SEE A SVR
WXR PUSH THROUGH OUR CWA THU/FRI. THE GREATEST SVR RISK WILL BE WELL
OFF TO OUR NORTH BUT WE COULD BE ON THE END OF A STRONG SQAULLINE.
THIS IS STILL 6-7 DAYS OUT BUT THE ECMWF HAS BEEN HINTING AT A
SIGNIFICANT EVENT ACROSS THE CNTRL CONUS FOR SOME TIME NOW. NOW WITH
THE GFS TRENDING TWRDS IT CONFIDENCE IS SLOWLY INCREASING THAT
HAZARDOUS WEATHER COULD AFFECT OUR REGION LATE NET WEEK.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
NORTHWESTERLY WINDS OF 7 TO 10 KNOTS WILL CALM OVERNIGHT AND BECOME
MORE EASTERLY SUNDAY. 95/DM

&&

.MARINE...THE COASTALS WILL REMAIN QUIET THROUGH MON AS HIGH
PRESSURE DOMINATES THE AREA BUT THINGS COULD QUICKLY CHANGE COME MON
NIGHT. CYCLOGENESIS IN THE WRN/NWRN GULF WILL CAUSE WINDS TO QUICKLY
VEER BACK AROUND TO THE SE AND THEN S WHILE PICKING UP TO AROUND 20
KTS BY LATE MON NIGHT. CONVECTION WILL ALSO START TO DEVELOP ACROSS
THE COASTAL WATERS AND THIS COULD BE A BIG ISSUE DURING THE EARLY
MORNING HRS TUE. THERE WILL BE QUITE A BIT OF SHEAR AND GIVEN
THAT...WATERSPOUT DEVELOPMENT COULD BE QUITE FAVORABLE. THINGS WILL
QUITE DOWN A LITTLE LATE TUE BUT BY THU AND FRI LOOK FOR WINDS AND
SEAS TO PICK BACK UP AS A MUCH STRONG SYSTEM DEVELOPS ACROSS THE
PLAINS. /CAB/


New Orleans Local Weather thread - dkmac - 10-25-2009 06:08 AM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
417 AM CDT SUN OCT 25 2009

.SHORT TERM...
STRONG SYSTEM EXPECTED MON NIGHT INTO TUE MORNING. INSTABILITY IS
NOT A BIG PLAYER HERE BUT WE DON`T REALLY NEED THAT WHEN SEEING
THE STRENGTH OF DYNAMICS AT PLAY. THE CAUSE OF ALL THIS IS JUST
STARTING TO MOVE DOWN THE WEST COAST STATES CAUSING A VERY SHARP
TROUGH TO EXIST WITH ITS BASE OVER SOUTHERN CAL. JET LEVEL WINDS
OF 130KT WILL EVENTUALLY FALL TO THE BASE OF THIS TROUGH AS IT
MOVES NEAR THE CENTRAL GULF COAST. THE WINDS KICK OUT CAUSING THE
UPPER TROUGH TO QUICKLY KICK EAST. THIS ALL HAPPENS AS THE SYSTEM
MOVES OVER US. WE COME UNDER THE RR QUAD OF A 110KT JET AS THE
SHARP TROUGH STARTS TO KICK OUT ALONG WITH THE ASSOCIATED SURFACE
LOW. THIS WILL BE A QUICK SYSTEM TO MOVE THROUGH. BUT WE WILL FALL
IN TO THE WARM SECTOR FOR A BRIEF PERIOD. LONG STORY
SHORT...EXPECT A FEW TS TO GO SEVERE WITH THIS LATE MONDAY NIGHT
INTO TUE MORNING. THE FIRST HINT OF STRONG/SEVERE TS WILL BREAK
OUT OVER THE NE QUARTER OF TX BY MON MORNING. THE TS WILL DEVELOP
SOUTHWARD INTO THE COASTAL BEND OF TX BY MON EVENING. MANY OF
THESE SHOULD BE SEVERE FOR THE FOLKS OUT THAT WAY. THIS SAME
SYSTEM WILL MOVE INTO SE LA AND SOUTHERN MISS LATE MONDAY NIGHT.
ONE AREA OF STRONG AND SEVERE TS WILL ACCOMPANY THE SFC LOW AS IT
MOVES THROUGH AND ANOTHER STRONG TO SEVERE AREA OF TS WILL DEVELOP
OVER THE GULF. THE AREA BETWEEN THESE TWO WILL SEE STRONG
SUBSIDENCE CAPPING TS DEVELOPMENT. NOT A LOT OF CONFIDENCE ON WHERE
THIS WILL BE LOCATED BUT FIRST THOUGHT WOULD BE IN A NE TO SW
ORIENTATION FROM CENTRAL ALA DOWN THROUGH THE MISS GULF COAST.

.LONG TERM...
THE NEXT SYSTEM IS DUE THU NIGHT. THE ACCOMPANYING HIGH BEHIND THU
SYSTEM SHOULD STAY AROUND THROUGH THE FIRST OF NEXT WEEK KEEPING
THINGS COOL AND DRY.

&&

.AVIATION...
...PRELIMINARY 12Z AVIATION DISCUSSION...

VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE NEXT 24 HOURS AS
SURFACE HIGH PRESSURE MOVES EAST OF SOUTHEAST LA AND SOUTHERN MS. 18

&&

.MARINE...

SURFACE AND UPPER LEVEL RIDGING WILL CONTINUE TO MOVE EAST OF THE
REGION TODAY INTO TONIGHT WITH WIND FLOW SLOWLY INCREASING FROM THE
EAST. SURFACE LOW IS EXPECTED TO DEVELOP OVER NORTHWEST GULF MONDAY
AFTERNOON. THE ASSOCIATED UPPER LEVEL WAVE WILL BECOME NEGATIVELY
TILTED....THUS INCREASING LOW LEVEL FLOW DOWN TO THE SURFACE MONDAY
NIGHT INTO EARLY TUESDAY. BOUNDARY LAYER WINDS OF 20 TO 25 KNOTS
WILL LIKELY MIXED DOWN TO THE SURFACE. POSSIBLE SMALL CRAFT
ADVISORIES MAY BE ISSUED ON COASTAL WATERS AND TIDAL LAKES MONDAY
NIGHT AND TUESDAY. PRESSURE GRADIENT WILL COLLAPSE BY TUESDAY
AFTERNOON. STRONG SOUTH FLOW WILL DEVELOP OVER THE CENTRAL GULF
COAST WEDNESDAY NIGHT INTO THURSDAY AS A SURFACE LOW DEEPENS OVER
THE SOUTHERN PLAINS. 18

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 74 48 74 61 / 0 0 20 60
BTR 77 52 74 62 / 0 0 20 60
MSY 74 57 77 67 / 0 0 20 50
GPT 71 51 76 62 / 0 0 10 40