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New Orleans Local Weather thread - Printable Version +- Hardcore Weather (http://hardcoreweather.com) +-- Forum: Weather (/forum-4.html) +--- Forum: Local Weather (/forum-13.html) +--- Thread: New Orleans Local Weather thread (/thread-4989.html) Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 |
New Orleans Local Weather thread - dkmac - 04-05-2009 05:08 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 434 AM CDT SUN APR 5 2009 .SHORT TERM...WE HAVE HAD ISLTD TO SCT SHRA AND SPRINKLES THROUGH THE NIGHT ACROSS MUCH OF THE CWA. THESE HAVE BEEN CAUSED BY ISENTROPIC LIFT AND WILL CONTINUE THROUGH MUCH OF THE MORNING ACROSS SRN MS AND JUST ACROSS THE BORDER INTO LA. TODAY WILL ACTUALLY BE MOSTLY QUIET. THE LIGHT SHRA THAT ARE OVER THE AREA THIS MORNING SHOULD MOVE OFF TO THE NE BY LATE MORNING WITH THE COLD FRONT APPROACHING THE CWA BY EARLY/MID AFTN. MOISTURE WILL BE AN ISSUE AND B/C OF THAT WE ARE NOT EXPECTING AN AWFUL LOT OF ACTIVITY WITH THE FRONT IN FACT THERE IS A DECENT POSSIBILITY OF MOST OF THE AREA REMAINING DRY AFTER MIDDAY BUT GIVEN THE FRONT AND SOME UPPER LEVEL SUPPORT MOVING THROUGH ISLTD TSRA WILL BE POSSIBLE ESPECIALLY ACROSS SRN/COASTAL MS WHERE THE LIFT AND MOISTURE WILL BE IN BETTER SUPPLY. A FEW STORMS ACROSS COASTAL MS COULD BECOME STRONG TO SVR BUT THE POTENTIAL FOR THOSE WILL BE GREATER TO OUR EAST. HEADING INTO TONIGHT THINGS WILL PICK UP BUT NOT FROM A RAIN STAND POINT. THE FRONT WILL QUICKLY MOVE THROUGH WITH MUCH COLDER AND DRIER AIR MOVING IN BEHIND IT...WITH WINDS PICKING UP! STRONG HIGH PRESSURE WILL BUILD SOUTH THROUGH ERN TX CAUSING SFC PRESSURE RISES OF 6-7 MB IN 6 HRS TIGHTENING THE PRESSURE GRADIENT ACROSS THE CWA. H925 AND H85 WINDS WILL PICK UP TO 35 AND POSSIBLY EVEN 45 KTS RESPECTIVELY AFTER MIDNIGHT BECOMING UNIDIRECTIONAL WITH THE SFC WINDS BEFORE 12Z. ALSO AFTER MIDNIGHT THERE WILL VERY STRONG CAA AT H85 AND H7. ALL OF THIS FAVORS VERY EFFICIENT MOMENTUM TRANSFER TO THE SFC...ESPECIALLY OVER THE WARMER WATERS. FOR MORE ON THE EFFECT ON THE TIDAL LAKES AND COASTAL WATERS PLEASE REFER TO THE MARINE SECTION. NRLY TO NWRLY WINDS SHOULD REALLY BEGIN TO PICK UP JUST BEFORE MIDNIGHT ACROSS THE CWA AND CONTINUING TO INCREASE THROUGH THE MORNING. LOCATIONS ALONG AND SOUTHEAST OF A LINE FROM LAPLACE TO HOUMA WILL SEE WINDS PICK TO AROUND 25 MPH WITH GUSTS UP TO 35 MPH AT TIMES AND WITH THAT A WIND ADV HAS BEEN ISSUED FOR TONIGHT. WINDS WILL BEGIN TO SLACK OFF A FEW HRS AFTER SUNRISE BUT IT WILL STILL BE BREEZY THROUGH DAY WITH WINDS PICKING BACK UP MON NIGHT AS A REINFORCING SHOT OF COLD AIR MOVES INTO THE AREA. AS FOR TEMPS MON AND TUE...THINGS WILL BE RATHER COLD FOR APRIL. HIGHS WILL BE A GOOD 10-15 DEGREES BELOW NORMAL. H925 TEMPS BOTH DAYS WILL ONLY BE IN THE 3-5C RANGE AND THIS SUGGEST HIGHS IN THE MID TO UPPER 50S. GUI IS SLIGHTLY HIGHER AND WITH DAYLIGHT INCREASING EACH DAY AND WHAT SHOULD BE MOSTLY SUNNY TO SUNNY SKIES I WILL ONLY GO A DEGREE OR TWO BELOW GUI IN SOME LOCATIONS BUT NOT CALL FOR MID 50S YET. TUE SHOULD BE RATHER SIMILAR FROM A TEMP STAND POINT BUT WINDS WILL BE A GOOD BIT LIGHTER DURING THE DAY. AS FOR LOWS WE STILL LOOK LIKE WE WILL FLIRT WITH FREEZING TEMPS ACROSS THE NRN HALF/3RD TUE MORNING AND POSSIBLY AGAIN WED MORNING. THE BIGGEST ISSUES HURTING RAD COOLING CONDITIONS WILL BE WINDS TUE MORNING AND INCREASING LL TEMPS WED MORNING. GUI SEEMS TO BE A LITTLE TOO BULLISH WITH THE LOWS BOTH MORNINGS WHILE THE RAW OUTPUT TEMPS FROM BOTH THE GFS AND ECMWF ARE MUCH WARMER. WITH THAT WE HAVE GONE ABV GUI JUST A TAD BUT THAT SAID WE COULD STILL SEE AREAS ACROSS SRN MS AND JUST ACROSS THE BORDER DROP INTO THE LOWER 30S AND MAYBE ACROSS COASTAL MS WED MORNING. /CAB/ .LONG TERM...THE MEDIUM RANGE MDLS APPEAR TO BE IN A LITTLE BETTER AGREEMENT THIS MORNING THAN YESTERDAY. OVERALL THINKING HASNT CHANGED MUCH WITH MODERATING TEMPS WED AND THE NEXT SYSTEM AFFECTING THE REGION THU/FRI AND POSSIBLY ANOTHER SYSTEM LATE IN THE WEEKEND. WED THE RIDGE AXIS WILL CONTINUE TO SHIFT TO THE EAST INTO THE PLAINS STATES. OUR NEXT SYSTEM WILL BE MOVING TWRDS THE CONTINENTAL DIVIDE. RETURN FLOW WILL BE BEGIN WED AS THE SFC HIGH MOVES OVER FL WED AFTN. LL TEMPS WILL ACTUALLY ALREADY BE INCREASING WED MORNING WITH H925 TEMPS APPROACHING 11-12C BY AFTN. THIS ALONG WITH FULL SUN WILL ALLOW THE CWA TO BE ABOUT 10 DEGREES WARMER THAN TUE. MOISTURE ON THE OTHER HAND WILL BE MUCH SLOWER TO RETURN AND THIS COULD REALLY HURT RAIN CHANCES WITH OUR NEXT SYSTEM. THU THROUGH FRI WE WILL SEE THE NEXT DISTURBANCE WORK ACROSS THE CONTINENTAL DIVIDE...THROUGH THE CNTRL PLAINS AND INTO THE GREAT LAKES REGION BY FRI. THIS WILL INDUCE CYCLOGENESIS ON THE LEE OF THE ROCKIES AROUND THE OK/TX PANHANDLES WITH THE SFC LOW TRACKING TO THE ENE TWRDS THE OH/TN VALLEYS. ANOTHER COLD FRONT WILL MOVE INTO THE THE CWA LATE THU NIGHT AND STALL OVER THE REGION. ONE QUESTION IS HOW MUCH RAIN WILL WE SEE FROM THIS SYSTEM AND WHETHER ANY STRONG/SVR STORMS WILL DEVELOP. LATEST INDICATIONS ARE THAT WE WILL REALLY HAVE A HARD TIME RECOVERING AHEAD OF THIS SYSTEM WITH BOTH THE GFS AND ECMWF KEEPING THE REAL RICH MOISTURE WELL OFF TO OUR SOUTH. SECOND THE BULK OF THE UPPER LVL SUPPORT STAYS WELL OFF TO OUR NORTH. IN FACT BOTH MDLS ACTUALLY SHOW H5 HTS STEADY OR RISING AS THE FRONT MOVES INTO THE CWA. ADDITIONALLY WE WILL NOT BE IN A FAVORABLE REGION OF THE UPPER JET. LAPSE RATES WILL BE NOWHERE NEAR WHAT WE HAVE SEEN OVER THE LAST TWO WEEKS. WITH ALL OF THIS...THINKING IS THE RISK FOR SVR WEATHER IS EXTREMELY LOW BUT CANT RULE OUT THE POSSIBILITY OF A STRONG STORM OR TWO AT THIS TIME. AS FOR RAIN CHANCES GUI VALUES ARE NOT EXTREMELY HIGH ONLY IN THE 20-30% RANGE FROM THU NIGHT/FRI MORNING TIME RANGE AND I CAN BUY THAT. THE FRONT LOOKS LIKE IT WILL STALL OVER THE REGION FRI AND REMAIN OVER THE AREA UNTIL RETREATING BACK TO NORTH LATE SAT/EARLY SUN. WITH A BNDRY DRAPED ACROSS THE AREA AND ZONAL TO WEAK SW FLOW ALOFT SENDING WEAK IMPULSES ACROSS THE AREA...ISLTD SHRA AND TSRA WILL BE POSSIBLE THROUGH THAT TIME FRAME. BY THE END OF THE WEEKEND ANOTHER MUCH DEEPER SYSTEM WILL BE WORKING THROUGH THE SRN/CNTRL PLAINS. /CAB/ && .AVIATION... /PRELIMINARY 12Z TAF ISSUANCE/ CIGS AND VSBYS SHOULD BEGIN TO IMPROVE AFTER DAYBREAK. LOW CIGS WILL HANG AROUND FOR A FEW HOURS LONGER THAN THE LOWER VSBYS...BUT A RETURN TO MVFR OR BETTER CONDITIONS IS EXPECTED BY 17Z AT ALL TERMINALS. A STRONG COLD FRONT WILL MOVE THROUGH THE REGION THIS EVENING. AS THE FRONT PASSES THROUGH THE TERMINALS...EXPECT A WIND SHIFT TO THE NORTHWEST AND A SIGNIFICANT INCREASE GUSTS. FREQUENT GUSTS IN THE 20 TO 30 KNOT RANGE WILL BE COMMON AT ALL TERMINALS WITH THE HIGHEST WINDS EXPECTED AT MSY. 95/DM && .MARINE... EXPECT SOUTHEAST WINDS IN THE 15 TO 20 KNOT RANGE TO PERSIST TODAY AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT IS FORECAST TO MOVE THROUGH THE COASTAL WATERS TONIGHT. A SIGNIFICANT INCREASE IN WIND SPEEDS IS EXPECTED BEHIND THE FRONT AS STRONG COLD AIR ADVECTION TAKES HOLD OF THE REGION AND A STRONG HIGH BUILDS INTO THE AREA. WHILE SUSTAINED WIND SPEEDS ARE FORECAST TO REMAIN JUST BELOW GALE FORCE...FREQUENT GUSTS OF 35 TO 45 KNOTS ARE FORECAST TO AFFECT THE GULF WATERS AND TIDAL LAKES. SMALL CRAFT ADVISORIES AND GALE WARNINGS HAVE BEEN POSTED. IN RESPONSE TO THE HIGHER WINDS...SEAS WILL BUILD TO 9 TO 11 FEET LATE TONIGHT AND MONDAY MORNING...MAINLY OVER THE OUTER WATERS. WINDS WILL BRIEFLY DIMINISH INTO THE 20 TO 25 KNOT RANGE DURING THE AFTERNOON HOURS MONDAY...BUT A REINFORCING SURGE OF COOLER AIR WILL HELP MIX DOWN STRONGER WINDS AGAIN MONDAY NIGHT AND EARLY TUESDAY MORNING. ANOTHER ROUND OF GALE WARNINGS MAY BE WARRANTED. WINDS WILL FINALLY BEGIN TO WEAKEN TUESDAY AFTERNOON AND TUESDAY NIGHT AS THE CENTER OF THE RIDGE SETTLES IN OVER THE AREA. A RETURN TO ONSHORE FLOW CAN BE EXPECTED BY WEDNESDAY AFTERNOON AS THE HIGH SHIFTS EASTWARD AND ANOTHER COLD FRONT APPROACHES THE AREA FROM THE NORTHWEST. THIS SECOND COLD FRONT IS FORECAST TO AFFECT THE REGION LATE IN THE WORK WEEK. 95/DM New Orleans Local Weather thread - dkmac - 04-06-2009 06:04 AM [SIZE="4"]Freeze Watch[/SIZE] URGENT - WEATHER MESSAGE NATIONAL WEATHER SERVICE NEW ORLEANS LA 440 AM CDT MON APR 6 2009 ...STRONG GUSTY WINDS BEHIND THE COLD FRONT LATER TONIGHT... ... FREEZING TEMPERATURES POSSIBLE EARLY TUESDAY MORNING... .COLD HIGH PRESSURE BUILDING INTO THE REGION WILL MAINTAIN BREEZY CONDITIONS TODAY. THE COLD AIRMASS WILL SETTLE OVER THE AREA TONIGHT INTO TUESDAY MORNING WITH WINDS EXPECTED TO DROP OFF TO AROUND 5 MPH OR LESS BEFORE SUNRISE TUESDAY. THESE LIGHTER WINDS AND CLEAR SKIES WILL ALLOW TEMPERATURES TO FALL TO NEAR RECORD LOWS AND NEAR FREEZING FOR A COUPLE OF HOURS WEST OF BATON ROUGE...NORTH OF INTERSTATE 12...AND NEAR INTERSTATE 59. LAZ034>040-047-048-050-MSZ068>071-077-061745- /O.CON.KLIX.FZ.A.0005.090407T0800Z-090407T1300Z/ POINTE COUPEE-WEST FELICIANA-EAST FELICIANA-ST. HELENA-TANGIPAHOA- WASHINGTON-ST. TAMMANY-WEST BATON ROUGE-EAST BATON ROUGE- LIVINGSTON-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER- INCLUDING THE CITIES OF...NEW ROADS...LIVONIA... ST. FRANCISVILLE...JACKSON...CLINTON...GREENSBURG...MONTPELIER... HAMMOND...PONCHATOULA...BOGALUSA...FRANKLINTON...SLIDELL... MANDEVILLE...COVINGTON...LACOMBE...PORT ALLEN...ADDIS...BRUSLY... BATON ROUGE...DENHAM SPRINGS...WALKER...CENTREVILLE...WOODVILLE... GLOSTER...LIBERTY...CROSBY...MCCOMB...TYLERTOWN...PICAYUNE 440 AM CDT MON APR 6 2009 ...FREEZE WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH TUESDAY MORNING... AN UNSEASONABLY COLD AIRMASS WILL BRING NEAR RECORD LOW TEMPERATURES ACROSS MUCH OF THE AREA TONIGHT. LOWS IN THE FREEZE WATCH AREA MAY FALL TO AROUND FREEZING FOR ONE TO THREE HOURS PRIOR TO SUNRISE. PRECAUTIONARY/PREPAREDNESS ACTIONS... A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE. THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION. PRECAUTIONS SHOULD BE TAKEN TO PROTECT FRESHLY PLANTED SPRING GARDENS. TROPICAL AND SENSITIVE POTTED PLANTS SHOULD BE BROUGHT INDOORS FOR TONIGHT. OUTDOOR PETS SHOULD EITHER BE BROUGHT INDOORS OR MEASURES TAKEN TO PROTECT THEM FROM UNUSUALLY COLD CONDITIONS. AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 431 AM CDT MON APR 6 2009 .SHORT TERM... QUITE AN ANOMALOUS PATTERN EVOLVING WITH A VERY LATE COLD SNAP EXPECTED FOR THE NEXT COUPLE OF DAYS. MOST GUIDANCE NUMBERS ARE COMING IN CLOSE TO DAILY RECORD LOWS...POSSIBLY LATEST FREEZE DATES...FOR MANY LOCATIONS THAT ARE CHALLENGING THE VERY COLD SNAP IN APRIL 1971. BELOW IS A TABLE OF SELECTED CLIMATE SITES AND THE RECORD LOW FOR TONIGHT...APRIL 7, 2009. NEW ORLEANS INTERNATIONAL 35/1971 NEW ORLEANS AUDUBON PARK 40/1971 BATON ROUGE 36/1996 HAMMOND 31/1971 SLIDELL CITY 34/1971 MCCOMB 32/1971 GULFPORT 36/1971 BILOXI 36/1971 PASCAGOULA 38/1971 THE PROSPECTS FOR A FREEZE ARE NOT CLEAR CUT. THICKNESS TROUGHING SUPPORTS FREEZING TEMPERATURES BUT A VORTICITY LOBE MOVING THROUGH THE AREA BETWEEN MIDNIGHT AND DAYBREAK MAY MIX THE BOUNDARY LAYER ENOUGH TO PRECLUDE A FREEZE BUT THE WIND MAY LAY DOWN JUST ENOUGH PRIOR TO SUNRISE TO ALLOW FOR A SHORT DURATION POCKETS OF FREEZE. GIVEN THE TIME OF YEAR AND IN THE MIDST OF THE GROWING/PLANTING SEASON...IT IS PRUDENT TO MAINTAIN THE FREEZE WATCH AND ALLOW THE DAYSHIFT TO EVALUATE FOR POSSIBLE UPGRADE TO WARNING FOR SOME LOCATIONS. PRECAUTIONS WILL PROBABLY NOT GO FOR NAUGHT AND WILL BE STRESSED IN NPW ISSUANCE. OTHERWISE...NO RAIN CHANCES THROUGH WEDNESDAY NIGHT. 24/RR .LONG TERM... NEXT SYSTEM DEVELOPS IN THE PLAINS WEDNESDAY AND BRINGS A FRONT THROUGH THE AREA EITHER VERY LATE THURSDAY NIGHT OR EARLY FRIDAY. SHORT WAVELENGTH PATTERN OPENS THE GULF SATURDAY AND EARLY SUNDAY IN ADVANCE OF THE NEXT SYSTEM TO MOVE THROUGH THE AREA PIECEMEAL FROM LATE SUNDAY THROUGH LATE MONDAY. EXTENSIVE RAINFALL COVERAGE COULD BRING RENEWED FLOODING CONCERNS ALONG THE PEARL RIVER REACH NEXT WEEK BUT PROBABLY NOT TO THE EXTENT RECENTLY EXPERIENCED. 24/RR && .AVIATION... STRONG NW WINDS TODAY AT ALL TERMINALS BUT VFR WILL CONTINUE THROUGH TUESDAY. WINDS WILL DROP OFF BY TONIGHT. 17/TE && .MARINE... VERY DANGEROUS CONDITIONS ARE FOUND THIS MORNING OVER THE TIDAL LAKES AND GULF WATERS. WINDS ARE SUSTAINED AROUND 35 KNOTS WITH FREQUENT GUSTS UP TO 40 KNOTS SO FAR. THESE GALE CONDITIONS WILL CONTINUE FOR A WHILE THIS MORNING AS HIGH PRESSURE SETTLES INTO THE AREA. SMALL CRAFT ADVISORIES WILL REPLACE THE GALE WARNINGS BY LATE MORNING. WINDS ARE STILL EXPECTED TO GUST TO 35 KNOTS BUT SHOULD BE MUCH LESS FREQUENT THAN WHAT IS EVIDENT THIS MORNING. MARINE CONDITIONS SHOULD IMPROVE FOR THE LAKES DURING THE DAY TUESDAY AND OVER THE GULF WATERS TUESDAY NIGHT. ANOTHER COLD FRONT WILL BEGIN TO AFFECT THE COASTAL WATERS THURSDAY THROUGH FRIDAY. 17/TE New Orleans Local Weather thread - dkmac - 04-07-2009 05:28 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 415 AM CDT TUE APR 7 2009 .SHORT TERM... VORTICITY LOBE OVER THE AREA SEEMS TO HAVE BOTTOMED OUT AND NOW EJECTING EASTWARD. THIS FEATURE HAS MAINTAINED STRONGER WINDS AT AND ABOVE THE BOUNDARY LAYER TO HELP KEEP TEMPERATURES UP TONIGHT. WINDS HAVE BEEN REALLY AUGMENTED OVER THE WARMER WATERS WITH A HEALTHY 25 MPH GUSTS AT TIMES TO 45 MPH ALONG THE SOUTH SHORE LAKE FRONT AND OVER THE COASTAL MARSHES. WITH THE VORTICITY LOBE MOVING OUT...WINDS SHOULD START ABATING...AS EVIDENCED IN KLIX VAD WIND PROFILE WITH ABOUT HALF THE MAGNITUDE AT 0830Z THAN WHAT WAS OCCURRING IN THE LOWER GATES AT 06Z. THOUGH SOME ADDITIONAL RADIATIONAL COOLING WILL TAKE PLACE...IT DOES NOT APPEAR THAT ATTAINING 32F IS POSSIBLE BEFORE SUNRISE. THE LOWEST TEMPERATURE AT THIS TIME IS 40F AT KMCB WITH 5 TO 10 MPH SURFACE WINDS STILL BEING INDICATED UPSTREAM. CLOSE MONITORING OF FREEZE LINE PROGRESSION SHOWS SOUTHERNMOST EXTENT TO THE RED RIVER IN TEXAS AND DRAINAGE AXIS OVER APPALACHIANS TO NORTH CAROLINA/TENNESSEE BORDER. A THERMAL RIDGE IS ACTUALLY INDICATED ALONG THE LOWER AND MIDDLE MISSISSIPPI VALLEY. MILD TEMPERATURES TODAY. SURFACE HIGH SHOULD MOVE INTO THE NORTH GULF WITH SUBTLE SOUTHWEST RETURN FLOW IN THE LOWER LEVELS TO PROBABLY OFFSET ANY DRAINAGE ASPECTS. HAVE OPTED TO CANCEL FREEZE WATCH FOR TONIGHT GIVEN THIS RATIONALE AND FOR RISING THICKNESSES OVERNIGHT INDICATIVE OF WARM AIR ADVECTION. SOME PATCHY LIGHT FROST CAN NOT BE RULED OUT HOWEVER...BUT PROBABLY LIMITED TO RAISED SURFACES /ROOFTOPS AND AUTOS/. 24/RR .LONG TERM... NEXT SYSTEM FOR FRIDAY APPEARS TO BE LESS PRONOUNCED WITH EACH MODEL RUN THOUGH SOME CHANCES OF RAIN...ALBEIT LOW...SEEM PLAUSIBLE. THE GFS AND ECMWF BOTH WANT TO STRAGGLE THE FRONTAL ZONE OVER SOUTH LOUISIANA TO PROVIDE A FOCUS FOR RAINFALL INTO SATURDAY. THE ECMWF IS A WETTER SOLUTION. THIS BOUNDARY BECOMES WARM FRONTOGENETIC SUNDAY AND PROVIDES FOCUS AHEAD OF SPRING STORM THAT DEVELOPS OVER TEXAS SUNDAY. ASSOCIATED FRONT MOVES THROUGH FORECAST AREA SUNDAY NIGHT PER GFS OR MONDAY NIGHT PER ECMWF. HIGH PRESSURE BUILDS INTO THE AREA FOR MIDDLE NEXT WEEK. 24/RR && .AVIATION... /PRELIMINARY 12Z TAFS/ VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. MODERATE TO STRONG NORTHWEST WINDS OF 10 KNOTS WITH GUSTS IN THE 20 TO 25 KNOT RANGE WILL CONTINUE THROUGH ABOUT 10AM. 17/TE && .MARINE... HAZARDOUS CONDITIONS WILL PERSIST THROUGH THIS MORNING FOR THE GULF WATERS WHILE WIND AND WAVES WILL BEGIN TO DISSIPATE OVER THE TIDAL LAKES. ONSHORE FLOW IS EXPECTED TO START BY WEDNESDAY MORNING. ANOTHER COLD FRONT WILL BEGIN TO AFFECT THE COASTAL WATERS THURSDAY AND FRIDAY. 17/TE New Orleans Local Weather thread - dkmac - 04-08-2009 05:33 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 412 AM CDT WED APR 8 2009 .SHORT TERM... IN THE NEAR TERM...QUIET CONDITIONS WILL PREVAIL INTO THURSDAY. AFTER A COLD START TODAY...TEMPERATURES WILL BEGIN TO MODERATE BACK TOWARD CLIMATOLOGICAL VALUES AS SOUTH TO SOUTHWEST FLOW DEVELOPS ON THE BACKSIDE OF SURFACE HIGH PRESSURE RETREATING TO THE EAST. DEEPENING SOUTH TO SOUTHWEST FLOW AND MOISTURE WILL INCREASE ON THURSDAY IN ADVANCE OF A MID/UPPER LEVEL TROUGH/LOW OVER CALIFORNIA EARLY THIS MORNING THAT WILL TRANSLATE EASTWARD INTO THE CENTRAL AND SOUTHERN PLAINS ON THURSDAY. .LONG TERM... THE FIRST OF TWO POTENT SYSTEMS THAT WILL AFFECT THE REGION DURING THE NEXT WEEK WILL IMPACT THE FORECAST AREA THURSDAY NIGHT INTO FRIDAY. AS THE MID/UPPER LEVEL SYSTEM SHIFTS FROM THE PLAINS INTO THE LOWER OHIO VALLEY FROM LATE THURSDAY INTO FRIDAY...A SURFACE LOW WILL DEEPEN ACROSS THE SOUTHERN PLAINS AND TRACK EAST NORTHEAST INTO THE LOWER OHIO VALLEY PUSHING A COLD FRONT TOWARD THE FORECAST AREA LATE FRIDAY AND FRIDAY NIGHT. LARGE SCALE ASCENT ASSOCIATED WITH THIS SYSTEM ALONG WITH INCREASING INSTABILITY AND SUFFICIENT SHEAR WILL RESULT IN THE DEVELOPMENT OF CONVECTION ACROSS THE LOWER MISSISSIPPI VALLEY. SOME OF THIS CONVECTION WILL LIKELY BE STRONG TO SEVERE AND ACROSS THE LOCAL FORECAST AREA THE MOST LIKELY LOCATIONS TO SEE STRONG TO SEVERE THUNDERSTORMS WILL BE ACROSS OUR NORTHERN AND WESTERN ZONES...SOUTHWEST MISSISSIPPI AND THE BATON ROUGE AREA. THE COLD FRONT WILL BE SLOW TO PUSH SOUTH ACROSS THE AREA AND INTO THE COASTAL WATERS FRIDAY NIGHT INTO SATURDAY AS THE UPPER LEVEL SYSTEM CONTINUES TO MOVE OFF TO THE EAST. A LINGERING THREAT OF CONVECTION WILL PERSIST INTO SATURDAY. THE NEXT UPPER LEVEL SYSTEM WILL MOVE OUT OF THE SOUTHWEST U.S. OVER THE WEEKEND AND INTO THE CENTRAL CONUS SUNDAY INTO MONDAY. THIS SYSTEM IS FORECAST TO TAKE ON SOMEWHAT OF NEGATIVE TILT AS IT MOVES FROM THE SOUTHERN PLAINS ACROSS THE LOWER AND MID MISSISSIPPI VALLEY. AGAIN...IT APPEARS THAT STRONG TO SEVERE CONVECTION WILL BE POSSIBLE WITH THIS SYSTEM FROM LATE SUNDAY INTO EARLY MONDAY AS MOISTURE BULKS UP AHEAD OF THE SYSTEM AND INSTABILITY AND SHEAR INCREASES. THE GREATEST THREAT WILL AGAIN PROBABLY BE TO THE NORTH OF THE FORECAST AREA. THE COLD FRONT WITH THIS SYSTEM AND DRIER AIR WILL MOVE INTO THE AREA DURING THE DAY MONDAY... ALTHOUGH THE ECMWF IS A LITTLE SLOWER WITH THIS THAN THE GFS. FAIRLY QUIET WEATHER WILL RETURN TO THE AREA TUESDAY AND WEDNESDAY BEFORE ANOTHER POSSIBLE SYSTEM LATE NEXT WEEK. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. 17 && .MARINE... WINDS WILL GRADUALLY BACK TO AN ONSHORE FLOW TODAY. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN THURSDAY THROUGH THE WEEKEND AS A COLD FRONT APPROACHES THE AREA AND THEN STALLS NEAR THE GULF COAST. DUE TO THIS...WINDS WILL INCREASE TO 15 TO 20 KNOTS AND EXERCISE CAUTION HEADLINES MAY BE NECESSARY BY THURSDAY AFTERNOON...WITH BRIEF PERIODS OF SMALL CRAFT ADVISORY CONDITIONS POSSIBLE FRIDAY THROUGH SUNDAY. WITH REGARDS TO SEA CONDITIONS...A DEEP FETCH OVER THE GULF AT 20 TO 25 KNOTS WILL CAUSE SWELL OF 4 TO 5 FEET TO MOVE INTO THE COASTAL WATERS BY THURSDAY. WIND WAVES GENERATED ON TOP OF THIS WILL CAUSE TOTAL SEA HEIGHTS OF 6 TO 8 FEET BY THURSDAY OR THURSDAY NIGHT. THESE CONDITIONS WILL SUBSIDE AS THE FRONT STALLS FRIDAY NIGHT. 17 New Orleans Local Weather thread - dkmac - 04-09-2009 05:04 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 410 AM CDT THU APR 9 2009 .SHORT TERM... LOW LEVEL SOUTHERLY FLOW AND SOUTHWEST TO WESTERLY FLOW ALOFT WILL INCREASE TODAY IN ADVANCE OF OF AN UPPER TROUGH/LOW OVER THE CENTRAL ROCKIES THAT WILL MOVE INTO THE PLAINS TODAY AND ACROSS THE LOWER AND MID MISSISSIPPI VALLEY TONIGHT AND EARLY FRIDAY... BEFORE WEAKENING AS IT TRANSLATES ACROSS THE LOWER OHIO VALLEY AND MID ATLANTIC REGION FRIDAY NIGHT INTO SATURDAY. SURFACE LOW PRESSURE ASSOCIATED WITH THIS SYSTEM WILL DEEPEN OVER THE SOUTHERN PLAINS LATER TODAY AND THEN MOVE EAST ACROSS ARKANSAS AND SOUTHERN MISSOURI TONIGHT AND THE OHIO VALLEY ON FRIDAY. ALTHOUGH MOISTURE WILL BE ADVECTED INTO THE AREA IN ADVANCE OF THIS SYSTEM...MODELS FORECAST THAT MUCH OF THIS MOISTURE WILL BE IN THE LOWER LEVELS AND THAT DEEP MOISTURE WILL BE LACKING. THIS LACK OF DEEP MOISTURE IN ADDITION TO SOME CAPPING THAT WILL NEED TO BE OVERCOME WILL SERVE TO LIMIT CONVECTION COVERAGE AND INTENSITY TONIGHT DESPITE DECENT FORCING. THE GREATEST THUNDERSTORM COVERAGE AND THE BEST CHANCE OF SEEING STRONG TO SEVERE CONVECTION IS EXPECTED TO REMAIN NORTH OF THE FORECAST AREA. THE ATTENDANT COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL PUSH INTO THE FORECAST AREA LATE FRIDAY AND SLOWLY SHIFT SOUTH INTO THE NORTH GULF FRIDAY NIGHT INTO SATURDAY. ALTHOUGH THE BEST MOISTURE WILL SHIFT TO THE EAST OF THE AREA DURING THE DAY FRIDAY...THE CAP THAT IS EXPECTED TO INHIBIT CONVECTION TO SOME DEGREE TONIGHT WILL DIMINISH ON FRIDAY AS COOLER AIR IN THE MID LEVELS MOVES INTO THE REGION RESULTING IN STEEPENING LAPSE RATES. AS A RESULT...SCATTERED CONVECTION WILL BE IN THE OFFING THROUGH THE DAY FRIDAY. THE SHOWER AND THUNDERSTORM ACTIVITY WILL WANE FRIDAY NIGHT AND SATURDAY WITH ONLY A SMALL CHANCE FOR PRECIPITATION FORECAST FOR THE COASTAL WATERS AND SOUTHERN LAND ZONES. 11 .LONG TERM... THE NEXT SYSTEM THAT WILL AFFECT THE FORECAST AREA WILL BE MOVING INTO CALIFORNIA AND THE DESERT SOUTHWEST FRIDAY AND FRIDAY NIGHT. THIS UPPER TROUGH/LOW WILL ADVANCE INTO THE SOUTHERN PLAINS SUNDAY AND ACROSS THE LOWER MISSISSIPPI VALLEY AND INTO THE OHIO VALLEY SUNDAY NIGHT INTO MONDAY...TAKING ON A BIT OF A NEGATIVE TILT AS IT DOES SO. SURFACE LOW PRESSURE ASSOCIATED WITH THIS SYSTEM WILL DEVELOP OVER TEXAS AND DEEPEN AS IT MOVES ACROSS THE LOWER AND MID MISSISSIPPI VALLEY TOWARD THE OHIO VALLEY. IN CONTRAST WITH THE FIRST SYSTEM...IT APPEARS THAT THIS SYSTEM WILL HAVE AMPLE MOISTURE TO WORK WITH WHICH ALONG WITH SIGNIFICANT SHEAR AND INCREASING INSTABILITY AND FORCING SHOULD RESULT IN THE DEVELOPMENT OF NUMEROUS THUNDERSTORMS LATE SUNDAY INTO EARLY MONDAY. A FEW OF THESE STORMS MAY BE STRONG TO SEVERE SUNDAY NIGHT. THE LATEST ECMWF IS NOW MORE IN LINE WITH THE GFS AS FAR AS THE TIMING OF THIS SYSTEM...HOWEVER IT STILL REMAINS SLIGHTLY SLOWER. THE CONVECTION SHOULD GRADUALLY END FROM WEST TO EAST DURING THE DAY MONDAY WITH THE ASSOCIATED COLD FRONT PUSHING ACROSS THE AREA BY THE AFTERNOON HOURS. QUIET WEATHER SHOULD PREVAIL FOR TUESDAY AND WEDNESDAY BEFORE ANOTHER POSSIBLE SYSTEM IMPACTS THE REGION FOR THE END OF THE WEEK. 11 && .AVIATION... INCREASING HIGH LEVEL CLOUDS WILL CONTINUE TO STREAM IN ACROSS THE AREA UNDER NORTHWEST FLOW REGIME. LOWER CLOUDS WILL BEGIN DEVELOPING ACROSS THE AREA LATER THIS MORNING BUT SHOULD STAY IN THE LOW VFR CATEGORY. FOG COULD BECOME AN ISSUE AT MCB NEAR SUNRISE SO ADDED 4SM VIS TO THE TAFS. SOUTHERLY WINDS WILL INCREASE DURING THE DAY WITH SUSTAINED WINDS OF 15 TO 20 KTS AND GUSTS OF 25 TO 30 KTS. A PERSISTENT BKN030 DECK WILL GRADUALLY LOWER TO MVFR CIGS IN THE AFTERNOON. 12 && .MARINE... SURFACE HIGH PRESSURE CENTER CURRENTLY LOCATED OVER THE SOUTHEASTERN GULF WILL DRIFT INTO THE ATLANTIC NEAR THE FLORIDA COAST. MEANWHILE...AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE TEXAS PANHANDLE AND THROUGH OKLAHOMA. THIS WILL RESULT IN A TIGHTENING PRESSURE GRADIENT AND THUS INCREASING WINDS FOR THE COASTAL WATERS AND TIDAL LAKES. EXPECT 15 TO 20 KT WINDS IN THE INTERIOR LAKES AND 15 TO 25 KTS OVER THE INNER AND OUTER WATERS. SEAS WILL RISE TO 5 TO 7 FEET IN THE OFFSHORE AREAS AS WINDS INCREASE. THEREFORE...HAVE ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH MIDNIGHT FOR ALL COASTAL WATERS. WINDS WILL WEAKEN AS A COLD FRONT APPROACHES FRIDAY. HIGH PRESSURE WILL BE TOO FAR NORTH TO HAVE MUCH IMPACT ON THE AREA. ONSHORE FLOW WILL RETURN LATER THIS WEEKEND AS THE RIDGE SHIFTS EASTWARD TOWARDS TO ATLANTIC COAST. A STRONGER FRONT WILL MOVE THROUGH EARLY NEXT WEEK. 12 New Orleans Local Weather thread - dkmac - 04-10-2009 05:19 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 417 AM CDT FRI APR 10 2009 .SHORT TERM... A CONSIDERABLE AMOUNT OF CONVECTION HAS OCCURRED NORTH OF THE AREA OVERNIGHT AND EARLY THIS MORNING IN ASSOCIATION WITH A VIGOROUS UPPER LEVEL LOW MOVING ACROSS THE MID/LOWER MISSISSIPPI VALLEY. THIS SYSTEM WILL MOVE OFF TO THE EAST INTO THE LOWER OHIO VALLEY TODAY AND WEAKEN. AS IT DOES SO...IT WILL PUSH A SLOW MOVING COLD FRONT ACROSS THE AREA LATE TODAY AND TONIGHT. THE BOUNDARY WILL MOVE INTO THE COASTAL WATERS EARLY SATURDAY AND STALL. IN ADVANCE OF THIS FRONT TODAY WITH THE MAIN DYNAMICS MOVING OFF TO THE EAST...LIMITED AND MAINLY LOW LEVEL MOISTURE COMBINED WITH DECENT INSTABILITY WILL YIELD ISOLATED TO SCATTERED CONVECTION. ANY SHOWERS OR THUNDERSTORMS TONIGHT AND SATURDAY WILL BASICALLY BE CONFINED TO THE COASTAL WATERS AND ADJACENT COASTAL LAND AREAS NEAR THE FRONTAL BOUNDARY. 11 .LONG TERM... THE NEXT VIGOROUS UPPER LEVEL TROUGH/LOW WILL MOVE OUT OF THE SOUTHWEST U.S. OVER THE WEEKEND AND INTO THE CENTRAL CONUS BY LATE SUNDAY. IN CONTRAST TO THE PREVIOUS SYSTEM...THIS FEATURE WILL HAVE AMPLE MOISTURE TO WORK WITH...WHICH IN COMBINATION WITH SUFFICIENT INSTABILITY AND CONSIDERABLE SHEAR WILL RESULT IN THE THE DEVELOPMENT OF NUMEROUS THUNDERSTORMS BY LATE SUNDAY AFTERNOON THAT WILL CONTINUE THROUGH SUNDAY NIGHT AND INTO EARLY MONDAY. SOME OF THIS CONVECTION MAY BE STRONG TO SEVERE...WITH THE GREATEST SEVERE WEATHER THREAT BEING DAMAGING WINDS AND ISOLATED TORNADOES. THE STORM PREDICTION CENTER HAS PLACE THE ENTIRE FORECAST AREA WITHIN A SLIGHT RISK THREAT AREA. THE BEST CHANCE FOR SEVERE WEATHER ACROSS THE FORECAST AREA WILL BE SUNDAY NIGHT. THE CONVECTION WILL END FROM WEST TO EAST ACROSS THE FORECAST AREA MONDAY WITH A COLD FRONT PUSHING ACROSS THE REGION MONDAY AFTERNOON AND MONDAY NIGHT. FAIR WEATHER WILL PREVAIL TUESDAY AND WEDNESDAY BEFORE ANOTHER SYSTEM POTENTIALLY IMPACTS THE FORECAST AREA FOR THE END OF NEXT WEEK. THERE ARE STILL SOME DIFFERENCES WITH THE MODELS ON HOW THE SCENARIO WITH THIS NEXT SYSTEM FOR THE END OF NEXT WEEK WILL PLAY OUT...AND MODEL CONSISTENCY HAS BEEN RATHER POOR FROM RUN TO RUN. 11 && .AVIATION... SOUTH WINDS WILL GRADUALLY VEER TO MORE SOUTHWEST AS THE DAY PROGRESSES AS A COLD FRONT SLOWLY APPROACHES THE AREA. EXPECT WINDS TO BE ABOUT 5 KTS WEAKER THAN YESTERDAY...OR AROUND 10 TO 15 KTS WITH GUSTS NEAR 20 KTS. AMPLE MOISTURE IN PLACE FROM PERSISTENT ONSHORE FLOW WILL KEEP LOW CLOUDS IN PLACE. SHOULD SEE CIGS INCREASE FROM CURRENT MVFR TO LOW VFR BY AROUND NOON. VCSH WILL BE COMMON TODAY WITH LIMITED AFFECTS AT TERMINALS ALTHOUGH CANT RULE OUT A SHORT BURST OF MOD RAINFALL. FROPA IS EXPECTED TONIGHT...SHIFTING WINDS TO A NW DIRECTION. WIND SPEEDS SHOULD REMAIN WEAK BEHIND THIS BOUNDARY AS IT WILL BE VERY SLOW MOVING. 12 && .MARINE... DECIDED TO GO WITH SMALL CRAFT EXERCISE CAUTION FOR COASTAL WATERS TODAY. AREAS WEST OF THE MISSISSIPPI WILL LIKELY HAVE WINDS WEAKEN BELOW CRITERIA AROUND NOON WHILE EAST OF THE RIVER WILL HOLD ON TO 15 TO 20 KT WINDS TILL AROUND SUNSET. THEREFORE...HAVE SPLIT UP ZONES TO REFLECT THIS. A COLD FRONT WILL PROGRESS TOWARDS THE COASTAL WATERS TODAY. MOVEMENT WILL BE RELATIVELY SLOW DUE TO UPPER LOW BEING FAIRLY WEAK AND QUICKLY EJECTING. THIS BOUNDARY LIKELY WONT REACH THE COAST UNTIL SAT MORNING AND EVENTUALLY STALL ALONG THE NORTHERN GULF BEFORE LIFTING BACK NORTH AS A WARM FRONT LATER THIS WEEKEND. ONSHORE FLOW WILL RETURN SUNDAY WITH SOUTHERLY WINDS IN THE 15 TO 20 KT RANGE AND SEAS APPROACHING SCY CRITERIA. WILL NEED TO CONTINUE TO MONITOR. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE MONDAY AS A COLD FRONT ASSOCIATED WITH AN AREA OF LOW PRESSURE MOVES THROUGH. HIGH PRESSURE WILL QUICKLY SETTLE IN AND LIMIT WINDS AS WELL AS SEAS. 12 New Orleans Local Weather thread - dkmac - 04-11-2009 05:19 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 411 AM CDT SAT APR 11 2009 ...SEVERE WEATHER POSSIBLE EASTER SUNDAY... .SHORT TERM...OVERALL NOT TOO MUCH HAS CHANGED SAT WILL BE QUIET AND THEN THE NEXT SYSTEM MOVES THROUGH THE CNTRL CONUS SUN BRINGING THE CWA SHRA AND TSRA ONCE AGAIN WITH THE POSSIBILITY OF SEEING ISLTD TO SCT SVR STORMS. TODAY LOOK FOR MOSTLY MID/HIGH CLOUDS TO REMAIN OVER MOST OF THE AREA BUT WE WILL REMAIN DRY. THE FRONT WILL BEGIN TO LOSE A LITTLE OF ITS IDENTITY ALONG THE COAST AND SRLY WINDS WILL BEGIN TO RETURN LATE TONIGHT AS OUR NEXT SYSTEM CURRENTLY OVER THE BAJA BEGINS TO RAMP UP PUSHING EAST TWRDS THE SRN PLAINS. THIS WILL GET MOISTURE TO INCREASE ACROSS THE AREA. ISENTROPIC LIFT/WAA SHRA MAY ACTUALLY BEGIN TO DEVELOP ACROSS THE LA COAST EARLY SUN MORNING AND MOVE TWRDS THE NE THROUGH THE DAY SUN. I WILL KEEP TSRA WORDING IN FOR EARLY SUN MORNING AS THERE WILL BE SOME ELEVATED INSTABILITY. EASTER SUN THINGS WILL BEGIN TO PICK UP. OUR UPPER LOW WILL BE MOVING ACROSS THE SRN/CNTRL PLAINS WITH A DEVELOPING SFC LOW MOVING ACROSS NE TX AND TWRDS THE MID MS VALLEY. THIS WILL SEND ANOTHER COLD FRONT INTO THE CWA LATE EARLY MON WITH A PREFRONTAL TROUGH WELL AHEAD OF IT LATE SUN AFTN AND EVN. IT WILL BE WITH THIS PREFRONTAL TROUGH THAT PROVIDES THE BEST CHANCE FOR SVR ESPECIALLY TORNADO POTENTIAL. THAT SAID THERE ARE STILL A FEW QUESTIONS AS TO HOW MUCH IN THE WAY OF SVR WE WILL SEE. THE KINEMATIC FIELD IS IMPRESSIVE. WINDS VEER WITH HEIGHT ALL THE WAY TO H5 UNTIL ABOUT 4-5Z(0-1 HELICITY VALUES IN EXCESS OF 250 OVER THE ENTIRE AREA AND 0-3KM IN EXCESS OF 350M2/S2). THERE WILL ALSO BE DECENT SPEED SHEAR IN PLACE WITH H85 WINDS APPROACHING 45-50KTS. ONE PROBLEM I SEE IS THE PLACEMENT OF THE UPPER JET AS WE WILL NOT BE IN BEST LOCATION RELATED TO IT BUT THERE WILL BE GOOD DIVERGENCE EARLY ON DURING THE AFTN HRS. THE THERMODYNAMICS ARE NOT TOO SHABBY EITHER. ML CAPE VALUES LOOK TO RANGE FROM 1000-1500J/KG...SHOWALTERS OF -5 AND VT AROUND 27. MOISTURE WILL BE ON THE INCREASE AND ONE THING THAT IS VERY IMPRESSIVE WILL BE THE RICH GULF AIR THAT IS EXPECTED TO MOVE INTO THE REGION WITH THE MDLS INDICATING H85 THETA E AIR OF GREATER THAN 335K ADVECTING INTO THE CWA. AS FOR THE SYNOPTIC PATTERN THE SFC LOW LOOKS TO TRACK A LITTLE TOO FAR TO OUR NORTH WITH SFC PRESSURES RISING DURING THE EVN. H5 HEIGHTS SEEM TO BE ON THE UPPER END OF WHAT WE NEED SEE AND THE H10-H5 THICKNESS VALUES APPEAR TO BE A LITTLE HIGH AS WELL. ALL THAT SAID WITH THE POTENTIAL EXISTS FOR A DECENT SVR WEATHER EPISODE FOR THE CWA SUN AFTN/EVN. THINGS SHOULD BEGIN TO WIND DOWN ACROSS THE REGION AFTR MIDNIGHT AS THE BEST LL MOISTURE PUSHES EAST OF THE AREA. .LONG TERM...OVERALL CONFIDENCE IN THE EXTENDED PORTION OF THE FCST AFTER WED IS VERY LOW...BEFORE THAT NOT TOO BAD. THE GFS AND ECMWF HAVE SOME RATHER LARGE DIFFERENCES ON HOW TO HANDLE THE NEXT BIG SYSTEM DROPPING THROUGH THE PAC NW LATE TUE/WED. RIGHT NOW I HAVE JUST STUCK CLOSER TO THE GFS AND MEX GUI UNTIL THE MDLS HAVE A BETTER HANDLE ON THAT SYSTEM. MON AND INTO MON NIGHT...THE FRONT WILL CONTINUE TO WORK SOUTH ACROSS THE CWA MON AND SHOULD PUSH INTO THE GULF EARLY MON EVN. ALL OF THE SHRA AND TSRA SHOULD COME TO AN END MIDDAY MON ACROSS THE NW AND THEN LATE MON NIGHT ALONG THE COAST. HIGH PRESSURE WILL PUSH INTO THE REGION BEHIND THIS FRONT COOLING AND DRYING THINGS OUT FOR TUE AND WED. LOWS WILL ACTUALLY DROP BACK DOWN INTO THE UPPER 40S TO LOWER 50S WED MORNING AS THE SFC HIGH SITS OVER THE LOWER MS VALLEY. BY WED WE SHOULD START TO MODERATE AGAIN AS OUR NEXT UPPER LOW TAKES SHAPE OUT WEST. THIS WILL CAUSE THE UPPER RIDGE TO MOVE OVER THE AREA WARMING THINGS UP NICELY AND DEPENDING ON THE SPEED OF THE NEXT SYSTEM RAIN MAY RETURN TO THE REGION LATE THU BUT PROBABLY MORE SO FRI AND INTO NEXT WEEKEND. /CAB/ .AVIATION... COLD FRONT HAS BEEN SLOWLY TRACKING SOUTHWARD THROUGH THE AREA WITH THE BOUNDARY FINALLY SOUTH OF ALL TERMINALS. LIGHT SHOWERS HAVE DEVELOPED NORTH OF THE FRONT IN SW LA AND CURRENTLY MOVING EASTWARD. PRECIP DOES NOT APPEAR TO BE REACHING THE GROUND PER LATEST OBS UNDER THESE ECHOS...BUT A FEW SPRINKLES TO A TRACE ARE POSSIBLE. LIGHT NORTH WINDS WILL PERSIST TODAY ALONG WITH MID LEVEL CLOUD DECK. VFR IS EXPECTED TO PREVAIL THROUGH THE PERIOD AT ALL TERMINALS. && .MARINE... SEAS IN THE OUTER WATERS REFUSE TO DROP DESPITE RELATIVELY LIGHT WINDS. SEAS WILL REMAIN AROUND 6 FEET DURING THE MORNING. AS WAVE HEIGHTS SUBSIDE DURING THE DAY...WINDS WILL INCREASE TO 15 TO 20 KTS. SO...HAVE ISSUED SMALL CRAFT EXERCISE CAUTION FOR THE OUTER WATERS. COLD FRONT WILL EVENTUALLY STALL ALONG THE NORTHERN GULF OVER THE WEEKEND. A TROUGH OF LOW PRESSURE WILL DEVELOP OVER THE PLAINS STATES LATER THIS WEEKEND RESULTING IN TIGHTENING OF PRESSURE GRADIENT ACROSS THE AREA. WINDS WILL RESPOND WITH AREAL COVERAGE 15 TO 20 KT WINDS ALONG WITH INCREASING SEAS. ATTM...SMALL CRAFT CRITERIA LOOKS TO POSSIBLE DUE TO LONG FETCH OF SE WINDS. A COLD FRONT WILL MOVE THROUGH TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THIS BOUNDARY. New Orleans Local Weather thread - dkmac - 04-12-2009 05:14 AM :Easter: THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF COASTAL WATERS OF SOUTHEAST LOUISIANA AND SOUTH MISSISSIPPI...SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. .DAY ONE...TODAY AND TONIGHT THERE IS A MODERATE RISK FOR SEVERE WEATHER TODAY ACROSS SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. THE POTENTIAL EXISTS FOR AN OUTBREAK OF SEVERE WEATHER TO OCCUR. LONG TRACK...STRONG TORNADOES ALONG WITH LARGE HAIL AND DAMAGING WINDS WILL BE THE GREATEST THREATS AS A POTENT DISTURBANCE MOVES THROUGH THE AREA. MOST OF THIS ACTIVITY WILL OCCUR IN THE AFTERNOON AND INTO THE OVERNIGHT HOURS AS THE STORM SYSTEM PROGRESSES EASTWARD. AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 419 AM CDT SUN APR 12 2009 .SHORT TERM... BIGGEST CONCERN IS THE POTENTIAL FOR AN OUTBREAK OF SEVERE WEATHER ACROSS SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI TODAY. WATER VAPOR IMAGERY SHOWS A WELL DEVELOPED UPPER LEVEL LOW STEADILY TRACKING EASTWARD ACROSS THE CO/NM BORDER. THE ASSOCIATED SFC LOW CURRENTLY LOCATED IN WEST TEXAS NEAR KMAF WILL CONTINUE ON AN EAST NORTHEAST TRACK ACROSS TEXAS INTO SOUTHERN ARKANSAS BY EVENING. MEANWHILE...SE SFC WINDS WILL RESPOND TO TIGHTENING PRESSURE GRADIENT WITH SUSTAINED SPEEDS IN 20 TO 25 MPH RANGE. MODEL SOUNDINGS RECOGNIZE THIS WITH PWATS INCREASING TO WELL OVER 1.5 INCHES BY LATE AFTERNOON. IN TERMS OF SVRWX PARAMETERS...NOT A WHOLE LOT MISSING FROM THE PICTURE. JET MAX ON THE SE CORNER OF THE MAIN TROUGH WILL PASS ACROSS CENTRAL LA AND CONTINUE NEWD PUTTING THE CWA NEAR THE RIGHT REAR ENTRANCE REGION. SBCAPE WILL BE INCREASING FROM MORNING THROUGH THE NIGHT IN THE NEIGHBORHOOD OF 1500 J/KG. WHILE NOT OVERLY IMPRESSIVE ...STILL SUFFICIENT. MOISTURE IS THE LEAST OF CONCERNS WITH SUCH STRONG ONSHORE FLOW. EXPECTING TD/S IN THE MID TO UPPER 60S. IN TERMS OF TORNADO POTENTIAL...SRH OF GREATER THAN 400 M2/S2 WILL BE ACROSS THE AREA FROM 12Z THROUGH 00Z. 0-6KM BLKSHR VECTORS OF AT LEAST 50 KTS BY MID DAY AND STEADILY INCREASING. LLVL SHEAR LOOKS TO BE QUITE STRONG WITH 850H WINDS OF 40+KTS. THIS RAPID VEERING IN THE LOWER LEVELS WILL PROVIDE THE MEANS FOR SUSTAINED ROTATING UP DRAFTS AND THE POTENTIAL FOR LONG TRACKED TORNADOES WITH A FEW POSSIBLY QUITE STRONG. TOUGH CALL ON HOW MANY STORMS WILL BE DISCRETE. THINKING IS THAT MAIN LINE WILL BE MOVING ACROSS TEXAS TOWARDS THE CWA AND WILL HAVE EMBEDDED SUPERCELLS. WHILE THE THREAT FOR TORNADOES IS INCREASED...THERES ALSO THE INHERENT RISK FOR LARGE HAIL AND DAMAGING WINDS. FOR TIMING...LOOKING LIKE MORE OF A LATE AFTERNOON TO EVENING FOR AREAS ALONG THE ATCHAFALAYA AND THEN INTO THE OVERNIGHT HRS AS THE SYSTEM PROGRESSES EASTWARD. THE TAIL END OF THIS ACTIVITY LIKELY WONT EXIT THE CWA UNTIL MONDAY MID MORNING. CLEARING WILL BECOME EVIDENT IN THE GENERAL AREAS OF BTR AND MCB MONDAY AFTERNOON. TEMPERATURES BEHIND THE COLD FRONT WONT HAVE A BIG IMPACT ON THE AREA. EXPECT ONLY TO DROP TO NEAR NORMS WHICH IS MID 70S ON TUES WITH A QUICK RETURN TO THE 80S FOR THE REST OF THE WEEK. .LONG TERM... UPPER LOW WILL CONTINUE ON ITS EASTWARD TRACK TOWARDS THE EAST COAST. RIDGE WILL BUILD IN WHILE ANOTHER UPPER LOW DEVELOPS AND DIGS INTO THE WESTERN US NEAR THE 4 CORNERS REGION. PREFERRED THE ECMWF/S SLOWER TRACK ACROSS THE COUNTRY RATHER THAN THE GFS/S MORE PROGRESSIVE MOVEMENT. THIS WOULD RESULT IN A COLD FRONT STALLING ACROSS THE GULF COAST AND THE POTENTIAL FOR AN EXTENDED PERIOD OF RAINFALL. SO...WHILE NOT OVERLY AGGRESSIVE...HAVE UPPED POPS FOR THE LATTER PART OF THE WEEKEND. MEFFER && .AVIATION... CONDITIONS WILL DETERIORATE TO MVFR CATEGORY THIS MORNING AND AFTERNOON AS A WARM FRONT PASSES THROUGH THE AREA. AT LEAST TEMPO IFR CONDITIONS WILL BE POSSIBLE LATE IN THE AFTERNOON AND EVENING. AS THE STORM SYSTEM APPROACHES AND MOVES INTO THE REGION...THE CHANCE OF SHRA/TSRA WILL INCREASE THROUGH THE DAY AND INTO THIS EVENING. THERE WILL LIKELY BE A SOLID LINE OF STRONG TO SEVERE TSRA THAT MAY REQUIRE LONG DEVIATIONS TO CIRCUMNAVIGATE LATE THIS AFTERNOON AROUND KBTR AND EASTWARD TONIGHT INTO EARLY MONDAY. THERE IS A MODERATE RISK OF SEVERE TSRA AT KMCB...KBTR...AND KMSY THIS AFTERNOON AND TONIGHT WITH HAIL AND STRONG CONVECTIVE WIND GUSTS BOTH POSSIBLE. THERE IS A SLIGHT RISK OF TSRA AT KGPT MAINLY TONIGHT. 22/TD && .MARINE... STRONG GRADIENT FLOW BETWEEN LOW PRESSURE TO THE WEST AND HIGH PRESSURE TO THE EAST WILL INCREASE OVER THE TIDAL LAKES AND COASTAL WATERS THIS MORNING. WITH WINDS ALREADY IN /EXERCISE CAUTION/ CRITERIA...SMALL CRAFT ADVISORY /SCA/ CONDITIONS SHOULD DEVELOP BY MID MORNING. STRONG SOUTHEAST TO SOUTH WINDS WILL PERSIST INTO TONIGHT WITH CONTINUED ADVISORY CONDITIONS DUE TO SEAS PERSISTING INTO MONDAY MORNING. THE TROUGH AXIS TO THE WEST WILL BEGIN TO LIFT TO THE NORTHEAST MONDAY NIGHT...DRAGGING A FRONT THROUGH THE COASTAL WATERS. A PACIFIC AIRMASS WILL BUILD IN BEHIND THIS FRONT ON TUESDAY...WITH ONLY A BRIEF PERIOD OF WEAK COLD AND DRY AIR ADVECTION. DO NOT EXPECT ANY SUSTAINED SMALL CRAFT CONDITIONS IN THE WAKE OF THE FRONT DUE TO THIS WEAK ADVECTION. THE HIGH WILL ALSO BUILD IN VERY QUICKLY...AND THEN BECOME CENTERED OVER THE CENTRAL GULF COAST THROUGH WEDNESDAY. EXPECT LIGHT WINDS AND CALM SEAS TUESDAY NIGHT INTO WEDNESDAY. GOING INTO THURSDAY...THE RIDGE AXIS WILL SLIP TO THE EAST...AS ANOTHER STRONG UPPER LEVEL TROUGH BEGINS TO DIG INTO THE PLAINS STATES. WINDS SHOULD BEGIN TO INCREASE IN ADVANCE OF THIS TROUGH AS THE GRADIENT TIGHTENS...WITH A RETURN TO EXERCISE CAUTION OR ADVISORY CONDITIONS EXPECTED FOR FRIDAY AND SATURDAY. 22/TD New Orleans Local Weather thread - dkmac - 04-13-2009 04:17 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 429 AM CDT MON APR 13 2009 .SHORT TERM... TOR WATCH REMAINS FOR THE 3 COASTAL COUTIES IN MISSISSIPPI. CONVECTIVE LINE HAS ALL BUT STALLED OVER THE AREA AS WINDS BEGIN TO PARALLEL THE AXIS AND THE LINE IS BEGINNING TO FEEL THE TUG FROM THE SFC LOW MOVING OUT OF EAST TX. STRONG SUPRESSION BETWEEN THE SFC LOW AND PREFRONTAL CONVECTIVE LINE IS KEEPING MOISTURE FROM EARLIER RAINS LOCKED IN THE BL THIS MORNING CAUSING A DENSE FOG MASS TO FORM. SHOULD TAKE MUCH OF THE DAY FOR THE SFC LOW TO CATCH UP. ANOTHER AREA OF SH/TS SHOULD DEVELOP AS THE EXTRA FORCING BEGINS TO BUMP INTO THE MOISTURE NEAR THE PREFONTAL AXIS. THE FRONT WILL GET FORCED EAST TONIGHT AND SKIES SHOULD BEGIN TO CLEAR TOWARD BTR WHILE MORE TIME WILL BE NEEDED AT GPT. .LONG TERM... NEXT SYSTEM WILL BEGIN TO AFFECT THE AREA BY FRIDAY AND MAY EVEN HANG AROUND THROUGH THE WEEKEND. && .AVIATION... SCATTERED TSRA WITH TEMPO LIFR CONDITIONS WILL LINGER AROUND KGPT THROUGH ABOUT 12Z...AND SHRA WILL BE IN THE VICINITY OF KMSY THROUGH 10-11Z. OTHERWISE...LIFR TO IFR CIGS WILL LINGER AROUND KGPT MUCH OF TODAY AND POSSIBLY INTO TONIGHT...WITH MVFR CIGS MAINLY THIS MORNING AT KMSY. THE BIG FORECAST PROBLEM...ESPECIALLY FOR KBTR AND KMCB IS WHETHER OR NOT TO BRING IN THE VERY LOW STRATUS AND DENSE FOG THAT IS OCCURRING AS FAR EAST AS KESF-KARA. ALTHOUGH VERY LOW IFR CONDITIONS CANNOT BE RULED OUT...IT APPEARS THIS WOULD BE A BRIEF OCCURRENCE SO THE FORECAST WILL BE FOR MAINLY IFR CIGS THROUGH ABOUT MID MORNING. VFR WEATHER SHOULD PREVAIL AT ALL TAF SITES EXCEPT FOR KGPT THIS AFTERNOON. 22/TD && .MARINE... WINDS HAVE DIMINISHED BELOW SMALL CRAFT ADVISORY /SCA/ CRITERIA OVER LAKE PONTCHARTRAIN...BUT CONTINUE OVER PORTIONS OF THE COASTAL WATERS. WILL LET THE SCA CONTINUE THROUGH 9 AM OVER THE COASTAL WATERS. WINDS AND SEAS WILL DIMINISH DURING THE DAY TODAY BUT WILL INCREASE TO NEAR SMALL CRAFT CONDITIONS AGAIN BRIEFLY AGAIN TONIGHT NIGHT IN THE WAKE OF A COLD FRONT THAT WILL BE PUSHING ACROSS THE COASTAL WATERS LATE TODAY AND TONIGHT. HIGH PRESSURE WILL BUILD OVER THE COASTAL WATERS TUESDAY AND WEDNESDAY BEFORE SHIFTING TO THE EAST THURSDAY WITH ONSHORE FLOW RETURNING FOR THE END OF THE WORK WEEK. ONSHORE FLOW WILL INCREASE AND BECOME STRONG FRIDAY IN ADVANCE OF THE NEXT SYSTEM THAT WILL AFFECT THE REGION NEXT WEEKEND. 22/TD New Orleans Local Weather thread - dkmac - 04-14-2009 05:11 AM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 425 AM CDT TUE APR 14 2009 .SHORT TERM... NEXT 3 DAYS SHOULD BE RELATIVELY COMFORTABLE AND PLEASANT. HIGH PRESSURE TO SETTLE IN THROUGH AT LEAST THURSDAY. MID TO EXTENDED FCAST IS WHERE WE WILL FIND THE NEXT SYSTEM MOVING THROUGH. .LONG TERM... THURSDAY AND FRIDAY WE SEE THE FIRST SIGNS OF A MODERATE PULSE MOVING THROUGH THE MID LEVEL WESTERLY JET CAUSING SOME ACTIVITY TO BREAK OUT OVER THE NORTHERN GULF. IF THIS HOLDS TOGETHER...IT MAY REACH OUR SHORES BY FRIDAY NOON. THIS FEATURE IS ACTING MORE LIKE A WARM FRONT THAN A SINGLE ENTITY. THE FIRST FRONT WILL MOVE THROUGH TX FRIDAY WHILE SEVERAL DISTURBANCES MOVE THROUGH THE UPPER JET CAUSING SH/TS TO BREAK OUT. THIS ACTIVITY WILL MOVE EAST WHILE THE FRONT DETERIORATES BACK IN TX FRIDAY NIGHT. WE SHOULD SEE THE FIRST OF TWO MAIN DISTUBANCES MOVE THROUGH SAT MORNING. AS THESE DISTURBANCES LEAVE THEIR SOURCE REGION...THEY WILL ENCOUNTER BETTER STABILITY AND INHOSPITABLE MID AND UPPER LEVEL DYNAMICS. THIS SHOULD CAUSE THEM TO WEAKEN AS THEY MOVE INTO OUR AREA. THE NEXT STRONG DISTURBANCE IS THE ONE THAT WILL MAKE HEADLINES AT LEAST OVER SE TX AND SW LA. THIS ONE STARTS UP SAT NEAR THE CORPUS AREA AND MOVES SLUGGISHLY NE. VERY STRONG SUPPORT IS FOUND IN ALL DYNAMIC AND THERMAL FIELDS WITH THIS SYSTEM AS IT MOVES TOWARD THE HOUSTON AREA WITH STRONG TO SEVERE TS AND TRAINING HEAVY RAINFALL. THE MCC TYPE FEATURE WILL ENCOUNTER A COLD FRONT AS IT BEGINS TO LEAVE THE LCH AREA LATE SAT NIGHT. WILL NEED TO WATCH THIS FOR EARLY SUN MORNING THROUGH THIS AREA. SOME MID LEVEL DRY AIR WILL BE PROVIDED BY THE FRONT CAUSING THE DISTURBANCE TO WEAKEN A LITTLE. THE FRONT WILL ALSO CAUSE IT TO ACCELERATE AS IT MOVES THROUGH OUR AREA SO THAT IT BECOMES MORE PROGRESSIVE. WE SHOULD NOT SEE THE ISSUES THAT HOUSTON AND LCH MAY ENCOUNTER BUT THE SYSTEM WILL STILL HAVE THE POTENTIAL TO CAUSE SOME PROBLEMS HERE WITH STRONG TO SEVERE TS AND SOME HEAVY RAINFALL SUNDAY. MONDAY LOOKS COOL AND CLOUDY AS A 700MB THERMAL TROUGH MOVES THROUGH CAPPING THE LOW LEVELS. IMPROVING CONDITIONS SHOULD BE BACK BY TUE OF NEXT WEEK. && .AVIATION... SATELLITE SHOWS AREAS OF LOW CLOUDS WITH BASES MOSTLY 035-060 WILL CONTINUE TO CAUSE TEMPO CIGS EARLY THIS MORNING THEN DRIER AIR WILL CAUSE CLOUD COVER TO DECREASE TO CLEAR TO FEW BY AROUND 13Z. NW TO NNW WINDS WILL GUST AROUND 20 KT AT KMSY-KGPT THROUGH 13-14Z...THEN A RELAXING PRESSURE GRADIENT WILL CAUSE WINDS TO GRADUALLY DECREASE THROUGH THE DAY. VFR CONDITIONS WILL PREVAIL THE NEXT FEW DAYS. 22 && .MARINE... NORTH TO NORTHWEST WINDS HAVE INCREASED TO AROUND 20 KNOTS ON LAKE PONTCHARTRAIN AND 20 TO 25 KNOTS OVER THE COASTAL WATERS IN THE WAKE OF THE COLD FRONTAL PASSAGE. WILL EXTEND THE SMALL CRAFT ADVISORY /SCA/ OVER THE COASTAL WATERS UNTIL 10 AM/15Z AND KEEP THE SCA UNTIL 7 AM/12Z OVER THE TIDAL LAKES WITH EXERCISE CAUTION FROM 7 AM TO 10 AM. THE RIDGE OF HIGH PRESSURE WILL BUILD RIGHT OVER THE MARINE AREA ON WEDNESDAY THEN MOVE EAST THURSDAY. PRESSURE GRADIENT AND WINDS WILL INCREASE THURSDAY INTO FRIDAY AND SATURDAY IN ADVANCE OF THE NEXT STORM SYSTEM THAT WILL MOVE INTO THE PLAINS. |