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New Orleans Local Weather thread - ROLLTIDE - 10-31-2008 07:43 AM

000
FXUS64 KLIX 311141
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
641 AM CDT FRI OCT 31 2008

.AVIATION /12Z TAFS/...

VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT AT
MSY...GPT...BTR...MCB EXCEPT FOR LIGHT FOG AT MCB SATURDAY MORNING.
25


&&

.PREV DISCUSSION... /ISSUED 318 AM CDT FRI OCT 31 2008/

SYNOPSIS...
A SURFACE HIGH IS CENTERED OVER THE CAROLINAS WITH THE RIDGE AXIS
EXTENDING SOUTHWESTWARD THROUGH ALABAMA...GEORGIA AND LOUISIANA.
CLEAR SKIES ARE ONCE AGAIN ALLOWING EFFICIENT RADIATIVE COOLING
AND THERE SHOULD BE NO PROBLEM REACHING THE FORECAST LOWS THIS
MORNING.

DISCUSSION...
FEW CHANGES WERE MADE TO THE FORECAST PACKAGE AS THERE HAS BEEN NO
REAL CHANGE IN THE MODELS AND PRIOR REASONING STILL REMAINS SOUND.
MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE PERIOD.

AN UPPER LEVEL SHORTWAVE TROUGH CURRENTLY LOCATED OVER EASTERN
NEBRASKA WILL CONTINUE TO DIVE SOUTHEASTWARD TODAY. AS THE UPPER
TROUGH AXIS CROSSES THROUGH THE REGION...THIS WOULD ORDINARILY
RESULT IN ENOUGH FORCING TO FIRE OFF SOME SHOWERS AND
THUNDERSTORMS. HOWEVER...WITH A VERY DRY AIRMASS STILL IN PLACE...
THE ONLY EFFECT WE WILL SEE IS A SLIGHT INCREASE IN CLOUD COVER.

THE UPPER LOW IS EXPECTED TO BECOME CUT OFF FROM THE MAIN
WESTERLIES AND STALL OVER THE NORTHEASTERN GULF OF MEXICO THROUGH
THE WEEKEND AS WEAK RIDGING ONCE AGAIN BUILDS INTO THE NORTHERN
GULF COAST REGION.

BY TUESDAY...THE NEXT DEEP TROUGH WILL BE DIGGING INTO THE ROCKY
MOUNTAINS REGION. A SURFACE LOW IS EXPECTED TO DEVELOP OVER
WESTERN KANSAS WITH A TRAILING COLD FRONT BEHIND IT. AS THIS UPPER
TROUGH MOVES EASTWARD...THE SURFACE LOW IS EXPECTED TO HEAD
TOWARD THE GREAT LAKES WITH THE COLD FRONT TRAILING BEHIND. THERE
HAVE BEEN SOME TIMING ISSUES CONCERNING WHEN THE FRONT WILL MAKE
IT THROUGH THE NORTHERN GULF COAST REGION. AT THIS TIME...IT LOOKS
LIKE THE MOST LIKELY SCENARIO WILL BE SOME TIME ON THURSDAY.

BY THAT TIME...A PERSISTENT SOUTHERLY COMPONENT TO THE WINDS WILL
HAVE BROUGHT A GOOD AMOUNT OF LOW TO MID-LEVEL MOISTURE BACK INTO THE
REGION. THROW IN THE THE ENHANCED LIFT ALONG AND AHEAD OF THE
FRONT...AND IT SHOULD BE ENOUGH TO FIRE OFF AT LEAST SOME ISOLATED
SHOWERS AND THUNDERSTORMS. FOR NOW...WILL MAINTAIN THE SLIGHT CHANCE
WORDING ON THURSDAY AND INTO THURSDAY NIGHT.

BEHIND THE FRONT...HIGH PRESSURE ONCE AGAIN TAKES HOLD OF THE
REGION.

MARINE... WINDS AR EXPECTED TO BE EAST OR NORTHEAST ACROSS MOST
OF THE COASTAL WATERS AS RELATIVELY LIGHT FLOW WRAPS ROUND A
SURFACE RIDGE. THE HIGHEST WIND SPEEDS SHOULD NOT EXCEED 15 KTS
THROUGH EARLY NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB 75 43 75 44 / 0 0 0 0
BTR 76 47 77 47 / 0 0 0 0
MSY 75 54 74 53 / 0 0 0 0
GPT 73 47 74 47 / 0 0 0 0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.


New Orleans Local Weather thread - ROLLTIDE - 10-31-2008 04:17 PM

000
FXUS64 KLIX 312020
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
320 PM CDT FRI OCT 31 2008

.SHORT TERM...

SURFACE RIDGING REMAINS IN CONTROL OF THE AREA...AS A FAIRLY DEEP
VORT MAX CONTINUES TO SLIDE SOUTHWARD INTO THE LOWER MISSISSIPPI
VALLEY. ALTHOUGH THE VORT MAX IS STRONG...THERE IS VERY LITTLE
MOISTURE FOR THE SYSTEM TO WORK WITH. AS A RESULT...EXPECT NOTHING
MORE THAN A FEW CLOUDS TO PASS THROUGH AS THE UPPER LEVEL LOW
PULLS INTO THE NORTHEASTERN GULF OF MEXICO. ONCE THE SYSTEM HAS
MOVED EAST OF THE REGION...A DRY NORTHERLY FLOW ENHANCED BY STRONG
SUBSIDENCE ON THE BACK SIDE OF THE EXITING VORT MAX WILL ALLOW FOR
CLEARER SKIES ON SUNDAY. DUE TO THE EXTREMELY DRY AIRMASS
EXPECTED...A LARGE DIURNAL RANGE IN TEMPERATURES IS FORECAST.
OVERNIGHT LOWS WILL BE BELOW NORMAL...ESPECIALLY NORTH OF
INTERSTATE 10...WITH DAYTIME HIGHS NEAR NORMAL. UP TO A 30 DEGREE
TEMPERATURE RANGE WILL BE POSSIBLE.

.LONG TERM...

THE CUT OFF UPPER LEVEL LOW OVER THE NORTHEASTERN GULF WILL BEGIN
TO FEEL THE INFLUENCE OF A SHORT WAVE TROUGH PULLING INTO THE
PLAINS STATES BY MONDAY. THIS WILL ALLOW THE LOW TO PULL INTO THE
SOUTHEASTERN STATES...WHICH WILL IN TURN ALLOW FOR SOME WEAK UPPER
LEVEL RIDGING TO BUILD ACROSS THE CWA. SUBSIDENCE ASSOCIATED WITH
THE UPPER LEVEL RIDGING WILL ALLOW DAYTIME HIGHS TO WARM ABOVE
NORMAL MONDAY INTO TUESDAY. AT THE SAME TIME...SOME WEAK MOISTURE
ADVECTION WILL BEGIN TO TAKE PLACE...AS SOUTHERLY FLOW IN ADVANCE
OF THE APPROACHING SHORT WAVE TROUGH DEVELOPS. OVERALL DIURNAL
RANGES WILL DECREASE...WITH OVERNIGHT LOWS RETURNING TO MORE
NORMAL READINGS FOR THIS TIME OF YEAR.

THE UPPER LEVEL RIDGE WILL SLIDE TO THE EAST ON WEDNESDAY...AS AS
THE TROUGH AXIS IN THE PLAINS DIGS SOUTHWARD. SOUTHERLY FLOW WILL
INCREASE THROUGHOUT THE DAY...ALLOWING FOR DEEPER MOISTURE TO
OVERSPREAD LOUISIANA AND MISSISSIPPI. AT THE SAME TIME...A BROAD
AREA OF UPPER LEVEL ASCENT ASSOCIATED WITH DIFLUENT FLOW ALOFT AND
SOME POSITIVE VORTICITY ADVECTION TAKE HOLD. THIS SHOULD ALLOW FOR
SOME CONVECTIVE ACTIVITY LATE WEDNESDAY NIGHT INTO THURSDAY...AS
THE TROUGH AXIS AND ASSOCIATED SURFACE FRONT PUSH THROUGH THE
REGION. DUE TO THE INCREASED MOISTURE...WARM AND HUMID CONDITIONS
ARE EXPECTED WEDNESDAY INTO THURSDAY...WITH OVERNIGHT LOWS RUNNING
A GOOD 10 DEGREES ABOVE NORMAL. THE FRONT SHOULD PULL INTO THE
COASTAL WATERS ON FRIDAY...AS THE TROUGH AXIS BEGINS TO PULL EAST
OF THE REGION. IN THE WAKE OF THE FRONT...STRONG COLD AND DRY AIR
ADVECTION WILL ALLOW FOR COOLER TEMPERATURES AND CLEARING SKIES.


New Orleans Local Weather thread - dkmac - 11-01-2008 04:42 AM

000
fxus64 klix 010920
afdlix

area forecast discussion
national weather service new orleans la
420 am cdt sat nov 1 2008

.short term...
Strong cut-off upper low moving southward into a void of any real
weather systems. This motion will continue bringing the system
over the northern gulf near mobile before slowing and eventually
turning ne. The vorticity associated will be strong until it slows
and begins to turn ne. The system looks as if it weakens as it
moves south but in fact it encounters the east coast high ridging
back over this area from 500mb to the sfc. This effectively
splits the vort into two sections one to the nw and one to the se
of the ridge. Just as the main low reaches the south side of the
ridge axis...it slows and begins to turn ne. This is where it
starts to weaken. The system will remain strong enough to produce
rain where moisture is deepest. This will be mainly over the
coastal waters. A short wave trough is currently moving into west
texas. This feature will be responsible for kicking the upper low ne
over time.

.long term...
The next system that will give a better chance of rain is seen
approaching kodiak alaska this morning. The strong upper trough
over the west coast will quickly move out and swing back into the
main polar jet as the next upper trough takes its place. Will have
to see how this system is handled over the coming days. Looks as
if the mid level high behind the front will bridge the southern
end of the front as the main low occludes and move ne stretching
the southern end of the front decaying its moisture load. Current
models do not show this attm. Unless model solutions are missing
another feature to cause the amount of qpf on this end of the
front...namely in the form of a secondary low forming on the
southern end of the front as strong upper winds are found exiting
the base of the trough thursday night.

&&


New Orleans Local Weather thread - dkmac - 11-02-2008 07:16 AM

000
fxus64 klix 021120
afdlix

area forecast discussion
national weather service new orleans la
520 am cst sun nov 2 2008

.aviation /12z tafs/...
Vfr conditions should prevail through monday morning with exception
being patchy 5-6sm fog around the terminals near daybreak. 25

&&

.prev discussion... /issued 419 am cst sun nov 2 2008/

short term...
Upper low now slowed and beginning to move out. New system moving
into the rockies will swing northward while another stronger
system moves into the west coast. This will be the system that
swings a cold front through the area by thu. The front will slow
somewhat as it approaches before getting a secondary stronger
surge of dry cool air to force it through and well away from the
north central gulf coast. Not looking for a lot of rain with this
system. So no problems should be expected.

Long term...
After the cold front moves through...we will fall back into a dry
cool air regime sticking with us through most of next week.

Marine... Winds and seas to stay light through most of the week
until frontal passage.


New Orleans Local Weather thread - dkmac - 11-03-2008 06:41 AM

000
fxus64 klix 030950
afdlix

area forecast discussion
national weather service new orleans la
350 am cst mon nov 3 2008

.short term...
Clear weather will continue over much of the area today. Some
passing clouds and showers will invade the extreme southeast part
of la today. The next weather maker to move into the region will
be a cold front thu night into fri morning. It should help bring
the best chance of rain to the area in a while.

Fog will begin to set up tuesday night bringing some locations to
1/2 mile or less. Winds should pick up enough wed night to keep
low level clouds in but fog may stay above the boudary layer.

.long term...
The cold front moves through friday and brings back the dry cool
air for several more days. Another stronger cold front will make
its way to the region by the end of next week which is well beyond
the current fcast pack.

&&

.aviation...
/12z tafs/
scattered vfr clouds expected during daytime heating today but no
long term ceilings anticipated. Low level moisture gradually
increasing with marine layer air mass advecting into area to provide
a better chance of fog formation overnight/early tuesday morning and
again each morning through friday. Cold front expected to move
across terminals thursday night to bring lower ceilings and
pre-frontal shra/tsra coverage. 24

&&

.marine...
Moderate northeasterly flow today will be veering east tuesday...
Southeast by wednesday and southwest thursday before another wind
shift to northwest takes place with frontal passage late thursday
night or very early friday. Seas expected to remain in the 2-3 ft
range through thursday before building friday with cold high
pressure post-frontal. 24

&&

.fire weather...
Northeast flow today will likely veer southeast in response to gulf
breeze during the afternoon near the coast...then return to
prevailing east overnight and tuesday morning. Humidity levels will
increase steadily in the upcoming days as marine layer air moves off
teh gulf in advance of next frontal passage late thursday night or
very early friday. 24

&&


New Orleans Local Weather thread - dkmac - 11-04-2008 06:11 AM

000
fxus64 klix 040939
afdlix

area forecast discussion
national weather service new orleans la
339 am cst tue nov 4 2008

.short term...
No surprises with continued tranquil weather. This will change
starting the end of this week though. The first relatively weak
system is just now moving into the west coast. Strongest winds
will move to the east side of the upper trough accelerating it ne
as the sfc low moves ne as well. This will stretch the southern
end of the front allowing the mid/sfc high to the west to bridge
the front on its southern end. This will do two things...one keep
a low end chance of rain in the fcast and keep most activity low
topped and non-severe. This all takes place thu night into fri
morning.

The subsequent sytems get stronger and stronger over the next week or
so. The next system approaches the west coast with 140kt winds at
30h. Thermal gradients are not as strong over the central and
eastern part of the country at that level so these winds weaken
over time as the system moves east but not before kicking out
right over our area about the start of next week. This one
promises to bring an abundance of rain and possibly some strong to
severe weather with it.

.long term...
Not usually one to expound beyond the end of the 7 day fcast cycle
since errors are inherent in any and all models and tend to
increase over long time intervals.

Not just a few...but all global model suites are initializing
within a 5 kt tolerance of each other on a rather strong system
developing over the pacific and moving into the west coast by wed
or thu of next week. This system is advertised attm to have very
strong wind speeds of an incredible 185kt at 300 mb jet level. The
strong winds fall down the nva side of a developing upper ridge
over the west and produce a strong upper low over the central
plains which will move se then eventually ne through the end of
next week. This looks to kick off quite an explosive event
somewhere over the southern plains states. So between the early
week and late week systems...the weather is in for a drastic
change for the worse. At this time...we will not give any
placement or timing of where the weeks end system will be since
many variables are likely to change.

&&

.aviation...
/12z tafs/
vfr conditions to prevail though may see a brief period of mvfr vbsy
in br at kmcb and kbtr between 10z-13z. High pressure over eastern
u.s. Continues to hold firm but should slowly yield to frontal zone
approach thursday. More vfr sct clouds likely wednesday and possible
mvfr ceilings late thursday near frontal passage along with
scattered shra/isold tsra immediately along the front. 24

&&

.marine...
Ne to e flow today will become more se wednesday and southerly
thursday in advance of cold front to move across the coastal waters
late thursday night or early friday. Strong northwest winds after
front friday should only be a few hours duration before setlling to
lower levels late friday. The high pressure ridge that builds in the
wake of the front will not be as strong nor as persistent as current
ridge has been. 24

&&

.fire weather...
Any patchy light radiational fog near daybreak should burn off by 8
am cdt. Light e winds will likely become s for 2-3 hours during
mid-afternoon due to gulf breeze near the coast. Humidity levels
will gradually increase day-to-day through thursday evening prior to
next frontal passage still slated for late thursday or very early
friday. 24


New Orleans Local Weather thread - ROLLTIDE - 11-04-2008 06:50 PM

FXUS64 KLIX 042124
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
324 PM CST TUE NOV 4 2008

.SHORT TERM...
SURFACE HIGH PRESSURE OVER TN BEGINNING TO RETREAT EASTWARD AS
UPPER TROUGH DEEPENS OVER THE ROCKIES AND CENTRAL PLAINS. MOISTURE
SHOULD SLOWLY INCREASE OVER THE NEXT COUPLE OF DAYS AS WINDS
BECOME MORE EAST AND SOUTHEAST IN ADVANCE OF THE APPROACHING COLD
FRONT. WITH INCREASE IN MOISTURE EXPECT SOME AREAS OF RADIATONAL
FOG OVER LAND AREAS LATE TONIGHT AND AGAIN WEDNESDAY NIGHT AS
WINDS REMAIN LIGHT OVER LAND AREAS DURING THE NIGHT HOURS.

MODELS INDICATE THAT BULK OF ENERGY WITH CURRENT SYSTEM MOVING OUT
OF THE ROCKIES WILL REMAIN GENERALLY NORTH OF THE FORECAST AREA
WITH UPPER LOW MOVING FROM THE CENTRAL PLAINS INTO THE GREAT LAKES
BY FRIDAY. MODELS ARE SUGGESTING THAT SHORT WAVE TROUGH WILL
ROTATE THROUGH THE BASE OF THE TROUGH ACROSS TEXAS AND LOUISIANA
ON FRIDAY AND SATURDAY TO ACCELERATE FRONT EASTWARD. WILL KEEP
SCATTERED SHOWERS AND THUNDERSTORMS IN ADVANCE OF FRONTAL SYSTEM.
INSTABILITY INCREASES ON FRIDAY AFTERNOON ACROSS THE WESTERN TWO
THIRDS OF LOUISIANA WHICH COULD SUPPORT SOME STRONG TO ISOLATED
SEVERE THUNDERSTORMS...BUT INSTBILITY DIMINSHES DURING DURING
EVENING HOURS...WHICH DECRESES THREAT OF ANY TYPE OF SEVERE
WEATHER IN THE FOREAST AREA. PRECIPATION SHOULD END ACROSS THE
FORECAST AREA FROM WEST TO EAST ON FRIDAY AS FRONTAL SYSTEM MOVES
THROUGH.

.LONG TERM...
HIGH PRESSURE CENTERED OVER THE AREA ON THE WEEKEND SHOULD ALLOW
FOR A FAIRLY TRANQUIL WEATHER CONDTIIONS...DRY WITH SEASONABLE
WEATHER. MORE ACTIVE WEATHER PATTEN SHAPING UP FOR NEXT WEEK.
STRONG SHORT TROUGH MOVES THROUGH ON MONDAY AND TUESDAY TIME
PERIOD...WITH MUCH MORE ENERGY AT LOWER LATITUDE THAN THIS WEEKS
SYSTEM. SEVERE WEATHER THREAT IS POSSIBLE WITH THIS SYSTEM
DEPENDING ON QUALITY OF MOISTURE RETURN FROM GULF. BEYOND CURRENT
7 DAY ZONE FORECAST...MODELS ARE INDICATING OF ANOTHER POTENTIALLY
STRONG SYSTEM MOVING ACROSS THE GULF SOUTH REGION LATE NEXT WEEK.

&&

.AVIATION...
LIGHT SE WINDS THIS EVENING WILL LIKELY BECOME CALM OVERNIGHT.
INCREASED MOISTURE ALONG WITH WEAK FLOW AND GOOD RADIATIONAL COOLING
WILL RESULT IN BR AT ALL SITES. VISIBILITIES AT MCB AND GPT MAY DROP
TO 3SM WHILE BTR AND MSY SHOULD BE CLOSER TO 5SM. ASIDE FROM THESE
MVFR CONDITIONS...VFR WILL PREVAIL THROUGH THE REST OF THE PERIOD.
WINDS WILL BECOME MORE SOUTHERLY TOMORROW AND CONTINUED GENERALLY
SKC.

&&

.MARINE...
WINDS WILL GRADUALLY BECOME SE AND THEN SOUTH OVER THE NEXT TWO DAYS
AS THE POSITION OF THE SURFACE RIDGE SHIFTS SOUTHWARD. WAVE HEIGHT
WILL NOT LIKELY BE IMPACTED BY THIS WIND SHIFT AS WIND SPEEDS
DECREASE. BIGGEST CHANGE WILL BE A COLD FRONT ON FRIDAY. A PERIOD
PERSISTENT NNW WINDS OF 15 TO 20 KNOTS MAY RESULT IN WAVES
APPROACHING 5 FEET ON SATURDAY. MODELS INDICATING A QUICK TURN
AROUND IN WINDS BACK TO THE EAST AND SOUTH ON SUNDAY...BUT NOT
CONFIDENT IN THE SOLUTION BUT MAYBE ONE MORE OF A SLOWER SHIFT IN
DIRECTION.

&&

.FIRE WEATHER...
ABOVE AVERAGE TEMPERATURES WILL CONTINUE WED AND THURS WITH HIGHS
AROUND 80. EXPECT WINDS TO BECOME MORE SOUTHERLY THROUGH THE REST OF
THIS WEEK AS SURFACE HIGH PRESSURE NE OF THE REGION DRIFTS SWD. THE
RESULT OF THIS WIND CHANGE WILL BE INCREASE IN MOISTURE ACROSS THE
AREA. MIN RH/S WILL BE 40-50 PCT ON WED AND 50-60 PCT ON THURS. A
COLD FRONTAL PASSAGE EARLY FRIDAY WILL USHER IN MUCH DRIER AIR.
HUMIDITIES WILL DROP SIGNIFICANTLY INTO THE THIS WEEKEND WITH SAT
BEING THE DRIEST. RH/S MAY DROP BELOW 20 PCT ON THIS


New Orleans Local Weather thread - dkmac - 11-05-2008 06:55 AM

000
fxus64 klix 051022
afdlix

area forecast discussion
national weather service new orleans la
422 am cst wed nov 5 2008

.short term...
Deep blanket of very low level cloud cover has settled into the
area this morning. These ceilings will fall to ground level by
sunrise causing a very dense fog over most locations away from
warm bodies of water and a dense fog advisory will be posted for
these areas.

Fog will be a problem once again tonight as moisture pools well
ahead of the first of three cold fronts. The first front will move
through with some shower activity and isolated thunderstorms.
Severe wx is not expected with this front since the strongest
forcing will be well north. The sfc low moves quickly n and ne
well away from the area causing the front to stretch. This will
help the high to the west bridge the southern end causing a
weakining of activity along this end of the front.

The second cold front will be a little stronger with some strong
thunderstorms and isolated severe. The third...still outside our
fcast time...will prove to be even stronger with several severe
thunderstorms expected and widespread strong thunderstorms.

&&

.aviation...
/12z tafs/
patchy dense radiational/advective fog mix will impact the terminals
through about 1330z before conditions improve to vfr for the
remainder of today. Advective fog likely mainly after 03z tonight
near the coast and spreading northward through 06z and remaining
essentially ifr to patchy lifr through thursday morning. Fropa now
appears delayed until friday morning per latest model runs. 24

&&

.marine...
Persistent high pressure ridge finally weakening as an extratropical
low pressure system moves north along the carolinas coast into the
ridge. Flow expecting to become more southeasterly today and
southerly tonight through thursday in advance of cold frontal zone
currently moving out of the front range into the plains states. This
front now appears to not move east of the mississippi coastal waters
until mid-morning friday. As most of the dynamics and cold air
advection will be well north of the coast...only a short period of
enhanced northwest wind is indicated before settling to lower levels
saturday. 24

&&

.fire weather...
Above normal temperatures to prevail for another couple of days
along with steadily increasing humidity levels. There will be
concerns of advective/radiational fog mix during the next couple of
nights to reduce visibilities to 1/4 mile or less. Any burns should
be snuffed prior to sunset to avoid stagnant smoke dispersion with
fog. 24


New Orleans Local Weather thread - dkmac - 11-06-2008 07:38 AM

000
fxus64 klix 061028
afdlix

area forecast discussion
national weather service new orleans la
428 am cst thu nov 6 2008

.short term...
Moisture pooling ahead of the first cold front to come in. The
front will move rapidly se into central la. It then slows up quite
a bit causing a delay in timing for it to come through the area.
This is due to some stronger winds at 30h moving down the back
side of the upper trough today. This causes the trough to slow and
also begins to cause a stronger sheared trough axis to develop. A
sfc reflection of low pressure develops over the northern gulf.
This should help induce a little better rainfall chance. Severity
is still in question but the best opportunity for any strong
weather will be as the wind maxima rounds the base of the trough
and kicks out by friday. This would put the isolated risk area
over us for fri. Would like to see more in the way of dynamic
forcing and better thermal differences before going with severe
possibilities.

The second front looks to provide a better chance for severe wx as
well as plenty of rainfall by tue.

The third looks to provide an even better opportunity for strong
to severe wx by next thu or fri.


&&

.aviation...
Advective fog came in thick along the leading edge but mixing out to
mvfr or better visibilities due to strong southerly flow off the
surface running 20-30 kt. Have amended all tafs recently to soften
fog impacts a bit but will still have patchy coverage and short
periods of reduced visibility around daybreak. Frontal passage
appears to be during the morning hours friday with pre-frontal
convection onsetting later this afternoon mainly for kbtr-kmcb and
points westward...spreading east overnight. Moisture corridor
confined to southwest louisiana and east texas may have problems
bucking into drier airmass downstream...but coverage will be better
than lately. 24

&&

.marine...
East winds becoming more southeast and south today in advance of
strong dynamic cold front moving across the middle of the country
this morning. A pre-frontal boundary associated with deepest
moisture may move across the north gulf tonight several hours in
advance of the actual wind shift cold front friday morning.
Considerable amount of very dry air behind front will allow for
momentum transport and a few hours of gustiness through much of
friday and friday night before settling down saturday. A small craft
advisory may be needed friday night but winds may be more in the
15-20 kt range with several gusts 25 kt by saturday morning. 24

&&

.fire weather...
Column continues to moisten with some advective fog issues though
not as pronounced as anticipated due to stronger low level jet off
the gulf coastal plains in advance of cold frontal system. Wettable
rains are expected tonight and friday in advance of the front but
best coverage of moisture may be removed more north of forecast
area. Forecast will indicate a 50-60 percent chance but coverage may
need to be adjusted downward in subsequent forecast packages if
moisture axis diverges upon moving eastward into drier residual
airmass. Dewpoints will be falling off significantly post frontal
with humidities lowering into the 25-30 percentile saturday. 24


New Orleans Local Weather thread - ROLLTIDE - 11-06-2008 08:11 AM

NATIONAL WEATHER SERVICE NEW ORLEANS LA
428 AM CST THU NOV 6 2008

.SHORT TERM...
MOISTURE POOLING AHEAD OF THE FIRST COLD FRONT TO COME IN. THE
FRONT WILL MOVE RAPIDLY SE INTO CENTRAL LA. IT THEN SLOWS UP QUITE
A BIT CAUSING A DELAY IN TIMING FOR IT TO COME THROUGH THE AREA.
THIS IS DUE TO SOME STRONGER WINDS AT 30H MOVING DOWN THE BACK
SIDE OF THE UPPER TROUGH TODAY. THIS CAUSES THE TROUGH TO SLOW AND
ALSO BEGINS TO CAUSE A STRONGER SHEARED TROUGH AXIS TO DEVELOP. A
SFC REFLECTION OF LOW PRESSURE DEVELOPS OVER THE NORTHERN GULF.
THIS SHOULD HELP INDUCE A LITTLE BETTER RAINFALL CHANCE. SEVERITY
IS STILL IN QUESTION BUT THE BEST OPPORTUNITY FOR ANY STRONG
WEATHER WILL BE AS THE WIND MAXIMA ROUNDS THE BASE OF THE TROUGH
AND KICKS OUT BY FRIDAY. THIS WOULD PUT THE ISOLATED RISK AREA
OVER US FOR FRI. WOULD LIKE TO SEE MORE IN THE WAY OF DYNAMIC
FORCING AND BETTER THERMAL DIFFERENCES BEFORE GOING WITH SEVERE
POSSIBILITIES.

THE SECOND FRONT LOOKS TO PROVIDE A BETTER CHANCE FOR SEVERE WX AS
WELL AS PLENTY OF RAINFALL BY TUE.

THE THIRD LOOKS TO PROVIDE AN EVEN BETTER OPPORTUNITY FOR STRONG
TO SEVERE WX BY NEXT THU OR FRI.


&&

.AVIATION...
ADVECTIVE FOG CAME IN THICK ALONG THE LEADING EDGE BUT MIXING OUT TO
MVFR OR BETTER VISIBILITIES DUE TO STRONG SOUTHERLY FLOW OFF THE
SURFACE RUNNING 20-30 KT. HAVE AMENDED ALL TAFS RECENTLY TO SOFTEN
FOG IMPACTS A BIT BUT WILL STILL HAVE PATCHY COVERAGE AND SHORT
PERIODS OF REDUCED VISIBILITY AROUND DAYBREAK. FRONTAL PASSAGE
APPEARS TO BE DURING THE MORNING HOURS FRIDAY WITH PRE-FRONTAL
CONVECTION ONSETTING LATER THIS AFTERNOON MAINLY FOR KBTR-KMCB AND
POINTS WESTWARD...SPREADING EAST OVERNIGHT. MOISTURE CORRIDOR
CONFINED TO SOUTHWEST LOUISIANA AND EAST TEXAS MAY HAVE PROBLEMS
BUCKING INTO DRIER AIRMASS DOWNSTREAM...BUT COVERAGE WILL BE BETTER
THAN LATELY. 24

&&

.MARINE...
EAST WINDS BECOMING MORE SOUTHEAST AND SOUTH TODAY IN ADVANCE OF
STRONG DYNAMIC COLD FRONT MOVING ACROSS THE MIDDLE OF THE COUNTRY
THIS MORNING. A PRE-FRONTAL BOUNDARY ASSOCIATED WITH DEEPEST
MOISTURE MAY MOVE ACROSS THE NORTH GULF TONIGHT SEVERAL HOURS IN
ADVANCE OF THE ACTUAL WIND SHIFT COLD FRONT FRIDAY MORNING.
CONSIDERABLE AMOUNT OF VERY DRY AIR BEHIND FRONT WILL ALLOW FOR
MOMENTUM TRANSPORT AND A FEW HOURS OF GUSTINESS THROUGH MUCH OF
FRIDAY AND FRIDAY NIGHT BEFORE SETTLING DOWN SATURDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED FRIDAY NIGHT BUT WINDS MAY BE MORE IN THE
15-20 KT RANGE WITH SEVERAL GUSTS 25 KT BY SATURDAY MORNING. 24

&&

.FIRE WEATHER...
COLUMN CONTINUES TO MOISTEN WITH SOME ADVECTIVE FOG ISSUES THOUGH
NOT AS PRONOUNCED AS ANTICIPATED DUE TO STRONGER LOW LEVEL JET OFF
THE GULF COASTAL PLAINS IN ADVANCE OF COLD FRONTAL SYSTEM. WETTABLE
RAINS ARE EXPECTED TONIGHT AND FRIDAY IN ADVANCE OF THE FRONT BUT
BEST COVERAGE OF MOISTURE MAY BE REMOVED MORE NORTH OF FORECAST
AREA. FORECAST WILL INDICATE A 50-60 PERCENT CHANCE BUT COVERAGE MAY
NEED TO BE ADJUSTED DOWNWARD IN SUBSEQUENT FORECAST PACKAGES IF
MOISTURE AXIS DIVERGES UPON MOVING EASTWARD INTO DRIER RESIDUAL
AIRMASS. DEWPOINTS WILL BE FALLING OFF SIGNIFICANTLY POST FRONTAL
WITH HUMIDITIES LOWERING INTO THE 25-30 PERCENTILE SATURDAY. 24

&&