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New Orleans Local Weather thread - dkmac - 09-15-2008 05:41 AM

000
fxus64 klix 150831
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area forecast discussion
national weather service new orleans la
331 am cdt mon sep 15 2008

.discussion...

A cold front stretched from southeastern mississippi through
southeastern/south-central louisiana early this morning. The front
will slowly push southeastward through the rest of our pcwa today.
Along/ahead of the front scattered showers/thunderstorms will
continue today. Behind the front drier air will settle into the
area for much of the work week. Dew points should drop into the
50s and 60s across the area. Surface high pressure and upper-
level ridging will move from the plains states into the eastern
seaboard by next weekend...allowing moisture to return back to the
mississippi valley and bringing back precip chances to our area.

.aviation...

Mvfr conditions will prevail at the terminals this morning until
the drier air filters in behind the front. Convection will be
possible this morning around msy and gpt.


New Orleans Local Weather thread - dkmac - 09-16-2008 04:36 AM

Very nice here at the house this morning. 64°F, 61°F dewpoint, breeze from the North. I think fall is on its way.

000
FXUS64 KLIX 160841
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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
341 AM CDT TUE SEP 16 2008

.DISCUSSION...

RELATIVELY TRANQUIL WEATHER IS EXPECTED FOR THE NEXT FEW DAYS. THE
COLD FRONT HAS PUSHED INTO THE GULF OF MEXICO...BRINGING DRIER AIR
AND PUSHING MOST OF THE PRECIP OUT OF THE AREA. DEW POINTS WERE
FALLING INTO THE 50S AND 60S ACROSS THE AREA. CLOUDS SHOULD BEGIN
TO SCATTER OUT SOMEWHAT TODAY. HOWEVER...THE UPPER-LEVEL TROUGH IS
EXPECTED TO LINGER IN THE AREA THROUGH AT LEAST TOMORROW...AND
THIS WILL HELP TO KEEP SOME CLOUDS ACROSS THE AREA.
OTHERWISE...GENERALLY DRY CONDITIONS ARE EXPECTED UNTIL THE
SURFACE HIGH AND UPPER-LEVEL RIDGING SHIFTS FROM THE PLAINS STATES
INTO THE MID-ATLANTIC STATES BY THIS WEEKEND. MORE MOISTURE IS
EXPECTED TO PUSH INTO THE LOWER MISSISSIPPI VALLEY FOR THIS
WEEKEND...ALTHOUGH TODAYS 00Z GFS SHOWS LESS THAN YESTERDAYS. THIS
SHOULD BRING BACK AT LEAST A SLIGHT CHANCE FOR
SHOWERS/THUNDERSTORMS BY FRIDAY AND SATURDAY.

.AVIATION...

GENERALLY VFR CONDITIONS ARE EXPECTED TODAY WITH CEILINGS
REMAINING ABOVE 3500 FEET.

.MARINE...

WINDS BEHIND THE FRONT GENERALLY WILL REMAIN AROUND 15 KNOTS
TODAY AND TOMORROW BEHIND THE COLD FRONT.


New Orleans Local Weather thread - dkmac - 09-17-2008 05:26 AM

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fxus64 klix 170836
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area forecast discussion
national weather service new orleans la
336 am cdt wed sep 17 2008

.discussion...

No major changes are expected with this package. The front has
pushed well into the gulf of mexico early this morning...with the
upper-level trough extending from the mid-atlantic states into
louisiana. The 00z precip water at lix was around 1 inch. No
significant chances for precip are expected today or
tomorrow...except well offshore. The surface high pressure and
upper-level ridge were centered around the central plains states.
As these features move eastward this week...this will allow some
moisture to wrap around the high back into the north-central gulf
coast and bring back chances for precip this weekend. Temps
should remain a little below average today and begin to return
toward climo as the week progresses.

.aviation...

Vfr conditions should prevail today.

.marine...

Winds will be a little stronger today out of the northeast in the
coastal waters...reaching the 15 to 20 knot range...due to a
tighter pressure gradient. Otherwise...generally easterly flow
less than 15 knots should prevail through this weekend.


New Orleans Local Weather thread - dkmac - 09-18-2008 05:39 AM

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fxus64 klix 180905
afdlix

area forecast discussion
national weather service new orleans la
405 am cdt thu sep 18 2008

.short term...
One more pre-autumnal nice day today before an unsettled pattern
becomes established for the next several days. Deep layered dry
air migrating eastward with a moisture column extending from the
west gulf of mexico into the central plains in response to a short
wave trough moving out of the rockies. This short-wave may be
problematic in the long term periods in regards to rain chances
across the forecast area. Meanwhile...will hold off pops for today
and tonight as surface dewpoints remain rather off norms through
tonight before recovering early friday. Temperatures should warm
into the mid 80s today and settle into the 65-70 degree range
tonight. As high pressure remains settled over the appalachians
and eastern seaboard states...a predominantly easterly flow will
likely persist friday into early next week in the low levels. Will
indicate 30-40 percent rain chances friday and friday night for
convergent maritime flow becoming increasingly influenced by upper
short-wave trough that appears to take residence over the central
gulf states late friday and beyond.

.long term...
The period saturday through wednesday can be quite unsettled if
the gfs solution is close to correct. Upper trough in the lower
latitudes becomes orphaned from westerly flow at higher
latitudes...thereby placing a cold pool for instability and a
focusing mechanism to possibly enhance daily lake and gulf
breezes. Even if rainfall is not widespread...cloud cover should
be and this may have significant impacts on temperatures each day.
It would seem below normal maximum temperatures...near to above
normal minimum temperatures and at least near normal rain chances
are in order for the extended period.

&&

.aviation...
Bkn050 ceilings are intermittent at terminals over the southern half
of the area. Most of these should go to sct by late morning. This
still provides vfr conditions for today. Tonight more clouds will
begin to drift into the area as a weak disturbance begins to form on
the tail end of an old frontal boundary over the northern gulf. This
area is expected to move slowly northward over the weekend.
Conditions will become more ifr oriented by late friday through the
weekend. Sh/ts will be found at most sites over the weekend.

&&

.marine...
A weak disturbance begins to form on the tail end of an old frontal
boundary over the northern gulf today and tonight. This area is
expected to move slowly northward over the weekend. Winds and seas
are not forecast to exceed 15 knots over the weekend. This could
change depending on how deep the convection develops with the gulf
system. Any deepening of the pressure associated with this area will
cause winds and seas to respond quickly over the weekend.


New Orleans Local Weather thread - dkmac - 09-19-2008 07:03 AM

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fxus64 klix 190905
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area forecast discussion
national weather service new orleans la
405 am cdt fri sep 19 2008

.short term...
Interesting pattern developing that can be problematic for the
next few days over the forecast. A mid to upper level short-wave
impulse indicated on 00z 500 mb analysis has moved into the lower
mississippi valley. Meanwhile...a short wave trough dropping out
of the plains states will likely become stationary over the lower
mississippi valley later today. This is undercutting a large upper
level /250 mb/ ridge axis to provide upper level divergence and
over-riding easterly flow near the surface providing low level
convergence. A pronounced easterly wave feature is approaching
southeast louisiana from the florida panhandle gulf waters. This
feature is timed to arrive into st bernard and plaquemines parish
around 8 am this morning. Gulf buoys in the northeast gulf shows
20 knots of sustained winds with gusts in the 30-35 knot range
spreading westward. If this slug of wind holds together upon
reaching lower louisiana...then moisture and coastal convergence
can be quite pronounced to produce efficient rains. Isentropic
lift elevated convection was advancing towards the greater new
orleans area from the atchafalaya basin with mostly virga and some
sprinkles or very light rain reaching the surface. This process
will moisten the column prior to the easterly feature arrival.
Needless to say...placement of heavier rainfall today and tonight
will be difficult due to so many considerations. The gfs seems to
have convective feedback noise to produce a 5.16 inch bullseye
over the new orleans metro area by daybreak saturday...but the
synoptic pattern certainly could support such an episode and
current trends are a bit un-nerving. Will go with considerably
lower hpc qpf amounts...which still manage to show an areal 1 inch
or better accumulation through sunday across the region. Will not
hoist any kind of flood watches at this time...but as rainfall
onsets and pattern subtleties become more apparent...a watch may
be warranted at a later time. Have maintained rainfall chances
from previous package and only minor changes to temperature
forecast and weather grids through sunday night.

.long term...
The unsettled pattern of this weekend should improve by early next
week going into autumn. Models show drainage trajectories bringing
lower column relative humidities into the forecast area by mid
week to reduce daily rain chances to 20 percent or less from
tuesday through thursday. Temperatures should be slightly below
normal if drier drainage air affects morning lows...but quite
seasonable nonetheless.

&&

.aviation...
Mid level cloud deck with patchy light rain will start to affect
kbtr and kmsy by 12z. Moistening of the atmosphere from the top down
will continue in southeast louisiana while lower level moisture
increases from the east...starting near kgpt early this morning. Am
thinking that rain will not be persistent enough to produce any less
than vfr conditions this morning. The exception may be around kgpt
where higher reflectivity showers and deeper low level moisture may
produce occasional mvfr cigs and vsbys by mid to late morning. The
best chance of rain...isolated embedded tsra...and lower vsbys/cigs
will be this afternoon. Timing of upper disturbances will determine
waves of rain...scattered shra...isolated tsra...and associated
lower vsbys and cigs tonight into saturday. 22

&&

.marine...
Pressure gradient between high pressure over the mid atlantic and
southeast...and developing wave of low pressure over the western
gulf of mexico will result in persistent easterly winds over most of
the next 5 days. The gfs continues to show a weak low pressure area
off the louisiana coast tonight into saturday. This is still not
supported by the other model guidance...so have favored the nam
winds the first 84 hours. 15 knots winds and choppy waters can be
expected by late today into tonight. Rain with embedded
thunderstorms will start in the western waters and spread east while
bands of showers over the alabama waters move northwest. Easterly
winds may further increase to near small craft criteria with
increasing tides during the early to middle part of next week. 22


New Orleans Local Weather thread - ROLLTIDE - 09-19-2008 08:20 AM

000
fxus64 klix 190905
afdlix

area forecast discussion
national weather service new orleans la
405 am cdt fri sep 19 2008

.short term...
Interesting pattern developing that can be problematic for the
next few days over the forecast. A mid to upper level short-wave
impulse indicated on 00z 500 mb analysis has moved into the lower
mississippi valley. Meanwhile...a short wave trough dropping out
of the plains states will likely become stationary over the lower
mississippi valley later today. This is undercutting a large upper
level /250 mb/ ridge axis to provide upper level divergence and
over-riding easterly flow near the surface providing low level
convergence. A pronounced easterly wave feature is approaching
southeast louisiana from the florida panhandle gulf waters. This
feature is timed to arrive into st bernard and plaquemines parish
around 8 am this morning. Gulf buoys in the northeast gulf shows
20 knots of sustained winds with gusts in the 30-35 knot range
spreading westward. If this slug of wind holds together upon
reaching lower louisiana...then moisture and coastal convergence
can be quite pronounced to produce efficient rains. Isentropic
lift elevated convection was advancing towards the greater new
orleans area from the atchafalaya basin with mostly virga and some
sprinkles or very light rain reaching the surface. This process
will moisten the column prior to the easterly feature arrival.
Needless to say...placement of heavier rainfall today and tonight
will be difficult due to so many considerations. The gfs seems to
have convective feedback noise to produce a 5.16 inch bullseye
over the new orleans metro area by daybreak saturday...but the
synoptic pattern certainly could support such an episode and
current trends are a bit un-nerving. Will go with considerably
lower hpc qpf amounts...which still manage to show an areal 1 inch
or better accumulation through sunday across the region. Will not
hoist any kind of flood watches at this time...but as rainfall
onsets and pattern subtleties become more apparent...a watch may
be warranted at a later time. Have maintained rainfall chances
from previous package and only minor changes to temperature
forecast and weather grids through sunday night.

.long term...
The unsettled pattern of this weekend should improve by early next
week going into autumn. Models show drainage trajectories bringing
lower column relative humidities into the forecast area by mid
week to reduce daily rain chances to 20 percent or less from
tuesday through thursday. Temperatures should be slightly below
normal if drier drainage air affects morning lows...but quite
seasonable nonetheless.

&&

.aviation...
Mid level cloud deck with patchy light rain will start to affect
kbtr and kmsy by 12z. Moistening of the atmosphere from the top down
will continue in southeast louisiana while lower level moisture
increases from the east...starting near kgpt early this morning. Am
thinking that rain will not be persistent enough to produce any less
than vfr conditions this morning. The exception may be around kgpt
where higher reflectivity showers and deeper low level moisture may
produce occasional mvfr cigs and vsbys by mid to late morning. The
best chance of rain...isolated embedded tsra...and lower vsbys/cigs
will be this afternoon. Timing of upper disturbances will determine
waves of rain...scattered shra...isolated tsra...and associated
lower vsbys and cigs tonight into saturday. 22

&&

.marine...
Pressure gradient between high pressure over the mid atlantic and
southeast...and developing wave of low pressure over the western
gulf of mexico will result in persistent easterly winds over most of
the next 5 days. The gfs continues to show a weak low pressure area
off the louisiana coast tonight into saturday. This is still not
supported by the other model guidance...so have favored the nam
winds the first 84 hours. 15 knots winds and choppy waters can be
expected by late today into tonight. Rain with embedded
thunderstorms will start in the western waters and spread east while
bands of showers over the alabama waters move northwest. Easterly
winds may further increase to near small craft criteria with
increasing tides during the early to middle part of next


New Orleans Local Weather thread - ROLLTIDE - 09-20-2008 08:52 AM

NATIONAL WEATHER SERVICE NEW ORLEANS LA
328 AM CDT SAT SEP 20 2008

.SHORT TERM...
HIGH PRESSURE SITUATED OVER THE MID-ATLANTIC STATES PROVIDING A
DEEP LAYERED EASTERLY FLOW ACROSS THE GULF STATES. A CONSIDERABLE
AMOUNT OF DRY AIR IS BEING DRAWN FROM THE APPALACHIANS IN THE
LOWER LEVELS WHILE THE UPPER LEVELS ALSO APPEAR DRY IN CONVERGENT
FLOW AT BASE OF LOW AMPLITUDE BAROTROPIC TROUGH CURRENTLY OVER THE
MISSISSIPPI VALLEY. WATER VAPOR SATELLITE IMAGERY SHOWS EXTENSIVE
DRY COLUMN FROM UPPER MEXICO AND TEXAS THROUGH LOUISIANA AND
SOUTHERN MISSISSIPPI. PERSISTENT AREA OF CONVECTION OVER THE
CHANDELEURS AND OFF THE MOUTH OF THE MS RIVER HAS STRUGGLED TO
MAINTAIN OVER LAND DUE TO APPARENT DRYING THAT DOES NOT SEEM TO BE
REPRESENTED WELL IN MODEL SOUNDINGS. WEAK DISTURBANCES ROUNDING
THE BASE OF STATIONARY TROUGH ALOFT IS PRODUCING SOME STRATIFORM
AND HIGHLY ELEVATED PRECIPITATION ACROSS SOUTHWEST MISSISSIPPI AND
EAST-CENTRAL LOUISIANA THIS MORNING MAY WORK TO SATURATE THE
COLUMN IN TIME. THIS WAS ANTICIPATED TO OCCUR YESTERDAY BUT DID
NOT MATERIALIZE. WILL SHOW A 60 PERCENT CHANCE OF RAIN TODAY
ASSUMING THE COLUMN WILL SATURATE ENOUGH TO MEASURE IN MOST
LOCATIONS. WILL THEN DROP BACK TO 30 PERCENT FOR TONIGHT AND
SUNDAY AS FOCUS BECOMES LACKING AND UPPER DYNAMICS BECOMES LESS
FAVORABLE. TEMPERATURES WILL BE CONDITIONED TO CLOUD COVER TODAY
BUT LOWER 80S SEEM PLAUSIBLE...65 TO 70 TONIGHT AND MID 80S
SUNDAY.

.LONG TERM...
DYNAMICS ASSOCIATED WITH WEAK UPPER TROUGH IN BAROTROPIC AIRMASS
CONCEDES TO DRYING FROM THE NORTHEAST THAT SHOULD LINGER FOR
SEVERAL DAYS FROM TUESDAY ONWARD. WILL ONLY SHOW TOKEN 10 PERCENT
EACH PERIOD IN CCF AND PFM PRODUCTS WITH UNMENTIONABLE ZFP
CHANCES. TEMPERATURES SHOULD CONTINUE TO FEEL LIKE EARLY AUTUMN
AND NEAR NORMAL.

&&

.AVIATION...
A WEAK UPPER LEVEL TROUGH AXIS WILL CONTINUE TO BRING A MID LEVEL
DECK TO THE REGION THROUGH THE DAY. IN THE LOW LEVELS...A SCATTERED
DECK MAY DEVELOP DURING THE HEAT OF THE DAY AROUND 3000 TO 5000
FEET. HOWEVER...VFR CONDITIONS SHOULD PREVAIL. SOME SCATTERED
CONVECTION MAY DEVELOP NEAR THE TERMINALS...ESPECIALLY AFTER
18Z...BUT ANY PERIODS OF MVFR OR IFR CONDITIONS ASSOCIATED WITH THIS
CONVECTION WILL BE VERY SHORT LIVED. VFR CONDITIONS SHOULD CONTINUE
THROUGH 06Z TOMORROW. HOWEVER...AFTER 06Z...IT APPEARS THAT A
STRONG SURFACE BASED INVERSION WILL DEVELOP ACROSS THE AREA. THIS
INVERSION WILL LIMIT TURBULENT MIXING...WHICH WILL ALLOW FOR THE
FORMATION OF FOG. THUS...EXPECT MVFR...AND POSSIBLY A BRIEF PERIOD
OF IFR VISIBILITIES AT KMCB AND KBTR.

&&

.MARINE...

HAVE OPTED TO ISSUE A SMALL CRAFT EXERCISE CAUTION FOR THE OUTER
LEGS OF THE COASTAL WATERS FOR TODAY...AS A STRONG PRESSURE GRADIENT
BETWEEN A HIGH TO THE NORTH AND A LOW OVER THE WESTERN GULF ALLOWS
FOR PERSISTENT EASTERLY WINDS OF 15 TO 20 KNOTS TODAY. IN
FACT...IT APPEARS THAT THIS GRADIENT WILL STRENGTHEN OVER TIME WITH
SMALL CRAFT ADVISORY CONDITIONS POSSIBLE BY THE MIDDLE OF NEXT
WEEK. IN THE MORE IMMEDIATE TERM...A WEAK TROUGH AXIS SLIDING
THROUGH THE REGION WILL CONTINUE TO ALLOW FOR MARINE CONVECTION TO
DEVELOP OVER THE COASTAL WATERS. CONVECTION WILL BE MOST PREVALENT
DURING THE OVERNIGHT AND EARLY MORNING HOURS.

&&


New Orleans Local Weather thread - ROLLTIDE - 09-20-2008 10:36 PM

AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
401 PM CDT SAT SEP 20 2008

.DISCUSSION...
LATEST SURFACE ANALYSIS CONTINUE TO SHOW A BROAD RIDGE OVER EASTERN
CONUS EXTENDING WEST THROUGH THE MID AND LOWER MISSISSIPPI VALLEY.
SURFACE DEWPOINT ANALYSIS SHOWED 70F DEWPOINT ENCOMPASSING SOUTH HALF OF
LOUISIANA AND COASTAL MISSISSIPPI. UPPER AIR ANALYSIS REVEALED A
TROUGH AXIS FROM SOUTHERN ILLINOIS TO THE ARKLATEX REGION AND A
WEAK CONVEYOR BELT OF MOISTURE FROM SOUTHEAST LOUISIANA TO
NORTHERN ALABAMA. PRECIPITABLE WATER VALUE WAS 1.79 INCHES AT
SLIDELL SOUNDING THIS MORNING.

PW FIELDS OFF OF GFS..NAM AND NGM SHOWED THIS MOISTURE AXIS
ALIGNED WITH WATER VAPOR IMAGERY OFF OF SATELLITE. THE LIKELY
CHANCES OF RAIN FAIRLY REPRESENT THE ONGOING TREND. SLIDELL
SOUNDING ALSO REVEALED VARIABLE WINDS 7KFT BUT SOUTHWEST WINDS OF
15 TO 25 KNOTS AROUND 13 TO 20KFT. AT 3 AM...SOUTHEAST FLOW OF 10
TO 15 KNOTS WAS PRESENT FROM THE SURFACE TO 10KFT AND A WEST FLOW
OF 20 KNOTS WEST-NORTHWEST FLOW FROM 13 TO 19KFT...ACCORDING TO
VAD WIND PROFILE. STORM MOTION HAS BEEN NORTH AND NORTHEAST THIS
AFTERNOON AND NO REAL GOOD MOTION TO FOLLOW. AS A RESULT...TRAINING
HAS NOT BEEN A PROBLEM...BUT DEVELOPING AND SOMEWHAT STATIONARY
STORMS HAVE DUMPED RAIN UP TO 3 TO 4 INCHES IN MCCOMB AND
METAIRIE. LOOK FOR THIS TREND TO CONTINUE INTO THE EVENING...THEN
DIMINISHING AROUND 7 TO 8 PM. WILL EXTEND LIKELY RAIN CHANCES INTO
TONIGHT GRIDS TO 8/9 PM. OTHERWISE...RAIN SHOULD DIMINISH
OVERNIGHT. A SLIGHT REPEAT IS POSSIBLE FOR SUNDAY BECAUSE MOISTURE
AXIS REMAINS STATIONARY. HOWEVER...DYNAMIC DIMINISHES AS THE MAIN
TROUGH SLOWLY WEAKENS DUE TO ANOTHER TROUGH OVER THE ROCKIES
DEEPENING SUNDAY AFTERNOON INTO MONDAY. AS THE TROUGH CONTINUE TO
DISSOLVE OVER THE MID MISSISSIPPI VALLEY...THE SURFACE HIGH AND
UPPER LEVEL RIDGE WILL REBUILD OVER THE EAST COAST TO GULF COAST
TUESDAY INTO WEDNESDAY. THUS...A DRY FORECAST IS EXPECTED AFTER
TUESDAY.

&&
.AVIATION...
A WEAK UPPER LEVEL TROUGH AXIS WILL CONTINUE TO BRING A MID LEVEL
DECK TO THE REGION THROUGH THIS EVENING...OVERNIGHT AND SUNDAY
MORNING. SOME SCATTERED TO NUMEROUS CONVECTION WILL COME TO AN END
BETWEEN 00 TO 02Z SUNDAY. AFTER 06Z...IT APPEARS THAT A STRONG
SURFACE BASED INVERSION WILL DEVELOP ACROSS THE AREA. THIS
INVERSION WILL LIMIT TURBULENT MIXING...WHICH WILL ALLOW FOR THE
FORMATION OF FOG AT MCB...BTR AND GPT. THUS...EXPECT MVFR...AND
POSSIBLY A BRIEF PERIOD OF IFR VISIBILITIES AT KMCB AND KBTR.

&&


New Orleans Local Weather thread - dkmac - 09-21-2008 05:13 AM

000
fxus64 klix 210858
afdlix

area forecast discussion
national weather service new orleans la
358 am cdt sun sep 21 2008

.short term...
Forecast area remains under the influence of high pressure
situated over the mid-atlantic states and deep layered easterly
flow up to about 700 mb. An occluded barotropic low near the
missouri bootheel above 700 mb continues to fill and associated
weak trough that was over the region saturday evening appears to
have shifted eastward. Considerable amount of dry air over texas
and west louisiana to advect into southeast louisiana and southern
misssippi today...thereby drying the column in time. With maximum
temperatures into the mid 80s this afternoon a few showers and
thunderstorms are possible and will show 20 percent...closer to
the drier gfs guidance. Most precipiation should end early this
evening and a low pop day expected monday. 24

.long term...
Dry air moving in place from the appalachians will maintain a
stretch of dry days and near normal temperatures from wednesday
through sunday. 24

&&

.aviation...
As a weak trough axis slowly exiting the region will continue to
affect the terminals. In the short term...through around
14z...ample low level moisture combined with a developing inversion
over kbtr and kmcb will allow for the formation of low clouds and
fog. Ceilings may drop into the lifr range for a brief period of
time around 12z this morning at kmcb due to the ample low level
moisture in place. Visibilties may drop into the ifr range as
well. At kbtr and kmsy visbilities may drop into the mvfr range
this morning. At kgpt...lingering showers in the area will reduce
visbilties to mvfr and keep ceilings in the ifr range this morning.
After 14z...conditions will improve for all of the terminals...a
much drier airmass in the wake of the trough begins to settle in.
Vfr conditions should be rule for all of the terminals...with a only
a scattered deck expected around 3000 to 5000 feet and broken alto
cumulus deck at around 10000 feet. Going into tonight...patchy fog
may briefly drop visbilties at kbtr and kmcb after 08z into the mvfr
range. Otherwise...vfr conditions should continue. 32

&&

.marine...
A strong and persistent easterly wind will remain in place
through the week...as a tight pressure gradient between a low in
the bay of campeche and a high centered over the tennessee valley
sets up across the northern gulf. As the pressure gradient
strengthens...winds should increase into the exercise caution
range...with seas responding by tomorrow. However...winds and seas
should not increase to advisory range until later this week...when
the low should begin deepening in the southwest gulf. Due to this
persistent easterly flow...higher than normal tides and possibly
some coastal flooding issues could arise by the middle of the
week. 32

&&


New Orleans Local Weather thread - ROLLTIDE - 09-21-2008 03:31 PM

313 PM CDT SUN SEP 21 2008

.DISCUSSION...
LATEST SURFACE ANALYSIS CONTINUE TO SHOW A BROAD 1022MB HIGH OVER
THE TENNESSEE AND OHIO VALLEYS WITH RIDGING SOUTHWEST TO EAST
TEXAS AND NORTH GULF. A MOIST TONGUE REMAINED ACROSS LOUISIANA AND
ARKANSAS WITH DEWPOINT READINGS GREATER THAN 65F.
HOWEVER...RELATIVELY DRY AIR WITH DEWPOINT READINGS OF 56 TO 64F
WAS ACROSS EAST MISSISSIPPI AND ALABAMA. IN ADDITION...A LIGHT
NORTHEAST TO EAST FLOW WAS NOTED ACROSS THE LOWER MISSISSIPPI
VALLEY. THIS TREND WILL SLOWLY DRY THE LOW LEVELS OF THE ATM THROUGH
TONIGHT. MEANWHILE...UPPER LEVEL SHORT WAVE OVER THE MID
MISSISSIPPI VALLEY WILL SHIFT EAST OVER OHIO VALLEY AND THEN
POSSIBLY OVER THE MID ATLANTIC STATE. FOR SOME TIME...SHORT RANGE
MODELS HAVE INDICATED AN UPPER LEVEL LOW DEVELOPING ALONG THE
CAROLINAS COAST MONDAY INTO TUESDAY...NOT ASSOCIATED WITH THE
SYSTEM OVER PUERTO RICA. THE CIRCULATION AROUND UPPER LEVEL LOW
AND WELL ADVERTISED LARGE HIGH OVER THE NORTHEAST CONUS WILL
CREATE DRY NORTHEAST FLOW IN THE MID LAYERS OF ATM ACROSS THE
SOUTHEAST INCLUDING OUR FORECAST AREA THROUGH FRIDAY. AT THE
SURFACE...GFS NEVER REALLY DEVELOPS A SURFACE LOW WHILE EUROPEAN
DEVELOPS A DEEP SURFACE LOW UNDERNEATH THE UPPER LEVEL LOW OVER
NORTH FLORIDA/GEORGIA FRIDAY. THE SYNOPTIC PATTERN IN THE MID
LAYERS ARE THE SAME ON GFS AND EUROPEAN WITH THE LOW RETROGRADING
BACK SOUTHWEST TO THE NORTHEAST GULF. IN BOTH CASES...MID LAYER
MOISTURE ROTATES AROUND THE LOW ACROSS OUR AREA NEXT WEEKEND.
WILL INTRODUCE SLIGHT CHANCE FOR NOW.

&&

.AVIATION...
ISOLATED SHOWERS DOTTING SOUTHEAST LOUISIANA. ONLY TERMINAL THIS
APPEARS TO POSSIBLY AFFECT THIS AFTERNOON WOULD BE BTR. NO LIGHTNING
NOTED WITH THESE SHOWERS. CEILINGS SHOULD REMAIN VFR. GOING INTO
TONIGHT...PATCHY FOG MAY BRIEFLY DROP VISIBILITIES AT KMCB AFTER 08Z
INTO THE MVFR TO IFR RANGE. OTHERWISE...VFR CONDITIONS SHOULD
CONTINUE. 35
&&

.MARINE...
A STRONG AND PERSISTENT EAST TO NORTHEASTERLY WIND WILL REMAIN IN PLACE
THROUGH THE WEEK...AS A TIGHT PRESSURE GRADIENT BETWEEN A LOW IN THE
BAY OF CAMPECHE AND A HIGH CENTERED OVER THE TENNESSEE VALLEY SETS
UP ACROSS THE NORTHERN GULF. WINDS WILL GENERALLY BE IN THE 15 TO
20 KNOT RANGE...ESPECIALLY OVER THE OUTER COASTAL WATERS. WILL
CONTINUE THE EXERCISE CAUTION HEADLINE TONIGHT. AT SOME POINT DURING
THE WEEK...PROBABLY TUESDAY...WE WILL HAVE WINDS STRONG ENOUGH FOR A
SMALL CRAFT ADVISORY. SEAS WILL REMAIN IN THE 3 TO 6 FOOT RANGE FOR
MUCH OF THE WEEK BEFORE THE GRADIENT RELAXES SOMEWHAT TOWARD THE END
OF THE WEEK. 35
&&