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New Orleans Local Weather thread - dkmac - 02-19-2009 06:52 AM

Area forecast discussion
national weather service new orleans la
336 am cst thu feb 19 2009

.short term...
Cold front pushing through the coastal waters this morning. Return
will be quick to come around by fri night. Moisture feed for the
next system will be via the southern gulf into the western gulf
the into the central plains. Sat we should see some shower
activity ahead of the cold front. A strong canadian air mass will
quickly fall through the plains states and arrive here by sat
night with a strong deep dome of high pressure. A strong moisture
gradient should follow the cold front introducing a very evident
cloud line. Most of the weather with this system looks to be
overnight sat into sun morning. We will be watching for areas that
fall in the warm sector as a sfc low forms along the front near
the central coast of la by sat evening. Ros model runs are trying
to show the area south of the tidal lakes getting into the warm
sector for a short time late sat night. Dynamic and thermal
instability will be fairly strong in this region throughout the
column and will have to be watched carefully over the next few
days to determine if it will indeed find itself over se la. Some
of the most efficient directional and speed shear showing up on
sounding profiles from the sfc to 6km by sun between 03z and 06z
than we have seen in a while. Usually one may see veering or speed
shear in this layer...where only one exists to such a strong
degree. Sometimes they will couple but will be individually weak.
This time they couple and are quite strong causing 0-6k helicity
values to almost jump off the chart at ~923 m2/s2.

.long term...
After fropa sunday...cold dry air moves in through mid week.

&&

.aviation...
/12z taf issuance/
after last vestiges of cirrus and lingering ac south of kmsy moves
farther south then cavu conditions to onset by early morning and
continuing next 24-36 hours. 24/rr

&&

.marine...
Cold front demarked by convection with most pronounced moving across
the outer coastal waters east of the mississippi river generally in
the viosca knoll...main pass and upper mississippi canyon lease
areas...moving east around 40 knots. West of this cluster is just a
narrow line of showers into the upper green canyon waters. Cold and
dry high pressure will build into the north gulf today to bring an
increase in offshore winds mainly this morning. A secondary upper
level disturbance swings into the north gulf tonight and early
friday to perhaps bring a short duration of strong gustiness. Models
are contnuing to indicate an area of low pressure developing in the
middle gulf saturday and moving east....becoming enhanced by more
cold air moving into the west gulf. This will bring long duration
high winds saturday and sunday at least in small craft advisory
range and possibly in low end gale warning range. 24/rr


New Orleans Local Weather thread - dkmac - 02-20-2009 05:42 AM

Area forecast discussion
national weather service new orleans la
331 am cst fri feb 20 2009

.short term...
Cold front will move through the area quickly saturday night. Sfc
low develops along the front stays well offshore and does not
bring the warm sector to the coast. Due to this, guidance numbers
are much lower this morning with regards to strong ts activity.
Will not mention ts at all over land but will continue over marine
areas with a strong ts possible over the outermost waters from
20-60nm.

.long term...
Convergent axis/warm front will move through se la and southern
miss tue night into wed morning. The cold front will be a little
slower to get through the gulf states. Current solutions call for
the front to move through next sat morning. Weak forcing behind
the front would tend to cause the front to slow quite a bit.
Attm...can not even be sure that the front will even reach this
area until the beginning of the next work week. But this is past
the 7day fcast and won`t speculate outside these bounds.

&&

/12z taf issuance/
vfr cavu conditions will prevail through saturday. 24/rr
&&

.marine...
Dry air interactions with relatively warmer water temperatures
maintaining thermally driven gustiness this morning over the coastal
waters. The cold air advection should be abating by mid-morning as
the center of the high settles along the coast. Will monitor trends
and probably update the coastal package around 7 or 8 am cst to drop
advisory once conditions improve. Seas should diminish during the
day in response to decreasing winds. Models continue to downplay
what was a gulf low development for this weekend...now only alluding
to just an open mechanical wave that gets absorbed in the flow by
late sunday/monday. This scenario also fits better with a shunting
air mass taht spares the north gulf a full brunt of colder air.
Small craft advisory conditions still seem probable for the weekend
and early next week. 24/rr


New Orleans Local Weather thread - dkmac - 02-21-2009 05:59 AM

Area forecast discussion
national weather service new orleans la
412 am cst sat feb 21 2009

.short term...
Surface high pressure is currently situated east of the area across
central al/ga. Near calm conditions and low dewpoints have led to
below average temperatures this morning with freezing temps already
at mcb. An upper level low spinning eastward across the upper
mississippi valley will pivot around the great lakes today. As this
trough deepens and digs southward...a cold front will swing through
the gulf coast. This boundary is currently tracking southward across
the texas panhandle through central ok and nwrn arkansas. At its
current speed of around 30kts...cold front would be here around
21z. Slowing is expected after sunrise and should see the front
reach nw portions of the cwa around 00z. Models are in relatively
good agreement in the evolution of this feature in terms of timing
and precip. Most rainfall associated with this boundary should be
along and behind it...so pops have been adjusted to represent
this. Better lift looks to be ne of the area as well as offshore
to the sw. So...generally less than a tenth of an inch of
rainfall will be most common with upwards of one quarter of an
inch near the houma area and possibly in swrn ms. Best potential
for rainfall will be btw 00z and 06z. The cold front will push
well into the gulf as high pressure builds in. Below average temps
will settle in sunday and monday. Highs on sunday will be limited
to mostly upper 50s followed by overnight lows in the lower to mid
30s for much of the gulf coast.

.long term...
A gradual warming will ensue as heights increase and a zonal pattern
sets in. The return of moisture is expected by mid week as sfc high
pressure shifts east and winds turn south. Should be back into the
lower 70s by this time and could start seeing a slight increase in
pops. However...upper trough tracking along the northern conus looks
to be too shallow to push a front to the deep south...so higher pops
will likely stay north of the area through most of the week.

Meffer
&&

.aviation...
/12z taf issuance/
short term tafs will remain vfr with perhaps a brief period of mvfr
vsby in ground fog at kmcb closer to daybreak. Currently tracking
strong clipper front moving through plains states and extended from
fort smith ar /kfsm/ to ardmore ok /kadm/ to roswell nm /krow/ at
09z...moving sse around 35 knots. High winds currently observed
should be about 10 knots less upon arrival within the forecast area
between 21z and 00z today. Some high based showers at vfr ceilings
should demark frontal zone during the afternoon. Vfr conditions
return post-frontal passage for tonight and sunday. 24/rr

&&

.marine...
Strong cold front dropping through lower plains states this morning
is expected to move off the louisiana coast this evening with north
winds becoming brisk and developing a high sea for tonight and
sunday. A small craft advisory will likely be required but will
defer to day shift packages for issuance. Winds and seas should
settle a bit for monday before lowering appreciably tuesday but
remaining at moderate levels...3-4 feet...through friday. 24/rr


New Orleans Local Weather thread - dkmac - 02-22-2009 07:19 AM

Area forecast discussion
national weather service new orleans la
358 am cst sun feb 22 2009

.short term...
Cold front has cleared the land areas and is tracking southward
across the northern gulf of mexico. Only a few lingering showers
left in the coastal waters. This activity will exit the region
shortly. A cirrus deck associated with surface low in the bay of
campeche continues to stream across the state. Clearing will
commence today as this low shifts southeastward. High pressure will
build in behind the boundary today with northerly winds ushering in
cooler/drier air. Most areas will only see highs in the upper 50s
with coastal la and possibly btr the only locations to see temps of
60 or slightly higher. A cold night is in store for tonight. Went on
the cold side of guidance using mostly nam temps. Lows are
expected to drop to or below the freezing mark as far south as a
slidell to woodville line. La coastal areas should stay in the
lower 40s.

.long term...
Little change expected on monday aside from slight bump in
temperatures. Clear skies and light ne winds will persist as surface
ridge shifts from the upper mississippi valley to the ohio river
valley. This high will continue towards the east coast resulting
in winds turning to onshore by tuesday afternoon. Moisture will
then begin to return to the region...tds around 50 tues evening.
Temperatures will gradually rise through the week...highs reaching
the 70s by wed. A few shortwave impulses moving along the southern
states could fire off a few showers mid week...so added slght chc
pops on wed. Should be dry on thurs...but increased activity to
begin this weekend. Surface ridge will get shoved off the coast as
zonal pattern over the area this week shifts to a trough digging
across the high central plains. An associated cold front will
approach the area by the end of this week. Models seem to be in
good agreement in rain chances increasing friday afternoon as the
front reaches the cwa. Looks to be enough instability for a few
thunderstorms to develop along and ahead of this boundary...so
added this into the forecast. How much of a cool down is tough to
say at this point as models indicate that this cold front will
stall along the gulf coast and possibly lift back north as a warm
front due to the northerly track of the upper trough. Will have
to continue to monitor for changes.

Meffer
&&

.aviation...
/12z taf issuance/
mvfr ceiling line was roughly wayne co ms to slidell to patterson la
and slowly advancing eastward. Vfr cavok conditions already at kmcb
and kbtr and should spread to kmsy and kgpt by around 14z. Large
convective complex in southwest gulf of mexico spreading large
cirrus shield into se la and s ms airspace. Otherwise...vfr
cavok/cavu conditions expected at all terminals after 14z thru
monday. 24/rr

&&

.marine...
Thermal mixing taking place over tidal lakes as cold air advection
interacts with warmer water temperatures. Knew and midl1 continue to
gust around 30kt this morning but this should abate once cold air
advection runs its course and center of high moves over area during
the day today. Strong offshore flow should continue over coastal
waters through today before becoming less gusty later this
afternoon. Moderate northeast flow through tuesday becomes onshore
by mid-week. Next cold front to approach the north gulf appears to
be late friday but may stall just along the coast based on latest
model runs. 24/rr


New Orleans Local Weather thread - dkmac - 02-23-2009 07:47 AM

Area forecast discussion
national weather service new orleans la
407 am cst mon feb 23 2009

.short term...
High clouds to the northwest are struggling to make much progress
into the extremely dry local column. 00z sounding confirms this
with precip water of 0.16 which is only slightly higher than the
previous flight. Influences of high pressure over the area will
result in tranquil weather today. Highs will only be a few
degrees warmer today at around 60. Surface ridge will progress
eastward during the day and into tonight. This position in
proximity to the area tends to keep colder temps along the ne
perimeter of the cwa...so adjusted lows accordingly. Stuck close
to models...which have little variation for nighttime temps.

.long term...
A gradual warming will commence beginning tuesday as ridge shifts
eastward and southerly flow returns. Clouds should start filtering
in from the nw but have little effect on highs. Dewpoints will
continue to rise through the week as gulf moisture surges
northward through the central plains. Biggest change from recent
trends will be the increase in overnight lows. Forecasted
nighttime temps will only be 5 to 10 degrees cooler than climo
highs towards the end of the week. Thus...highs in the mid to
upper 70s with a possible 80 not out of the question. Upper level
flow over the area will generally be zonal with an upper trough
clipping the northern conus late this week. Kept low end pops on
wed but wouldn/t be surprised if precip doesn/t occur. The more
significant chances come into play as early as late thurs night. A
cold front is progged progress southward and stall north of the
cwa. Thats about where model consistency ends. Have pretty low
confidence in weekend rain chances. Went 20 to 40 pops for the
most part...but position of the front could make higher or lower
adjustments needed. Do like the ecmwf the most though. Upper
pattern evolution follows closest to most recent events where the
cold front initially stalls and then gets a delayed push as a
secondary upper low swings around the great lakes.

Meffer
&&

.aviation...
/12z taf issuance/
vfr conditions will continue at each of the taf sites for the next
24 to 36 hours. 22

&&

.marine...
Winds and seas remain marginally close to small craft advisory
criteria...so will let the advisory run until its current expiration
time of 6 am this morning. It will remain a bit breezy through mid
morning...so will keep /small craft exercise caution/ headline for
all coastal waters until 10 am. Wind and seas are expected to
diminish late in the morning and afternoon with offshore flow
becoming more easterly tonight and southeasterly tuesday into
wednesday as the surface ridge shifts to the east. Onshore flow will
continue through the end of the work week with the next cold front
moving into the coastal waters saturday. 22


New Orleans Local Weather thread - dkmac - 02-24-2009 06:56 AM

[FONT="Comic Sans MS"][SIZE="4"]Happy Mardi Gras![/SIZE][/FONT]

Area forecast discussion
national weather service new orleans la
424 am cst tue feb 24 2009

.short term...
High pressure has held strong enough to keep dry air mass in place
across the area. As the ridge advances eastward today...winds will
shift to the south and bring moisture back to the region. Northwest
flow regime will bring increasing high clouds to the area as the day
progresses. Continued moderation in temps today as heights
increase. Mid 60s will be most common with near 70 at btr and la
coastal parishes. Will see a relatively moderate increase in lows
tonight with better established cloud deck and rising dewpoints.
Expecting temps to be about 15 degrees warmer than this morning.
Otherwise...no significant weather for the short term.

.long term...
Upper ridge currently to the west of the area will flatten this week
as an upper trough swings across the northern conus. Models indicate
very low rain chances wed and thurs but just not confident enough to
put any into the forecast. Continued warming over the course of the
next few days with increasing thicknesses. Thurs looks to be the
hottest day with highs approaching the 80 degree mark. This is
only a few degrees below record temps...but relatively confident
reaching that point isnt going to occur.

A cold front associated with a deepening upper trough will
progress southward across the country. Theres good model agreement
that the boundary will be nearing northern portions of the cwa on
friday. Morning time shwrs will be confined mostly to the
southwestern ms counties and possibly la/ms border parishes.
Activity will steadily progress southward throughout the day.
Indications are that there will be enough instability and lift for
thunderstorms to develop...but without any appreciable strength.
The heaviest showers could remain mostly just north of the cwa
friday night...but likely will bleed over into the bordering
regions. From this point...there are big discrepancies in the
evolution in the upper pattern. The ecmwf digs a closed low across
the central gulf coast and through florida. This is an atypical
pattern for this time of year...so basically through that one out
from a forecast stand point. Thus...went with the gfs and dgex
with the northern stream trough track. This does gradually push
the cold front into the gulf of mexico...but stalls it and then
eventual dissipation. So...could have an extended period of low in
pops into next week. Slow progression of the boundary will allow
for air mass modification and result in near normal temperatures
from sunday onward.

Meffer
&&

.aviation...
Vfr conditions will continue at each of the taf sites for the next
24 to 36 hours...except for a brief period of mvfr vsbys/possible
cigs 09z-13z wednesday at kmcb and kbtr. 22

&&

.marine...
Light to moderate easterly winds will start becoming southeast over
northern/western sections of the marine area today as the high
pressure ridge continues to shift east. Onshore flow will continue
through the end of the work week with south winds peaking 15 to 20
knots on thursday as the pressure gradient tightens. The preferred
model guidance blend suggests the next cold front will move through
the coastal waters saturday into early saturday night followed by
moderate to strong northeast winds late saturday night into sunday.
22


New Orleans Local Weather thread - dkmac - 02-25-2009 07:22 AM

Area forecast discussion
national weather service new orleans la
442 am cst wed feb 25 2009

.short term...
Gulf moisture has moved back into the region as expected with
dewpoints into the 50s. Low level cloud deck continues to spread
southward across the state which should keep temps from dropping
much more before daybreak. Conditions today will likely be a near
repeat from yesterday except with a few more clouds and warmer
temperatures. Expecting highs in the lower to mid 70s areawide.
Southerly flow to persist through the day with a strong sfc high
pressure off the east coast and additional moisture will be forced
in. About another 5 degree bump in nighttime lows tonight...so
expect temps to only drop into the mid to upper 50s. Zonal flow
across the area will continue through the rest of week. So...above
climo temps to persist. Will see on and off clouds during this
time.

.long term...
A northern stream upper trough pass across canada will send a cold
front towards the gulf coast late this week. Showers chances will
begin to increase friday afternoon ahead of this boundary but mainly
along the northern periphery of the cwa. The cold front progression
will be slow late friday as forcing from the upper trough shifts
eastward. Meanwhile...a secondary trough tracking sewd across the
rockies towards the area will bring the need push to get this front
through. Sfc cyclogenesis will begin across central portions of the
state friday night. This low will deepen and track newd across the
southeast us on saturday. Highest pops will be highest during the
time of the lows development in combination with lift along the cold
front. Attm...qpf appears to be relatively low at only a few tenths
of an inch. The front will then sweep through saturday night. Model
agreement is good on the this scenario playing out. Theres only a
few differences in exact timing of the front...but looks to be
marginal with the gfs only slightly faster. In comparison to
yesterdays forecast...fropa is faster and thus dropped highs and
lows about 5 degrees on saturday. High pressure to build in behind
the front. A cool down will follow on sunday with highs in the upper
50s. Sat night lows will follow suit as clear skies set in and winds
drop. Will possibly drop close to freezing in mcb...mid 30s for
interior portions and mid 40s along the la coast. For next
week...will gradually warm back into the 70s and little to no rain
chances as upper level ridging takes over.

Meffer
&&

.aviation...
Current observations around south la and south ms indicate cigs are
not lowering yet. Model soundings also suggest the cigs will remain
up near 4000 feet this morning...so will likely remove the mvfr cigs
from the tafs. The clouds and wind should prevent vsbys from
dropping below 6 nm this morning...except for a brief period at
kmcb. Vfr conditions will prevail through the day and into the
evening...then light to moderate advection/radiation fog with
ifr/mvfr vsbys and possible lifr cigs is possible...mainly at the
coastal airports including kgpt after 06z tonight through around 15z
thursday. 22

&&

.marine...
Southeast winds from around 10 knots to 10 to 15 knots will prevail
today and tonight with high pressure to the east and developing low
pressure over the southern plains. The pressure gradient will
tighten and southerly winds will rise as low pressure strengthens
and lifts northeast across the mid mississippi valley thursday and
thursday night. A long fetch will bring seas up to 4 to 5 feet
thursday afternoon and 5 to 6 feet late thursday night into friday
and friday night. The cold front is expected to move through the
coastal waters saturday with strong west winds shifting to northwest
then north saturday afternoon and saturday night. A stronger high
pressure area with colder air is expected due to the strength of the
upper system passing across the southern states. Have gone with a
blend of the ecmwf and gfs during this time which raises northerly
winds as high as 25 to 30 knots over the outer coastal waters late
saturday night and around 25 knots sunday morning. Small craft
advisories will be required. 22


New Orleans Local Weather thread - dkmac - 02-26-2009 07:46 AM

Area forecast discussion...corrected
national weather service new orleans la
534 am cst thu feb 26 2009

.short term...
A general mix of clouds and sun can be expected for today.
Southerly flow will increase today as high pressure off the east
coast remains stationary while a surface low to the west races
across the central plains...creating a sharp pressure gradient.
South to southeast winds of 15 to 20 mph with higher gusts will be
common areawide...especially in the afternoon. With such strong
flow... Dewpoints of at least 60 will easily be reached across the
cwa. Models have indicated low pops mainly east of interstate 55.
Confidence is not high enough to bring shwrs in so went dry. Highs
today are expected to be about 15 degrees above normal. Guidance
is tightly clustered in the mid to upper 70s so stayed close but
on the slightly warmer side. A broad upper trough is currently
swinging across southern canada. A weak cold front draped through
the central plains to the great lakes will begin moving southward
today as the upper trough digs deeper over the northern conus.
This boundary is expected to be in the southern ok/ar vicinity by
friday morning. Could see a few shwrs during this time mainly
along the northern periphery of the cwa. Meanwhile...an upper low
which is clearly seen on water vapor this morning spinning in the
pac northwest will quickly track se across the rockie mountains.
This low will give the cold front a strong push friday night to
swing it through the area. Have increased pops into the 40 to 60
pct range late friday night through saturday afternoon.
Enhancement will come in the form of a surface low developing and
tracking newd across the state and through ms/al. Negative li/s
and upper level dynamics still look to support thunderstorms. A
few thunderstorms could be strong to severe. Good model agreement
gives way to higher confidence in timing and locations of
fronts...sfc low...and upper level features.

.long term...
Only a few lingering showers are expected to be around by sunday
morning over the coastal waters. Gfs indicates some wrap around
moisture near the upper low during this time...but not going to
include in any products for now as it would likely be light if any
does occur. Heights and thicknesses will drop considerably behind
the cold front on sunday. Highs will struggle to reach 60 degrees. A
light freeze will be possible along the northeastern edge of the cwa
monday morning as this cold air mass moves in. Cold temperatures
will remain again on monday as northerly winds persist. The cool
down will be short lived as upper level ridging quickly builds in
from the west early/mid next week. Will be back into the 70s by
tuesday and close to 80 by thurs.

Meffer
&&

.aviation...
Broken cigs with bases 3500 to 6000 range will prevail this
morning...but some tempo cigs down around 2500 feet may still
develop 11-14z mainly at kbtr and kmcb...with vsbys 3 to 5 miles at
kmcb through 15z. Except cigs to improve to vfr conditions around
16z. Mvfr cigs and/or vsbys are likely again late tonight and early
friday morning. 22

&&

.marine...
The pressure gradient will tighten and southerly winds will increase
to 15 to 20 knots today as low pressure moves across the mid
mississippi valley. Seas offshore will build to 5 to 6 feet. Small
craft exercise caution is in effect today across the coastal waters
and this afternoon over the tidal lakes. Forecast sea conditions of
6 to 7 feet are expected on friday into friday night due to long
fetch and duration of se winds in 15 to 20 knots range. Small craft
advisories may be required by late tonight or friday based on sea
conditions. Cold front should move through the region saturday
afternoon and evening with strong northerly winds possibly nearing
30 knots with frequent gusts over gale force developing saturday
night and sunday as strong high pressure and cold air surge into the
region. Small craft advisories will be required with a gale warning
possible. Winds will gradually become ne to e on monday with
decreasing speed with onshore flow returning on tue. 22


New Orleans Local Weather thread - dkmac - 02-27-2009 06:52 AM

Area forecast discussion
national weather service new orleans la
351 am cst fri feb 27 2009

.short term
active weather pattern setting up for the next 48 hours. Initial
short wave has forced a surface boundary into n ms and n al early
this morning. This boundary will become a focus of increasing
convection today as a powerful vorticity max dives southeastward
into the se united states. In response to the approaching strong
vorticity center a surface low should develop along the boundary
in central ms / al later this evening...deepen and move ewd. The
combination of the strong short wave and deepening surface low
should cause the front to surge southeast later this evening and
into the coastal waters by noon saturday. Ample low level moisture
has streamed nwd from the gulf...however forecast soundings
indicate that warm air at mid levels will continue to suppress
convection until late today. Very cool mid level temps associated
with the falling heights will spread se this evening and allow
convection to become scattered to numerous...especially after
midnight. Front should sweep through the region during the morning
on saturday...with some lingering showers into the afternoon
especially from extreme se la into coastal mississippi. Strong to
locally severe thunderstorms will be possible this evening into
mid morning saturday with hail and straight-line winds the primary threats.
Per spc discussion...area in slight risk generally north of a btr
to pql line.


Much colder temperatures along with very windy conditions will be
in store for area saturday evening into sunday. Intense upper
vorticity center and strong cold advection will allow for
efficient downward transport of winds...so gust around 40 mph
quite likely saturday night into early sunday...especially areas
south of the lake pontchartrain into ms coast. Temperatures will
fall into the 30s in most areas except south of lake pontchartrain
on saturday night...with light freeze possible early monday
morning northeast of woodville...hammond...slidell line.


.long term...
After a cold start to the week monday morning...temps should
moderate slowly through the week as nw flow regime becomes more
westerly by late week as upper ridge begins to build over area.
Temps should return to more normal levels by the wed/thu with
strong subsidence in place...especially first part of the
week...dry conditions should prevail. 21

&&

.aviation...
Mostly mvfr category cigs and possible mvfr vsbys will prevail
this morning with south winds increasing after 16-17z to near 15
knots with gusts 20-25 knots. Ceilings will probably vary from lower
mvfr friday morning to 3500-5000 ft vfr decks late morning and
afternoon. Bulk of convection should stay north of terminals except
kmcb. Some convection may occur at other times from 15z fri through
00z sat but limited tempo to the 18z-21z time frame for most likely
time of occurrences. 22

&&

.marine...
Small craft should exercise caution over inner coastal waters today
and small craft advisories /sca/ remains in effect for the outer
coastal waters. Extended the sca for the outer waters through
saturday as sea heights should remain up near 7 feet due to just
enough swell and wind waves. Could have changed back to /sca for
hazardous seas/ for later this morning through saturday morning as
winds will be dropping into 15 to 20 knots range...however...prefer
the leave as a generic sca for now.

A strong cold front will be moving through the coastal waters on
saturday. Westerly winds will likely increase to near sca criteria
ahead of the front by late morning or midday saturday...especially
over the eastern waters. Behind the front...strong downward
transport of strong northwest/north winds will occur due to a very
strong combination of pva extending south from the mid/upper
vortex...strong cold air advection...and a potential vorticity /pvu/
intrusion well down into the mid levels of the atmosphere. All the
models pressure forecast pressure gradients alone along with
forecast 1000 mb winds will support 35 knots or higher of sustained
winds...especially east of the ms river...with gusts as high as 45
knots over lake pontchartrain and from 45 to around 50 knots over
the coastal waters. A gale warning will likely be required for all
or most of the marine area saturday night and sunday morning. Nws
policy is to issue the gale warning 24 hours in advance...so the
likely issuance time would be late this afternoon or this evening.
22


New Orleans Local Weather thread - dkmac - 02-27-2009 09:51 PM

hazardous weather outlook
national weather service new orleans la
820 pm cst fri feb 27 2009

gmz530-550-555-570-575-laz034>040-046>050-056>070-msz068>071-077-
080>082-010230-
lake pontchartrain and lake maurepas-
coastal waters from the southwest pass of the mississippi river
to lower atchafalaya river la out 20 nm-
coastal waters from pascagoula ms to the southwest pass of the
mississippi river out 20 nm-
coastal waters from the southwest pass of the mississippi river
to lower atchafalaya river la from 20 to 60 nm-
coastal waters from pascagoula ms to the southwest pass of the
mississippi river from 20 to 60 nm-pointe coupee-west feliciana-
east feliciana-st. Helena-tangipahoa-washington-st. Tammany-
iberville-west baton rouge-east baton rouge-ascension-livingston-
assumption-st. James-st. John the baptist-upper lafourche-
st. Charles-upper jefferson-orleans-upper plaquemines-
upper st. Bernard-upper terrebonne-lower terrebonne-
lower lafourche-lower jefferson-lower plaquemines-
lower st. Bernard-wilkinson-amite-pike-walthall-pearl river-
han****-harrison-jackson-
820 pm cst fri feb 27 2009

this hazardous weather outlook is for portions of coastal waters
of southeast louisiana and south mississippi...southeast
louisiana and southern mississippi.

.day one...tonight
thunderstorms...isolated thunderstorms are expected to develop
tonight and persist into mid morning saturday along and just ahead
of an approaching cold front and strong upper level disturbance.
These thunderstorms are generally expected to remain weak.

Marine hazards...a small craft advisory for hazardous seas is in
effect for the outer gulf coastal waters. Persistent southerly
winds of 15 to 20 knots will continue to maintain seas of 6 to 7
feet in this area.

.days two through seven...saturday through thursday
thunderstorms...any thunderstorm activity should be diminishing
by mid morning saturday over southeast louisiana and coastal
mississippi as cooler air spreads into the area.

Winds...strong north winds of 20 to 30 mph are expected to affect
most of the area saturday night. Winds will be highest across
areas south of lake pontchartrain and along the mississippi gulf
coast. In these areas...wind gusts of 40 mph will be possible and
a wind advisory may be required.

Cold temperatures...much colder air will spread across the region
late saturday. Overnight lows saturday night will be in the mid
30s and lower 40s. These low temperatures will also be
accompanied by strong and gusty winds which will help to drop wind
chill values into the mid to upper 20s late saturday night and
sunday morning. Additionally...a light freeze will be possible
late sunday night and monday morning for areas generally north of
a baton rouge to gulfport line.

Marine hazards...as the cold front sweeps through the coastal
waters on saturday...a strong ridge of high pressure will
build into the area and will result in winds of 25 to 35 knots
over the gulf coastal waters and lake pontchartrain. Frequent
gale force gusts are expected and gale warnings will likely be
required.