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Area forecast discussion 
National Weather Service New Orleans la
406 am CST Friday Jan 30 2015

Short term...our first cold front is already pushing through the
County Warning Area with winds quickly shifting out of the north and northwest overnight. Temperatures
have fallen nicely behind it with as much as 10-15 degrees in about
3 hours. One thing to note...most if not all sites have likely seen
their high temperature for the day already as everyone at 6z were in the
upper 50s to lower 60s.

Look for a mostly quiet forecast for the next 36-42 hours. Newly
established northwest flow will dominate today but our airmass will not get
as much of a southern push and actually start to nudge east late in the
day. H925 temperatures will drop to around 6-8c today leading to a rather
cold day with daytime highs in the middle 50s to near 60. Again the
official high for the calendar day has likely already occurred just
about everywhere in the County Warning Area. Temperatures will be slow to warm as cold air advection will
likely continue through the day but given what should be mostly
sunny skies surface temperatures will likely still warm about 5-10 degrees.
This will feel cold with respect to yesterday as we will be
about 15-20 degrees cooler than yesterday.

Tonight as ridging aloft starts to occur and our surface high pushes
into Appalachia and eventually twrds the middle and southeastern Atlantic coast
ll temperatures will start to slowly rebound. Moisture will also slowly
recover. The bulk of the changes though will occur Sat night and
more so on sun and into Sun night. A deep closed low currently
digging into the Baja California will slowly nudge twrds Mexico Sat night
before digging once again twrds the southern Baja California Sun night. This along
with another northern stream short wave will break the ridge down sun. Moisture
will increase across the region and as this northern stream short wave drops southeast
across the northern plains and into the middle MS valley it will send
another cold front twrds the region. This front...increasing
moisture...lowering hghts in the middle levels along with tapping into
the subtropical jet should provide more than ample support for num
rain showers sun. There is even a small window for a few thunderstorms and rain Sun afternoon as
there will be a little elevated instability and the rrq of the jet
to work with.

Rain will continue into the evening sun but we should see it slowly
taper off from northwest to southeast overnight as our cold front moves through
the region. /Cab/

Long term...some uncertainty in the long range forecast as the Euro and
GFS have pretty large strength and timing issues beginning overnight
Tuesday. Euro has had the largest shift from last nights run but is
quite similar to yesterdays 12z run. The GFS has been the more
consistent model timing wise but is weaker than last nights run.
With the uncertainty will stick with a blend of the models with a
slight lean to twrds the GFS which has support from its MOS along
with the gfes and Gem. The Euro at this time appears to be the
outlier cold model but will closely watch to see where the models
trend.

Eastern Continental U.S. Trough becomes reestablished Sun night and will send our
second cold front and airmass into the area Monday. This will keep US
cool and dry through Monday night but the cold front that moved through
Sun night will stall over the Gulf. This old frontal zone will
become activated as the old closed low over the Baja California is finally
lifting out across Mexico and into Texas leading to cyclogenesis in the
southwestern Gulf Tuesday. As the disturbance lifts into Texas Tuesday night it will
open up and put the region under SW flow aloft. The developing surface
low will continue to deepen and start lifting to the NE twrds our
County Warning Area. This will increase the rain chances Wednesday. As previous fcster
mentioned we are still on the cold wet side of the system so not
anticipating much if any thunderstorms and rain.

Third re-enforcing cold front will move in for the latter half of
the week. Colder and drier airmass will move in behind this surface low
but there are questions to how cold this airmass will be. The Euro
has shifted significantly cooler than last night but is also at odds
with its own MOS which is significantly warmer than the raw model. The
GFS has been more consistent so as mentioned earlier will use a
blend with a lean twrds the GFS. /Cab/

&&

Aviation...
a dry cold front is currently moving through the area...now south of
msy and should be approaching hum shortly. VFR conditions will
generally prevail at the terminals through the taf forecast period.
Gusty north winds will be observed downwind of Lake Pontchartrain at
knew and kmsy after frontal passage through the morning hours.

Meffer

&&

Marine...
latest observations show that cold front is currently just south of
Lake Pontchartrain and the Mississippi Sound...steadily progressing
southward. So will go ahead and start previously issued Small Craft
Advisory and exercise caution headline as wind speeds should ramping
up quickly. Small craft condition duration will be quite short...
ending by around noon as the pressure gradient quickly begins to
weaken. Only other change made to the forecast today is adding
exercise caution headline for this afternoon for offshore waters.

A repeat of winds rotating back around to onshore by late Saturday
is expected as progressive pattern keeps the ridge to the north
moving east towards the Atlantic coast. A more substantial cold
front still looks to be coming in by 12z Monday morning. It should
bring small craft conditions to the area with a brief period of
winds sustained in the upper 20s and a few gusts above 30 knots
between midnight and 6am. A Small Craft Advisory will likely be needed but improving
conditions in the afternoon should keep duration once again fairly
limited. East to northeast flow will remain in place through the
middle of next week as high pressure builds in from the north and
then northeast. Speeds will stay elevated as a surface low develops
in the western Gulf and tracks east across the northern Gulf.
Exercise caution at the least can be expected as it nears the
coastal waters.

Meffer

&&

Decision support...
dss code...blue.
Deployed...none.
Activation...none.
Activities...slurry support
Small Craft Advisory this morning

Decision support services (dss) code legend
green = no weather impacts that require action
blue = long fused watch/warning/advisory in effect or high
visibility event
yellow = heightened impacts with short fused
watch/warning/advisory issuances; radar support
Orange = high impacts - slight to moderate risk severe; nearby
tropical events; hazmat or other large episodes
red = full engagement for moderate to high risk severe
and/or direct tropical threats; events of National
significance.



&&

Preliminary point temps/pops...
mcb 58 34 60 50 / 0 0 0 30
btr 60 38 61 52 / 0 0 10 30
asd 60 36 60 53 / 0 0 0 30
msy 59 42 61 56 / 0 0 10 30
gpt 59 36 58 51 / 0 0 0 20
pql 59 33 60 50 / 0 0 0 20

&&

Lix watches/warnings/advisories...
la...none.
GM...Small Craft Advisory until noon Friday for the following zones:
Breton Sound...Chandeleur Sound...coastal waters from
Boothville la to the Southwest Pass of the Mississippi
River out 20 nm...coastal waters from Pascagoula MS to
Stake Island la from 20 to 60 nm...coastal waters from
Pascagoula MS to Stake Island la out 20 nm...coastal waters
from Port Fourchon to lower Atchafalaya River from 20 to 60
nm...coastal waters from Port Fourchon to lower Atchafalaya
River out 20 nm...coastal waters from Stake Island la to
the Southwest Pass of the Mississippi River from 20 to 60
nm...coastal waters from the Southwest Pass of the
Mississippi River to Port Fourchon from 20 to 60 nm...and
coastal waters from the Southwest Pass of the Mississippi
River to Port Fourchon out 20 nm.

MS...none.
GM...Small Craft Advisory until noon Friday for the following zones:
Breton Sound...Chandeleur Sound...coastal waters from
Boothville la to the Southwest Pass of the Mississippi
River out 20 nm...coastal waters from Pascagoula MS to
Stake Island la from 20 to 60 nm...coastal waters from
Pascagoula MS to Stake Island la out 20 nm...coastal waters
from Port Fourchon to lower Atchafalaya River from 20 to 60
nm...coastal waters from Port Fourchon to lower Atchafalaya
River out 20 nm...coastal waters from Stake Island la to
the Southwest Pass of the Mississippi River from 20 to 60
nm...coastal waters from the Southwest Pass of the
Mississippi River to Port Fourchon from 20 to 60 nm...and
coastal waters from the Southwest Pass of the Mississippi
River to Port Fourchon out 20 nm.

&&

$$

Short/long term: cab
marine/aviation: meffer

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