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Area forecast discussion 
National Weather Service New Orleans la
318 PM CST Wednesday Feb 10 2016

Short term...

The biggest change occurring over the short term is a significant
warming of temperatures expected over the next couple of days.
This warming will be driven by a combination of strong solar
insolation...increasing negative vorticity advection and
subsidence aloft...and southwest flow in the low levels ushering
in warmer air from the southwest Gulf and Mexican plateau. There
should be a decent diurnal range each day of 20 to 25 degrees given
the dry airmass and clear skies remaining over the area...with
highs rising into the lower to middle 70s both Thursday and Friday
and lows cooling into the 40s and lower 50s.

A clipper system diving through the Great Lakes states and into
the middle-Atlantic and northeast Friday into Saturday will force a
backdoor cold front through the region Friday night. Winds should
shift back to the northeast and some colder air will advect into
the area. This front will have little to no moisture to work
with...so only a few passing clouds are expected as the front
moves through. With 925mb temperatures falling into the upper 30s
and lower 40s both Saturday and Sunday...daytime highs should only
climb into the upper 50s and lower 60s both days. These readings
are near to slightly cooler than average. Additionally...the
coldest night of the forecast period will be Saturday night as
temperatures fall back to near freezing over the northern parts of
the County Warning Area.

Long term...

Confidence has increased concerning rain potential for next Monday
into Monday night. A vigorous short wave trough and associated
front will sweep through the Gulf south during this period. Strong
forcing will develop throughout the atmospheric column as the
front at the surface and a strong 110 knot jet streak aloft
interact. A surge of moisture in the middle- levels will promote
cloud development as early as Sunday evening. With moisture
advection increasing...precipitable water values should rise nearly half an inch
between Sunday evening and Monday evening. Lapse rates do not look
very steep with this system...but there should be just enough
instability in place to allow for a slight chance of some
thunderstorms developing on Monday. However...scattered to
numerous showers are expected to be more likely than any
thunderstorms Monday into Monday evening. With increasing moisture
over the area...overnight lows Sunday night will be much warmer
than on Saturday night...with readings expected in the upper 40s
and lower 50s. Daytime highs will be near normal on Monday with
temperatures expected to rise back into the middle 60s.

Complete frontal passage through the forecast area is expected to
occur by Tuesday morning...and have clearing skies and diminishing
rain chances developing by late Monday night. By Tuesday
afternoon...skies should begin to clear completely over all of the
County Warning Area. Even though the area will be Post-frontal...the airmass
advecting into the area will not be significantly cooler as it has
a Pacific based origin. This will allow temperatures to remain
fairly close to seasonal norms on Tuesday. By Wednesday...the
strong solar insolation and subsidence over the area should allow
highs to approach 70 degrees again.

&&

Aviation...

VFR conditions with clear skies and winds mostly less than 10
knots will prevail through Thursday. 22/dew point

&&

Marine...

Much calmer conditions are expected over the coastal waters
tonight and tomorrow...as a ridge of high pressure remains
centered over the area. Winds should remain between 5 and 15 knots
and shift to a more southwest direction by tomorrow. Seas will
generally remain at 3 to 4 feet or less. A slight increase in the
pressure gradient over the eastern waters may occur beginning
tomorrow night and continuing into Friday as a frontal boundary
approaches the area. This could push winds back into exercise
caution range Thursday night and Friday...and also increase seas
to around 5 feet by Friday morning. In the wake of the
front...winds will shift to the northeast...and a general period
of 15 to 20 knot winds and higher seas is expected over the open
Gulf waters through the weekend. The sounds and lakes should see
the northeast flow remain in the 10 to 15 knot range during this
period. By Monday...winds should shift back to an onshore
component as another cold front approaches from the northwest.
There will continue to be a decent gradient over the northern
Gulf...so winds should remain in exercise caution range over the
offshore waters throughout the day. 32

&&

Decision support...

Dss code....blue.
Deployed...none.
Activation...none.
Activities...river flooding continues on the Pearl River.

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 risk severe and/or direct
tropical threats; events of National significance



&&

Preliminary point temps/pops...
mcb 40 73 48 70 / 0 0 0 0
btr 42 75 51 73 / 0 0 0 0
asd 39 71 49 69 / 0 0 0 0
msy 47 72 55 71 / 0 0 0 0
gpt 41 69 48 68 / 0 0 0 0
pql 38 69 48 69 / 0 0 0 0

&&

Lix watches/warnings/advisories...
la...none.
GM...none.
MS...none.
GM...none.
&&

$$

32

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