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Area forecast discussion
National Weather Service New Orleans la
248 PM CST Thu Nov 14 2019

Short term...
region covered by extensive cloud cover and mostly stratiform rain
with embedded convective features from high based nimbus decks. This
is in response to weak area of low pressure, about 1018 mb, over the
west Gulf this afternoon. There is a 8 mb gradient between it and
surface high situated near Monroe, la, providing a large scale
isentropic shallow slope to support the rain process this afternoon.
The low pressure circulation becomes suppressed as new surge of cold
air builds southward into the Gulf this evening, shutting off the
over-running upglide. Rain should come to an end for all areas by
midnight. Lows to remain at or above freezing tonight and below
daily normals as cold pool trough swings through. High pressure axis
pretty much stays parked over the middle and lower MS River Valley
Friday into Saturday with dry and cold to cool temperatures to
prevail.



Long term...
there appears to be an extended period of cool and dry days well
into next week as high pressure area slowly moderates. Another
southern branch impulse enters the west Gulf Monday but models want
to suppress it well south of the forecast area as upper level trough
amplifies over the eastern U.S. European model (ecmwf) does show some convective
response to upper level forcing on a diving impulse, but it would be
bringing its own moisture and does appear to be limited with no
return flow enhancement to augment. Will maintain low end pops
during that period, otherwise, it rather dry forecast through the
extended period. Some slow veering to onshore flow around next
Thursday may impart a shot at sea fog considerations with warm
moisture advection over what is now cooling coastal waters.

&&

Aviation...
VFR ceiling and visibility OK all terminals despite periods of -r/-rw through about 03z,
tapering to spotty coverage through 06z, then clearing to VFR ceiling and visibility unlimited
after 06z from west to east. There is a slim chance that some fog
may attempt to form from residual moisture but any formation
should dissipate soon after drier air moves into the region. Given
low confidence of this, will withhold mention at this time in the
tafs and amend as needed.

&&

Marine...
offshore flow regime to remain in place the entire forecast period
with some gradient enhancement to north-NE winds this evening and again
Monday night into early Tuesday as surface reflections of upper
level disturbances traverse the central and lower Gulf waters.



&&

Decision support...
dss code: blue.
Deployed: none.
Activation: none.
Activities: river flooding. Forecast support to city of New Orleans
for building collapse. National oceanic and atmospheric administration Cox Bay operation support.

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

&&

Preliminary point temps/pops...
mcb 35 56 31 58 / 40 0 0 0
btr 37 56 33 58 / 20 0 0 0
asd 38 59 34 60 / 0 0 0 0
msy 43 58 40 59 / 0 0 0 0
gpt 40 58 35 60 / 20 0 0 0
pql 40 61 35 63 / 20 0 0 0

&&

Lix watches/warnings/advisories...
la...none.
GM...Small Craft Advisory from 6 PM this evening to 6 PM CST Friday
for gmz550-552-570-572.

Small Craft Advisory until 6 PM CST Friday for gmz536-538-555-
557-575-577.

MS...none.
GM...Small Craft Advisory from 6 PM this evening to 6 PM CST Friday
for gmz552-570-572.

Small Craft Advisory until 6 PM CST Friday for gmz538-555-557-
575-577.

&&

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