Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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FXUS64 KLIX 082036

National Weather Service New Orleans LA
336 PM CDT Sat Aug 8 2020

The CWA is currently stuck in a region underneath upper level
weakness between 2 ridges. Lack of moisture had inhibited convective
development but that changed today as moisture levels begin to rise.
This morning`s PW rose from around 1.3" to well over 1.8" on the LIX
sounding. Model PW indicates 2"+ south of Lake Pontchartrain which is
precisely where most of the convection has fallen so far today.
These showers and storms are diurnally driven and will dissipate
with the loss of daytime heating.

Moving into Sunday, a similar pattern is expected with the greatest
coverage of storms being south of Lake Pontchartrain. One slight
modification might be a shift to the northwest of there towards
Baton Rouge. Models show higher PW`s creeping up from the GOM to the
Mississippi River. Global and MESO models actually indicate higher
POPS in that region as well, thus this afternoon`s forecast shows 40-
50% coverage from BTR to MSY and southward. From a temp perspective,
should be sitting well into the 90s with a few locations touching
mid 90s. That combined with low to mid 70 dewpoints will yield 100-
107 heat indicies. We watched heat indicies closely today and they
have stayed in that range. Not seeing any significant changes in the
upper level pattern to create more warming and with generally higher
POP coverage, feel like we`ll just be border-line heat advisory
across the CWA Sunday.


At the moment, Monday is looking like a very similar setup as this
weekend, so holding the forecast then to be about the same. Tuesday
will be a transition day into what will become higher rain chance
days for the entire CWA. Models show a broad trough dipping between
the aforementioned ridges. This will open up and create a larger
area of weakness between them. The CWA, right in the middle of those
areas, will see the least subsidence inhibition. That means with
daytime heating, probably looking at likely POPs on a daily basis
from Wednesday into next week. Think 60-90% coverage during that
timeframe. Locally heavy rainfall may become an issue over the
weekend as PW`s start inching (pun intended) towards 2.3".


VFR conditions will dominate the forecast period with short
durations of SHRA/TSRA impacts. HUM to MSY/NEW will be the most
likely terminals to see these temporary drops in ceilings and
visibilities. Ongoing scattered convection is diurnally driven and
should dissipate as the sun sets. Expect mostly VFR conditions
overnight with a repeat of daytime scattered storms on Sunday.


Fairly benign conditions expected for the marine areas outside of
daily convection as the pressure gradient over the region will be
quite weak for the forecast period. Surface high pressure centered
in the northeastern GOM will gradually migrate west through the
week. This will keep southwesterly flow in place with mild nocturnal
increasing of winds in the sounds. But generally speaking, expect
winds to remain fairly light (10 knots or less) with seas in the 1
to 2 foot range.


MCB  75  93  75  92 /  10  20   0  40
BTR  75  94  76  94 /  20  40   0  40
ASD  76  95  76  94 /  20  40  10  50
MSY  80  93  77  94 /  30  40   0  50
GPT  77  91  77  91 /  20  30  10  40
PQL  76  94  76  94 /  20  30  10  40



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