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

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FXUS64 KLIX 090911

Area Forecast Discussion
National Weather Service New Orleans LA
411 AM CDT Sun Aug 9 2020

.SHORT TERM...What a difference just 12 hrs made yesterday and
things continued to change overnight. Moisture increased
significantly like expected just a little faster and with a very
moisture rich airmass in place convection started rather quickly
across the coastal waters overnight.

Overall the biggest change today from yesterday will be just deeper
moisture in place. There is still the residual imprint of a trough
axis draped over the area but like mentioned yesterday it is more of
just a weakness aloft as we remain between the ridge centered over
southern Plains and ARKLATEX region and the other ridge still
centered near the Bahamas. We actually look to fall under a col
region aloft. Once again synoptic winds in the LL are rather weak so
the seabreeze will not get a great push north which is why the
highest PoPs remain closer to the coast. Also think there is a good
chance of the seabreeze colliding with the lake breeze over the
southshore which could increase the rain potential and will show a
PoP of around 60 in the city. Things could look rather similar to
yesterday but maybe just a tad more coverage. Still anticipate the
best chance for measurable rain from near Baton Rouge to New Orleans
and to the southwest. Also scattered convection along the MS coast
is expected. Elsewhere look for isolated storms.

Heat will be a concern again but with slightly better coverage of
storms and cloud cover will once again hold off on a heat adv. That
said it is quite likely isolated locations will climb to 108 degrees
or even slightly higher but most of the area will range from 100-
107. Yeah I know, WOW thats so much cooler, just remember to drink
lots of fluids, preferably water ;) and try to take breaks and cool
off when possible.

Monday could be fairly similar to today but the ridge will slide
over the region, however it is expected to be a little weaker.
Moisture will still be plentiful with PWs near 2" still and it still
doesn`t look like a moderate to strong onshore flow will have
developed yet. With that expecting the seabreeze to take a little
while to get active again and will not push very far north so most
of the convection should remain closer to the coast and tidal lakes.
Greatest chance for rain could be at the collision of the seabreeze
and lake breeze over the Southshore and then with the seabreeze over
coastal MS. As for temps and heat, it will still be oppressive so
make sure to take precautions to prevent heat illness. /CAB/

.LONG TERM (Tuesday through Saturday)...Models continue to show
upper ridges to the east and west of the area for much of the week.
The ECMWF tending to show somewhat less of a weakness between the
ridges across the area, with correspondingly lower PoPs. Blends
continue to be more aggressive on PoPs than either operational model
or most of their ensemble members. Would anticipate a bit of a
downward trend in blended guidance PoPs for at least the early
portion of the extended on Tuesday and Wednesday. Forecast soundings
do moisten up compared to previous packages by Thursday into the
weekend as precipitable water values return to around 2 inches.
Northern/western portions may be a little slower on the moisture
increase by about 12 to 24 hours, most likely on Friday. Most
convection will start to fire up around mid-day with a rapid
decrease in coverage by sunset each day. High temperatures will
remain on the high end of guidance unless convective development at
a location occurs prior to 18-19z. 35


.MARINE...Not much to really discuss as the weather will be fairly
benign. High pressure remains in control and will slowly slide east.
This should eventually allow for onshore to finally become re-
established across the area but it will likely be more like Tuesday
or Wednesday. Winds will still be impacted by diurnal fluctuations
each day as the synoptics winds will still be on the weaker side.
Main concern will continue to be convection overnight. Any storm
will be have the potential for locally higher winds and seas along
with waterspouts. /CAB/


.AVIATION...VFR conditions expected through the forecast period
outside of thunderstorms. Isolated to scattered convection
expected beyond 18z Sunday, but don`t expect areal coverage to be
high enough to justify more than VCTS at this point. Least likely
terminal to be impacted will be KMCB. Storms will continue to be
slow moving, as has been the case the last few days, and are most
likely to produce IFR or lower visibilities if they directly
impact a terminal area. Would expect a rapid decrease in
convection toward 00z Monday. 35


MCB  94  75  93  75 /  10  10  30  10
BTR  95  76  95  76 /  50  10  30   0
ASD  96  76  95  76 /  20   0  40  10
MSY  94  78  93  78 /  40   0  40   0
GPT  93  77  92  77 /  20  10  30  10
PQL  96  76  95  76 /  20   0  40  10



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