Special Weather Statement, NWS New Orleans, LA

AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
352 AM CDT Mon Jul 19 2021

.SHORT TERM (Today through Wednesday)...
The seemingly never-ending wet period continues. The upper level
pattern isn't particularly normal for the middle of the summer. A
deep, slow moving trough extends from Vermont down to almost
Louisiana. A frontal boundary associated with the trough may make it
to I-20, but thats about it. Regardless, this trough over the
general region means absolutely no inhibition to stop numerous
showers and thunderstorms from developing. Looking at model PW's,
they look to jump up from 2" yesterday to 2.3-2.4" today. That'll
give those numerous storms today the potential to produce very heavy
rainfall rates. With a similar environment last week, we saw hourly
rainfall rates of 2-4" in an hour and isolated areas of 6+ inches.
Expect that today. Where it falls will determine if flash flooding
occurs. What makes this environment different from say this past
weekend, is its not diurnally driven. Even though the sun sets,
we'll probably still have waves of convection passing across the CWA
tonight. It'll roll into Tuesday with a yet another day of near 100%
coverage like today.

The trough will finally start to slowly shift east on Wednesday.
While appreciable changes locally will be hard to see, will probably
start to see small drop in coverage and lower high-end rainfall
totals for the day.

MEFFER
&&

.LONG TERM (Thursday through next Weekend)...
Thursday and Friday still looks to be wet as PWs still hitting
around to 2 inch mark, but the upper level trough that has been
parked over the eastern part of the US should finally move as the
ridge to our west in the central CONUS begins to build in.
Saturday and Sunday we will have weak high pressure build in along
with a little less moisture which should help cut down on the PoPs a
bit. Unfortunately, the slightly drier pattern would mean our
temperatures will likely get into the 90s with dew points around the
70s, which will bring heat indices into the 100s easily. The ridging
over the central CONUS continues to amplify but still expecting
diurnally driven thunderstorms through the whole period, just not to
the extent that we have been stuck in for the past couple of weeks.

BL
&&

.AVIATION...
VFR to MVFR conditions are expected the rest of this early morning
with ceilings bouncing from clear to 2kft decks. Isolated showers
with substantially increase in coverage  Temporary drops into
MVFR/IFR are possible for any terminal impacted by any showers and
thunderstorms throughout the day.

&&

.MARINE...
High pressure is currently building in across the Gulf of Mexico
from the east. That ridge is centered in the western Atlantic. It's
far enough away that the local pressure gradient is fairly weak but
strong enough to keep flow consistent. Expect mostly 5 to 10 knot
winds with seas 2 feet or less. A boundary will approach from the
north early this week but not make it to the coastal waters. As it
dissipates, a new surface ridge will develop in the eastern Gulf and
slowly track across the coastal waters. That will break down the
local wind field and bring seas to not more than a light chop at
best.

MEFFER
&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  87  71  84  71 / 100  90  90  40
BTR  89  73  86  73 / 100  90 100  50
ASD  89  74  86  74 /  90  90 100  60
MSY  90  78  87  77 /  90  90  90  70
GPT  88  74  86  75 /  80  90  90  70
PQL  88  74  86  75 /  80  80  90  70

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

Special Weather Statement
National Weather Service New Orleans LA
149 PM CDT Mon Jul 19 2021

MSZ069-070-191930-
Pike-Amite-
149 PM CDT Mon Jul 19 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN PIKE AND
SOUTHEASTERN AMITE COUNTIES...

At 149 PM CDT, a strong thunderstorm was located near Gillsberg, or 9
miles southeast of Liberty, moving east at 20 mph.

Winds in excess of 40 mph and dangerous lightning will be possible
with this storm.

Locations impacted include...
Mccomb, Liberty, Magnolia, Gillsberg and Mccomb Airport.

This includes Interstate 55 in Mississippi between mile markers 4 and
17.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 3131 9056 3123 9046 3109 9047 3100 9052
      3100 9079 3114 9083 3120 9089
TIME...MOT...LOC 1849Z 268DEG 18KT 3106 9070

KLG