Area Forecast Discussion Issued by NWS New Orleans/Baton Rouge, LA
000
FXUS64 KLIX 292051
AFDLIX
Area Forecast Discussion
National Weather Service New Orleans LA
351 PM CDT Wed Jun 29 2022
.SHORT TERM...(through Saturday)
Forecast through the short term is basically a rinse and repeat
situation. We will stay in a deep tropical air mass owing to deep
high pressure centered over the SE CONUS/western Atlantic and a
developing low pressure over the western Gulf. This will keep
winds generally south to southeasterly from the surface up through
about 500mb, pumping plenty of moisture into the local area.
Model forecast soundings keep precipitable water near or above 2
inches through the period. As mentioned in previous discussions,
there really isn`t any large scale forcing to speak of, but with
ample moisture and instability, will be carrying likely to
categorical POPs each day.
With deep moisture and slow storm motions, expect some storms to
be efficient rainmakers with rainfall rates in excess of 1-2" per
hour. Instantaneous rates will likely be significantly higher.
This will continue to lead to a threat of locally heavy rainfall
and localized nuisance or even flash flooding, and it`s not
surprise that WPC keeps a daily marginal risk of excessive
rainfall across the entire area through at least Friday.
As is typical in this kind of air mass, expect showers and storms
to fire over the coastal waters overnight and into the morning
hours, waning in those areas as the morning progresses. Over land,
expect the best rain chances during the afternoon and early
evening hours most places - the main exception being in coastal
areas where marine storms could wander onto land in some areas.
Given the expected cloud cover and convection, highs should
generally top out in the upper 80s to lower 90s, though there is
certainly potential for higher temperatures if convective onset is
delayed or the cloud cover breaks for long enough. Overnight lows
will fall into the low to mid 70s north and into the mid to upper
70s south, with a few places along the immediate coast only
dropping to around 80 degrees.
Other than bumping up POPs during the first part of the evening
since convection rarely shuts off completely right at 00z, really
didn`t make any significant changes to the NBM starting point.
.LONG TERM...(Sunday and beyond)
By Sunday, upper ridging builds back into the local area, but
isn`t strong enough to substantially suppress convection. Even
with the weak upper ridge, we maintain southerly/southeasterly
flow up to almost 10kft which means continued tropical moisture
access with precipitable water continuing to sit near or above 2
inches through the early part of next week, so we should still see
at least scattered storms each day. The ridging will result in
some reduction of coverage, though, with POPs generally peaking
around 50-60% each day rather than 70-80% each day. That being
said, will likely see just a tad more warming, and will carry
afternoon temperatures in the lower 90s most places through the
period.
&&
.AVIATION...
Outside of convection, expect conditions to generally remain VFR.
Timing of showers and thunderstorms at individual TAF sites
continues to be a challenge and may require amendments. Any
heavier showers/storms will be capable of causing IFR visibilities
and MVFR ceilings. A few of the stronger thunderstorms may also
result in gusty/erratic winds.
&&
.MARINE...
Daily showers and thunderstorms will be the main marine concern.
Expect a typical summertime diurnal cycle, with showers and
storms firing over the open waters during the overnight hours,
then waning during the daylight hours. Protected waters will see
showers and thunderstorms mainly during the daylight hours.
Outside of convection, expect light to moderate south or
southeasterly flow resulting from high pressure to the east and
developing low pressure to the west. Winds and seas will be higher
in the vicinity of thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 71 88 72 88 / 30 80 20 80
BTR 73 90 74 90 / 20 80 20 80
ASD 74 89 74 90 / 40 80 30 80
MSY 78 89 77 88 / 40 80 30 80
GPT 76 88 76 89 / 60 80 40 80
PQL 76 86 75 87 / 60 80 50 80
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
95/DM