Freeze Warning 3, NWS New Orleans, LA

Area Forecast Discussion
National Weather Service New Orleans LA
1150 PM CST Sun Nov 29 2020

.UPDATE...

Updated for 06z TAF discussion.

&&

.AVIATION...

Mostly VFR conditions due to lower CIGS will be temporarily
scattering out/clearing and lifting into a VFR deck from northwest
to southeast for several hours overnight before an area of lower
MVFR category CIGS redevelops and moves back south into the
region during the late overnight and early morning hours. These
clouds will scattered then clear out again during the morning to
midday hours leading to prevailing VFR with mostly clear skies
and excellent visibilities the remainder of the day into Monday
night.

&&

22/TD

.PREV DISCUSSION... /issued 324 PM CST Sun Nov 29 2020/

SHORT TERM [Through Tuesday Night]...

As of 3PM, a surface low continues to move northeast through
southeast LA with a warm front moving north, now situated east and
northeast of Slidell, LA. The cold front is already through
central LA with winds from the NW and temps dropping into the 50s
behind this final band of rainfall. There is an occasional rumble
of thunder, along the warm front, where instability is maximized.
The area should be rain free after midnight. Much cooler air with
strong cold advection will move in, with wind gusts of 25 to 30
MPH, and lows dropping into the lower to mid 40s.

Deep ridging builds eastward Monday with a surface high pressure
area encompassing much of the central and south central United
States. This will clear out skies by Monday afternoon, along with
slackening winds, with high temps only in the upper 40s in
southwestern MS to lower to mid 50s elsewhere. As strong cold
advection continues, it looks like much of the area will see the
first freeze of the season Monday night, with lows dropping into
the 20s (not a typo) for all areas except south of Lake
Pontchartrain and coastal SE LA. A Freeze Watch remains in effect
for those regions. Patchy frost is also likely.

The high pressure and ridge remain through Tuesday night with
highs Tuesday warming into the middle 50s and lows Tuesday night,
right around freezing and above.

LONG TERM [Wednesday through Sunday Night]...

A deep upper low cuts off over OK/KS on Wednesday with southeast
flow returning to the local area. The upper low stays to the
north with a shortwave moving through SE Texas. A trough/weak cold
front then pushes across the area west to east with rain possible
Wed afternoon through Thu afternoon. There could be a few rumbles
of thunder but nothing widespread or severe looks possible at this
time. Highs will warm into the upper 50s to mid 60s and lows in
the mid 40s to mid 50s, ahead of the system, and only fall a few
degrees Thursday since the front will move through Thursday
evening.

Winds quickly shift back to the northwest behind it with cooler
air moving in. Lows Thu night fall into the lower to mid 40s. Dry
weather returns for the weekend, with highs in the mid to upper
50s and lows in the mid 30s to mid 40s.

AVIATION...through 18z Monday...

Rain has ended at BTR and MCB with only light showers remaining at
HUM and HDC. Moderate to heavy rain expected still at the
remaining terminals but did remove the mention of thunder. A very
isolated rumble is possible but chances aren't high enough to
include in the TAFS. Generally IFR CIGS and VIS but some are
bouncing to MVFR/IFR and that will be temporary. Winds around
10-15 knots with gusts up to 25 knots possible from the NW will
occur with the cold front. CIGS will slowly lift overnight from
the southwest to the northeast and should be VFR by the end of the
day Monday.

MARINE...

Moderate to heavy rain will continue to end west to east tonight
into Monday morning followed quickly by a cold front with strong
north northwest winds behind it. This will will raise winds, seas
and waves and the Small Craft Advisory will stay in effect
through Tuesday morning. High pressure returns conditions subsiding
through the second half of the week. Another cold front moves
through Wednesday into Thursday with conditions increasing once
more.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  42  50  30  55 /  10  10   0   0
BTR  43  51  29  56 /  10   0   0   0
ASD  43  54  30  56 /  10   0   0   0
MSY  47  53  38  54 /  10   0   0   0
GPT  44  53  33  54 /  10   0   0   0
PQL  43  54  29  56 /  20   0   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Freeze Watch from Monday evening through Tuesday morning for
     LAZ034>037-039-040-046>050-056>059-065-071-072.

GM...Small Craft Advisory until 6 AM CST Tuesday for GMZ530-532-534-
     536-538-550-552-555-557-570-572-575-577.

MS...Freeze Watch from Monday evening through Tuesday morning for
     MSZ068>071-077-080>082.

GM...Small Craft Advisory until 6 AM CST Tuesday for GMZ532-534-536-
     538-550-552-555-557-570-572-575-577.

&&