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

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KLIX 200133
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
833 PM CDT Thu Apr 19 2018


.SOUNDING DISCUSSION...
The upper air release this evening was successful with no
problems encountered. The 00z sounding depicted a dry and stable
atmosphere with a strong inversion present in the 875 to 780 mb
layer. The precipitable water value was 0.46 inch. North winds
prevailed in the lower levels of the atmosphere while westerly
flow was present throughout the mid and upper levels. 11


&&

.PREV DISCUSSION... /issued 347 PM CDT Thu Apr 19 2018/

DISCUSSION...
Cold front has finally pushed into the Gulf and drier air is
filtering into the area. Here in Slidell, the dewpoint has dropped
from the lower 60s this morning to the upper 40s this afternoon.
With mostly clear skies and low dewpoints, expect overnight lows
to drop well below normal tonight. Expecting generally mid 40s
along/north of the I-10/12 corridor and upper 40s and lower 50s
south of the interstates. Tomorrow will be a gorgeous day, with
mostly clear skies, low humidity, and temperatures topping out
around 70 degrees.

Saturday continues to look like a transitional day as surface
high pressure shifts eastward. The shift will cause winds to
become more eastward and then southeastward by evening. This will
allow moisture to begin returning to the area. Also by Saturday
night, an upper low will be moving into the middle Mississippi
Valley, with a surface low and cold front following suit. The
front should arrive in the local area some time around or shortly
after midnight and will traverse the area slowly through the day
Sunday.

Am carrying likely to categorical PoPs across the region during
this time frame. Instability looks rather meager, but the wind
profile does indicate both directional and speed shear. That being
said, can`t rule out a few strong to severe thunderstorms, and SPC
has included most of the area in a Marginal Risk area for late
Saturday night. Would not be surprised if that risk carries into
Sunday for the remainder of the area as the front moves through.

The front should clear the area by late Sunday, but wrap around
moisture on the back side of the low could keep some isolated
showers in the area Monday. Air mass behind the front won`t be
quite as cool as the one currently moving into the local area, but
should be enough to keep temperatures near or slightly below
normal for the first half of the work week.

AVIATION...
VFR CAVU conditions all terminals next 24-30 hours as high pressure
settles into the region.

MARINE...
Small craft advisory is in effect for the coastal waters as cold air
advection influences over the warmer waters provide thermal mixing
until the advection neutralizes Friday morning. Flow becomes
easterly by Friday night into Saturday then onshore oriented ahead
of next frontal system Sunday. Frontal passage will be slow
evolution through the coastal waters, finally getting east of the MS
coast by late Sunday night. Short-lived modified continental airmass
settles winds and seas a bit Tuesday before another surge of high
pressure builds through the Plains States into the north Gulf
midweek.

DECISION SUPPORT...
DSS code: Blue.
Deployed: None.
Activation: None.
Activities: Assessing thunderstorm risk for Sat night/Sun
            Sandhill Crane NWR Outreach support
            NOLA Navy Week Support

Decision Support Services (DSS) Code Legend
Green  = No weather impacts that require action.
Blue   = Long-fused watch, warning, or advisory in effect or
         high visibility event; Marginal risk severe or excessive rain.
Yellow = Heightened impacts with short-fused watch, warning or
         advisory issuances; radar support for Slight risk severe or
         excessive rain.
Orange = High Impacts; Enhanced risk severe; nearby tropical events;
         HazMat or other large episodes.
Red    = Full engagement for Moderate to high risk of severe and/or
         direct tropical threats; Events of National Significance.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  68  43  69  49 /  10   0   0   0
BTR  72  46  70  52 /  10   0   0   0
ASD  74  46  70  50 /  10   0   0   0
MSY  75  53  69  57 /  10   0   0   0
GPT  77  49  69  56 /  10   0   0   0
PQL  75  46  71  52 /  10   0   0  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Small Craft Advisory until 6 AM CDT Friday for GMZ532-536-538-
     550-552-555-557-570-572-575-577.

     Small Craft Advisory until 6 AM CDT Friday for GMZ530-534.

MS...None.
GM...Small Craft Advisory until 6 AM CDT Friday for GMZ536-538-550-
     552-555-557-570-572-575-577.

     Small Craft Advisory until 6 AM CDT Friday for GMZ534.

&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.