Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
FXUS64 KLIX 272104
Area Forecast Discussion
National Weather Service New Orleans LA
404 PM CDT FRI MAY 27 2016
.SHORT TERM (Tonight through Memorial Day)...
The effects of a mid to upper level ridge has continued to
dominate the central Gulf coast weather, although a few showers
have brushed the far northwest portion of the forecast area. A
very favorable pattern for very heavy rainfall and some strong to
severe thunderstorms has been observed the last day or so over
southeast Texas with a coupled upper jetstream and strong
divergence along with a slow moving shortwave trough. Some of this
energy with the latest batch of storms over northwest/west central
Louisiana into the Houston area could push what should be
weakening thunderstorms into southwest Mississippi and portions of
east central Louisiana near or west of Baton Rouge this evening.
Most of this rain should be gone after midnight tonight, however
trailing effects of both upper divergence and a weak shortwave
trough should provide a focus for some isolated mainly afternoon
showers and thunderstorms on Saturday, mainly inland from the
Shortwave trough will exit the region Saturday night into Sunday,
and be replaced by a mid/upper ridge building over the western to
central Gulf coast region. Not all is clear cut, however as the
models show a weakness in the 500 mb ridge moving near the
western border of our forecast area along with a pool of slightly
higher precipitable water and some mid/upper divergence. Have
kept a mention of a slight chance of showers and thunderstorms in
the northwest to west portion of the area.
On Memorial Day, the mid/upper ridge should flatten out with some
mid/upper level divergence continuing to provide some favorable
conditions for isolated diurnal convection, so have a slight
chance PoP. Temperatures will be seasonally warm to hot, and it
will remain on the humid side through the Holiday weekend with
less breeze on Sunday and Memorial Day.
.LONG TERM (Tuesday through Friday Night)...
Tuesday and Wednesday looks similar to Memorial Day with isolated
diurnal showers and thunderstorms and very warm temperatures,
except Wednesday could be completely dry. The models show a
wetter pattern developing late in the week as more troughing aloft
sets up over the southern plains to lower Mississippi valley. Have
followed a blend with higher rain chances in the forecast and
temperatures not quite as hot.
Expect mainly VFR conditions to prevail over the next few hours.
Some lower cigs are possible as a line of showers and thunderstorms
move into central and southwest Louisiana this evening and
overnight. We will have to watch and see how far this line moves
into the area and if it will stay together. Have indicated a few
showers being possible over the western portions of the forecast
area through sunset. We may have to amend TAFs if showers and
Tighter pressure gradient between high pressure over the eastern
states and low pressure over the plains will gradually slack off
later tonight and especially on Saturday as low pressure pulls
northeast through the plains towards the upper Mississippi
Valley. This will allow the elevated moderate southeast winds and
associated seas from today to ease. This will lead to a weak
pressure pattern and lighter winds Saturday night through the
Memorial Day holiday and early next week.
DSS code: Green.
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.
Yellow = Heightened impacts with short-fused watch, warning
or advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby
tropical events; HazMat or other large episodes.
Red = Full engagement for Moderate risk of severe and/or
direct tropical threats; Events of National Significance.
.PRELIMINARY POINT TEMPS/POPS...
MCB 68 88 67 90 / 20 20 10 20
BTR 70 88 70 90 / 20 20 10 20
ASD 69 87 69 89 / 10 20 10 10
MSY 72 87 71 89 / 10 20 10 10
GPT 72 86 70 88 / 10 10 10 10
PQL 68 86 68 88 / 10 10 10 10
Rest of Discussion...22/TD