Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
FXUS64 KLIX 290900
Area Forecast Discussion
National Weather Service New Orleans LA
400 AM CDT FRI JUL 29 2016
A broad area of lower pressure and weak omega aloft will linger
over the forecast area through tomorrow. As a result, scattered
showers and thunderstorms should redevelop beginning late this
morning and persisting through the afternoon hours as instability
increases with daytime heating. Once the daytime heating wanes
shortly after sunset the vast majority of the convection should
quickly dissipate leaving dry conditions and partly cloudy skies
behind. There could be another round of patchy fog development
over interior areas of the forecast area late tonight due to the
weak boundary layer winds and moist low level airmass in place.
Temperatures will be near seasonal norms in the lower to middle
90s both today and tomorrow.
It looks like increased upper level ridging will bridge across the
forecast area by Sunday. An increase in subsidence and drop in
atmospheric moisture content will lead to lower overall convective
development during the afternoon hours on Sunday. Given the
expected conditions, POP has been reduced to 20 to 30 percent for
Sunday. Temperatures should also be warmer and expect to see highs
easily climb into the middle 90s Sunday afternoon. This increased
ridging aloft will remain over the region on Monday, and very
similar conditions to those forecast for Sunday can be expected.
The heart of the upper level ridge axis should shift to the west
over Texas and Southern Plains for Tuesday and Wednesday placing
the forecast area on the eastern periphery of the upper level
high. This should allow a series of weak upper level impulses to
slide down from the north on the eastern side of the ridge which
should allow for an increase in convective coverage both Tuesday
and Wednesday. Have chance POPs of 40 to 50 percent in place by
Wednesday when the influence of the ridge is expected to be
weakest. Temperatures will remain seasonably warm with highs
climbing into the lower to middle 90s each day.
The ridging is forecast remain in place across the Southeast and
South- Central United States on Thursday and Friday, but an
inverted upper level trough is expected to slide along the
southern periphery of this ridge and across the forecast area.
With an increase in vorticity and forcing aloft, convective
coverage should remain somewhat elevated at around 40 percent or
higher both days. Temperatures will also be near average with
highs climbing into the lower to middle 90s each day. Overall, a
very typical South Louisiana and Southern Mississippi Summer
pattern is expected throughout the forecast period.
Mainly VFR conditions are expected to prevail through Saturday
morning. The exceptions will be some patchy fog and low stratus over
areas of inland south Mississippi into adjacent southeast Louisiana
through about 13z Today, mainly impacting KMCB. Scattered SHRA/TSRA
are expected to develop again with daytime heating, and have placed
a PROB30 for TSRA in the afternoon across all TAF airports. 22/TD
Aside from thunderstorms, prevailing winds will remain generally
around 10 knots or less with seas 2 feet or less due to a persistent
ridge of high pressure the next five days. Late next week, a
tropical wave could approach the north Gulf coast region, and
that would likely bring a period of more inclement weather. 22/TD
DSS code: Green.
Activities: Jefferson Parish public safety support for Grand Isle.
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 94 73 95 74 / 40 30 50 30
BTR 95 75 94 74 / 40 30 50 30
ASD 94 78 92 78 / 40 30 50 30
MSY 93 78 93 78 / 40 20 50 30
GPT 91 79 91 79 / 40 30 40 20
PQL 92 78 91 78 / 40 30 30 20