Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
FXUS64 KLIX 241634 AAA
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1134 AM CDT SUN JUL 24 2016
Updated grids and forecast products to lower high temperatures a
bit, to around 90 degrees, and increase rain chances, primarily
over the coastal waters. Convective temperatures in the mid 80s
have made development of showers and thunderstorms fairly common.
No changes to later periods of the forecast at this time. 35
.PREV DISCUSSION... /issued 814 AM CDT SUN JUL 24 2016/
The sounding this morning continues to depict a moist and unstable
atmosphere. PW is at 2.0 inches and mixed layer CAPE is at 2100
J/KG. With a warm cloud depth of about 15000 feet storms will
again have the opportunity to be heavy rain makers. The 500 mb
temperature is very warm at -5 C... and indicative of a tropical
profile. Winds are westerly from the sfc to 850 mb then switch to
easterly but remain light.
PREV DISCUSSION... /issued 400 AM CDT SUN JUL 24 2016/
Two upper highs over the southern conus this morning. The
interesting thing about these is that one is maritime and the
other is continental. It`s easy to tell which is which. The upper
maritime high will help cool convective temps back today from 94
around noon to 90 by late afternoon. As the upper maritime high
moves south today, it will also help in the development of a weak
surface trough over the northern gulf today and Monday. We should
see plenty of convection over the northern gulf from this with
plenty of waterspout activity. It will be possible to even see a
weak couterclockwise surface swirl in the cloud patterns over the
north central gulf today and Monday with all the sh/ts present.
Convective temps actually fall back into the mid to upper 80s by
Monday and gulf water temps near the coast will match this very
well as the water temps will help cause sh/ts to errupt quite
The major large scale supressive upper high over west Tx will
eventually absorb this mesoscale upper high and move back over
the Southwest. The monsoon season is in full swing as disturbance
after disturbance moves into Arizona and New Mexico. The synoptic
scale upper high over west Tx is the main steering current for all
these disturbances bringing them out of the desert southwest into
the central conus then down into our area. This is where our
current meso upper maritime high that will affect us today and
Monday comes from. Once these features are able to get over an
area of deeper moisture, the fireworks begin and we have plenty
today at almost 2.25" pw values.
After today, the line of TUTT lows will begin to make their way
across the gulf. The first has already broke away from its parent
upper trough over the east coast and is now on its way across Fl.
This will help keep sh/ts chances high for Monday and Tuesday.
The upper low becomes more linear and shears out as it moves west
by Tuesday while the next upper low will then begin to make its
voyage across the gulf. That one is located just west of Puerto
Rico this morning. This should keep sh/ts chances high for
Wednesday and Thursday. Next weekend may see some what drier
conditions but hot as some dry air may move over the area from the
A few showers and thunderstorms have developed along the Louisiana
coast and over the Gulf of Mexico this morning. Currently all
terminals are reporting VFR conditions and expect that to continue
through the morning hours. We do expect showers and thunderstorms to
develop this afternoon and that could take some terminals down to
IFR conditions for a short time. Outside of the thunderstorms most
places should see mainly VFR conditions. 13/MH
No changes to the forecast. A fairly stagnant summer pattern with
regards to winds and waves will remain in place with generally a
weak ridge of high pressure extending west from the Bermuda high to
the east and north Gulf coast. One feature of concern will be a
easterly wave feature that will move near the central Gulf coast
Monday into Tuesday. Lines or clusters of thunderstorms could become
active during that period which will also be associated with locally
much stronger winds and high waves. Waterspouts will also be
possible during shower and thunderstorm development. 22/TD
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 89 74 91 73 / 60 30 50 20
BTR 90 75 91 74 / 60 30 60 20
ASD 89 77 91 76 / 60 30 50 20
MSY 89 78 90 76 / 60 30 60 30
GPT 88 78 90 77 / 50 30 50 20
PQL 88 77 91 76 / 50 30 50 20