Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
FXUS64 KLIX 240109
Area Forecast Discussion
National Weather Service New Orleans LA
809 PM CDT SAT JUL 23 2016
An unstable and moist atmosphere persists over the region with
the precipitable water value near 2 inches. As the zone of high
pressure over the central Plains has moved back toward the Western
US, 500mb, 700mb, and 850mb temperature and heights are not
breaking records, but still well above normal. Winds have also
responded to the lessening influence of the high pressure with
winds above 700mb from the northeast.
00z balloon info: A routine flight reaching a height of 21.1 miles
above the ground bursting over the western part of Lake Maurepas
44 miles downrange from the office. The ascent lasted for 112
.PREV DISCUSSION... /issued 404 PM CDT SAT JUL 23 2016/
(Tonight through Tuesday night)...
The large mid/upper level high currently over the southwest to
central U.S. will gradually weaken and retrograde slightly through
early next week. An upper level maritime ridge just inland from
the central Gulf coast will also gradually move west while another
deep layer ridge develops near the mid to southern atlantic coast.
An easterly wave/inverted trough mainly in the mid to upper levels
will move across the region Monday into Tuesday. After having
fewer showers and thunderstorms (mostly isolated) around today,
it is anticipated that more scattered to possibly numerous
coverage will return each day through Tuesday, peaking over land
during late morning to afternoon and over water late at night into
the morning. The threat of severe thunderstorms will likely remain
low through the period, however, a few strong thunderstorms may
occur each day and even some at night with stronger gusty winds,
frequent lightning, and locally heavy rainfall.
(Wednesday through Saturday Night)...
The westerlies may become suppressed slightly due to a series of
shortwave troughs moving southeast and east across the upper
Mississippi valley and Great Lakes, however a narrow/weak
mid/upper level, maritime ridge should start to build across the
southern Atlantic coast with an axis into the north Gulf coast
region states. Since will be a maritime ridge, it is likely there
will remain scattered showers and thunderstorms, however coverage
should lower slightly late in the week. 22/TD
Widespread cumulus field in place, but most locations currently VFR.
Areal coverage of convection isn`t much more than 20-30 percent and
has been slow moving. Will continue to carry TEMPO for another
couple hours, but as happened yesterday, expect a diminishing trend
after about 22Z with most convection done prior to 00Z. Any
convection could have wind gusts to 30 knots and brief MVFR/IFR
conditions. Cannot rule out a brief period of MVFR visibilities due
to light fog around sunrise, but if this occurs, would likely be
limited to KHUM and KHDC. Will not include in forecast for now.
We will again see cumulus development Sunday morning 15-16Z with
scattered showers developing, much like this morning. TSRA mention
on Sunday likely to be after 18Z. 35
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 74 92 73 92 / 20 60 30 50
BTR 75 92 75 91 / 20 60 30 60
ASD 75 91 74 92 / 20 60 30 50
MSY 78 92 77 90 / 20 60 30 60
GPT 76 90 75 89 / 20 50 30 50
PQL 74 91 73 90 / 20 50 30 50