Severe Thunderstorm Warning 249, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
330 PM CDT FRI SEP 1 2000

THE ETA MODEL APPEARS TO HAVE A DECENT HANDLE ON THE SITUATION AT
THE MOMENT...TARGETING THE AREA SURROUNDING THE MID/UPPER LOW OVER
AL AND A POCKET OF MID LEVEL MOISTURE OVER THE ALKLATEX REGION INTO
CENTRAL LA. A WEDGE OF DRY AIR OVER THE WRN HALF OF MS NOTED ON
SATELLITE HAS BEEN SUPPRESSING CLOUD COVER TODAY. WHILE THE MAIN
SURFACE TROUGH REMAINS ACROSS N CENTRAL LA INTO S CENTRAL MS...
ANOTHER CONVERGENCE BOUNDARY HAS DEVELOPED NEAR THE MS/LA BORDER
BETWEEN KBTR AND KMCB EXTENDING E INTO SE MS. IN ADDITION...RUC DATA
SHOWS AN 850 MB TROUGH BECOMING POSITIONED ACROSS THIS SAME AREA.
VISIBLE IMAGERY SHOWS SOME TCU/SMALL CBS JUST SW OF MCB.

WITH THIS IN MIND...IT APPEARS THERE WILL NOT BE A REPEAT OF THE
WIDESPREAD THUNDERSTORMS/MCS LIKE YESTERDAY. HOWEVER...WIDELY
SCATTERED TO SCATTERED THUNDERSTORMS SHOULD STILL DEVELOP ACROSS THE
REGION LATE THIS AFTERNOON AND EVENING WITH THE -8 TO -12 LIFTED
INDICES SUPPORTING SEVERE THUNDERSTORMS. WILL INCLUDE A REMAINDER OF
THIS AFTERNOON GROUPING TO ACCOUNT FOR THIS.

THE MODELS SHOW THE UPPER LOW MEANDERING NEAR THE LA/GA BORDER
THROUGH SUNDAY...THEN THE LOW SLOWLY FILLS AND MAYBE DRIFTS SOUTH
TOWARDS THE GULF SUNDAY NIGHT INTO TUESDAY. OUR FORECAST AREA WILL
REMAIN IN A GRADIENT REGION OF MOISTURE BETWEEN DRY AIR OVER THE
LOWER MS VALLEY THE MOIST AIR NEAR THE LOW. AT THE SURFACE...A
SURFACE TROUGH WILL REMAIN W-E ACROSS THE GULF COAST REGION WHICH
WILL CONTINUE TO BE A FOCUS FOR THE CONVECTION. LOOKING AT HOW
THINGS ARE DEVELOPING TODAY...WILL TWEAK THE POPS A LITTLE LOWER...
BUT STILL KEEP THEM IN 20 TO 40 PERCENT RANGE THROUGH SUNDAY.

REGARDING THE HEAT AND TEMPERATURES...DRY AIR AND LITTLE CLOUD COVER
HAS ALLOWED THE TEMPERATURE TO SOAR TO 104 DEGREES AT MCB AT 3 PM
WITH THE DEWPOINT DOWN TO 61. MODEL GUIDANCE WILL CONTINUE HAVE A
PROBLEM WITH THE RECORD HEAT WITH THE EXCEPTION OF THE ETA SURFACE
TEMPS WHICH ARE ACTUALLY TOO HIGH IN SOME AREAS. WILL CONTINUE TO GO
MORE WITH PERSISTENCE RATHER THAN THE MUCH COOLER FWC/FAN NUMBERS
FOR DAYTIME HIGHS. NIGHTTIME TEMPS SHOULD CONTINUE TO DROP BELOW
80... EXCEPT NEW ORLEANS AND COASTAL AREAS COULD STAY UP NEAR 80 IF
RAIN DOES NOT COOL THINGS DOWN AND WINDS STAY UP.

FOR THE EXTENDED PERIOD...STATUS QUO LOOKS GOOD ON LABOR DAY...HEAT
WITH ISOLATED TO SCATTERED AFTERNOON THUNDERSTORMS. SOME SLIGHT
COOLING MAY OCCUR TUESDAY AND WEDNESDAY WITH SOME THICKNESS COOLING
OCCURRING WITH A SHARPENING TROUGH OVER THE ERN U.S.

MCB 070/103/070/102 2222   BTR 074/101/074/100 2322
MSY 076/097/077/096 3333   GPT 074/095/075/093 3334

.NEW...NONE
.LA...NONE.
.MS...NONE.

22