Severe Thunderstorm Warning 166, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
320 AM CDT THU AUG 10 2000

UPPER AIR ANALYSIS OF 00Z DATA SHOWS AN AMPLIFYING PATTERN BEGINNING
TO TAKE SHAPE AS THE MODELS ADVERTISED. THE 200 AND 500 MB HIGH
PRESSURE CENTERS HAVE SHIFTED NORTH AND EAST WITH A STRONG TROUGH
BUILDING INTO THE NE US. AT 850 AND 700 MB THE AREA OF HIGH PRES HAS
EXPANDED WEST AND SLIGHTLY NORTH AS A REFLECTION OF THE UPPER
LEVELS. THIS HAS LET A 500 MB TROUGH MOVE ACROSS THE NE GULF WITH AN
ASSOCIATED AREA OF 200 MB DIVERGENCE. AHEAD AND ALONG OF THIS
FEATURE THE LIX WSR88D SHOWING 30 TO 40 PERCENT COVERAGE OF SHOWERS
AND A FEW THUNDERSTORMS IN COASTAL MS MOVING WSW AT 8Z.

THE 00Z MODEL RUNS BACK OFF IN THEIR FORECASTS OF THE 200 MB
DIVERGENCE FIELDS ACROSS THE SE PORTIONS OF THE AREA WITH THEIR
FORECASTS SHOWING THE MOST FAVORABLE DIVERGENCE PATTERN FROM 18 TO
00Z TODAY. PROBLEM WILL BE WHERE THIS EARLY MORNING CONVECTION WILL
LEAVE OUTFLOW BOUNDARIES AND HOW AIRMASS WILL RECOVER OVER COASTAL
MS. OTHER THAN THESE CONCERNS THE EVENING NEWAFDNEW DISCUSSION FROM
WED LOOKS ON TRACK WITH ONLY QUESTION BEING JET DYNAMICS. WILL HOLD
TEMPS AT LEVELS NEAR WED HIGHS AND WILL TREND POPS FROM 50 AT GPT TO
30 AT BTR. WILL CONTINUE CHANCE CATEGORY POPS SOUTH OF LAKE TONIGHT
WITH TROPICAL INFLUENCE.

NEXT FEATURE OF IMPORTANCE IS IN THE EXTENDED PACKAGE FROM AVN/MRF WITH
NORTHERLY STEERING WINDS AND UPPER LEVEL SUPPORT PUSHING A FRONT
INTO SE LA ON SATURDAY. FOR LOCALES NORTH OF THE LAKE WILL GO WITH
ISOLATED ON SUN AS AVN AND PANELS OF THE MRF SHOW DRIER AIR BEHIND
THE SYSTEM. WILL KEEP CHANCE WORDING FOR PRECIPITATION FORECAST
THROUGH THE EXTENDED PACKAGE SOUTH OF LAKE AND ALONG COAST AS FRONT
IS EXPECTED TO REMAIN IN THE VICINITY.

MCB 96/72/96/71 4241    BTR 95/74/94/73 3231
MSY 95/75/94/74 4341    GPT 91/74/93/73 5241

.NEW...NONE
LA...NON/E
MS...NONE.

13

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-111200-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1110 AM CDT THU AUG 10 2000

AN UPPER LEVEL DISTURBANCE AND COMPLEX OF THUNDERSTORMS OVER THE
NORTH CENTRAL GULF OF MEXICO JUST SOUTH OF THE SOUTHEAST LOUISIANA
COAST WILL MOVE SOUTHWEST TODAY. ANOTHER UPPER LEVEL DISTURBANCE
WILL APPROACH THE CENTRAL GULF COAST REGION FROM THE NORTHEAST LATE
TODAY AND TONIGHT.

WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON AS THE AIRMASS BECOMES VERY UNSTABLE. THUNDERSTORMS WILL
BECOME MORE NUMEROUS AND LOCALLY STRONG TO NEAR SEVERE LIMITS NEAR
THE TIDAL LAKES AND COAST WHERE THUNDERSTORM OUTFLOW BOUNDARIES
INTERSECT THE SEA BREEZE. THE STRONGEST THUNDERSTORMS WILL PRODUCE
WIND GUSTS UP TO 50 MILES PER HOUR...LOCALLY HEAVY RAIN AMOUNTS UP TO
3 INCHES AND FREQUENT LIGHTNING. ORGANIZED SEVERE THUNDERSTORMS ARE
NOT EXPECTED THROUGH TONIGHT.:

FOR MORE WEATHER INFORMATION VISIT OUR WEB-SITE AT
WWW.SRH.NOAA.GOV/LIX (ALL LOWER CASE).