Severe Thunderstorm Warning 103, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
335 PM CDT TUE JUN 3 2003

SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND THE ETA/NGM CONTINUE TO
BE THE BIGGEST FORECAST CHALLENGE...PARTICULARLY DURING THE
WEDNESDAY THROUGH THURSDAY PERIOD. LOOKING AT THE SHORT TERM...THE
MODELS ARE NOT HAVING ANY MAJOR INITIALIZATION PROBLEMS...SO IT IS
HARD TO DETERMINE WHICH MODEL TO HANG YOUR HAT ON. THE ETA APPEARS
TO BE CLOSEST AT 18Z WITH THE SURFACE DEWPOINTS NEAR THE SURFACE
COLD FRONT ACROSS NORTHEAST/CENTRAL LA...BUT THE GFS MAY BE A BIT
BETTER DRIVING THE DRIER AIR ON A MORE SOUTHERN TRAJECTORY. FOR
NOW...WILL COMPROMISE AND GO WITH AN ETA/GFS BLEND.

DISTURBANCES MOVING IN NORTHWEST/WEST FLOW ACROSS THE CENTRAL GULF
COAST REGION WILL CONTINUE TO INTERACT WITH A MOIST UNSTABLE AIRMASS
AND DAYTIME HEATING. CURRENT CLUSTERS AND LINES OF SHOWERS AND
THUNDERSTORMS SHOULD DIMINISH BEFORE SUNSET TONIGHT LEAVING ONLY
ISOLATED SHOWERS AND THUNDERSTORMS AFTER 7 PM. ON WEDNESDAY...THE
GFS DRIES OUT PW/S TO AROUND 1.5 INCHES WHILE THE ETA/NGM KEEP
VALUES UP NEAR 2 INCHES. PREFER THE MORE NORTHERN POSITION OF THE
COLD FRONT ADVERTISED BY THE ETA. THIS BRINGS THE FRONT INTO COASTAL
MISSISSIPPI AND THE FLORIDA PARISHES OF SOUTHEAST LA ON WEDNESDAY
AND THURSDAY BEFORE THE BOUNDARY RETREATS NORTH ON THURSDAY. WITH
THE BOUNDARY IN PLACE NORTH AND DEEPER MOISTURE HANGING ON AT LEAST
IN THE SOUTHERN ZONES...WILL KEEP BUMP POPS UP INTO THE CHANCE
CATEGORY (30 PERCENT) ON WEDNESDAY. THIS MAY HAVE TO RAISED CLOSER
TO 50 PERCENT LATER IF DRIER AIR DOES NOT FILTER IN AS MUCH AS THE
GFS INDICATES. THIS SAME ARGUMENT APPLIES ON THURSDAY...SO WILL
MAINTAIN LOW CHANCE POPS WHICH IS HIGHER THAN THE DRY GFS AND LOWER
THEN THE WET ETA/NGM.

FRIDAY INTO SUNDAY...UPPER LEVEL SHORTWAVE TROUGHS MOVING FROM
SOUTHWEST TO NORTHEAST ARE EXPECTED TO TRAVERSE THE FORECAST AREA
WITH DEEP TROPICAL MOISTURE STREAMING IN FROM THE SOUTH. WILL
CONTINUE MENTION OF A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
WILL ALSO KEEP THIS CHANCE OF CONVECTION IN ON MONDAY AND TUESDAY AS
ANOTHER WEAK COLD FRONT MAY GET PUSHED BACK SOUTH INTO THE FORECAST
AREA.

MCB 67/87/66/87 1323    BTR 70/88/67/88 1323
MSY 72/88/72/88 2323    GPT 71/87/68/87 2323

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

22

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-041100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1110 AM CDT TUE JUN 3 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST LOUISIANA AND
EXTREME SOUTHWEST AND COASTAL MISSISSIPPI.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EARLY
TONIGHT AS A DISTURBANCE ALOFT MOVES SOUTHEAST INTO THE LOWER
MISSISSIPPI VALLEY AND ENCOUNTERS INCREASING MOISTURE AND
INSTABILITY.  AT THIS TIME...SEVERE WEATHER IS NOT EXPECTED.
HOWEVER...LOCALLY HEAVY RAINS OF ONE TO TWO INCHES IN A SHORT PERIOD
OF TIME WILL BE POSSIBLE MAINLY THIS AFTERNOON AND EARLY TONIGHT.
STRONG GUSTY WINDS TO 40 MPH...SMALL HAIL...AND FREQUENT LIGHTNING
WILL BE LIKELY WITH THE STRONGER STORMS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

STRONG THUNDERSTORMS AND HEAVY RAINFALL WILL BE POSSIBLE OVER
SOUTHWESTERN MISSISSIPPI AND PORTIONS OF EAST CENTRAL AND SOUTHEAST
LOUISIANA THIS WEEKEND AS ANOTHER STRONG DISTURBANCE ALOFT AND AN
ASSOCIATED WEAK COLD FRONT MOVES EAST INTO THE LOWER MISSISSIPPI
VALLEY.

.SPOTTER INFORMATION STATEMENT...

THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS AND EMERGENCY
MANAGEMENT PERSONNEL...IN SUPPORT OF SEVERE WEATHER OPERATIONS...IS
NOT REQUESTED AT THIS TIME.