Severe Thunderstorm Warning 46, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
330 PM CST WED MAR 26 2003

IR IMAGERY SHOWED AN ANTICYCLONIC CIRCULATION OVER SOUTHWEST
LOUISIANA AND COASTAL WATERS. WATER VAPOR IMAGERY REVEALED DRY AIR
ENTRAINMENT ON THE BACKSIDE OVER SOUTH CENTRAL LOUISIANA TOWARD LAKE
PONTCHARTRAIN. LATEST SURFACE ANALYSIS CONTINUE TO SHOW THE FRONTAL
BOUNDARY FROM JUST SOUTH OF HATTIESBURG TO MCCOMB TO JUST EAST OF
MORGAN CITY. IN ADDITION...A BROAD SURFACE LOW WAS LOCATED OVER
NORTH CENTRAL GULF.

SHORT RANGE MODELS ARE HAVING SOME PROBLEMS PLACING THE MID LAYER
DRY AIR THIS FAR NORTH...HOWEVER UPPER LEVEL COOL CORE CIRCULATION
IS EXPECTED TO TRACK ACROSS THE FORECAST ARE TONIGHT WITH SCATTERED
SHOWERS AND A FEW THUNDERSTORMS. THE NEXT UPPER LEVEL SYSTEM WILL
CONTINUE TO PLOW INTO WASHINGTON AND OREGON. SEVERAL STRONG
DISTURBANCES AHEAD OF THE MAIN TROUGH WILL TRACK NORTHEAST AS THE
TROUGH BECOMES A LONG WAVE TROUGH FROM THE GREAT LAKES TO TEXAS
COAST FRIDAY INTO SATURDAY. SUBTROPICAL JET PULLS NORTH AS THE MAIN
TROUGH APPROACHES SOUTHEAST CONUS. HOWEVER...VERTICAL VELOCITY/OMEGA
INCREASES JUST TO THE EAST OF THE FORECAST AREA SATURDAY. TROUGH IS
COMING IN POSITIVELY TILTED...SO WILL HOLD OFF ON SEVERE WORDING FOR
NOW. THE ASSOCIATED SURFACE LOW OVER THE PLAINS CURRENTLY WILL
REMAIN STATIONARY TIL THE TROUGH TRACKS EAST. THE LOW WILL TRACK
NORTHEAST TOWARD THE GREAT LAKES FRIDAY DRAGGING A COLD FRONT ACROSS
THE FORECAST AREA BETWEEN 03 AND 15Z SATURDAY. SIGNIFICANT COLD AIR
ADVECTION BEHIND THE FRONT WITH THICKNESS VALUES FROM 1000 TO 500MB
DROPPING FROM 5630 METER FRIDAY MORNING TO GENERALLY 5330 TO 5420
METERS BY SUNDAY MORNING. COASTAL WATER AND TIDAL LAKE TEMPS NEAR
70F WILL CREATE LOW LEVEL INSTABILITY ABOVE THE WATER. STRONG NORTH
WINDS AND ROUGH WAVES AND SEAS CAN BE EXPECTED EARLY SATURDAY
THROUGH SUNDAY. ZONAL FLOW WILL REPLACE THE LONG WAVE TROUGH SUNDAY
THROUGH TUESDAY. A CLIPPER WILL TRY TO DRIVE A WEAK DISTURBANCE INTO
THE MID SOUTH LATE WEDNESDAY. WILL KEEP THE FORECAST DRY SUNDAY
THROUGH WEDNESDAY.

HERE ARE SOME NUMBERS TO PONDER:

MCB BB 052/078 055/077 055 400
BTR BB 054/079 057/079 056 400
MSY EA 058/077 058/080 058 400
GPT EA 055/077 059/077 058 400=

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

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LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-271230-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1030 AM CST WED MAR 26 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 ACROSS AREAS
MAINLY OVER SOUTHWEST MISSISSIPPI AND SOUTHEAST LOUISIANA AS A COLD
FRONT APPROACHES FROM THE NORTHWEST. A FEW OF THE THUNDERSTORMS WILL
PRODUCE OCCASIONAL LIGHTNING AND BRIEF HEAVY RAINFALL. IN
ADDITION...COOLER TEMPERATURES IN THE MID LAYERS OF THE ATMOSPHERE
WILL BE CONDUCIVE FOR SMALL HAIL FROM A VERY FEW STRONG
THUNDERSTORMS THIS AFTERNOON. THE HAIL SIZE SHOULD REMAIN BELOW
THREE QUARTERS OF AN INCH IN DIAMETER OR BELOW SEVERE LIMITS.
OTHERWISE...HAZARDOUS WEATHER IS NOT EXPECTED THIS AFTERNOON OR
TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP WITH ANOTHER COLD FRONT
MOVING THROUGH FRIDAY NIGHT INTO EARLY SATURDAY MORNING. HAZARDOUS
WEATHER CONDITIONS ARE POSSIBLE FRIDAY NIGHT AS A STRONG DISTURBANCE
ALOFT AND COLD FRONT MOVE INTO THE AREA. STRONG WINDS ASSOCIATED
WITH THIS FRONTAL PASSAGE WILL PROMPT THE ISSUANCE OF A SMALL CRAFT
ADVISORY ACROSS THE TIDAL LAKES IN LOUISIANA AND COASTAL WATERS
FRIDAY THROUGH SUNDAY MORNING. HAZARDOUS WEATHER CONDITIONS ARE NOT
EXPECTED THURSDAY OR SUNDAY AFTERNOON THROUGH TUESDAY.

.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.

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