Severe Thunderstorm Warning 437, NWS Jackson, MS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
416 AM CDT MON AUG 19 2002

FORECAST PROBLEM THIS PACKAGE...
RAIN CHANCES MID-WEEK

THE EARLY MORNING SUBJECTIVE SURFACE ANALYSIS HAS A COLD FRONT
EXTENDING FROM THE CHICAGOLAND AREA...SOUTHWEST TO TOPEKA...TO A
SURFACE LOW JUST WEST OF GAGE OKLAHOMA.  CLOSER TO HOME...THE
WEATHER WORD IS RIDGING...AS HIGHER HEIGHTS CONTROL THE WEATHER IN
OUR NECK OF THE WOODS.

UNFORTUNATELY...THE FRONT WILL NOT MAKE IT THIS FAR SOUTH...AS
RIDGING WILL TEND TO KEEP MOST OF THE SHOWER AND THUNDERSTORM
ACTIVITY AT BAY EARLY THIS WEEK.  FOR TODAY...WITH PRECIPITABLE
WATER VALUES REMAINING GREATER THAN 100 PERCENT OF NORMAL AND
FALLING THETA SURFACES (INDICATING LARGE-SCALE SUBSIDENT
MOTION)...WIDESPREAD PRECIPITATION IS NOT EXPECTED OVER MUCH OF THE
REGION.  HOWEVER...EASTERN PARTS OF THE FORECAST AREA MAY SEE A
LITTLE BETTER COVERAGE THANKS TO SLIGHTLY ENHANCED UPWARD VERTICAL
MOTION DUE TO A LINGERING SHORTWAVE OVER ALABAMA.  ANYTHING THAT
FIRES THOUGH SHOULD DISSIPATE SHORTLY AFTER SUNSET.

AN EASTERLY WAVE IS FORECAST TO MOVE ACROSS THE NORTHERN GULF AT
MID-WEEK...AND MAKE LANDFALL IN SOUTH MISSISSIPPI.  AS THIS
OCCURS...PRECIPITABLE WATER VALUES WILL INCREASE TO 2 INCHES OR
GREATER ACROSS MOST OF THE FORECAST AREA WEDNESDAY.  HOWEVER...IM
NOT ALL THAT IMPRESSED WITH THE WAY THIS SYSTEM IS LOOKING AT THIS
TIME.  ISENTROPICALLY...THE UPGLIDE IS VERY WEAK ABOVE THE BOUNDARY
LAYER (310 K SURFACE AND ABOVE) WITH RELATIVELY HIGH CONDENSATION
PRESSURE DEFICITS.  FROM THE LOOKS OF THINGS...MOST OF THE ENHANCED
UPWARD VERTICAL MOTION IS CONFINED TO COASTAL AREAS SOUTH AND EAST
OF THE FORECAST AREA.  THINGS DO LOOK A LITTLE BETTER THROUGH THE
BOUNDARY LAYER AND BELOW...WITH WEAK UPGLIDE AND PRESSURE DEFICITS
OF 35 MB.  SO...WILL PLAN ON GOING WITH LOW GRADE CHANCE TERRITORY
OVER MOST OF THE FORECAST AREA WITH SLIGHTLY HIGHER RAIN CHANCES
ACROSS THE SOUTHERN TIER OF COUNTIES/PARISHES.

DAYS 4 THROUGH 7 LOOK TO BE IN GOOD SHAPE AND WILL NOT MAKE ANY
CHANGES AT THIS TIME.

PRELIMINARY NUMBERS FOLLOW BELOW.

FCSTID = 10
JAN   94  73  94  73 /  20  20  20  20
MEI   93  73  94  72 /  30  20  20  20

.JAN...
AR...NONE.
LA...NONE.
MS...NONE.

BUTTS

...UPDATED TO INCLUDE PRELIMINARY NUMBERS...