Severe Thunderstorm Warning 232, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
246 PM CDT WED JUL 03 2002

FORECAST PROBLEMS THIS PACKAGE...
SHOWER AND THUNDERSTORM CHANCES
TEMPERATURES AND PRECIP CHANCES (EXTENDED)

FOR THE VERY NEAR-TERM...I AM CONCERNED ABOUT THE COLDER
TEMPERATURES PRESENT AT 500 MB EAST OF THE FORECAST AREA.  I FEEL
THAT SOME OF THIS COLDER MID-TROPOSPHERIC AIR COULD WORK ITS WAY
INTO THE FORECAST AREA THIS EVENING AND STEEPEN AREA LAPSE RATES IN
ADVANCE OF AN APPROACHING SHORTWAVE.  LAPS DATA INDICATES THE
HIGHEST CAPE VALUES ACROSS THE WESTERN HALF OF THE AREA.  FEEL THAT
ANY CONVECTION THAT DEVELOPS OVER (ESPECIALLY NORTHWEST) ALABAMA
THIS AFTERNOON COULD MAKE IT INTO OUR AREA TONIGHT.  FORCING IN OUR
AREA WILL CONTINUE TO BE ENHANCED BY VARIOUS OUTFLOW BOUNDARIES AND
THE PERSISTENT (PESKY?) 500-700 MB SHEAR AXIS.  ILL PLAN ON USING
SCATTERED COVERAGE IN THE FIRST PERIOD...BUT AS USUAL WILL BASE
RAIN CHANCES ON ONGOING RADAR TRENDS.

IN GENERAL...THIS MORNINGS MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
EACH OTHER...WITH ONLY MINOR DIFFERENCES.  THE AVN IS SLIGHTLY
WEAKER WITH RIDGING IN THE MIDWEST...AND ETA/MESO-ETA CONTINUES WITH
A BETTER REPRESENTATION OF THE 500-700 MB SHEAR AXIS.

THE GOOD NEWS?  THE MID- AND UPPER-LEVEL SHEAR AXIS WILL GRADUALLY
WEAKEN FOR THE FOURTH.  UNFORTUNATELY...AS THIS OCCURS...A
SHORTWAVE...EVIDENT IN WATER VAPOR IMAGERY OVER THE WESTERN
CAROLINAS THIS MORNING...WILL MOVE INTO THE FORECAST AREA THURSDAY.
WITH A WEAK SURFACE PRESSURE TROUGH IN PLACE (CLOSE TO INTERSTATE
20) AND PRECIPITABLE WATERS REMAINING GREATER THAN 100 PERCENT OF
NORMAL...A SLIGHTLY BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED.  ILL TENTATIVELY PLAN TO REMOVE ANY AFTERNOON/EVENING
WORDING IN THE CURRENT ZONES.

FURTHER EAST...SURFACE LOW PRESSURE WILL DEVELOP OVER SOUTHEAST
ALABAMA THURSDAY NIGHT THEN BEGIN TO MOVE WEST ACROSS THE NORTHERN
GULF.  I EXPECT OUR AREA TO BEGIN FEELING THE INFLUENCE OF THIS
SYSTEM POSSIBLY AS SOON AS EARLY FRIDAY MORNING AS INCREASING
AMOUNTS OF GULF MOISTURE ARE PUMPED INTO THE REGION.  KNOWING THIS
AND THE CONTINUED INFLUENCE OF THE SHORTWAVE (ESPECIALLY SOUTH)...I
WILL CONTINUE SCATTERED-TYPE WORDING FOR FRIDAY AND SATURDAY FOR
MOST PLACES.

THE MEDIUM-RANGE MODELS ARE FAIRLY CONSISTENT WITH THEIR SOLUTION
FROM YESTERDAY...AND ARE IN GOOD AGREEMENT WITH EACH OTHER.  IT
APPEARS AS IF THE AVN EXTENDED WANTS TO HAVE THE UPPER RIDGE AXIS
SLIGHTLY FURTHER WEST THAN YESTERDAY...WHILE THE CANADIAN MAINTAINS
STRONGER UPPER RIDGING OVER OUR NECK OF THE WOODS.  SURFACE LOW IS
MOVING ACROSS THE NORTHERN GULF A LITTLE SLOWER THAN EXPECTED
YESTERDAY...SO I DONT KNOW IF WE CAN KEEP A TOTALLY DRY FORECAST
FOR THE SUNDAY/MONDAY TIME FRAME.  A COLD FRONT IS STILL FORECAST TO
APPROACH THE NORTHERN PART OF OUR FORECAST AREA TUESDAY...THEN SLOW
DOWN A BIT AS IT WAITS FOR A 500 MB LONGWAVE TROUGH TO APPROACH FOR
THE END OF THE WEEK.  AT ANY RATE...ILL PLAN ON BUMPING TUESDAY AND
WEDNESDAY UP TO CHANCE WORDING WITH THE APPROACH OF THE FRONT.

PRELIMINARY NUMBERS FOLLOW BELOW.

FCSTID = 10
JAN   72  90  72  93 /  30  50  40  30
MEI   70  90  72  92 /  40  50  40  40

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

BUTTS

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
041200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
235 PM CDT WED JUL 03 2002

...THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON
AND EVENING OVER PORTIONS OF NORTHEAST LOUISIANA...SOUTHEAST
ARKANSAS...AND MUCH OF MISSISSIPPI. ISOLATED SEVERE STORMS ARE
POSSIBLE...WITH WIND GUSTS TO 60 MPH.

A VERY MOIST AND UNSTABLE AIRMASS CONTINUES OVER THE LOWER
MISSISSIPPI RIVER VALLEY. THIS AIRMASS...COMBINED WITH HEATING
WILL CONTRIBUTE TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. A WEAK UPPER LEVEL DISTURBANCE WILL HELP TO
MAINTAIN ANY ACTIVITY THROUGH MIDNIGHT.

THE ACTIVATION OF EMERGENCY MANAGEMENT PERSONNEL AND STORM
SPOTTERS SHOULD NOT BE NEEDED THROUGH TONIGHT.

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.SRH.NOAA.GOV/JAN. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.