Severe Thunderstorm Warning 685, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
300 PM CDT MON AUG 18 2003

MAIN FORECAST CHALLENGES REMAIN THE HEAT IN THE SHORT TERM AND THE
CHANCES OF PRECIP THROUGHOUT THE ENTIRE FORECAST PERIOD.

HEAT INDICES CONTINUE AROUND 105 IN NORTHWEST AREAS.
HOWEVER...OVERNIGHT MINS CONTINUE IN THE LOWER TO MIDDLE 70S. THIS
LOOKS TO BE THE TREND AT LEAST THROUGH THURSDAY.

FOR THE FIRST PERIOD...SCATTERED SHOWERS AND THUNDERSTORMS HAVE
CONTINUED TO DEVELOP OVER THE EASTERN HALF OF THE CWFA...ISOLATED IN
THE SOUTHWEST. WILL MORE THAN LIKELY HAVE 30% POPS IN THE
EAST...HOWEVER LAST MINUTE ADJUSTMENTS MAY BE MADE ACCORDING TO
RADAR TRENDS BEFORE ISSUANCE.

HIGH PRESSURE RIDGE POSITIONED SOUTHWEST TO NORTHEAST OVER THE CWFA
WILL CONTINUE THROUGH THURSDAY. SHORTWAVES WILL CONTINUE TO ROTATE SOUTHWEST
OVER THE CWFA AROUND THE PERIPHERY OF THE HIGH CENTER.
UNFORTUNATELY...THESE SHORTWAVES ARE VERY HARD TO TIME AND ARE NOT
PROGGED ALIKE BY THE MODELS. THE FIRST SHORTWAVE IS PROGGED TO
APPROACH NORTHEAST PORTIONS OF THE CWFA DURING THE EARLY TUESDAY
MORNING AND CONTINUE SOUTHWEST ACROSS THE REMAINDER OF THE CWFA
DURING MAX HEATING. THE SECOND SHORTWAVE IS PROGGED TO APPROACH
WEDNESDAY NIGHT AND CONTINUE THROUGH THE CWFA. BY LATE THURSDAY A
WEAKNESS IN THE RIDGE FORMS AND A TROUGH BEGINS DIGGING OVER THE
EAST BY EARLY FRIDAY. TROUGH BEGINS TO DIG AND THE MRF DEVELOPS AN
UPPER LOW OVER THE EASTERN HALF OF THE CWFA BY THE LATTER HALF OF
THE WEEKEND. THIS FEATURE WILL BECOME THE FOCUS FOR CONVECTION INTO
THE EARLY PART OF NEXT WEEK.

AT THE SURFACE...BACKDOOR FRONT TRIES TO SLIP IN OVER EASTERN PARTS
OF THE FORECAST AREA BEGINNING LATE TONIGHT INTO THE EARLY MORNING.
CONSIDERING THE ETA BRINGS A SHORTWAVE SOUTHWEST ALONG THE
BOUNDARY...THIS LOOK FEASIBLE. BOUNDARY LOOKS TO REMAIN IN PLACE AND
SLOWLY WEAKEN THROUGH LATE TUESDAY. THIS BOUNDARY WILL SERVE...ALONG
WITH THE SHORTWAVES...TO FOCUS CONVECTION OVER THE FORECAST AREA
UNTIL LATE IN THE WEEK WHEN ANOTHER FRONTAL BOUNDARY BEGINS
APPROACHING...JUST IN TIME FOR THE WEEKEND. BY 12Z FRIDAY THE
BOUNDARY LOOKS TO APPROACH THE MISSISSIPPI RIVER AND SLOWLY MOVE
SOUTH AND WEAKEN THROUGH THE WEEKEND. BY MONDAY...THE 500MB LOW IS
SITTING OVER THE EASTERN HALF OF THE STATE...WITH AN INVERTED TROUGH
UNDERNEATH. NOT REAL SURE THIS IS GOING TO PAN OUT...BUT WILL KEEP
POPS AT LEAST 30% THROUGH THE EXTENDED IN THE AFTERNOON. NO MAJOR
CHANGES TO THE EXTENDED FORECAST WERE MADE...HOWEVER A FEW TWEAKS
FOR TEMPS AND POPS WERE NECESSARY.

JAN BB 074/095 073/093 073 00243
    BBBBB 092/073 092/071 091/069 090/068 090 32323232323
MEI BB 073/094 072/092 072 00343
    BBBBB 092/072 091/071 091/069 090/067 090 42423232323

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

32/LISTEMAA

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
192041-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
341 PM CDT MON AUG 18 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL MISSISSIPPI...
NORTHEAST LOUISIANA...AND EXTREME SOUTHEAST ARKANSAS

.DAY ONE...TONIGHT AND TUESDAY...

...THUNDERSTORMS...
THUNDERSTORMS WILL BE SCATTERED OVER EAST MISSISSIPPI THIS
EVENING. THUNDERSTORMS WILL BE ISOLATED ACROSS SOUTHEAST
ARKANSAS...NORTHEAST LOUISIANA AND WEST MISSISSIPPI THIS EVENING.
THUNDERSTORMS WILL BE SCATTERED OVER ALL OF THE REGION TUESDAY.
SEVERE STORMS ARE NOT LIKELY THROUGH TOMORROW.

THUNDERSTORMS WILL SCATTERED OVER EAST MISSISSIPPI THIS
EVENING... ESPECIALLY EAST OF A LINE FROM GRENADA TO JACKSON TO
MONTICELLO. STORMS WILL REMAIN MORE ISOLATED IN NATURE WEST OF
THIS LINE. THE AIR MASS IS HUMID AND VERY UNSTABLE AND AFTERNOON
HEATING WILL PRODUCE SCATTERED TO ISOLATED CONVECTION. SEVERE
STORMS ARE NOT LIKELY BUT STRONG THUNDERSTORMS WILL HAVE THE
POTENTIAL FOR WIND GUSTS TO 40 MILES AN HOUR. THUNDERSTORMS WILL
DIMINISH IN COVERAGE AFTER SUNSET.

A VERY MOIST AIRMASS WILL REMAIN IN PLACE OVER THE LOWER
MISSISSIPPI VALLEY TUESDAY. THUNDERSTORMS WILL DEVELOP AGAIN
DURING THE AFTERNOON AND EVENING ACROSS SOUTHEAST
ARKANSAS...NORTHEAST LOUISIANA AND MUCH OF MISSISSIPPI.

...SEASONAL THREATS...
AFTERNOON HEAT INDICES WILL EXCEED 105 DEGREES OVER MOST OF THE
OUTLOOK AREA.

HIGH PRESSURE WILL CONTINUE JUST TO OUR WEST AND WILL ENHANCE DAY
TIME HEATING OVER THE LOWER MISSISSIPPI VALLEY REGION. THE
COMBINATION OF TEMPERATURES IN THE MID 90S AND HIGH RELATIVE
HUMIDITY...WILL RESULT IN HIGH HEAT INDICES DURING THE AFTERNOON.
PERSONS WORKING OUTDOORS THIS AFTERNOON SHOULD TAKE FREQUENT
BREAKS...AND DRINK PLENTY OF WATER TO HELP AVOID HEAT EXHAUSTION.

.DAYS TWO THROUGH SEVEN...TUESDAY NIGHT THROUGH MONDAY...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS...IS NOT ANTICIPATED THROUGH TONIGHT.

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