Severe Thunderstorm Warning 471, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
318 AM CDT THU SEP 26 2002

FORECAST PROBLEM THIS PACKAGE:
TROPICAL STORM ISIDORE

SATELLITE IMAGERY OVER THE PAST SEVERAL HOURS HAS SHOWN COOLING
CLOUD TOPS AS CONVECTION FIRED AROUND THE CENTER OF TROPICAL STORM
ISIDORE.  AREA RADARS HAVE SHOWN PERSISTENT RAINBANDS MOVING OVER
MUCH OF THE FORECAST AREA...WITH THE HEAVIEST CONVECTION MAINLY
CONFINED TO THE COAST.  AREA RADARS SHOW ISIDORES CENTER IN EASTERN
TERREBONE PARISH...NEAR THE LOUISIANA COAST.

NOW THAT ISIDORE APPEARS TO BE ONSHORE...THE NUMERICAL WEATHER
MODELS ARE POINTING TOWARD A COUPLE OF DIFFERENT SCENARIOS.  THE ETA
FORECASTS THE STORMS CENTER TO SLOW FOR A WHILE OVER SOUTH
MISSISSIPPI...THEN MOVE NORTH-NORTHEAST.  MEANWHILE...THE AVN
DOESNT BOTHER SLOWING ISIDORE DOWN.  I PLAN ON LEANING MORE TOWARD
THE AVN...SINCE ITS TRACK HAS BEEN MORE CONSISTENT AND HAS
TRADITIONALLY DONE BETTER WITH LANDFALLING TROPICAL SYSTEMS.

OVERALL...THE ONGOING FORECAST APPEARS TO BE ON TARGET.  I WILL MAKE
A FEW CHANGES TO THE CURRENT ADVISORIES IN PLACE OVER MUCH OF THE
FORECAST AREA.  WINDS AROUND THE CENTER OF THE SYSTEM SHOULD
DIMINISH AS THE STORM ENCOUNTERS THE ADDITIONAL FRICTION OF THE LAND
SURFACE AND BEGINS MOVING NORTH-NORTHEAST.  HOWEVER...WINDS OF 20 TO
30 MPH WITH GUSTS TO TROPICAL STORM FORCE MAY BE SEEN OVER THE
FORECAST AREA...ESPECIALLY OVER OUR SOUTHEASTERN COUNTIES.  WINDS
SUCH AS THESE SHOULD CONTINUE NEAR THE CENTER OF THIS SYSTEM AS IT
MOVES ACROSS THE FORECAST AREA (PER COORDINATION WITH THE HURRICANE
CENTER).  I DO NOT THINK OUR FORECAST AREA WILL RECEIVE SUSTAINED
TROPICAL STORM FORCE WINDS...AND WILL NOT RE-ISSUE THE INLAND
TROPICAL STORM WATCH.  BUT...WELL PLAN ON KEEPING A WIND ADVISORY
IN EFFECT FOR MUCH OF CENTRAL AND SOUTH MISSISSIPPI.  THIS AREA WILL
BE GENERALLY SOUTH OF A SCOOBA TO PICKENS TO REDWOOD MISSISSIPPI
LINE.

RAINBANDS WILL CONTINUE MOVING OVER MOST OF THE FORECAST AREA
TODAY.  SINCE FLASH FLOOD GUIDANCE VALUES ARE LOW OVER THE
REGION...I PLAN ON KEEPING THE STATUS QUO WITH THE FLOOD WATCH
THROUGH TODAY.  ADDITIONAL RAINFALL OF AROUND 3 TO 5 INCHES MAY BE
POSSIBLE WITH THIS SYSTEM...ESPECIALLY EAST OF WHERE THE CENTER
MOVES.

WIND SHEAR VALUES WILL BE SUFFICIENT TO SUSTAIN A THREAT OF ISOLATED
TORNADOES OVER PARTS OF THE FORECAST AREA TODAY...MAINLY ALONG AND
TO THE EAST OF WHERE THE CENTER TRACKS.  0 TO 3 KM STORM-RELATIVE
HELICITY VALUES FROM OUR 0600 UTC SOUNDING SHOW 305 M2/S2.  THIS
VALUE SHOULD ONLY INCREASE AS THE LOW MOVES NORTHEAST AND WINDS VEER
AROUND TO THE SOUTHEAST.  PLEASE SEE STATEMENTS FROM THE STORM
PREDICTION CENTER FOR FURTHER DETAILS.

RAINFALL SHOULD GRADUALLY COME TO AN END TONIGHT AS ISIDORES
REMNANTS MOVE NORTHEAST OF THE FORECAST AREA AND DRIER AIR MOVES
INTO THE FORECAST AREA.  RIGHT NOW...IT LOOKS LIKE HIGH PRESSURE
WILL BUILD INTO THE AREA JUST IN TIME FOR THE WEEKEND.

DAYS 4 THROUGH 7 (SUNDAY THROUGH WEDNESDAY) LOOK OK...AND WILL NOT
MAKE ANY CHANGES AT THIS TIME.

THANKS GO OUT TO NHC...AND WFOS MOBILE AND SLIDELL FOR COORDINATION
THIS MORNING.

.JAN...
AR...NONE.
LA...NONE.
MS...FLOOD WATCH TODAY MSZ018-019-025>066-072>074.  WIND ADVISORY
TODAY MSZ043>066-072>074.

BUTTS