Severe Thunderstorm Warning 344, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
330 AM CDT TUE OCT 19 2004

.DISCUSSION...
QUASISTATIONARY SURFACE TROUGH DRAPED ACROSS AR THIS MORNING. LOW
LEVEL MOISTURE PUSH PERSISTS WITH DEWPOINTS FROM THE LOW TO MID 70S
ACROSS THE FORECAST AREA. MEAN SHEAR WILL REMAIN STRONG ACROSS THE
AREA TODAY WITH 500 MB WINDS REACHING 45-55 KT RANGE EARLY. OF
INTEREST IS FACT THAT MODELS AGREE IN LOCATING STRONGEST SHEAR SRN
ZONES THIS AFTERNOON. WILL SEE BEST INSTABILITY NWRN ZONES IN AREA
OF BEST CONVERGENCE DOWNSTREAM OF SURFACE BOUNDARY BUT AIR MASS WILL
DESTABILIZE ACROSS MUCH OF FORECAST AREA THIS AFTERNOON. STRONG JET
NOSES INTO THE AREA ALTHOUGH MODEL DIVERGENCE REMAINS LIMITED DURING
THE DAY. HEALTHY SHORTWAVE MOVING THIS WAY IN ZONAL FLOW SHOULD
OFFER SUFFICIENT DYNAMICS TO GET ACTIVITY STARTED. MAIN QUESTION
WILL BE HOW FAR SOUTH STRONGER CONVECTION WILL DEVELOP.

PRESSURE GRADIENT RELAXES A LITTLE TODAY. ALTHOUGH 30 KTS NOTED JUST
OFF GROUND ON 19/00Z SOUNDING...WILL REFRAIN FROM LAKE WIND ADVISORY
ISSUANCE BUT THIS WILL NEED TO BE WATCHED AGAIN TODAY.

MODELS DIFFER ON BOUNDARY LOCATION OVER NEXT SEVERAL DAYS...
BEGINNING TONIGHT. THE GFS SHIFTS THE FRONT SWD AS THE ETA MAINTAINS
NEARLY STATIONARY BOUNDARY OVERNIGHT...LIFTING IT NWD
WEDNESDAY. WILL WORK WITH GFS SOLUTION FOR NOW CONSIDERING MEAN
UPPER FLOW GRADUALLY VEERING TO THE NW WITH TIME...WHICH WILL MEAN
SLIGHTLY COOLER TEMPS TO THE REAR OF THE BOUNDARY FOR LATER IN THE
WEEK. WILL MAINTAIN SLIGHT CHANCE POPS FOR WEDNESDAY AS ANOTHER
WEAKER SHORTWAVE TRACKS THROUGH DURING THE DAY AND MODELS REMAIN
UNCERTAIN OF FRONTAL POSITION BY THAT TIME.

UPPER RIDGING AMPLIFYING UPSTREAM WEDNESDAY NIGHT. HIGH PRESSURE
ALOFT AND LOW LEVEL NWLY FLOW WILL CONTROL WEATHER THROUGH THURSDAY
NIGHT. 850 MB FLOW BACKS MORE SWLY FRIDAY AND UPPER RIDGE SLIDES
INTO ERN ZONES. WILL KEEP SLIGHT CHANCE AFTERNOON CONVECTION FOR
FRIDAY AFTERNOON. DYNAMICS LOOKING A BIT HEALTHIER THAN PREVIOUSLY
ADVERTISED FOR THE WEEKEND AS THE NEXT FRONT DROPS INTO NW
ARKANSAS...PRECEDED BY AN INCREASING THETAE FIELD NW ZONES. A
POSSIBLE SHORTWAVE ALSO NOTED ACROSS NRN ZONES BY SATURDAY
AFTERNOON. EVOLUTION OF SURFACE BOUNDARY UNCLEAR AT THIS TIME AND
REMNANTS OF THE BOUNDARY NOTED ACROSS CENTRAL ZONES SUNDAY WITH AN
UPPER JET NOSING INTO THE AREA. INCREASED SUNDAY POPS TO SLIGHT
CHANCE BUT LEFT MONDAY DRY DUE TO LOW CONFIDENCE IN FORCING FEATURES
FOR BEGINNING OF NEXT WEEK.

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
541 AM CDT TUE OCT 19 2004

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
201041-
ADAMS-ASHLEY-ATTALA-BOLIVAR-CARROLL-CATAHOULA-CHICOT-CHOCTAW-
CLAIBORNE-CLARKE-CLAY-CONCORDIA-COPIAH-COVINGTON-EAST CARROLL-
FORREST-FRANKLIN LA-FRANKLIN MS-GRENADA-HINDS-HOLMES-HUMPHREYS-
ISSAQUENA-JASPER-JEFFERSON-JEFFERSON DAVIS-JONES-KEMPER-LAMAR-
LAUDERDALE-LAWRENCE-LEAKE-LEFLORE-LINCOLN-LOWNDES-MADISON LA-
MADISON MS-MARION-MONTGOMERY-MOREHOUSE-NESHOBA-NEWTON-NOXUBEE-
OKTIBBEHA-RANKIN-RICHLAND-SCOTT-SHARKEY-SIMPSON-SMITH-SUNFLOWER-
TENSAS-WARREN-WASHINGTON-WEBSTER-WEST CARROLL-WINSTON-YAZOO-
541 AM CDT TUE OCT 19 2004

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

.DAY ONE...TODAY AND TONIGHT...

...THUNDERSTORMS...
THERE IS A CHANCE OF ISOLATED SEVERE THUNDERSTORMS ALONG AND
NORTH OF A CROSSETT TO KOSCIUSKO TO MACON LINE THIS AFTERNOON AND
EVENING.  THE MAIN RISK WITH THESE STORMS WILL BE HAIL GREATER
THAN THREE QUARTERS OF AN INCH AND ISOLATED TORNADOS.

THERE IS ALSO A CHANCE OF STRONG THUNDERSTORMS AS FAR SOUTH AS
INTERSTATE 20 THIS AFTERNOON AND EVENING.  THE MAIN RISK WITH
THESE STORMS WILL BE HAIL LESS THAN THREE QUARTERS OF AN INCH AND
WINDS AROUND 50 MPH.

A STRONG UPPER LEVEL DISTURBANCE WILL MOVE  ACROSS THE REGION
THIS EVENING.  AS THE DISTURBANCE MOVES EAST...STRONG SOUTHERLY
WINDS WILL BRING IN WARM MOIST AIR FROM THE GULF OF MEXICO.  THIS
ALONG WITH AN ALREADY PRESENT AND NEARLY STATIONARY
BOUNDARY...WILL PROVIDE ENOUGH INSTABILITY OVER THE AREA FOR
THUNDERSTORMS TO DEVELOP.  ADDITIONALLY THERE WILL BE A
SUFFICIENT AMOUNT OF WIND SHEAR IN THE LOWER LAYERS OF THE
ATMOSPHERE AND...AS A RESULT...ISOLATED TORNADOS MAY BE POSSIBLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY 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 HAZARDOUS WEATHER
OPERATIONS...MAY BE NEEDED  THIS AFTERNOON NEAR THE HIGHWAY 82
CORRIDOR.

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
753 AM CDT TUE OCT 19 2004

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0630 AM     TSTM WND DMG     6 E BAY SPRINGS         31.98N 89.18W
10/18/2004                   JASPER             MS   EMERGENCY MNGR

            15 TO 20 TREES AND ONE POWERLINE DOWN.

&&

WILSON