Hail and Damaging Winds in Mississippi, August 17 to 18, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
353 PM CDT FRI AUG 17 2007

.SHORT TERM...ISOLATED CONVECTION OCCURRING OVER EAST MS THIS
AFTERNOON. DEWPOINTS HAVE MIXED OUT TO THE MID AND UPPER 60S OVER
MUCH OF THE REGION AND CIRRUS FROM ERIN HAS HAMPERED INSOLATION AND
ITS CONTRIBUTION TO DESTABILIZING THE AIR MASS. HOWEVER LAPSE RATES
REMAIN RELATIVELY HEALTHY AND A FEW STORMS OVER ERN AREAS WILL HAVE
THE POTENTIAL FOR HEALTHY DOWNBURST. DEWPOINTS ARE HIGHEST OVER SWRN
ZONES BUT THAT AREA REMAINS MORE STABLE THAN OTHERS. EXPECT
CONVECTION TO DIMINISH TOWARD SUNSET.

WILL SEE A SLIGHT INCREASE IN LOW LEVEL MOISTURE FOR MOST AREAS
SATURDAY...PARTICULARLY WITH 850 MB DEWPOINTS. GFS MOS SHOWS LITTLE
IN THE WAY OF POPS FOR TOMORROW BUT THIS REPRESENTS THE DRIEST OF
THE GFS ENSEMBLES AND IS SIGNIFICANTLY DRIER THAT EITHER THE NAM OR
NGM. WITH THE POSSIBILITY OF A WEAK UPPER JETLET IN THE REGION AND
WEAK LOW LEVEL TROUGHING MOVING THROUGH THE BOTTOM OF THE UPPER
RIDGE...WILL INCREASE POPS FOR MUCH OF THE AREA BUT KEEP THEM IN
ISOLATED CATEGORY FOR NOW. A PRECIP BULLSEYE IS FORECAST FOR
SATURDAY EVENING OVER SERN MS THAT TRACKS WWD ACROSS SRN SECTIONS OF
THE FORECAST AREA. THIS IS APPARENTLY A FEEDBACK ISSUE ACCORDING TO
THE VORTICITY AND CONVECTIVE RAINFALL PATTERN. A SECOND...MUCH LESS
INTENSE...UPPER WAVE IS FORECAST TO TRACK WWD UNDERNEATH THE RIDGE
SATURDAY NIGHT. WILL FOLLOW LOW END ENSEMBLE MEMBERS SATURDAY NIGHT
DUE TO INFLUENCE OF FEEDBACK...KEEPING ISOLATED POPS INTERSTATE 20
AND SWD FOR NOW.

.LONG TERM...(SUNDAY THROUGH FRIDAY)...FORECAST PERIOD STARTS OUT
QUIET ENOUGH FOR THE FIRST FEW DAYS OF NEXT WEEK WITH PERSISTING
UPPER SUBTROPICAL RIDGE AXIS LYING E-W ACROSS THE TN VALLEY AND A
TUTT CIRCULATION MOVING NWWD THROUGH THE CENTRAL GULF SUNDAY. THE
RIDGE SPLITS A BIT ON MONDAY AS THE TUTT MOVES INTO SERN TX AND
DRAGS UP DEEPER LAYERED MOISTURE(PWATS NEAR 2.1 INCHES) INTO THE
LOWER MS VALLEY. THE INCREASED SLY FLOW SHOULD ALLOW FOR ISOLATED TO
SCATTERED TSRA MAINLY DURING THE AFTERNOONS TO SURGE FARTHER N
THROUGH THE CWFA. WILL MAINTAIN BEST DIURNAL POPS OVER SRN 1/3 OF
THE CWFA AS THE TUTT MOVES INTO THE RED RIVER VALLEY OF N TX.

FROM THIS POINT ON...THE FORECAST WILL GREATLY HINGE ON THE FORECAST
TRACKS OF MAJOR HURRICANE DEAN NOW ROARING THROUGH THE ERN CARRIBEAN
SEA. UNTIL DEAN APPROACHES OUR LONGITUDE...TEMPS WILL STILL BE HOT
SUNDAY AND MONDAY...BUT TEMPERATURES SHOULD BE HELD IN THE MIDDLE
90S FOR  MOST ALL AREAS WITH HEAT INDEXES APPROACHING 105F.

BY TUESDAY...AT THE VERY MINIMUM WE SHOULD BEGIN SEEING CIRRUS
OUTFLOW FROM DEAN AND SOME MINOR TEMPERATURE EFFECTS. IF LANDFALL OF
DEAN GETS SHIFTED FARTHER N...THE SUBSEQUENT INFLUX OF TROPICAL
MOISTURE AND ASSOCIATED PRECIPITATION INTO THE LOWER MS VALLEY COULD
BE SUBSTANTIAL. THIS IS IN CONTRAST TO HOTTER AND DRIER CONDITIONS
THAT WOULD COME ABOUT IF THE SCENARIO OFFERED BY THE GFS MODEL
OCCURS. NOT MUCH TO GAIN FROM DIFFERING WITH GUIDANCE WHICH STAYS
JUST ABOVE CLIMATOLOGY ANYWAY. NO BIG CHANGES TO PREVIOUS FORECAST
IN THAT REGARD EXCEPT TO BOOST WINDS JUST A BIT WEDNESDAY/THURSDAY.
/40/

&&

.AVIATION...ISOLATED THUNDERSTORMS CAN BE EXPECTED FOR ALL BUT THE
DELTA REGION THIS EVENING. THIS ACTIVITY WILL DIMINISH AROUND OR
SOON AFTER SUNSET. OTHERWISE GENERALLY VFR CONDITIONS EXPECTED
THROUGH THE NIGHT. AREAS OF LIGHT FOG/HAZE WILL LOWER VSBYS AROUND 5
MILES BUT WILL CLEAR SOON AFTER SUNRISE.

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       71  98  74  96 /   7  15  19  18
MERIDIAN      70  98  72  95 /  10  14  17  16
VICKSBURG     72  98  72  95 /   7  18  18  20
HATTIESBURG   72  97  73  94 /  10  19  18  21
NATCHEZ       73  94  74  91 /  15  21  23  24
GREENVILLE    70  96  72  97 /   6  21  11  17
GREENWOOD     71  98  73  97 /   6  18  13  14

&&

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

03/40
99/99/99

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
405 PM CDT FRI AUG 17 2007

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
182115-
ASHLEY-CHICOT-MOREHOUSE-WEST CARROLL-EAST CARROLL-RICHLAND-
MADISON-FRANKLIN-CATAHOULA-TENSAS-CONCORDIA-BOLIVAR-SUNFLOWER-
LEFLORE-GRENADA-CARROLL-MONTGOMERY-WEBSTER-CLAY-LOWNDES-CHOCTAW-
OKTIBBEHA-WASHINGTON-HUMPHREYS-HOLMES-ATTALA-WINSTON-NOXUBEE-
ISSAQUENA-SHARKEY-YAZOO-LEAKE-NESHOBA-KEMPER-WARREN-HINDS-RANKIN-
SCOTT-NEWTON-LAUDERDALE-CLAIBORNE-COPIAH-SIMPSON-SMITH-JASPER-
CLARKE-JEFFERSON-ADAMS-LINCOLN-LAWRENCE-JEFFERSON DAVIS-COVINGTON-
JONES-MARION-LAMAR-FORREST-
405 PM CDT FRI AUG 17 2007

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

.DAY ONE...TONIGHT AND SATURDAY

ISOLATED STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE OVER EAST
MISSISSIPPI THIS AFTERNOON AND EVENING AS A WEAK FRONT DROPS INTO
ALABAMA. ISOLATED THUNDERSTORMS WILL HAVE THE POTENTIAL FOR GUSTY
DOWNBURST WINDS. A FEW MAY BECOME SEVERE FOR A BRIEF PERIOD WITH THE
POTENTIAL FOR DAMAGING WIND GUSTS TO 60 MPH.

ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE AGAIN SATURDAY
AFTERNOON OVER THE ARKLAMISS. THE AIR MASS WILL REMAIN SOMEWHAT UNSTABLE.
SOUTHERLY FLOW WILL MEAN A GRADUAL INCREASE IN LOW LEVEL HUMIDITY
WHICH WILL RESULT IN ISOLATED TO SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS.

AFTERNOON HIGHS SATURDAY WILL RANGE FROM THE MID TO UPPER 90S. THE
GRADUAL INCREASE IN MOISTURE OVER THE AREA WILL RESULT IN AFTERNOON
HEAT INDEX VALUES GENERALLY RANGING FROM 100 TO 107 DEGREES.
RESIDENTS SHOULD KEEP THIS IN MIND WHEN PLANNING OUTDOOR ACTIVITIES.

.DAYS TWO THROUGH SEVEN...SATURDAY NIGHT THROUGH THURSDAY

ALTHOUGH AFTERNOON HIGHS WILL RANGE INTO THE MIDDLE 90S FOR THE
FIRST PART OF NEXT WEEK...AFTERNOON HEAT INDEX VALUES SHOULD
GENERALLY RANGE FROM 100 TO 105 DEGREES. RESIDENTS OF THE ARKLAMISS
SHOULD KEEP THIS IN MIND WHEN PLANNING OUTDOOR ACTIVITIES.

BY TUESDAY NIGHT...ALL EYES WILL BE FOCUSING ON THE TROPICS AS
HURRICANE DEAN CROSSES THE GULF OF MEXICO. THE FORECAST TRACKS
FOR DEAN WILL HAVE TO MONITORED CLOSELY THROUGH THE MIDDLE AND END
OF THE WEEK...OTHERWISE 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 NEXT FRIDAY.

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

03/40

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
406 PM CDT FRI AUG 17 2007

MSZ030-033-172205-
CLAY MS-OKTIBBEHA MS-
406 PM CDT FRI AUG 17 2007

STRONG THUNDERSTORMS CAPABLE OF PRODUCING 40 TO 50 MPH WINDS AND
FREQUENT LIGHTNING STRIKES ARE DEVELOPING OVER CLAY AND OKTIBBEHA
COUNTIES...AND MOVING SLOWLY TO THE WEST. THE STORMS SHOULD MAINLY
AFFECT THE AREA FROM NEAR MONTPELIER TO STARKVILLE...AND EVENTUALLY
COULD AFFECT STURGIS AND MABEN.

PEOPLE IN CLAY AND OKTIBBEHA COUNTIES...INCLUDING THE CITIES OF
MONTPELIER AND STARKVILLE...SHOULD MONITOR THIS STORM CLOSELY.

EEC