Severe Thunderstorm Warning 697, NWS Jackson, MS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
830 PM CDT SAT AUG 2008

.UPDATE...SPC HAS PUT MOST OF CENTRAL MISSISSIPP UNDER A SEVERE
THUNDERSTORM WATCH UNTIL 2 AM. A COMPLEX OF STRONG-SEVERE STORMS
WAS DEVELOPING SOUTHWEST FROM NORTHEAST MISSISSIPPI. SO HAVE INCREASED
POPS ACROSS THE ARKLAMISS FOR MOST OF THE NIGHT. HAVE ADJUSTED HOURLY
TEMPS. THIS WAS DUE TO AN UPPER LEVEL DISTURBANCE THAT WAS MOVING
ACROSS THE REGION IN NORTHERLY FLOW ALOFT. THE REST OF FORECAST APPEARS
TO BE ON TRACK../17/

./PREVIOUS DISCUSSION...251 PM CDT SAT AUG 2 2008/

.SHORT TERM...THE BIG STORY FOR THE NEXT SEVERAL DAYS FOR THE
ARKLAMISS REGION CONTINUES TO BE THE HEAT.  WATER VAPOR IMAGERY THIS
AFTERNOON SHOWS UPPER RIDGING TO THE WEST OF THE AREA THAT IS
BUILDING EAST. SURFACE OBSERVATIONS SHOWS A WEAK BOUNDARY STRETCHED
NORTH OF THE AREA ACROSS AR AND AROUND EXTREME NORTH MS/SOUTH TN.
HIGH PRESSURE IS STRETCHED ALONG THE GULF COAST STATES...WITH THE
EXCEPTION OF A SURFACE LOW THAT IS DEVELOPING OVER THE NORTHEASTERN
GULF. VISIBLE IMAGERY SHOW CLOUDS HAVE STRUGGLED TO FORM THIS
AFTERNOON AS A RESULT OF THE DECENT SUBSIDENCE SHOWN BY THIS
MORNINGS KJAN SOUNDING.  A FEW ISOLATED SHOWERS AND STORMS ARE
DEVELOPING ALONG AND SLIGHTLY AHEAD OF THE WEAK SURFACE BOUNDARY.
GUI CAME IN DRY FOR THE AREA FOR TONIGHT.  FOR THE MOST PART AGREE
WITH THIS.  ALTHOUGH A FEW VERY ISOLATED STORMS CAN NOT BE RULED OUT
FOR A FEW HOURS IN THE EARLY EVENING...MAINLY ALONG AND NORTH OF
INTERSTATE 20 AS THIS DISTURBANCE DRIFTS SOUTH. SO HAVE INCREASED
POPS VERY SLIGHTLY TO THROW IN ISOLATED WORDING INTO THE WX GRIDS
FOR AREAS NORTH OF INTERSTATE 20. WITH DECENT INSTABILITY IN PLACE A
FEW OF THESE STORMS COULD BECOME STRONG IF THEY CAN MANAGE TO
DEVELOP.

AS MENTIONED BEFORE THE MAIN CONCERN IS THE HEAT THROUGH THE NEXT
SEVERAL DAYS.  HIGH PRESSURE IS BUILDING OVER THE REGION THROUGH THE
NEXT FEW DAYS.  THIS WILL SUPPRESS CLOUD COVER AND AFTERNOON
CONVECTION EACH DAY. IN ADDITION...DEWPOINTS SHOULD BE IN OR AROUND
THE MIDDLE 70S FOR THE REGION.  WITH HIGH TEMPERATURES REACHING THE
UPPER 90S TO EVEN THE TRIPLE DIGITS IN SOME LOCATIONS...MAINLY
ACROSS THE NORTHWEST...HEAT INDICES WILL BE ABLE TO BE BETWEEN 105
AND 110 DEGREES.  SOME LOCATIONS...MAINLY ACROSS THE DELTA
REGION...WILL BE ABLE TO EXCEED 110 DEGREE HEAT INDICES DURING THE
PEAK OF THE AFTERNOON. LOWS THROUGH THE NEXT SEVERAL NIGHTS WILL
ONLY FALL TO THE MIDDLE 70S. AS A RESULT...THE HEAT ADVISORY WILL BE
CONTINUED THROUGH SUNDAY MORNING FOR AREAS NORTHWEST OF THE NATCHEZ
TRACE.  FOR SUNDAY...THE HEAT ADVISORY WILL  BE EXPANDED FOR THE
REMAINDER OF THE AREA...AND AN EXCESSIVE HEAT WARNING WILL BE ISSUED
FOR THE NORTHWESTERN PORTIONS OF THE FORECAST AREA.  WILL CONTINUE
THE HEAT WATCH ON MONDAY AND EXTEND IT INTO TUESDAY AS WELL AS THE
HEAT IS EXPECTED TO CONTINUE INTO THE MIDDLE OF NEXT WEEK.

OVERALL THE AREA WILL REMAIN DRY THROUGH THE NEXT FEW DAYS. THERE
IS AN AREA OF LOW PRESSURE OVER THE NORTHEASTERN GULF OF MEXICO.
THIS FEATURE IS EXPECTED TO TRACK WEST ACROSS THE NORTHERN GULF OF
MEXICO. THIS COMBINED WITH SEE SEA BREEZE ACTIVITY SUNDAY AND MONDAY
AFTERNOONS WILL GIVE SMALL RAIN CHANCES FOR MAINLY HWY 84 AND SOUTH.
OTHERWISE THIS FEATURE IS NOT EXPECTED TO AFFECT THE AREA TOO MUCH.
IT MAY HOWEVER AT LEAST BRING A RELIEF TO THE HEAT TO EXTREME
SOUTHERN PORTIONS OF THE FORECAST AREA. OVERALL HAVE REMAINED WITH
GUI POPS FOR THE NEXT FEW DAYS. /14/

.LONG TERM...TUESDAY THROUGH NEXT FRIDAY. MEDIUM RANGE MODELS ARE IN
FAIR AGREEMENT WITH A HOT START FOR THE LONG TERM AND LOW RAIN
CHANCES THROUGH NEXT WEEK THAT SHIFT FROM THE SOUTH INITIALLY THEN
TO THE NORTH TOWARD THE END OF THE PERIOD. THE HEAT AND HUMIDITY
WILL CONTINUE INTO WEDNESDAY FOR OUR NORTHWEST AS THE LARGE DOME OF
HIGH PRESSURE SLOWLY WEAKENS OVER OUR REGION. THIS WILL OCCUR AS THE
UPPER LEVELS AMPLIFY WITH RIDGING OVER THE ROCKIES AND TROUGHING
OVER THE EASTERN CONUS. THE RESULTING NORTHWEST FLOW ALOFT OVER OUR
REGION WILL BRING US SEVERAL DISTURBANCES AND A COUPLE OF FRONTAL
BOUNDARIES THAT WILL HELP INCREASE CLOUDS AND RAIN CHANCES IN OUR
NORTHERN ZONES. BY THURSDAY THE FIRST FRONT IS EXPECTED TO STALL
OVER NORTHERN MISSISSIPPI. STORMS THAT INITIATE ALONG THE FRONT
THURSDAY WILL TRACK TO THE SOUTHEAST AND ENTER INTO OUT NORTHEAST
COUNTIES. A DISTURBANCE IN THE NORTHWEST FLOW WILL COMBINE WITH THE
BOUNDARY AND DAYTIME HEATING TO RESULT IN SCATTERED COVERAGE OF
STORMS OVER OUR NORTHERN ZONES FRIDAY. THE GULF SEABREEZE WILL BRING
A SLIGHT CHANCE OF RAIN TO OUR SOUTHERN MOST COUNTIES NEXT WEEK. A
POTENT SHORTWAVE IS EXPECTED TO BRING A SECOND FRONTAL BOUNDARY INTO
NORTHERN MISSISSIPPI NEXT SATURDAY. THIS SYSTEM MAY PROVE TO BE OUR
NEXT BEST CHANCE FOR WIDESPREAD COVERAGE OF RAIN OVER THE CWFA
THROUGH THE PERIOD. MAV GUIDANCE HIGHS FOR MONDAY AND TUESDAY WERE A
LITTLE TOO COOL AND AMONG THE LOWEST ENSEMBLE MEMBERS FOR MUCH OF
OUR AREA. WENT SEVERAL DEGREES ABOVE GUIDANCE TOWARD HIGHEST
ENSEMBLE MEMBERS. MAV POPS WERE GENERALLY ACCEPTED THROUGH THE
PERIOD. /22/

&&

.AVIATION...MOSTLY SCATTERED CLOUDS 4-5K FEET SHOULD BE THINNING OUT
RAPIDLY 23-01Z TO OCCASIONALLY BROKEN ABOVE 12K FEET AND WILL GIVE
WAY TO SKC CONDS BY 03Z THIS EVENING. ISOLATED SHRA/TSRA ALONG AND S
OF HIGHWAY 98 AND ACROSS THE HIGHWAY 82 CORRIDOR MAY FORM THROUGH
02Z AS BEST POTENTIAL INSTABILITY REMAINS SITUATED OVER THE DELTA
REGION. PATCHY MVFR FOG COULD DEVELOP 08-13Z SUNDAY MORNING FOLLOWED
BY VFR CONDS WITH SCATTERED CUMULUS 3-4K FEET FORMING 15-23Z./40/

&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON       73  99  76  99 /  41  14   6   7
MERIDIAN      72  96  73  97 /  54  14   3   6
VICKSBURG     73 100  76  99 /  25  12  10   9
HATTIESBURG   74  97  75  95 /  51  18  11  14
NATCHEZ       73  98  75  95 /  25  19  19  10
GREENVILLE    75 102  74 101 /  24   7   8   9
GREENWOOD     74 101  75 101 /  34   9   6   8

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY FROM 10 AM SUNDAY TO 6 AM CDT MONDAY FOR MSZ039-
     046-051-052-056>058-061>066-072>074.

     EXCESSIVE HEAT WATCH FROM MONDAY MORNING THROUGH TUESDAY
     AFTERNOON FOR MSZ018-019-025>066-072>074.

     EXCESSIVE HEAT WARNING FROM 10 AM SUNDAY TO 6 AM CDT MONDAY FOR
     MSZ018-019-025>038-040>045-047>050-053>055-059-060.

     HEAT ADVISORY UNTIL 10 AM CDT SUNDAY FOR MSZ018-019-025>038-
     040>045-047>050-053>055-059-060.

LA...EXCESSIVE HEAT WATCH FROM MONDAY MORNING THROUGH TUESDAY
     AFTERNOON FOR LAZ007>009-015-016-023>026.

     EXCESSIVE HEAT WARNING FROM 10 AM SUNDAY TO 6 AM CDT MONDAY FOR
     LAZ007>009-015-016-023>026.

     HEAT ADVISORY UNTIL 10 AM CDT SUNDAY FOR LAZ007>009-015-016-
     023>026.

AR...EXCESSIVE HEAT WATCH FROM MONDAY MORNING THROUGH TUESDAY
     AFTERNOON FOR ARZ074-075.

     EXCESSIVE HEAT WARNING FROM 10 AM SUNDAY TO 6 AM CDT MONDAY FOR
     ARZ074-075.

     HEAT ADVISORY UNTIL 10 AM CDT SUNDAY FOR ARZ074-075.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
230 PM CDT SAT AUG 2 2008

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
031930-
ASHLEY-CHICOT-MOREHOUSE-WEST CARROLL-EAST CARROLL-RICHLAND-
MADISON LA-FRANKLIN LA-CATAHOULA-TENSAS-CONCORDIA-BOLIVAR-
SUNFLOWER-LEFLORE-GRENADA-CARROLL-MONTGOMERY-WEBSTER-CLAY-LOWNDES-
CHOCTAW-OKTIBBEHA-WASHINGTON-HUMPHREYS-HOLMES-ATTALA-WINSTON-
NOXUBEE-ISSAQUENA-SHARKEY-YAZOO-MADISON MS-LEAKE-NESHOBA-KEMPER-
WARREN-HINDS-RANKIN-SCOTT-NEWTON-LAUDERDALE-CLAIBORNE-COPIAH-
SIMPSON-SMITH-JASPER-CLARKE-JEFFERSON-ADAMS-FRANKLIN MS-LINCOLN-
LAWRENCE-JEFFERSON DAVIS-COVINGTON-JONES-MARION-LAMAR-FORREST-
230 PM CDT SAT AUG 2 2008

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

.DAY ONE...TONIGHT AND SUNDAY

ISOLATED STRONG TO LOCALLY SEVERE THUNDERSTORMS ARE POSSIBLE EARLY
THIS EVENING AND AGAIN SUNDAY AFTERNOON ACROSS PORTIONS OF THE REGION.
THE RISK AREA THIS EVENING WILL GENERALLY BE CONFINED TO LOCATIONS
NORTH OF INTERSTATE 20 WHILE THE RISK ON SUNDAY AFTERNOON WILL SHIFT
TO LOCATIONS SOUTH OF INTERSTATE 20. THE MAIN IMPACT RISK WITH ANY
STORM WILL BE DAMAGING WIND GUSTS UP TO 60 MPH...ALTHOUGH HAIL
GREATER THAN THE SIZE OF DIMES WILL ALSO BE POSSIBLE.

A WEAK DISTURBANCE MOVING SOUTH INTO A VERY HOT AND UNSTABLE AIRMASS
IN PLACE OVER THE REGION IS EXPECTED TO TRIGGER THE ISOLATED
THUNDERSTORMS THIS EVENING AND AGAIN LATER ON SUNDAY.

OTHERWISE...A VERY HOT PERIOD OF WEATHER HAS BEGUN ONCE AGAIN AND
WILL RESULT IN AFTERNOON TEMPERATURES AROUND 100 DEGREES NORTHWEST
OF THE NATCHEZ TRACE CORRIDOR ON SUNDAY...WITH READINGS ELSEWHERE
EXPECTED TO PEAK BETWEEN 96 AND 99 DEGREES. THE COMBINATION OF HEAT
AND HUMIDITY WILL BRING HEAT INDICES BETWEEN 105 AND 110 DEGREES FOR
A FEW HOURS. A HEAT ADVISORY HAS BEEN POSTED THROUGH TONIGHT WEST OF
THE NATCHEZ TRACE AND WILL BE UPGRADED TO AN EXCESSIVE HEAT WARNING
ON SUNDAY. A HEAT ADVISORY WILL GO INTO EFFECT ON SUNDAY FOR
SOUTHEAST MISSISSIPPI AS WELL. PLEASE SEE THE ASSOCIATED HEAT
ADVISORY FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH FRIDAY

HEAT STRESS CONDITIONS ARE LIKELY TO REMAIN HIGH SUNDAY NIGHT
THROUGH TUESDAY AS HIGH TEMPERATURES WILL PEAK FROM 97 TO 102 DEGREES
AND DAYTIME HEAT INDEX VALUES WILL VARY FROM 106 TO 112 DEGREES.
OVERNIGHT LOWS WILL FREQUENTLY ONLY RECOVER TO THE MIDDLE 70S. THE HEAT
ADVISORIES AND WARNINGS OF SUNDAY WILL REMAIN IN PLACE FOR MONDAY AND
THE EXCESSIVE HEAT WATCH WILL BE EXTENDED INTO TUESDAY FOR MUCH OF
THE ARKLAMISS...ESPECIALLY ALONG AND NORTH OF INTERSTATE TWENTY.

REVIEW YOUR HEAT STRESS SAFETY RULES AND MAKE PLANS NOW TO AVOID
PROLONGED EXPOSURE TO THESE EXPECTED HOT CONDITIONS.

.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 EXPECTED THROUGH NEXT FRIDAY.

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

40/14

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
433 PM CDT SAT AUG 2 2008

LAZ023-024-022205-
CATAHOULA LA-FRANKLIN LA-
433 PM CDT SAT AUG 2 2008

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PEA TO DIME SIZE HAIL AND
40 TO 50 MPH WINDS WAS LOCATED 5 MILES NORTHEAST OF ENTERPRISE AT 433
PM CDT...MOVING SOUTH AT 3 MPH.

VERY HEAVY RAIN ALONG WITH FREQUENT CLOUD TO GROUND LIGHTNING ARE
ALSO POSSIBLE WITH THIS STORM.

HIGH WINDS CAN BRING DOWN TREES AND LARGE LIMBS RESULTING IN SERIOUS
INJURY OR PROPERTY DAMAGE. EXERCISE EXTREME CAUTION WHEN OUTDOORS
DURING SUCH STRONG WINDS...AND BE ESPECIALLY AWARE OF OLDER TREES.

PEOPLE IN SOUTHWESTERN FRANKLIN AND NORTH CENTRAL CATAHOULA PARISHES
SHOULD MONITOR THIS STORM CLOSELY.

EEC

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
653 PM CDT SAT AUG 2 2008

MSZ031-030010-
LOWNDES MS-
653 PM CDT SAT AUG 2 2008

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PEA TO DIME SIZE HAIL AND
40 TO 50 MPH WINDS WAS LOCATED 7 MILES NORTHEAST OF CALEDONIA AT 653
PM CDT...MOVING SOUTH AT 20 MPH.

VERY HEAVY RAIN ALONG WITH CONTINUOUS CLOUD TO GROUND LIGHTNING ARE
ALSO POSSIBLE WITH THIS STORM.

HIGH WINDS CAN BRING DOWN TREES AND LARGE LIMBS RESULTING IN SERIOUS
INJURY OR PROPERTY DAMAGE. EXERCISE EXTREME CAUTION WHEN OUTDOORS
DURING SUCH STRONG WINDS...AND BE ESPECIALLY AWARE OF OLDER TREES.

PEOPLE IN NORTHEASTERN LOWNDES COUNTY SHOULD MONITOR THIS STORM
CLOSELY.

EEC