Special Weather Statement, NWS Jackson, MS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
932 PM CDT FRI AUG 12 2011

.DISCUSSION...ISOLATED CONVECTION HAS DISSIPATED ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA THIS EVENING AS DAY TIME HEATING CONTINUES
TO WANE.  ONCE AGAIN...AS HAS BEEN THE CASE EACH EVENING THIS
WEEK...ANOTHER DISTURBANCE EMBEDDED IN NORTHWEST FLOW CONTINUES TO
SINK EAST SOUTHEAST ACROSS CENTRAL ARKANSAS AND TOWARDS THE NORTHERN
HALF OF THE FORECAST AREA TONIGHT.  THE COMPLEX OF SHOWERS AND
STORMS ASSOCIATED WITH THIS DISTURBANCE SHOULD MAKE A BIT BETTER
PUSH TOWARDS MY NORTH THROUGH THE NIGHT.  IT'S HERE...PARTICULARLY
THE DELTA...THAT THE INSTABILITY IS AT IT'S BEST ACROSS THE FORECAST
AREA...WHILE FURTHER SOUTH PER THE 00Z KJAN RAOB...A MUCH LESS
UNSTABLE ENVIRONMENT EXISTS.

THE CURRENT FORECAST REFLECTS THIS AS THE BETTER RAIN CHANCES
TONIGHT REMAIN ACROSS MY NORTH. I WILL HOWEVER UP POPS IN THE DELTA
A BIT.  THIS...AS WELL AS SOME ADJUSTMENTS TO THE HOURLY GRIDS AS
THE RESULT OF CURRENT TRENDS...WILL BE THE ONLY CHANGES I MAKE TO
THE FORECAST ON THIS UPDATE.  THE REMAINDER OF THE FORECAST IS IN
PRETTY GOOD SHAPE. /19/

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH
MUCH OF THE FORECAST PERIOD.  ISOLATED TO SCATTERED CONVECTION
WILL BE POSSIBLE OVER HIGHWAY 82 CORRIDOR...KGLH...KGWO...AND
KGTR...AS YET ANOTHER DISTURBANCE PUSHES EAST SOUTHEAST TOWARDS THE
NORTHERN HALF OF THE AREA AFTER MIDNIGHT.  THIS...IN ADDITION TO THE
POTENTIAL FOR ISOLATED TO SCATTERED AFTERNOON AND EVENING CONVECTION
SATURDAY...WILL CAUSE A BRIEF PERIOD OF MVFR/IFR CEILINGS AND/OR
VISIBILITIES AT SITES WHERE ANY CONVECTION IS OBSERVED. /19/

&&

.PREV DISCUSSION... /ISSUED 401 PM CDT FRI AUG 12 2011/

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...STORMS ARE BEGINNING TO
DEVELOP ACROSS PORTIONS OF THE ARKLAMISS...MAINLY SOUTH AND WESTERN
AREAS. SLIGHTLY DRIER AIR HAS MOVED INTO NORTH AND EASTERN PORTIONS
IN THE WAKE OF THE MORNING SHORTWAVE/MCV THAT WENT THROUGH WHICH HAS
LIMITED CONVECTION THIS AFTERNOON. TEMPERATURES THIS AFTERNOON HAVE
WARMED INTO THE LOWER 90S ACROSS THE HIGHWAYS 82 AND 84 CORRIDORS...
AND INTO THE MID 90S ALONG I-20. THIS STORM ACTIVITY IS EXPECTED TO
DIMINISH THROUGH THE EVENING HOURS TONIGHT.

MUCH OF THE NIGHT WILL BE QUIET. THE REGION WILL REMAIN UNDER
NORTHWEST FLOW ALOFT AND THERE WILL BE THE POTENTIAL FOR ANOTHER MCS
TO COME INTO OR CLOSE TO THE NORTHWESTERN ZONES OF MY CWA BY EARLY
SATURDAY MORNING. WILL CONTINUE TO LEAVE LOW END POPS FOR THE
NORTHWEST DUE TO THIS POTENTIAL. BY SATURDAY...AN UPPER LOW WILL
SWING ACROSS THE GREAT LAKES REGION AND A MID LEVEL TROUGH WILL DIG
INTO THE ARKLAMISS REGION. THIS WILL BRING A COLD FRONT TOWARD THE
REGION. MOST MODELS AGREE THAT THIS WILL BE SLOW TO TRAVERSE THE CWA.
THE NAM IS VERY BULLISH IN BRINGING IN THE RAIN FOR SATURDAY WHILE
THE ECMWF/SREF/GFS ARE NOT AS ROBUST. EVEN NATIONAL HI-RES WRF MODELS
INDICATE THAT THERE SHOULD BE SOME SHOWERS AND THUNDERSTORMS AHEAD OF
THE FRONTAL PASSAGE ON SATURDAY BUT THAT THEY SHOULD BE RATHER
ISOLATED IN NATURE. TEMPERATURES WILL BE WARM AGAIN TOMORROW WITH
READINGS IN THE MID AND UPPER 90S. THE NAM...WITH ITS HIGHER CHANCES
FOR RAIN...SHOWED HIGHS IN THE LOWER 90S FOR TOMORROW...BUT FEEL THAT
GIVEN ITS FASTER SOLUTION...THIS MIGHT BE TOO COOL FOR TOMORROW.

THE FRONT WILL BE MOVING THROUGH THE ARKLAMISS SATURDAY NIGHT INTO
SUNDAY. THIS WILL KEEP RAIN CHANCES IN THE FORECAST THROUGH
SUNDAY...ESPECIALLY FOR THE EAST AND SOUTH. GIVEN FORCING FROM THE
FRONT...COOLER TEMPERATURES ALOFT WITH THE PASSAGE OF THE UPPER
TROUGH AND DECENT LAPSE RATES...THERE COULD BE SOME STRONG STORMS
ALONG OR AHEAD OF THE FRONT WITH WIND AND HAIL BEING THE MAIN
HAZARDS. TEMPERATURES IN THE NORTH MAY BE COOLER WITH FRONTAL
PASSAGE EARLIER ON SUNDAY AND HIGHS SHOULD BE CLOSER TO NORMAL. THE
FRONT SHOULD BE THROUGH THE REGION BY SUNDAY EVENING BUT THE
INFILTRATION OF DRIER AIR WILL BE DELAYED A FEW HOURS.
HOWEVER...MODELS SHOW THE DRIER AIR MOVING IN SUNDAY EVENING INTO
OVERNIGHT SUNDAY NIGHT. PW VALUES PROGGED TO REACH THE HIGHWAY 82
CORRIDOR AROUND 00Z MONDAY WITH VALUES AROUND ONE INCH. OVERNIGHT
LOWS SUNDAY NIGHT WILL BE COOLER THAN WHAT WE HAVE SEEN AND IN THE
UPPER 60S AND LOWER 70S. THE REST OF THE LONG TERM REMAINS THE SAME
AND THE PREVIOUS DISCUSSION IS APPENDED BELOW. /28/

LONG TERM...MMONDAY THROUGH FRIDAY...NORMAL LOWS FOR NEXT WEEK
ARE AROUND 79 DEGREES. BELOW NORMAL LOWS ARE EXPECTED FOR MUCH OF
THE AREA MONDAY MORNING AS TEMPERATURES BOTTOM OUT IN THE MID TO
UPPER 60S. THE UPPER LEVEL TROUGH WILL BE SLOW TO SHIFT EAST THROUGH
WEDNESDAY MAINTAINING A NORTHWEST FLOW ALOFT OVER OUR REGION.
SURFACE HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS SUNDAY WILL
SLOWLY SHIFT EAST THROUGH WEDNESDAY AS WELL RESULTING IN A LOW LEVEL
NORTHERLY FLOW THAT WILL MAINTAIN OUR DRIER AIRMASS. NORMAL DAYTIME
HIGHS NEXT WEEK ARE IN THE LOWER 90S. NEAR NORMAL HIGHS ARE EXPECTED
MONDAY AND TUESDAY BUT AFTERNOON HIGHS WILL SLOWLY WARM NEXT WEEK.
OVERNIGHT LOWS WILL REMAIN BELOW NORMAL WITH LOWS IN THE 60S EACH
MORNING THROUGH WEDNESDAY MORNING. THE GFS IS DRY THROUGH WEDNESDAY
OVER OUR AREA BUT THE ECMWF HINTS AT A DISTURBANCE IN THE NW FLOW
ALOFT THAT MAY BRING RAIN WEDNESDAY, ELSE THE RIDGE OVER THE
SOUTHERN PLAINS WILL FLATTEN AS IT SPREADS EAST ACROSS OUR CWA FOR
THE END OF THE WEEK. WARMER TEMPERATURES AND A SLOW INCREASE IN DEEP
MOISTURE IS PROGGED THURSDAY AND FRIDAY. BOTH GFS AND ECMWF SHOW A
SECOND COLD FRONT STALLING JUST NORTH OF OUR CWA BY FRIDAY. THE
PROXIMITY OF THIS FRONT MAY HELP INCREASE POPS BY THE END OF THE
WEEK FOR OUR NORTHERN ZONES. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       72  98  72  96 /  10  16  20  19
MERIDIAN      68  99  69  95 /  10  16  24  21
VICKSBURG     71  96  71  96 /  13  17  18  17
HATTIESBURG   73  97  74  97 /  17  22  19  20
NATCHEZ       73  94  73  96 /  14  19  21  20
GREENVILLE    73  97  73  94 /  29  22  24  11
GREENWOOD     70  97  72  95 /  22  20  29  15

&&

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

19

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
121 PM CDT FRI AUG 12 2011

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
131830-
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-
121 PM CDT FRI AUG 12 2011

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

.DAY ONE...TONIGHT AND SATURDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

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

A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE ON SUNDAY. THE
PRIMARY SEVERE RISK WITH THESE STORMS WILL BE DAMAGING WINDS BUT
HAIL TO THE SIZE OF HALF DOLLARS WILL ALSO BE POSSIBLE...ESPECIALLY
IN AREAS NORTH OF THE I-20 CORRIDOR WHERE THE CHANCE OF SEVERE STORMS
WILL BE HIGHEST. STORMS WILL DEVELOP AHEAD OF AND ALONG A COLD FRONT
THAT WILL MOVE ACROSS THE AREA SUNDAY MORNING THROUGH THE AFTERNOON.

.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 THURSDAY.

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.SRH.NOAA.GOV/JAN.

ALLEN

MSZ018-019-025>027-130520-
SUNFLOWER MS-LEFLORE MS-BOLIVAR MS
1152 PM CDT FRI AUG 12 2011

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
1152 PM CDT FRI AUG 12 2011

A LINE OF STRONG WINDS AHEAD OF A LARGE THUNDERSTORM COMPLEX ACROSS
NORTH MISSISSIPPI AND SOUTHEAST ARKANSAS WILL BE CAPABLE OF
PRODUCING 35 TO 50 MPH WINDS IS LOCATED ACROSS COAHOMA AND QUITMAN
COUNTIES AT 1148 PM CDT...MOVING SOUTH AT 35 TO 40 MPH.

PEOPLE IN BOLIVAR...NORTHERN LEFLORE AND NORTHEASTERN SUNFLOWER
COUNTIES SHOULD MONITOR THESE STORMS AND STRONG WINDS CLOSELY.

LAT...LON 3399 9065 3398 9044 3382 9044 3378 9017
      3376 9019 3382 9012 3364 9004 3368 9104
      3377 9115 3378 9099 3397 9110 3396 9098
      3409 9088 3412 9096 3412 9095 3413 9066
TIME...MOT...LOC 0448Z 353DEG 35KT 3411 9097 3411 9037

JA

ARZ074-LAZ007-130805-
ASHLEY AR-MOREHOUSE LA-
221 AM CDT SAT AUG 13 2011

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
221 AM CDT SAT AUG 13 2011

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PEA TO DIME SIZE HAIL AND
40 TO 50 MPH WINDS WAS LOCATED 6 MILES SOUTHWEST OF CROSSETT AT 220
AM CDT...MOVING SOUTHEAST AT 10 MPH. THE STORM WILL MOVE INTO
NORTHERN MOREHOUSE PARISH THROUGH 3 AM.

VERY HEAVY RAIN IS ALSO LIKELY WITH THIS STORM.

PEOPLE IN SOUTHWESTERN ASHLEY COUNTY...AND NORTHERN MOREHOUSE PARISH
SHOULD MONITOR THIS STORM CLOSELY.

LAT...LON 3318 9200 3295 9153 3278 9203 3299 9209
      3301 9208 3303 9210 3307 9211
TIME...MOT...LOC 0720Z 311DEG 10KT 3305 9202

7