Severe Thunderstorm Warning 311, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
406 PM CDT THU JUN 27 2013

.DISCUSSION...
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...PRIMARY CONCERNS OVER
THE NEXT FEW DAYS WILL CENTER AROUND THUNDERSTORM CHANCES THROUGH
SATURDAY...WHEN A COLD FRONT WILL PUSH ACROSS THE REGION.

LATEST UA ANALYSIS AND WATER VAPOR IMAGERY INDICATE LONGWAVE RIDGING
OVER THE WESTERN AND CENTRAL UNITED STATES WITH TROUGHING OVER THE
EASTERN SEABOARD AND NORTHERN ATLANTIC. THIS LEAVES OUR AREA IN
NORTHERLY FLOW ALOFT...WHICH HAS BEEN BRINGING PERIODIC UPPER
DISTURBANCES RESULTING IN THUNDERSTORM COMPLEXES PASSING NEAR THE
AREA. ONE SUCH COMPLEX PASSED JUST EAST OF THE AREA EARLY THIS
MORNING.

SO FAR TODAY IT HAS BEEN MOSTLY CLEAR ALLOWING TEMPERATURES TO WARM
INTO THE LOW TO MID 90S. DEWPOINTS ARE HANGING IN THE LOW TO MID
70S...MAKING IT A RATHER UNCOMFORTABLE DAY WITH HEAT INDICES IN THE
TRIPLE DIGITS. THE ATMOSPHERE IS QUITE UNSTABLE THIS AFTERNOON...
WITH SBCAPES INDICATED BY SPC MESOANALYSIS TO BE IN THE 3000-4000
J/KG RANGE ACROSS THE AREA. WE WILL LIKELY SEE SCATTERED CONVECTION
DEVELOP LATER THIS AFTERNOON OVER EASTERN MS...WHERE OUTFLOW FROM
THE THUNDERSTORM COMPLEX THIS MORNING COULD HELP SERVE AS A FOCUS
FOR DEVELOPMENT. ANOTHER DISTURBANCE WILL TRACK ACROSS THE REGION
OVERNIGHT AND MAY BRING ANOTHER DYING COMPLEX INTO THE MIDSOUTH.
SOME OF THIS ACTIVITY COULD REACH THE HIGHWAY 82 CORRIDOR BEFORE 12Z.

ON FRIDAY THE UPPER TROUGH WILL BUILD SOUTHWARD AND WESTWARD PUSHING
A SURFACE FRONT SOUTHWARD TOWARD THE REGION. THOUGH SOME
PRECIPITATION IN THE FORM OF A DYING THUNDERSTORM COMPLEX MAY BE
ONGOING IN THE MORNING...THE BETTER CHANCE FOR MORE POTENT STORMS
WILL COME IN THE LATE AFTERNOON AND EVENING HOURS. BY THIS TIME...
INSTABILITY WILL BE MAXIMIZED WITH GUIDANCE PROGGING CAPES OVER 3500
J/KG AND 0-6 KM BULK SHEAR MAGNITUDES WILL BE INCREASING TO THE 30-40
KT RANGE INTO THE EVENING. THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS NORTH MS EASTWARD INTO NORTH AL AND MOVE SOUTHWARD THROUGH THE
EVENING. GIVEN THE ABUNDANT INSTABILITY AND SHEAR...SEVERE STORMS
WILL BE POSSIBLE WITH DAMAGING WIND GUSTS BEING THE PRIMARY CONCERN.
HAIL TO QUARTER SIZE WILL ALSO BE POSSIBLE. THESE THREATS WILL
CONTINUE TO BE MENTIONED IN THE HWO AND GRAPHICAST PRODUCTS.

THE FRONT WILL PUSH SOUTH OF THE AREA EARLY ON SATURDAY...WITH RAIN
CHANCES ONLY LINGERING ACROSS THE PINE BELT DURING THE DAYTIME. ASIDE
FROM ENDING RAIN CHANCES...ANOTHER PLEASANT IMPACT FROM THE FRONT
WILL BE A SOMEWHAT DRIER AIR MASS. DEWPOINTS IN THE 60S WILL MAKE
HIGHS NEAR 90 QUITE A BIT MORE TOLERABLE THAN THE DEWPOINTS IN THE
70S HAVE BEEN THE PAST FEW DAYS. /DL/

LONG TERM (SUNDAY THROUGH NEXT THURSDAY)...NEAR NORMAL TO SLIGHTLY
BELOW NORMAL TEMPERATURES ANTICIPATED IN THE LONG TERM WITH
INCREASED RAIN CHANCES DURING THE EARLY PART OF THE NEXT WEEK.

POPS SUNDAY THROUGH TUESDAY ARE TRICKY AND WILL BE DETERMINED BY
POSITIONING OF LARGE SCALE TROUGH AXIS, SMALL PERTURBATIONS PASSING
THROUGH, AND AVAILABLE LOW-LVL MOISTURE. MAV GUIDANCE NUMBERS SEEMED
LOW GIVEN OVERALL PATTERN OF TROUGHING PATTERN WITH DYNAMICALLY
INDUCED LIFT EXPECTED BUT DID LOWER INHERITED GRIDS TO KEEP SOME
CONSISTENCY. CAVEAT TO WHY MAV HAD LOWER POPS IS LIKELY RELATED TO
MODEL TROUGH AXIS POSITIONING WITH SOME SUGGESTING AXIS FARTHER
EAST...PLACING THE ARKLAMISS IN SUBSIDENCE VS. BETTER DIVERGENCE
ALOFT IF AXIS WAS FARTHER WEST. REGARDLESS, TEMPS WILL BE BELOW
NORMAL BY ABOUT 5 DEGREES WITH HIGHS IN THE MID TO UPPER 80S VS. THE
MORE NORMAL LOWER TO MID 90S THIS TIME OF YEAR.

FOR MID TO LATE WEEK, DECENT AGREEMENT FOR GFS/EC SUGGESTS A CLOSED
LOW REMAINING ACROSS CNTRL CONUS WITH SUBTLE SUBTROPICAL RIDGING
BUILDING BACK INTO THE SE CONUS. PWATS WILL CLIMB BACK INTO 1.5-1.8"
RANGE AND MORE DIURNAL PATTERN OF SHOWERS AND THUNDERSTORMS LOOKS
PROBABLE UNDER MORE SW FLOW ALOFT TOWARDS THE FOURTH OF JULY.

MAV TEMPS WERE GENERALLY FOLLOWED FOR HIGHS WITH NEW GUIDANCE LOWER
THAN PREVIOUS OUTPUT. LOWS WERE RAISED 1-3 DEGREES MOST MORNINGS AS
CLOUDS AND WARM GROUND SHOULD KEEP TEMPS FROM FALLING TO DEWPOINT.
/ALLEN/

&&

.AVIATION...VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. THERE
COULD BE SOME BRIEF MVFR TO IFR CONDITIONS LATE TONIGHT AS THERE IS
SOME CHANCE OF STRONG STORMS AROUND GTR/CBM. CONFIDENCE TOO LOW AT
THIS POINT TO INCLUDE IN TAF OTHER THAN VCTS. FEW TO SCATTERED CU TODAY
WITH BASES FROM 4 TO 6 KFT AND SOUTH TO SOUTHWEST WINDS FROM 8 TO 15
MPH. ADDITIONAL TSRA MORE LIKELY FRIDAY AFTERNOON AND EVENING AHEAD
OF A COLD FRONT MOVING SOUTH. /28/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       74  94  74  90 /  21  22  50  14
MERIDIAN      72  94  73  92 /  25  31  61  19
VICKSBURG     73  96  73  91 /  18  14  39   9
HATTIESBURG   73  95  75  93 /  18  39  38  27
NATCHEZ       74  94  71  89 /   8  16  24   6
GREENVILLE    77  96  71  89 /  33  24  32   9
GREENWOOD     75  94  72  89 /  34  31  37  10

&&

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

DL/28/ALLEN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
314 PM CDT THU JUN 27 2013

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025-034-035-040-
041-047-053-059>061-282015-
ASHLEY-CHICOT-MOREHOUSE-WEST CARROLL-EAST CARROLL-RICHLAND-
MADISON LA-FRANKLIN LA-CATAHOULA-TENSAS-CONCORDIA-BOLIVAR-
SUNFLOWER-LEFLORE-WASHINGTON-HUMPHREYS-ISSAQUENA-SHARKEY-WARREN-
CLAIBORNE-JEFFERSON-ADAMS-FRANKLIN MS-
314 PM CDT THU JUN 27 2013

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

.DAY ONE...TONIGHT AND FRIDAY

STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE FRIDAY AFTERNOON AND
EVENING. THE MOST INTENSE STORMS COULD CONTAIN WIND GUSTS UP TO
60 MPH AS WELL AS HAIL UP TO THE SIZE OF QUARTERS. MANY STORMS
WILL BE CAPABLE OF PRODUCING FREQUENT CLOUD TO GROUND LIGHTNING
STRIKES AND HEAVY DOWNPOURS.

IN ADDITION...HOT AND HUMID CONDITIONS ARE ANTICIPATED ACROSS THE
AREA AGAIN FRIDAY. THE COMBINATION OF TEMPERATURE AND HUMIDITY
WILL BRING AFTERNOON HEAT INDEX VALUES TO NEAR 105 DEGREES FROM
MIDDAY INTO THE AFTERNOON.

.DAYS TWO THROUGH SEVEN...FRIDAY NIGHT THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS...MAY BE NEEDED FRIDAY AFTERNOON INTO FRIDAY NIGHT.

MSZ026>033-036>039-042>046-048>052-054>058-062>066-072>074-282015-
GRENADA-CARROLL-MONTGOMERY-WEBSTER-CLAY-LOWNDES-CHOCTAW-OKTIBBEHA-
HOLMES-ATTALA-WINSTON-NOXUBEE-YAZOO-MADISON MS-LEAKE-NESHOBA-
KEMPER-HINDS-RANKIN-SCOTT-NEWTON-LAUDERDALE-COPIAH-SIMPSON-SMITH-
JASPER-CLARKE-LINCOLN-LAWRENCE-JEFFERSON DAVIS-COVINGTON-JONES-
MARION-LAMAR-FORREST-
314 PM CDT THU JUN 27 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MISSISSIPPI.

.DAY ONE...TONIGHT AND FRIDAY

STRONG TO SEVERE THUNDERSTORMS MAY BE POSSIBLE LATE THIS EVENING INTO
TONIGHT. THE MOST INTENSE STORMS COULD CONTAIN WIND GUSTS UP TO 60
MPH AS WELL AS HAIL UP TO THE SIZE OF QUARTERS. MANY STORMS WILL BE
CAPABLE OF PRODUCING FREQUENT CLOUD TO GROUND LIGHTNING STRIKES AND
HEAVY DOWNPOURS.

STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE FRIDAY AFTERNOON AND
EVENING. THE MOST INTENSE STORMS COULD CONTAIN WIND GUSTS UP TO
60 MPH AS WELL AS HAIL UP TO THE SIZE OF QUARTERS. MANY STORMS
WILL BE CAPABLE OF PRODUCING FREQUENT CLOUD TO GROUND LIGHTNING
STRIKES AND HEAVY DOWNPOURS.

IN ADDITION...HOT AND HUMID CONDITIONS ARE ANTICIPATED ACROSS THE
AREA AGAIN FRIDAY. THE COMBINATION OF TEMPERATURE AND HUMIDITY
WILL BRING AFTERNOON HEAT INDEX VALUES TO NEAR 105 DEGREES FROM
MIDDAY INTO THE AFTERNOON.

.DAYS TWO THROUGH SEVEN...FRIDAY NIGHT THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS...MAY BE NEEDED FRIDAY AFTERNOON INTO EVENING.

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

28

MSZ018-019-280230-
SUNFLOWER MS-BOLIVAR MS-
851 PM CDT THU JUN 27 2013

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
851 PM CDT THU JUN 27 2013

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PENNY TO NICKEL SIZE HAIL
AND 40 TO 50 MPH WINDS WAS LOCATED OVER SHELBY AT 851 PM CDT...MOVING
SOUTH AT 25 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 EASTERN BOLIVAR AND NORTH CENTRAL SUNFLOWER COUNTIES SHOULD
MONITOR THIS STORM CLOSELY.

LAT...LON 3403 9065 3399 9065 3399 9060 3365 9059
      3366 9090 3404 9087
TIME...MOT...LOC 0151Z 000DEG 21KT 3394 9076

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