Special Weather Statement, NWS Jackson, MS

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE JACKSON MS
1115 AM CDT WED MAY 30 2012

...SEVERE STORMS POSSIBLE THIS AFTERNOON WITH AN ADDITIONAL RISK LATER ON
THURSDAY...

.UPDATE...LATEST SATELLITE IMAGERY SHOWS AN OUTFLOW BOUNDARY
ASSOCIATED WITH AN MCV...WHICH CAME FROM SOME CONVECTION IN THE
SOUTHERN PLAINS OVERNIGHT. IT WAS MOVING TOWARD THE MS RIVER OVER
NORTHEAST LOUISIANA. ALSO A WEAK SURFACE BOUNDARY WAS NOTED ACROSS
THE NORTHWEST DELTA REGION. THESE FEATURES WILL HELP TO PROVIDE A
LOW LEVEL MECHANISM  FOR SOME POSSIBLE SEVERE WEATHER ACROSS THE
REGION FOR THIS AFTERNOON. HIGH RES MODELS FOCUS STORMS SPREADING
ACROSS THE REGION FROM THE WEST NORTHWEST FOR THIS AFTERNOON. ALSO A
SERIES OF WEAK DISTURBANCES WAS MOVING THROUGH THE SOUTHERN STREAM
FROM THE SOUTHERN PLAINS. UPPER AIR ANALYSIS SHOWS AN AREA OF
DIVERGENCE ALOFT MOVING TOWARD THE REGION FROM THE SOUTHERN PLAINS
WITH SOME APPROACHING SUBTROPICAL JET ENERGY. AT THIS TIME AREA
RADARS WERE SHOWS SOME ISOLATED TO SCATTERED ACTIVITY FROM ARK TO
NORTHEAST TEXAS. THE LOW LEVEL LOOKED PRETTY CAPPED THIS MORNING IN
UPPER AIR AND SATELLITE IMAGERY FOR MOST OF THE REGION. AREA
SOUNDINGS WERE PRETTY DRY COMPARED TO YESTERDAY. LOW LEVEL FLOW WAS
RATHER WEAK WITH MIDLEVEL FLOW AROUND 15 TO 20 KNOTS AND UPPER WEST
NORTHWEST FLOW AT 30 TO 35 KNOTS. CAPES AT JAN WERE OVER 3000.
DCAPES WERE OVER 1000. SO WITH THIS IN MIND HAVE DELAY THE START OF
THE CONVECTION IN THE GRIDS BY LOWERING THE POPS FOR LATE THIS
MORNING...BUT KEPT THE SAME DECENT POPS FOR THIS AFTERNOON. THE
PRIME TIME FOR CONVECTION STILL LOOKS TO BE BETWEEN NOON AND 7 PM.
MAIN RISK WILL CONTINUE TO HAIL AND DAMAGING WINDS. CURRENT HIGHS
STILL LOOK TO BE ON TRACK./17/

./PREVIOUS DISCUSSION...407 AM CDT WED MAY 30 2012
SHORT TERM...FORECAST FOCUS WILL BE ON CONVECTIVE POTENTIAL TODAY
AND THEN AGAIN LATER THU-THU NGT AS THE MAIN SYSTEM AND STRONG COLD
FRONT MOVE THROUGH THE REGION.

MAIN PLAYERS TODAY WILL BE THE STALLING FRONT OVER THE N/NE CWA AND
THE S/WV(MCV) THAT MOVES E/SE INTO THE AREA FROM THE SOUTHERN PLAINS
COMPLEX. ALL THE LATEST MODEL DATA SHOW THE SLOW MOVING SFC FRONT
JUST N/NE OF THE CWA MAKING SOME LOW PROGRESS EARLY TODAY AND
STALLING OVER A PORTION OF THE AREA. WITH MORE OF A NE PUSH TO THE
LOW LEVEL FLOW...THE STALLING FRONT WILL TAKE AN INTERESTING
ORIENTATION WITH A MUCH MORE PRONOUNCED SE SAG OVER THE NE/E-CENTRAL
PART OF THE CWA. WITH MORE OF THIS BOUNDARY INTO THE CWA...LOOK FOR
BETTER LOW LEVEL CONVERGENCE ASSOCIATED WITH THIS FEATURE. THE OTHER
MAJOR PLAYER IS THE REMNANT MCV THAT WILL MOVE THROUGH THE CWA FROM
THE CURRENT SOUTHERN PLAINS STORM COMPLEX. LOOK FOR THE COMBINATION
OF THESE FEATURES TO SUPPORT A MORE FAVORABLE SETUP OVER THE CWA FOR
STORMS TODAY. THE GLOBAL MODELS INDICATE THESE SUCH FEATURES BUT
OFFER DIFFERING SOLUTIONS IN HOW PRECIP DEVELOPS. WHAT GUID IS MOST
CONSISTENT AND REPRESENTS THE MASS FIELDS IN ITS QPF OUTPUT IS THE
HI-RES MODELS. ALL FOUR (SPC WRF/NSSL WRF/NMM/ARW NCEP WRF'S) ARE IN
SOLID AGREEMENT ON CONVECTIVE POTENTIAL TODAY AND DEVELOP QUITE A
BIT OF STORMS OVER THE CWA. THIS MULTI CONSENSUS OUTPUT MAKES SENSE
AND WILL BE THE PRIMARY BASIS FOR THE NEXT 12-24 HRS OF THE FORECAST.

ALL MODELS CONTINUE TO SHOW COOLING ALOFT AND LINGERING LOW LEVEL
WARMTH TODAY. THIS WILL RESULT IN VERY STEEP LAPSE RATES WITH 29-30
VERTICAL TOTALS. THIS THERMO SETUP WILL YIELD AN UNSTABLE
ENVIRONMENT AS TEMPS RISE TO THE LOWER 90S AND COMBINE WITH
MID/UPPER 60S SFC DEWPTS. LOOK FOR A RANGE OF 2000-3000 J/KG OF
ML/SBCAPE WITH LI'S (-9 TO -12) SUPPORTING ROBUST UPDRAFTS AS MID
LEVEL FORCING INCREASES FOR AFTERNOON. LOW LEVEL FLOW BELOW 700MB
WILL BE WEAK BUT STRONGER MID/UPPER FLOW WILL EXIST IN RESPONSE TO
THE S/WV. MID LEVEL FLOW OF 20-25KTS WILL BE POSSIBLE AND HIGHER
VALUES ARE NOT OUT OF THE QUESTION DEPENDING ON INFLUENCES OF THE
MCV. LIMITATIONS ARE ANY ENHANCED CAPPING AND LINGERING DRY AIR
WHICH WAS AROUND YESTERDAY AND SUPPRESSED EVEN CLOUD DEVELOPMENT.
OVERALL...LOOK FOR A FAIRLY EVEN MIX OF SVR HAIL AND DAMAGING WIND
GUSTS BASED OFF THE MULTI-CELL APPEARANCE OF THE HI-RES CONVECTIVE
STORM MODE. DMG WIND COULD DOMINATE IF STRONGER FLOW DEVELOPS ALOFT
AND A WELL DEVELOPED COLD POOL GETS GOING. AS FOR HAIL...QUARTER TO
GOLFBALL SIZE FITS THE THERMO SETUP WITH A FEW LARGER STONES
POSSIBLE IF THINGS SETUP JUST RIGHT. AS FOR TIMING...THINGS COULD
GET GOING AS EARLY AS 11AM BUT THE MAIN TIMEFRAME LOOKS TO BE
BETWEEN NOON AND 7PM.

AS FOR FORECAST SPECIFICS...GUID POPS WERE WAY TOO LOW AND VALUES
WERE SIGNIFICANTLY INCREASED. POPS WILL BE IN THE 40-60% RANGE WHICH
I FEEL IS A MUCH BETTER REPRESENTATION OF WHAT'S EXPECTED. GUID HIGH
TEMPS WERE DECENT AND FIT THE TREND OF A QUICK WARMUP WITH THE UPPER
END JUST A TAD LESS THAN PREV DAYS. AS FOR TONIGHT...HAVE LOWERED
POPS ACROSS THE N HALF DUE TO EXPECTED EARLY START TO THE STORMS
TODAY. WHILE SOME LOW END CHANCES WILL EXIST TONIGHT...MOST OF THIS
PERIOD WILL BE IN THE LULL BEFORE ACTIVITY INCREASES FOR THU
AFTERNOON.

FOR THU-THU NGT...MODELS CONTINUE TO BE IN DECENT AGREEMENT ON THE
POTENT UPPER TROUGH AND STRONG LATE SEASON COLD FRONT TO MOVE
THROUGH THE CWA. STORM EVOLUTION IS NOT AS CLEAR DUE TO THE COMPLEX
EVOLUTION OF THE NEAR TERM STORM SYSTEMS. HOWEVER...CONDITIONS WILL
EXIST FOR MORE STORMS DUE TO INCREASING MOISTURE AND STRONG LIFT.
INCREASING WIND FIELDS WILL ALSO ADD TO THE SITUATION AND AS
EVERYTHING COMBINES...MORE SEVERE STORMS WILL BE POSSIBLE. AT THIS
POINT...LATE THU AFTERNOON AND EVENING SEEM TO BE THE MAIN TIME FOR
THE MOST ROBUST STORMS AND GREATEST COVERAGE OF STORMS. DAMAGING
WINDS AND HAIL WILL BE THE PRIMARY RISK. HOWEVER...WIND SHEAR WILL
INCREASE THU NGT AND THERE COULD BE A PERIOD WHERE A TORNADO OR TWO
MAY BE POSSIBLE. JUST SOMETHING TO KEEP AN EYE ON. /CME/

.LONG TERM... (FRIDAY THROUGH WEDNESDAY)
THE LONG TERM PORTION OF THE FORECAST WILL FEATURE A BRIEF BREAK
FROM ABOVE NORMAL TEMPS FRIDAY INTO SATURDAY...FOLLOWED BY
MODERATING CONDITIONS FOR THE LATE WEEKEND INTO EARLY NEXT WEEK.

LATEST GUIDANCE HAS SPED UP THE TIMING OF THE COLD FRONT...WITH THE
BOUNDARY PUSHING EAST OF THE CWA BY DAYBREAK FRIDAY AND LINGERING
SHOWER ACTIVITY MOVING OUT OF THE AREA BEFORE NOON. THE ASSOCIATED
UPPER TROUGH WILL SHIFT EASTWARD AND SET UP SHOP OVER THE ATLANTIC
SEABOARD OVER THE WEEKEND AND INTO NEXT WEEK...WITH UPPER RIDGING
BUILDING OVER THE GREAT PLAINS. THIS WILL PLACE THE AREA IN
NORTHWEST FLOW ALOFT. UNFORTUNATELY...OR FORTUNATELY DEPENDING UPON
ONES PERSPECTIVE...THE SURFACE HIGH PRESSURE AXIS WILL HAVE ALREADY
SHIFTED EAST THE REGION BY LATE SATURDAY. THUS THE RESPITE FROM
SUMMERLIKE TEMPERATURES WILL BE RATHER BRIEF AS RETURN FLOW
COMMENCES LATE SATURDAY/SUNDAY.

THE HIGH CENTER WILL REMAIN SITUATED OVER THE EASTERN GULF THROUGH
NEXT WEEK...WITH PWATS RETURNING TO AROUND 1.5 INCHES AS EARLY AS
SUNDAY. AS UPPER DISTURBANCES TRAVERSE THE REGION IN NORTHWESTERLY
FLOW...ISOLATED CONVECTION WILL BE POSSIBLE ALONG THE PERIPHERY OF
THE SURFACE RIDGE. 00Z GUIDANCE INDICATES ISOLATED RAIN CHANCES WILL
INITIALLY BE CONFINED TO NORTHERN SECTIONS OF THE CWA...WITH BETTER
CHANCES ACROSS THE REMAINDER OF THE AREA BY WEDNESDAY. MEANWHILE
DAYTIME HIGH TEMPS IN THE LOW TO MID 90S WILL MAKE A RETURN.

WITH RESPECT TO FORECAST DETAILS...TEMPERED MEX POPS AND TENDED
TOWARD ECMWF FOR LATE THIS WEEKEND AND EARLY NEXT WEEK. GIVEN THE
INFLUENCE OF NWLY FLOW ALOFT...MORE THAN ONE ROUND OF PRECIPITATION
WILL BE POSSIBLE IN THIS TIME PERIOD...BUT NOT PARTICULARLY
CONFIDENT IN GOING AS HIGH AS THE GFS IS FOR EACH PERIOD AS IT IS
DIFFICULT TO PIN DOWN A FAVORED TIME FRAME THIS FAR OUT.
OTHERWISE...NO SIGNIFICANT ADJUSTMENTS WERE MADE TO MEX TEMPS DURING
THE PERIOD. /DL/

&&

AVIATION...VFR CONDITIONS HAVE RESUMED ACROSS THE AREA WITH SKC
ONGOING ACROSS TAF SITES. CONVECTION EXPECTED TO DEVELOP THIS AFTN
AND PUSH GENERALLY E/SE ACROSS THE AREA. TIMING LOOKS TO BE AS EARLY
AS 17Z. STORMS COULD BRING GUSTY WINDS AND HAIL ALONG WITH MVFR TO
IFR VIS RESTRICTIONS. AFTER STORMS PASS(LIKELY AFTER 00-02Z)...VFR
CONDITIONS EXPECTED TO PREVAIL FOR NEARLY ALL OF THE NIGHT PERIOD.
/28/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       94  69  88  66 /  62  30  48  73
MERIDIAN      95  68  89  67 /  48  25  33  69
VICKSBURG     93  69  87  61 /  59  31  56  71
HATTIESBURG   96  71  89  71 /  35  20  32  49
NATCHEZ       91  71  86  65 /  52  26  45  65
GREENVILLE    94  70  88  61 /  61  28  71  68
GREENWOOD     94  68  89  62 /  59  31  65  73

&&

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

17/28/CME/DL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
226 PM CDT WED MAY 30 2012

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
311930-
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-
226 PM CDT WED MAY 30 2012

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

.DAY ONE...TONIGHT THROUGH THURSDAY NIGHT

SEVERE STORMS WILL BE POSSIBLE TODAY AS A DISTURBANCE MOVING OUT OF
SOUTHERN ARKANSAS COMBINES WITH A STALLED BOUNDARY. THE MAIN TIME FOR
THIS SEVERE ACTIVITY WILL BE UNTIL 7 PM. THE MAIN RISK WILL BE FOR
DAMAGING WIND GUSTS AND HAIL UP TO GOLF BALL SIZE.

SEVERE STORMS WILL AGAIN BE POSSIBLE THURSDAY AFTERNOON INTO
THURSDAY NIGHT AS A POTENT DISTURBANCE AND STRONG COLD FRONT MOVE
THROUGH THE REGION. THE PRIMARY RISKS WILL BE DAMAGING WIND GUSTS AND
QUARTER SIZED HAIL OR LARGER. ONE OR TWO TORNADOES CAN NOT BE RULED
OUT FOR THURSDAY NIGHT AS WIND SHEAR INCREASES. LOCALLY HEAVY
RAINFALL WILL ALSO BE POSSIBLE...ESPECIALLY WHERE STORMS MOVE
REPEATEDLY OVER THE SAME AREAS.

.DAYS TWO THROUGH SEVEN..FRIDAY THROUGH TUESDAY

NO WIDESPREAD HAZARDOUS WEATHER IS EXPECTED FOR THE PERIOD.

.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 LATER TODAY AND THURSDAY INTO THURSDAY NIGHT.

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

17

MSZ018-301810-
BOLIVAR MS-
1239 PM CDT WED MAY 30 2012

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
1239 PM CDT WED MAY 30 2012

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PENNY TO NICKEL SIZE HAIL
AND 40 TO 50 MPH WINDS WAS LOCATED 4 MILES NORTHEAST OF BENOIT AT
1240 PM CDT...MOVING NORTHEAST AT 20 MPH.

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

PEOPLE IN SOUTHERN BOLIVAR COUNTY SHOULD MONITOR THIS STORM CLOSELY.

LAT...LON 3385 9084 3364 9073 3353 9110 3359 9115
      3362 9114 3365 9119 3369 9122 3371 9117
      3367 9111 3368 9104 3371 9107 3370 9112
      3372 9114
TIME...MOT...LOC 1740Z 243DEG 18KT 3370 9092

JC

MSZ034-301810-
WASHINGTON MS-
1241 PM CDT WED MAY 30 2012

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
1241 PM CDT WED MAY 30 2012

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PENNY TO NICKEL SIZE HAIL
AND 40 TO 50 MPH WINDS WAS LOCATED OVER LELAND AT 1241 PM CDT...
MOVING NORTHEAST AT 10 MPH.

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

PEOPLE IN WASHINGTON COUNTY SHOULD MONITOR THIS STORM CLOSELY.

LAT...LON 3337 9076 3314 9095 3322 9109 3328 9105
      3328 9108 3324 9110 3329 9114 3335 9114
      3342 9106 3345 9106 3339 9112 3338 9116
      3342 9117 3343 9113 3347 9112 3350 9117
      3353 9109 3353 9077
TIME...MOT...LOC 1741Z 224DEG 9KT 3342 9093

JC

ARZ075-MSZ034-301915-
CHICOT AR-WASHINGTON MS-
134 PM CDT WED MAY 30 2012

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
134 PM CDT WED MAY 30 2012

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PENNY TO NICKEL SIZE HAIL
AND 40 TO 50 MPH WINDS WAS LOCATED 3 MILES WEST OF GREENVILLE AT 135
PM CDT...MOVING EAST AT 10 MPH.

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

PEOPLE IN NORTHERN WASHINGTON AND NORTHEASTERN CHICOT COUNTIES SHOULD
MONITOR THIS STORM CLOSELY.

LAT...LON 3332 9082 3327 9115 3352 9122 3353 9086
      3353 9083
TIME...MOT...LOC 1835Z 257DEG 11KT 3338 9108

JC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
139 PM CDT WED MAY 30 2012

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

0137 PM     HAIL             GREENVILLE              33.39N 91.05W
05/30/2012  E0.88 INCH       WASHINGTON         MS   EMERGENCY MNGR

            DIME TO NICKEL SIZE HAIL

&&

AWEBER

MSZ018-019-025-301920-
SUNFLOWER MS-LEFLORE MS-BOLIVAR MS-
141 PM CDT WED MAY 30 2012

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
141 PM CDT WED MAY 30 2012

A LINE OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING PENNY TO NICKEL
SIZE HAIL AND 40 TO 50 MPH WINDS WAS LOCATED FROM 4 MILES EAST OF
RENOVA TO 4 MILES SOUTH OF INVERNESS AT 141 PM CDT...MOVING EAST AT
25 MPH.

VERY HEAVY RAIN ALONG WITH CONTINUOUS CLOUD TO GROUND LIGHTNING ARE
ALSO POSSIBLE WITH THESE STORMS.

PEOPLE IN SOUTHEASTERN BOLIVAR...WESTERN LEFLORE AND SUNFLOWER
COUNTIES SHOULD MONITOR THESE STORMS CLOSELY.

LAT...LON 3381 9035 3331 9032 3331 9034 3328 9036
      3328 9037 3324 9037 3324 9042 3327 9046
      3333 9046 3333 9056 3327 9056 3327 9076
      3379 9078
TIME...MOT...LOC 1841Z 273DEG 22KT 3377 9064 3329 9058

JC

MSZ039-302045-
NOXUBEE MS-
300 PM CDT WED MAY 30 2012

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
300 PM CDT WED MAY 30 2012

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PEA TO DIME SIZE HAIL AND
40 MPH WINDS WAS LOCATED 3 MILES NORTH OF GHOLSON AT 259 PM
CDT...MOVING NORTHEAST AT 10 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 NOXUBEE COUNTY SHOULD MONITOR THIS STORM
CLOSELY.

LAT...LON 3300 8861 3300 8860 3293 8861 3293 8875
      3293 8876 3292 8881 3308 8881 3304 8860
TIME...MOT...LOC 1959Z 235DEG 8KT 3299 8871

19