Severe Thunderstorm Warning 337, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
320 PM CDT SUN MAY 27 2001

UPPER LOW OVER GREAT LAKES...WITH WARM FRONT STRETCHING FROM CENTRAL
MS TO AR INTO PLAINS. ABUNDANT MOISTURE OVER CWFA IN SUSTAINED S TO
SW FLOW. ATTM...WIDELY SCATTERED THUNDERSTORMS DEVELOPING. MSAS LIS
IN -4 TO -8 RANGE OVER CWFA. POTENTIAL FOR SEVERE WEATHER TONIGHT.

AIRMASS EXPECTED TO FURTHER DESTABILIZE THROUGH EVENING AS NEXT
SHORTWAVE APPROACHES. JET INTENSIFIES...WITH LOWER MS RIVER VALLEY
IN FAVORABLE LEFT FRONT QUADRANT. RUC CAPES 2500 J/KG TO 4500+ J/KG
THROUGH EVENING...WITH GREATEST VALUES ACROSS CENTRAL ZONES. MES0-
ETA SOUNDINGS NOT QUITE AS STRONG AS EARLY ON. HOWEVER...BY 06Z
MON...MESO-ETA CRANKS 2500 J/KG TO 3000+ J/KG OVER CENTRAL ZONES.
THOUGH TIMING SLIGHTLY DIFFERS BETWEEN MODELS...WILL MENTION
ISOLATED SEVERE TONIGHT.

SOME DISAGREEMENT ON INTENSITY OF SYSTEMS THROUGH FORECAST. ALSO
TEMPORAL/SPATIAL DIFFERENCES IN SOLUTIONS. MODELS CONTINUE PREVIOUS
TRENDS...WITH MORE SHORTWAVES PUSHING ACROSS AREA IN W-NW FLOW
ALOFT. LEANED TOWARDS ETA SOLUTION THROUGH 00Z TUE. CONSENSUS
FORECAST AFTER 00Z TUE... WITH FRONT MOSTLY OVER NRN ZONES. MORE
TOWARDS NOGAPS SOLUTION FOR EXTENDED.

UPPER LOW OVER GREAT LAKES SHIFTING E THROUGH MON. UPPER RIDGE OVER
ROCKIES GRADUALLY SHIFTING E. SIGNIFICANT SHORTWAVE PUSHES INTO
LOWER MS RIVER VALLEY MON THEN INTO ERN ZONES MON NIGHT...AS ANOTHER
SHORTWAVE AT MS RIVER. MODELS DIFFER ON JUST WHERE WARM FRONT
BECOMES ALIGNED/WHEN. ETA WAVERS BOUNDARY FROM NRN TO CENTRAL ZONES
THROUGH 00Z TUE...WHILE AVN PUSHES FRONT INTO NRN ZONES/LEAVES IT
NEAR STATIONARY OVER N MS/AR UNTIL 06Z TUE. AIRMASS UNSTABLE AGAIN
MON NIGHT...WITH OMEGA VALUES FORECAST IN -4 TO -8 RANGE. CAPE
VALUES AROUND 2000 J/KG IN SOUNDING PROGS. THROUGH MON...HEAVIEST
RAINFALL PROGGED OVER NRN ZONES...WITH PRECIP WATER VALUES AVERAGING
NEAR 1.5. TUE/TUE NIGHT BASICALLY A REPEAT ACTION. AXIS OF HEAVIEST
RAINFALL SHIFTS INTO CENTRAL ZONES TUE.

AVN SCENARIO INTERESTING. AFTER 06Z TUE...AVN PUSHES WARM FRONT INTO
CENTRAL ZONES AS LARGE HIGH PRESSURE AREA BECOMES CENTERED OVER IL.
AS SURFACE HIGH BUILDS OVER MID MS RIVER VALLEY...MODEL PUSHES FRONT
INTO S MS BY 18Z TUE. NRN ZONES DRY OUT/PRECIP WATER VALUES DIP
BELOW 1. BY 06Z WED...AVN PUSHES FRONT TO GULF COAST...THOUGH
PRECIP WATER VALUES OVER MOST OF CWFA AROUND 1.5.

.EXTENDED FORECAST...
TX LOW PRESSURE AREA EXPECTED TO DEEPEN WED/LIFT NE INTO PLAINS BY
THU...WITH TRAILING COLD FRONT TO PUSH INTO LOWER MS RIVER VALLEY. A
WARM FRONT DEVELOPS OVER LOWER MS RIVER VALLEY AFTER 18Z WED...WITH
PRECIP WATER VALUES WELL OVER 1.5. AVN SEEMS TO WEAKEN TX SYSTEM/
LAG COLD FRONT BACK OVER PLAINS. BY 18Z THU...AVNS FRONT REACHES
ARLATX THEN PUSHES INTO NRN MS BY 06Z FRI.

NOGAPS DEVELOPS CLOSED SURFACE LOW PRESSURE AREA OVER CENTRAL PLAINS
BY 00Z THU...WITH ASSOCIATED COLD FRONT INTO SRN PLAINS. NOGAPS
FRONT INTO ARLATX BY 12Z THU/INTO NRN MS BY 00Z FRI. MODEL IMPROVES
CONDITIONS AFTER 12Z FRI/PUSHES FRONT TO SRN ZONES BY 00Z SAT.

ETA/AVN/NOGAPS DYNAMICS SUPPORT POSSIBILITY OF THUNDERSTORMS THROUGH
EXTENDED. DIURNAL HEATING WITH SHORTWAVES WILL PROVIDE BUMPY RIDE
THROUGH NEXT SEVERAL DAYS. POTENTIAL FOR HEAVY RAINFALL WILL
REMAIN...PARTICULARLY FOR STORMS FORMING INVOF ANY SYNOPTIC OR
MESO-SCALE BOUNDARIES.

PRELIM NUMBERS:
JAN 67/85/66/86  4433
MEI 66/85/65/86  4433

.JAN...
MS...NONE.
LA...NONE.
AR...NONE.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
154 PM CDT SUN MAY 27 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ...COUNTY LOCATION....

0128 PM                              MS   0.88 INCH HAIL
05/27/01   HOLMES                         GREENWOOD EOC REPORTED
                                          NICKEL HAIL ON THE
                                          HOLMES/LEFLORE COUNTY
                                          LINE JUST EAST OF HWY 49.

0128 PM                              MS   0.88 INCH HAIL
05/27/01   LEFLORE                        GREENWOOD EOC REPORTE
                                          NICKEL HAIL ON THE
                                          LEFLORE/HOMLES COUNTY
                                          LINE.

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-2812
00-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
300 PM CDT SUN MAY 27 2001

...THUNDERSTORMS...
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH TONIGHT ACROSS EXTREME
SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA...AND MUCH OF MISSISSIPPI.
THE BEST COVERAGE OF SEVERE THUNDERSTORMS WILL OCCUR LATE THIS
AFTERNOON OVER PORTIONS OF EAST CENTRAL MISSISSIPPI...FROM KOSCIUSKO
AND CARTHAGE...TO MACON AND MERIDIAN. LARGE HAIL AND DAMAGING WINDS
WILL BE THE PRIMARY SEVERE WEATHER THREATS. ACTIVATION OF STORM
SPOTTERS MAY BE NECESSARY THROUGH TONIGHT...ESPECIALLY OVER EAST
CENTRAL PORTIONS OF MISSISSIPPI.

THE AIRMASS OVER THE LOWER MISSISSIPPI VALLEY REGION WILL BE MOIST
AND HIGHLY UNSTABLE. A FAVORABLE UPPER LEVEL ENVIRONMENT WILL HELP
INITIATE THUNDERSTORM COMPLEXES THAT WILL MOVE EAST ACROSS THE
REGION THROUGH TONIGHT. THE DEGREE OF INSTABILITY COMBINED
WITH A FAVORABLE UPPER LEVEL WIND PROFILE WILL ALLOW SOME OF THE
THUNDERSTORMS TO BECOME SEVERE.

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