Severe Thunderstorm Warning 166, NWS Jackson, MS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
345 AM CDT WED APR 4 2001

LATEST SURFACE ANALYSIS INDICATES A FRONTAL BOUNDARY APPROACHING THE
NORTHEAST CORNER OF THE CWFA. SHORTWAVE OVER EASTERN TEXAS CAN BE
SEEN MOVING STEADILY EAST ON THE WATER VAPOR LOOP. AIRMASS IS MOIST
WITH DEWPOINTS IN THE MID AND UPPER 60S ACROSS THE REGION.

ANOTHER LOW CONFIDENCE FORECAST ON TAP FOR THIS PACKAGE. ETA SEEMS
TO HAVE COME MORE INTO LINE WITH THE AVN...BUT PERFORMANCE WISE AVN
HAS PROVED ITSELF SUPERIOR TO THE ETA IN THE LAST COUPLE OF
DAYS...SO WILL LEAN MORE HEAVILY ON THE AVN AGAIN. SEVERAL
UNCERTAINTIES IN THE FORECAST...BOTH SYNOPTIC SCALE AND MESOSCALE.

500MB RIDGING FORECAST TO BUILD OVER THE SOUTHEAST AND SLOWLY MOVE
EAST THROUGH 120HOURS. UPPER FLOW SHOULD BECOME MORE SOUTHWEST BY
LATE FRIDAY. SEVERAL SHORTWAVES WILL COME THROUGH THE FLOW. AT THE
SURFACE...FRONTAL BOUNDARY TO THE NORTH WILL VERY SLOWLY SINK
SOUTHWARD THROUGH TODAY AND IS VERY HARD TO FIND IN THE SURFACE AND
WIND PATTERN BY THU AFTERNOON. GRADIENT BEGINS TO TIGHTEN EARLY
FRIDAY AS HIGH PRESSURE BUILDS DOWN THE EAST COAST AND LOW PRESSURE
OVER THE PLAINS DEEPENS AND BEGINS MOVING EAST. ASSOCIATED BOUNDARY
WILL BE APPROACHING THE MS RIVER OVERNIGHT FRIDAY...BUT AS THE BEST
DYNAMICS SHOOT WELL NORTH OF HERE...BOUNDARY SEEMS TO GET HUNG OVER
NORTH CENTRAL MS AND BECOME SOMEWHAT DIFFUSE BY LATE SAT.

IN THE SHORT TERM...ENTIRE AREA PRETTY UNSTABLE. LIS ARE FORECAST TO
RANGE FROM -4 TO -6 OVER MOST AREAS TODAY. CAPES RANGE FROM 2-3K
J/KG IN THE NORTH AND CENTRAL AREAS. BROAD UPPER DIVERGENCE ALSO
EXISTS IN THESE AREAS.  HARD TO TELL WHAT WILL FOCUS PRECIP TODAY
(OR WHAT AREAS WILL STAY CAPPED)...MESOSCALE BOUNDARY LAID DOWN BY
EARLIER CONVECTION COULD GET PRECIP STARTED...SHORTWAVE WILL ENHANCE
PRECIP...SOUTHWARD MOVING FRONTAL BOUNDARY COULD ALSO PROVIDE A LOW
LEVEL FOCUS...PLUS A 330K THETA E RIDGE ACROSS CENTRAL SECTIONS.

BREAKING IT DOWN: BEST DYNAMICS WILL BE IN THE NORTH TODAY.
SHORTWAVE OVER EAST TX WILL MOVE EAST TODAY AND CROSS THE NORTHERN
TIER OF ZONES IN THE FIRST 12 HOURS OF THE FORECAST PERIOD. WITH
CLOSE PROXIMITY OF WARM FRONT IN THAT REGION...THINK HIGH END POPS
FOR TODAY ARE WARRANTED. FOR CENTRAL AREAS...THETA E RIDGE IN PLACE
ALONG THE INTERSTATE 30 CORRIDOR. 88D SHOWING SOME SHOWERS
DEVELOPING OVER NORTHEAST LA AND MOVING EAST ALONG THIS FEATURE. IN
TALKING WITH SPC...SOME BACK BUILDING FROM COMPLEX OVER AL IS
POSSIBLE ALONG THIS RIDGE...SO WILL INCLUDE CHANCE POPS IN THIS
REGION FOR TODAY. IN THE SOUTH NO REAL STRONG FOCUSING FEATURE TO
NAIL DOWN...BUT WILL HAVE CHANCE POPS IN PLACE.

FOR TONIGHT...POPS WILL BEGIN DECREASING AS SHORTWAVE MOVES EAST AND
FRONTAL BOUNDARY BECOMES DIFFUSE. WILL LEAVE IN CHANCE POPS FOR ANY
LINGERING PRECIP. THURSDAY AFTERNOON AND THURSDAY NIGHT LOOK DRY AND WARM.

EXTENDED LOOKS FINE AND WILL MAKE ONLY COSMETIC CHANGES FOR SLIGHT
ZONE RE-ARRANGEMENT.

AS FAR AS QPF GOES...AVN HAS BEEN DOING MUCH BETTER THAN THE ETA.
STILL KEEPS AXIS OF BEST PRECIP ACROSS NORTH AND CENTRAL AREAS.
NCEP>S AMOUNTS LOOK REASONABLE.

TEMP GUIDANCE LOOKS GOOD. POPS ALSO LOOK REASONABLE.

.PRELIM NUMBERS
JAN 82/65/84/63 4300
MEI 83/65/86/62 5300

.JAN...
MS...NONE.
LA...NONE.
AR...NONE.
32

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>
074-051200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
600 AM CDT WED APR 04 2001

...THUNDERSTORMS...
SCATTERED SEVERE THUNDERSTORMS ARE POSSIBLE ALONG AND WEST OF A LINE
FROM GRENADA TO CARTHAGE TO LAUREL. ONLY ISOLATED SEVERE
THUNDERSTORMS ARE POSSIBLE WEST AND SOUTH OF THIS LINE.

AN UPPER LEVEL DISTURBANCE AND A SOUTHWARD MOVING FRONTAL BOUNDARY
WILL COMBINE IN THE EASTERN PORTIONS TO ENHANCE THUNDERSTORM
DEVELOPMENT. SCATTERED SEVERE THUNDERSTORMS CONTAINING LARGE
HAIL...VERY GUSTY WINDS AND TORRENTIAL RAINFALL ARE POSSIBLE OVER
THIS AREA.

FOR ALL OTHER AREAS...ISOLATED SEVERE STORMS ARE POSSIBLE. GENERAL
INSTABILITY AND OUTFLOW BOUNDARY WILL ACT TOGETHER TO FIRE
THUNDERSTORM ACTIVITY. LARGE HAIL WILL BE THE MAIN THREAT FROM THESE
STORMS.

PERSONS SHOULD KEEP ABREAST OF THE LATEST WEATHER DEVELOPMENTS
TONIGHT. BE PREPARED FOR RAPIDLY CHANGING WEATHER CONDITIONS
AND KEEP A NOAA WEATHER RADIO NEAR YOUR BED-SIDE.

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

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>
074-051200-

HAZARDOUS WEATHER OUTLOOK ...CORRECTED...
NATIONAL WEATHER SERVICE JACKSON MS
600 AM CDT WED APR 04 2001

...THUNDERSTORMS...
SCATTERED SEVERE THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF A LINE
FROM GRENADA TO CARTHAGE TO LAUREL. ONLY ISOLATED SEVERE
THUNDERSTORMS ARE POSSIBLE WEST AND SOUTH OF THIS LINE.

AN UPPER LEVEL DISTURBANCE AND A SOUTHWARD MOVING FRONTAL BOUNDARY
WILL COMBINE IN THE EASTERN PORTIONS TO ENHANCE THUNDERSTORM
DEVELOPMENT. SCATTERED SEVERE THUNDERSTORMS CONTAINING LARGE
HAIL...VERY GUSTY WINDS AND TORRENTIAL RAINFALL ARE POSSIBLE OVER
THIS AREA.

FOR ALL OTHER AREAS...ISOLATED SEVERE STORMS ARE POSSIBLE. GENERAL
INSTABILITY AND OUTFLOW BOUNDARY WILL ACT TOGETHER TO FIRE
THUNDERSTORM ACTIVITY. LARGE HAIL WILL BE THE MAIN THREAT FROM THESE
STORMS.

PERSONS SHOULD KEEP ABREAST OF THE LATEST WEATHER DEVELOPMENTS
TONIGHT. BE PREPARED FOR RAPIDLY CHANGING WEATHER CONDITIONS
AND KEEP A NOAA WEATHER RADIO NEAR YOUR BED-SIDE.

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