Severe Thunderstorm Warning 541, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
205 AM CDT WED JUL 11 2001

ON SATELLITE VAPOR IMAGERY...UPPER RIDGE WAS CONTINUING TO SHOW SOME
WEAKENING...AS UPPER LEVEL IMPULSES WERE TRIGGERING SCATTERED
CONVECTION ACROSS THE REGION ON TUESDAY. SOME BLOW OFF OF UPPER THIN
CLOUDS WERE ONCE AGAIN MOVING ACROSS THE REGION FROM THE NORTHWEST.
UNDER HUMID CONDITIONS SURFACE DEWPOINTS WERE IN THE LOWER TO
MIDDLE 70S. THERE WERE SOME ISOLATED SHOWERS AND THUNDERSTORMS OVER
CENTRAL MISSISSIPPI.

LOOKING AT THE SHORT TERM...GENERAL UPPER PATTERN WILL REMAIN UNCHANGE
THROUGH THURSDAY. A SHORTWAVE WILL MOVE SOUTHEASTWARD ACROSS THE
REGION WEDNESDAY INTO THURSDAY. THIS WILL PUSH A SURFACE BOUNDARY
TO THE CENTRAL SECTION BY THIS EVENING. BOTH THE AVN/ETA
MODELS KEEP THE SURFACE BOUNDARY AROUND THE THE CENTRAL SECTIONS
THROUGH THURSDAY...WHICH IS A CHANGE FROM THE PREVIOUS RUN OF THE
ETA MODEL. BY LATE THURSDAY AFTERNOON THE AVN/NGM MODEL PUSHES THE
BOUNDARY INTO SOUTHERN MISSISSIPPI...WHILE ETA KEEPS IT STATIONARY.
THE ETA COMES AROUND TO THE AVN SOLUTION BY EARLY FRIDAY...PUSHING
THE BOUNDARY TO THE SOUTHERN SECTION OF THE REGION. THE COMBINATION
OF THE FRONTAL BOUNDARY..DAYTIME HEATING...INSTABILITY...WEAKENING
UPPER RIDGE AND GOOD LOW LEVEL MOISTURE WILL PROVIDE THE MECHANISM
FOR SCATTERED CONVECTION.

THE MODELS PUT SOME DECENT QPF VALUES OF .25 INCH OR LESS WITH
ISOLATED AMOUNTS OF .5 INCH OR HIGHER FOR TODAY AND TONIGHT.
PRECIPITABLE WATER VALUES WILL RANGE FROM 1.5 TO 2.25 INCHES FOR
TODAY THROUGH THURSDAY. AS NOTED BY DAYSHIFT COULD GET SOME
BRIEF HEAVY RAINS.

FOR TODAY WILL PUT SCATTERED POPS ACROSS THE REGION WITH THE BEST
COVERAGE IN THE NORTH...AS THE FRONTAL BOUNDARY INVADES THAT REGION.
FOR TONIGHT AND THURSDAY WILL PUT BEST SCATTERED POPS ACROSS THE
CENTRAL AND SOUTHERN SECTIONS. FOR THURSDAY NIGHT WILL PUT THE
SAME SCATTERED POPS ACROSS THE COUNTY WARNING AREA...SINCE SPECIFICS
OF WEATHER PATTERN ARE NOT TOTALLY CLEAR AT THIS TIME. AS FAR AS
TEMPS ARE CONCERN WILL GO CLOSE TO PERSISTENCE FROM THE PREVIOUS
FORECAST.

EXTENDED PERIOD...FRIDAY THROUGH TUESDAY....
WITH SOME DIFFERENCES IN MODEL SOLUTIONS...GENERALLY THE UPPER
RIDGE AXIS WILL REMAIN JUST EAST OF THE 4 CORNERS REGION. THIS
WILL ALLOW MORE SHORT WAVES TO COME ON THE BACK SIDE OF THE
EASTERN US TROF FOR MORE SCATTERED CONVECTION THROUGH MONDAY.
ON SUNDAY INTO MONDAY THE UPPER RIDGE BEGINS TO REBUILD ACROSS THE REGION
FROM THE WEST AS WEST COAST TROF DEEPENS. THIS WILL ALLOW
TUESDAY TO BE RATHER DRY. SO WITH THIS IN MIND THE CURRENT EXTENDED
APPEARS TO BE ON TRACK.

PRELIM NUMBERS...
JAN 096/074 095/074 094 43433
MEI 096/073 095/072 092 42433

.JAN...
MS...NONE.
LA...NONE.
AR...NONE.
17

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
121200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
104 PM CDT WED JUL 11 2001

...THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON
INTO THIS EVENING...WITH ENOUGH INSTABILITY IN PLACE FOR A FEW OF
THESE THUNDERSTORMS TO BECOME SEVER. AN OUTFLOW BOUNDARY
STRETCHING ACROSS CENTRAL AND SOUTHEAST MISSISSIPPI WILL PROVIDE
THE FOCUS FOR THE BEST CHANCES FOR SEVERE WEATHER ACROSS THESE
AREAS. DAMAGING WINDS GUSTING TO 60 MPH AND HAIL TO THE SIZE OF
DIMES ARE THE PRIMARY THREATS.

ACTIVATION OF STORM SPOTTERS AND AMATEUR RADIO OPERATORS SHOULD
NOT BE NECESSARY THROUGH TONIGHT.

...SEASONAL THREATS...
HOT AND HUMID CONDITIONS WILL COMBINE TO PRODUCE DANGEROUS HEAT
INDEX VALUES OF AROUND 105 DEGREES THIS AFTERNOON...ACROSS
SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA...AND MUCH OF
MISSISSIPPI.

IF YOU MUST WORK OUTDOORS...TRY TO DO YOUR WORK DURING THE EARLY
MORNING OR LATE EVENING HOURS. DRINK PLENTY OF WATER...AND GET IN
THE SHADE AS OFTEN AS POSSIBLE.

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