Severe Thunderstorm Warning 1, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
230 PM CST SAT FEB 15 2002

...FORECAST CHALLENGES...
MAIN FORECAST QUESTIONS ON THE SHORT TERM FOR THIS PACKAGE CONCERN
THE POTENTIAL FOR SOME HEAVY RAINFALL AND SEVERE POTENTIAL FOR TONIGHT WITH
THE SLOW SPEED OF THE DEPARTING SYSTEM. FOR SUNDAY IT WILL BE THE
LINGERING LIGHT RAIN IN THE MORNING WITH LITTLE TEMPERATURE RANGES
AFTER THE FRONTAL PASSAGE. FOR SUNDAY NIGHT THROUGH MONDAY NIGHT IT
WILL BE MAINLY TEMPS. FOR THE LONG TERM IT WILL BE TO DETERMINE
THE CHANCES OF RAIN AS MOISTURE GRADUALLY INCREASES AHEAD OF A
SOUTHERN STREAM SYSTEM FOR FRIDAY AND SATURDAY. OTHERWISE IT WILL BE
MAINLY TEMPS FOR TUESDAY THROUGH THURSDAY.

...CURRENTLY...
SATELLITE IMAGERY SHOWS BAND OF STONG CONVECTION FROM SOUTH CENTRAL
LOUISIANA INTO SOUTHWEST MISSISSIPPI THIS AFTERNOON...GENERALLY
ALONG GOOD LOW LEVEL WARM ADVECTION AND 250 SPEED MAX. THIS WAS
ASSOCIATED WITH A BROAD UPPER TROUGH MOVING ACROSS THE CENTRAL AND
SOUTHERN PLAINS. THERE WERE SEVERAL STRONG SHORT WAVES APPROACHING
THE LOWER MISSISSIPPI VALLEY. THE COLD FRONT WAS LOCATED FROM
ARKANSAS THROUGH LOUISIANA AND WAS APPROACHING THE DELTA REGION WITH
DEWPOINTS IN THE LOWER 60S AHEAD OF THE FRONT. PRECIPITABLE WATER
WAS RUNNING AT AROUND 1.5 INCHES.

SHORT TERM...TONIGHT THROUGH MONDAY NIGHT...
THE AVN/ETA WERE CONVERGING TOWARD THE UKMET SOLUTION IN THE UPPER LEVELS
THROUGH MONDAY NIGHT. FOR TONIGHT THE BROAD UPPER TROUGH WILL
APPROACH THE REGION...SENDING A COLD FRONT THROUGH. THE BEST
HELICITY/SHEAR WILL BE ALONG THE FRONTAL BOUNDARY. SHOWERS AND
THUNDERSTORMS WILL BEGIN TO DECREASE FROM THE WEST MAINLY AFTER
MIDNIGHT. WILL PUT A FEW POSSIBLY SEVERE OVER THE EAST/SOUTHEAST
EARLY THIS EVENING...WHERE INSTABILITY WILL BE A LITTLE BETTER WITH
VGP NEAR .2  AND EHI .3 TO .45 JUST AHEAD OF THE FRONTAL PASSAGE.
CHECKING JET STRUCTURE A WEAK LOW LEVEL JET WILL BE OVER THE
EAST/SOUTHEAST THIS EVENING...ALONG WITH A WEAK SPEED MAX. LAPSE
RATES WILL BE AROUND 6 DEGREES. ELSEWHERE A FEW OF THE STORMS COULD
BE STRONG ALONG AND JUST AHEAD OF THE FRONT...CAUSING SOME BRIEF
HIGH WIND GUSTS. SOME OF THE STRONGER STORMS COULD COME OUT OF THE
SOUTH AND PUSH ACROSS THE EAST AND SOUTHEAST EARLY THIS EVENING.
CHECKING THE HEAVY RAIN POTENTIAL PRECIPITABLE WATER WILL HOLD AT
AROUND 1.5 FOR TONIGHT WITH MANUAL PROGS GOING AT 1 TO 2
INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE FROM TRAINING. BELIEVE
A FLOOD WATCH WILL NOT BE NECESSARY AT THIS TIME...BUT WILL CONTINUE
TO MONITOR...TRAINING ACTIVITY TO THE SOUTH. REGIONAL CROSS
SECTIONS/TIME SERIES SHOWS STRONG OMEGA VALUES MAINLY BEFORE
MIDNIGHT. SO WILL KEEP RAINFALL HEAVY AT TIMES. ON SUNDAY THE RAINS
WILL TAPER OFF IN THE MORNING. THE COMBINATION OF THE UPPER TROUGH
PASSAGE AND THE 850 THERMAL TROUGH WILL KEEP CLOUDS AROUND WITH A
COOLER AIRMASS MOVING INTO THE REGION. FOR SUNDAY NIGHT INTO MONDAY
PER MESOETA MODEL SOUNDING...THERE MAY BE ENOUGH COOL AIR AND LOW
LEVEL MOISTURE TO SQUEEZE OUT SOME FREEZING DRIZZLE...BUT ITS TOO
EARLY TO SPECULATE AT THIS TIME. THE 850 THERMAL TROUGH...ACCORDING
TO THE ETA/GFS WILL DEPART THE REGION ON LATE MONDAY. SO WILL
DECREASE THE CLOUDS ON MONDAY NIGHT. AS THE UPPER TROUGH MOVES OUT A
FLAT SOUTHERN STREAM ZONAL PATTERN WILL REDEVELOP ACROSS THE LOWER
MISSISSIPPI VALLEY. WILL GO WITH A BLEND OF ETA/MAV TEMPS AND POPS.

LONG TERM...TUESDAY THROUGH SATURDAY...
THE GFS CONTINUED TO SHOW A PROGRESSIVE SOUTHERN STREAM PATTERN.
HIGH PRESSURE WILL BE PREVALENT ON TUESDAY THROUGH WEDNESDAY AHEAD
OF AN APPROACHING SYSTEM IN THE PLAINS. LOW LEVEL SOUTHERLY RETURN
WILL GRADUALLY INCREASE MEAN MOISTURE SOME FOR WEDNESDAY OVER THE
NORTH HALF...BUT NOT ENOUGH FOR ANY RAINFALL AS A WEAK PACIFIC FRONT
MOVES THROUGH THE AREA. FOR THURSDAY INTO FRIDAY A STRONG SHORTWAVE
WILL ENTER THE SOUTHERN PLAINS AND BRING INTO GOOD MEAN MOISTURE FOR
THURSDAY INTO FRIDAY...AS A STORM SYSTEM DEVELOPS IN THE REGION. THE
SYSTEM WILL BRING IN BREEZY CONDITIONS WITH SOME RAIN AND
THUNDERSTORMS FOR FRIDAY AS THE COLD FRONT MOVES THROUGH. THE UPPER
LEVEL TROUGH WILL MOVE ACROSS THE FORECAST AREA ON
SATURDAY...BRINGING INTO SOME LIGHT POST FRONTAL RAIN FOR SATURDAY
MORNING BEFORE DEPARTING. BREEZY CONDITIONS WILL CONTINUE ON
SATURDAY. THE EUROPEAN/UK MODELS AND THE CANADIAN WERE GENERALLY
SIMILAR WITH THE UPPER FEATURES THROUGH EARLY THURSDAY...BUT
EUROPEAN/UK WAS A LITTLE LOWER IN MOVING THE PACIFIC FRONT ON EARLY
THURSDAY...WHILE THE CANADIAN HELD THE PACIFIC SYSTEM IN THE
PLAINS...THROUGH EARLY THURSDAY...AS A MORE POTENT SYSTEM
APPROACHES. THE NOGAPS WAS EVEN SLOWER WITH THE PROGRESSION OF THE
SURFACE AND UPPER PATTERN. SO WITH THIS IN MIND WILL PUT IN CHANCE
OF RAIN FOR LATE IN THE WEEK AND GO CLOSE TO MEX TEMPS.

PRELIM NUMBERS:
JAN 48/53/32/50/28 9200
MEI 52/57/32/48/27 9400

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

17

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
161200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
328 PM CST SAT FEB 15 2003

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

.DAY ONE...TODAY AND TONIGHT...

...THUNDERSTORMS...
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS...PRIMARILY
DURING THE LATE AFTERNOON AND EVENING HOURS...FOR PORTIONS OF
SOUTH AND EAST MISSISSIPPI. THE RISK AREA IS GENERALLY ALONG AND
SOUTHEAST OF A BROOKHAVEN TO DEKALB MISSISSIPPI LINE. THE PRIMARY
RISK FROM ANY SEVERE STORMS WILL BE FOR DAMAGING WIND GUSTS TO 60
MPH...AND ISOLATED TORNADOES.

ABUNDANT GULF MOISTURE WILL COMBINE WITH AN APPROACHING FRONTAL
SYSTEM AND UPPER AIR DISTURBANCES TO PRODUCE WIDESPREAD SHOWER
AND THUNDERSTORM ACTIVITY. THE AIRMASS OVER SOUTHEAST MISSISSIPPI
HAS HEATED SIGNIFICANTLY...CREATING AN UNSTABLE ENVIRONMENT FOR
THUNDERSTORMS TO DEVELOP. IN ADDITION...LOW LEVEL WIND FIELDS
HAVE INCREASED AND RESULTED IN A MORE FAVORABLE ENVIRONMENT FOR
WEAK TORNADOES.

...FLOODING...
LOCALLY HEAVY RAINFALL WILL RESULT IN THE PONDING OF WATER ON
AREA ROADWAYS AND IN LOW-LYING AREAS THROUGH THIS EVENING...OVER
THE ENTIRE OUTLOOK AREA. ADDITIONAL RAINFALL OF UP TO TWO INCHES
MAY OCCUR OVER MUCH OF THE OUTLOOK AREA...WITH THE HEAVIEST
RAINFALL EXPECTED ALONG AND EAST OF INTERSTATE 55.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

...DAYS TWO AND THREE...
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

...DAYS FOUR THROUGH SEVEN...
A STRONG LOW PRESSURE SYSTEM MAY DEVELOP OVER THE LOWER
MISSISSIPPI VALLEY REGION LATE THIS WEEK. IF THE SYSTEM
DEVELOPS...THERE WILL BE A CHANCE FOR STRONG THUNDERSTORMS.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...AMATEUR RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS...WILL BE NECESSARY OVER EAST MISSISSIPPI.

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
346 PM CST SAT FEB 15 2003

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

0300 PM    10E NATCHEZ               MS   FLOODING
02/15/03   ADAMS                          CAR HYDROPLANED OFF OF
                                          HIGHWAY 84. REPORTED BY
                                          ADAMS COUNTY SHERIFFS
                                          OFFICE.