Severe Thunderstorm Warning 571, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
305 AM CDT FRI JUL 18 2003

FORECAST CHALLENGES THIS PACKAGE...TEMPS AND POPS THROUGH THE ENTIRE
PERIOD.

CURRENTLY...IR SAT IMAGERY INDICATED MCS/S OVER THE OHIO RIVER
VALLEY AND WESTERN LA.  TEMPS/DEWPOINTS HAVE DROPPED MARGINALLY...
INTO THE LOWER 70S...NEARLY AREA WIDE AND WILL PROVIDE A SLIGHTLY
COOLER START TO TODAY VS YESTERDAY.

IN THE SHORT TERM...ANOTHER DAY IN THE MID 90S ON TAP.  WILL USE
PERSISTENCE FOR HIGH TEMPS TODAY.  MOS GUIDANCE KEEPS THE REGION IN
THE MID 90S...WITH UPPER 90S IN THE NW ZONES.  MAV GUIDANCE ACTUALLY
REACHES THE 100 MARK AT KGLH.  WITH DEWPOINTS IN THE MID 70S...WILL
KEEP HEAT ADVISORY GOING IN NW ZONES FOR HEAT INDICES REACHING THE
105 TO 110 RANGE.

YESTERDAY PROVED JUST HOW TRICKY NORTHWEST FLOW ALOFT CAN BE...AND
THE NEXT SEVERAL DAYS WILL BE NO EXCEPTION.  A BARRAGE OF
DISTURBANCES ALOFT WILL KEEP SCT POPS IN THE FORECAST EVERYDAY.
AGREE WITH PREVIOUS DAY SHIFT IN THAT CONVECTION WILL NOT
NECESSARILY BE LIMITED TO JUST THE AFTERNOON AND EVENING. THUS...
KEPT THE GOING FORECAST AS IS WITH MINOR TWEAKS TO TEMPS.

ISOLATED TO SCATTERED SEVERE STORMS WILL BE POSSIBLE THROUGH THE
WEEKEND. LINGERING BOUNDARIES...AMPLE MOISTURE...PWS NEAR 2 INCHES
AND KIS GREATER THAN 34...GOOD INSTABILITY...LIS LESS THAN -6C AND
SBCAPE NEAR 4000 J/KG...WILL BE IN PLACE...AND WITH A DISTURBANCE
PROGGED TO RACE THROUGH THE REGION NEARLY EVERYDAY...MARGINALLY
SEVERE HAIL AND WIND GUSTS IN THE 60 TO 70 MPH RANGE WILL BE
POSSIBLE.  AM ANTICIPATING ISOLATED SEVERE STORMS TODAY AND
SCATTERED SEVERE STORMS ON SATURDAY AS A MORE VIGOROUS WAVE ENTERS
THE REGION.  IN ADDITION...HEAVY RAINFALL IS LIKELY AND FLASH
FLOODING WILL BE A CONCERN WITH ANY STORM THAT DEVELOPS.

IN THE EXTENDED...MED RANGE MODEL CONSENSUS OF RIDGE WEST/TROUGH
EAST OVER THE CONUS CONTINUES. BELOW NORMAL TEMPS IN STORE FOR THE
REGION BY THE MIDDLE AND LATTER PORTIONS OF NEXT WEEK.  THE EFFECT
OF UPPER LEVEL TROUGH/SFC HIGH PRESSURE WILL HAVE A MORE PROFOUND
EFFECT ON LOWS RATHER THAN HIGHS...ESPECIALLY LATE NEXT WEEK.  WILL
UNDERCUT MEXMOS...ESPECIALLY ON LOWS.  AS ENSEMBLE MEXMOS HINTS...
LOWS COULD BE AS MUCH AS 7 DEGREES BELOW NORMAL BY THURSDAY MORNING.
WILL MAINTAIN HIGH TEMPS IN THE NEAR 90 RANGE...HOWEVER UPPER 80S
WOULD NOT BE OUT OF THE QUESTION.  TIMING DISTURBANCES IN THIS
NORTHWEST FLOW WILL CONTINUE TO BE VERY TRICKY EARLY IN THE WEEK.
GOING FORECAST HANDLES POPS WELL...WITH ONLY CHANGES TO TREND LOWS
DOWN ON WED AND THUR.

JAN 96/74/93/73/93 434
MEI 96/73/93/72/93 434

AR...HEAT ADVISORY 74>75.
LA...HEAT ADVISORY 07>09.
MS...HEAT ADVISORY 18-19-34-35-40-41.

GAGAN

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
191932-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
232 PM CDT FRI JUL 18 2003

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

.DAY ONE...TONIGHT AND SATURDAY...

...THUNDERSTORMS...
SCATTERED SEVERE THUNDERSTORMS WILL BE POSSIBLE LATE FRIDAY
AFTERNOON THROUGH SATURDAY AFTERNOON ACROSS LOCATIONS IN
SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA...AND MISSISSIPPI ALONG
AND WEST OF INTERSTATE 55. ISOLATED SEVERE THUNDERSTORMS WILL BE
POSSIBLE DURING THIS SAME TIME PERIOD FOR THE REST OF EASTERN
MISSISSIPPI. THE MAIN RISK WITH STORMS WILL BE HIGH WINDS AND
HAIL.

A CONVECTIVE COMPLEX AND MID LEVEL DISTURBANCE IS FORECAST TO
PUSH SOUTH INTO THE LOWER MISSISSIPPI VALLEY LATE FRIDAY
AFTERNOON INTO FRIDAY EVENING. THUNDERSTORMS ASSOCIATED WITH
THESE FEATURES ARE EXPECTED TO BEGIN TO AFFECT LOCATIONS IN THE
DELTA REGION AND LOCATIONS IN NORTH CENTRAL MISSISSIPPI BEFORE
MIDNIGHT. THE COMBINATION OF LARGE ATMOSPHERIC INSTABILITY
PARAMETERS AND MODEST SHEAR WILL ALLOW SOME STORMS TO PRODUCE
WINDS UP TO...OR OVER...60 MPH...AS WELL AS HAIL UP TO NICKEL
SIZE. THESE STORMS SHOULD WEAKEN SOMEWHAT DURING THE EARLY
MORNING HOURS...BUT COULD STILL BE SEVERE...AS THEY MOVE SOUTH TO
THE INTERSTATE TWENTY CORRIDOR ALONG AND WEST OF THE JACKSON
METROPOLITAN AREA. THE REMNANTS OF THESE STORMS AND THE
POSSIBILITY OF ANOTHER CONVECTIVE COMPLEX WILL PROMPT MORE
POTENTIALLY SEVERE STORMS ACROSS THE WESTERN HALF OF THE AREA BY
MIDDAY SATURDAY.

OTHERWISE...ANTICIPATE ISOLATED THUNDERSTORMS TO FORM FRIDAY
AFTERNOON ACROSS EASTERN AND SOUTHERN MISSISSIPPI AND NORTHEAST
LOUISIANA. MOST OF THIS ACTIVITY WILL END DURING THE EVENING.
MORE WIDESPREAD CONVECTION SHOULD DEVELOP BY SATURDAY AFTERNOON
IN EASTERN MISSISSIPPI. DUE TO HIGH INSTABILITY AND MINOR PULSES
OF ENERGY ALOFT...THESE STORMS WILL ALSO HAVE THE POTENTIAL TO
PRODUCE HAIL AND DAMAGING WINDS.

...FLOODING...
THE COMPLEX OF THUNDERSTORMS EXPECTED TO AFFECT PORTIONS OF
NORTHEAST MISSISSIPPI...SOUTHEAST ARKANSAS...AND NORTHEAST
LOUISIANA FRIDAY EVENING AND EARLY SATURDAY MORNING COULD BRING 1
TO 2 INCHES OF RAINFALL TO LOCATIONS IN THE AREA. COMBINED WITH
LOCALLY HEAVY RAINFALL FROM THURSDAY...PRECIPITATION AMOUNTS OF
THIS MAGNITUDE WILL CREATE AREAS OF PONDING WATER...ESPECIALLY IN
LOW LYING AREAS. ADDITIONAL HEAVY RAIN COULD FALL ACROSS THESE
SAME LOCATIONS LATER ON IN THE DAY SATURDAY.

...SEASONAL THREATS...
A HOT AND HUMID AIRMASS WILL REMAIN OVER PORTIONS OF THE REGION
FOR ONE MORE AFTERNOON AS AN UPPER LEVEL HIGH PRESSURE SYSTEM
REMAINS IN CONTROL. HEAT INDICES WILL RANGE FROM 105 TO 110
DEGREES...MAINLY OVER THE MISSISSIPPI DELTA REGION FRIDAY
AFTERNOON...AS TEMPERATURES REACH THE MID TO UPPER 90S.

CONDITIONS SHOULD NOT BE QUITE AS HOT SATURDAY AFTERNOON AS
WIDESPREAD CLOUD COVER AND SCATTERED PRECIPITATION ARE EXPECTED
TO KEEP TEMPERATURES LOWER.

.DAYS TWO THROUGH SEVEN...SATURDAY NIGHT THROUGH FRIDAY...

...DAYS TWO AND THREE...SATURDAY NIGHT THROUGH MONDAY...
TURBULENT NORTHWEST FLOW WILL CONTINUE IN THE MID AND UPPER
LEVELS OF THE ATMOSPHERE SUNDAY AND MONDAY. A WEAK FRONTAL
BOUNDARY AT THE SURFACE WILL MEANDER ACROSS THE LOWER MISSISSIPPI
BOTH DAYS. THE INFLUENCE OF THIS BOUNDARY...ALONG WITH OTHER
TRANSIENT BOUNDARIES...WILL COMBINE WITH PULSES OF ENERGY ALOFT
AND ATMOSPHERIC INSTABILITY TO PRODUCE MORE THUNDERSTORMS
THROUGHOUT THE AREA. THUNDERSTORMS WILL BE MOST NUMEROUS DURING
AFTERNOON AND EVENING HOURS AND WILL HAVE THE POTENTIAL TO
PRODUCE DAMAGING WINDS GUSTS AND SMALL HAIL.

...DAYS FOUR THROUGH SEVEN...MONDAY NIGHT THROUGH FRIDAY...
ISOLATED TO SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL
CONTINUE TO BE POSSIBLE ACROSS THE ENTIRE LOWER MISSISSIPPI
VALLEY THROUGH TUESDAY AS A FAVORABLE UPPER LEVEL PATTERN IS
FORECAST TO BRING A UNUSUALLY STRONG SUMMER COLD FRONT THROUGH.
THIS FRONT...AND THE ASSOCIATED STRONG STORMS...ARE LIKELY TO
REMAIN IN THE VICINITY OF SOUTHERN MISSISSIPPI ON WEDNESDAY.

.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 THROUGH TONIGHT.

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
235 PM CDT FRI JUL 18 2003

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

0450 PM                              MS   WIND DAMAGE
07/17/03   ATTALA                         A FEW TREES DOWN IN THE
                                          EASTERN PORTION OF ATTALA
                                          COUNTY. REPORTED BY
                                          WINSTON COUNTY EMA.

0515 PM                              MS   WIND DAMAGE
07/17/03   CHOCTAW                        TREE AND POWERLINES DOWN
                                          IN SOUTHERN PORTION OF
                                          THE COUNTY.

0620 PM    3 E EDWARDS               MS   WIND DAMAGE
07/17/03   HINDS                          NUMEROUS TREES DOWN.
                                          PUBLIC REPORT.

0700 PM    DEER PARK                 LA   0.88 INCH HAIL
07/17/03   CONCORDIA

0700 PM                              MS   WIND DAMAGE
07/17/03   SMITH                          NUMEROUS TREES DOWN
                                          COUNTYWIDE.

0700 PM                              LA   WIND DAMAGE
07/17/03   CATAHOULA                      NUMEROUS POWERLINES DOWN
                                          COUNTYWIDE. REPORTED BY
                                          ELECTRIC POWER
                                          ASSOCIATION.

0715 PM    VICKSBURG                 MS   WIND DAMAGE
07/17/03   WARREN                         NUMEROUS TREES AND
                                          POWERLINES DOWN WITHIN
                                          THE CITY LIMITS AND AN
                                          ADDITIONAL TWENTY TREES
                                          DOWN IN THE SOUTHERN
                                          PORTION OF THE COUNTY.

0730 PM    4 N LOUIN                 MS   WIND DAMAGE
07/17/03   JASPER                         LARGE LIMBS DOWN...PUBLIC
                                          REPORT

0750 PM    5 SW ROSE HILL            MS   0.75 INCH HAIL
07/17/03   JASPER                         REPORTED BY PUBLIC...
                                          JASPER COUNTY CD ALSO
                                          REPORTED A LARGE TREE
                                          ACROSS HIGHWAY 503 NEAR
                                          THIS LOCATION

0815 PM    COLLINS                   MS   WIND DAMAGE
07/17/03   COVINGTON                      A FEW TREES DOWN NEAR
                                          TOWN.

0850 PM    BASSFIELD                 MS   WIND DAMAGE
07/17/03   JEFFERSON DAVIS                LARGE LIMBS SNAPPED OFF
                                          TREES...REPORTED BY PD