Severe Thunderstorm Warning 606, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
245 AM CDT SAT AUG 18 2001

AS HAS BEEN THE CASE PRETTY MUCH ALL SUMMER...A SPRING-LIKE SYNOPTIC
PATTERN CONTINUES THIS MORNING WHILE SUMMERTIME MOISTURE (PWAT/S
AROUND 2.00/DEW PTS 70S) REMAINS IN PLACE AHEAD OF SLOWING COLD
FRONT SITUATED FROM NE CO...TO WI. THIS WEEKEND LOOKS NO DIFFERENT.
UPPER HIGH SITUATED FROM GULF COAST...WNW BACK UP THROUGH THE
INTERMOUTAIN WEST. MEANWHILE...NUMEROUS STRONG SHORTWAVES MOVE UP
AND OVER WRN UPPER RIDGE...THEN DROP PRETTY FAR SOUTH THROUGH THE
PLAINS/MS RIVER VALLEY/GT LAKES REGION ON THE HEELS OF IMPRESSIVE
70-90KT UPPER JET FLOW WHICH USUALLY HUGS THE CANADIAN BORDER DURING
THIS TIME OF YEAR. NO MAJOR DIFFERENCES IN MODELS...BUT GOING ETA
/META THIS GO ROUND WITH HANDLING/TIMING OF SHORTWAVES EMBEDDED IN FLOW.

UPPER TROUGH SEEN NICELY ON WATER VAPOR IMAGERY CONTINUES CARVING
OUT OVER THE ERN 2/3 OF U.S BRING 582 DM LINE AT 500 MB TO NEAR
KMEM BY 12Z MON. DURING THIS TIME...TAIL END OF COLD FRONT TO OUR
NORTH CONTINUES SWD INTO MS/LA BUT AT A SLOWING PACE AS UPPER SUPPORT
IS LOST SOMEWHAT. FIRST SHORTWAVE SEEN FIRING CONVECTION IN OK/TX AT
THIS TIME ARRIVES OVER NRN ZONES EARLY TODAY. MORE POTENT SHORTWAVE
ROTATES THROUGH THE AREA LATE TONIGHT INTO SUNDAY AS FRONT AND
DECENT ISENTROPIC ASCENT APPROACHES FROM THE WEST AND ENCOUNTERS
HIGH MOISTURE VALUES.  FEEL LOCALLY HEAVY RAINFALL WORDING IS
WARRANTED AS A FEW SPOTS COULD EASILY SEE AMOUNTS OF 1-2 INCHES.
WILL MENTION ISOLATED SEVERE STORMS NRN/WRN AREAS WITH LAPSE RATES
INCREASING TO NEAR 6.5 C/KM...-8-(-9) 500 MB TEMPS DIVING SEWD INTO
THIS REGION LATER TODAY THROUGH SUNDAY NIGHT. THIS IN LINE WITH SPC
THINKING OF DAMAGING WINDS/ISOLATED LARGE HAIL. VERY REASONABLE
CONSIDERING RRQ OF UPPER JET SETS UP OVER NRN MS/TN VALLEY WITH
TOTAL TOTALS => 50 COMING IN. (SEE SWODY 1/2 FOR FURTHER DETAILS).

LIKE WETTER FWC MOS POPS IN THE SHORT TERM. AS FOR TEMPS...LIKE WHAT
PREVIOUS SHIFT HAS DONE WITH MAX TEMPS LITTLE LOWER THAN MAV/FWC
VALUES TODAY WITH EXPECTED CONVECTION...THEN A LITTLE WARMER SUNDAY.

.EXTENDED...SEE NO REASON TO CHANGE CURRENT EXTENDED AS FRONT HANGS
UP OVER SRN ZONES ON MONDAY WITH UPPER RIDGE BUILDING IN FOR MID-LATE
NEXT WEEK WITH UPPER TROUGH LIFTING NEWD OUT OF AREA. AS FOR TS CHANTAL
...ALL MODELS INCLUDING AVN BRING INTO THE GULF BUT HAVE SOMEWHAT
DIFFERENT POSITIONS AT 120 HRS (LATE WED/THURS). STAY TUNED.

.PRELIM NUMBERS:
JAN 88/73/91/70 5242
MEI 89/71/90/68 6342

.JAN...
MS...NONE.
LA...NONE.
AR...NONE.
05/

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
191200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
605 AM CDT SAT AUG 18 2001

...THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER MUCH OF
MISSISSIPPI...NORTHEAST LOUISIANA AND EXTREME SOUTHEAST ARKANSAS
THIS AFTERNOON INTO THIS EVENING. ISOLATED SEVERE THUNDERSTORMS
WILL BE POSSIBLE NORTH OF A LINE FROM BASTROP LOUISIANA TO YAZOO
CITY TO MACON MISSISSIPPI. THE MAIN THREAT WILL BE FROM DAMAGING
STRAIGHT LINE WINDS TO 60 MPH AND DIME SIZED HAIL. SOUTH OF THIS
LINE...THUNDERSTORMS WILL BE CAPABLE OF PRODUCING BRIEF GUSTY
WINDS TO 40 MPH. ACROSS ALL AREAS...FREQUENT CLOUD TO GROUND
LIGHTNING WILL ACCOMPANY ANY THUNDERSTORMS.

A STALLED FRONTAL BOUNDARY...OVER THE NORTHERN THIRD OF
MISSISSIPPI...WILL CONTINUE TO FOCUS LOW LEVEL MOISTURE AND
CONVERGENCE ACROSS CENTRAL MISSISSIPPI. ANOTHER CONTRIBUTING
FACTOR WILL BE A SECOND FRONT...AND UPPER LEVEL TROUGH...THAT
WILL BE DIVING INTO THE LOWER MISSISSIPPI VALLEY DURING THE
EVENING. THESE TWO SYSTEMS WILL HELP DEVELOP SCATTERED TO
NUMEROUS THUNDERSTORMS THROUGH THIS EVENING.

...FLOODING...
WITH DEEP MOISTURE ONCE AGAIN ACROSS THE REGION...THUNDERSTORMS
THAT DEVELOP WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL.
LOCALIZED AMOUNTS OF 1 TO 2 INCHES CAN BE EXPECTED WITH STRONGER
THUNDERSTORMS. THIS BRIEF HEAVY RAINFALL WILL CAUSE PONDING OF
WATER ON ROADWAYS ALONG WITH MINOR LOCALIZED FLOODING.

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