Flash Flood Warning 35, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
710 PM CDT THU OCT 26 2006

.DISCUSSION...SENT OUT AN UPDATE ALREADY TO FINE TUNE THE WEATHER
GRIDS FOR TONIGHT. REMOVED A LOT OF THE THUNDER WORDING FOR CENTRAL
AND NORTHERN MISSISSIPPI AND ONLY INCLUDED SPRINKLES FOR THE EARLY
PART OF THE EVENING ACROSS THESE AREAS AS WELL. ALSO KEPT THE SEVERE
WEATHER OUT OF THE SOUTH UNTIL AFTER MIDNIGHT. IN ADDITION TO THAT
WE REMOVED SOME COUNTIES AND PARISHES OUT OF THE FLOOD WATCH. THIS
IS ACROSS THE NORTHWEST. THERE ARE SOME CONCERNS WITH THE GOOD AREA
OF SHRA AND TSRA ACROSS SRN LA HURTING THE POTENTIAL FOR REAL HEAVY
RAIN THAT FAR NORTH. THIS AREA OF SHRA HAS HAD A HARD TIME MOVING
NORTH FROM THE COAST SO WE FEEL CONFIDENT THAT WE WONT HAVE TO
WORRY ABOUT FLOODING IN AR FAR NWRN ZONES BUT AS THE ACCENT MOVES
TWRDS THE LOWER MS VALLEY WIDESPREAD SHRA AND EMBEDDED TSRA SHOULD
HAVE NO PROBLEM FILLING IN NWRD IN THE CENTRAL MS.

&&

.PREV DISCUSSION....TONIGHT THROUGH FRIDAY...SWATH OF RAIN CONTINUES
TO PUSH ACROSS MISSISSIPPI THIS AFTERNOON WITH NO LIGHTNING STRIKES
AS OF YET. MOST AREAS ACROSS THE ARKLAMISS HAVE ALREADY RECEIVED 1/2
TO 1 1/2 INCHES OF RAIN...WITH 2 TO 3 INCHES IN THE LOUISIANA
PARISHES. CURRENTLY A WARM FRONT IS PUSHING NORTH INTO CENTRAL
MISSISSIPPI AND SHORT WAVES ARE MOVING ALONG THE MID LEVEL FLOW. ALL
OF THIS COMBINED WITH ABUNDANT MOISTURE AND 40KTS OF H850 FLOW ALONG
A THETA-E AXIS WILL CONTINUE TO BRING RAIN OVER THE AREA THROUGH THE
EVENING HOURS. THE LATEST EXCESSIVE RAINFALL GUIDANCE BRINGS NEAR 5
INCHES ACROSS CENTRAL MISSISSIPPI AND THIS IS SUPPORTED BY THE
MODELS. A FLOOD WARNING HAS ALREADY BEEN ISSUED...BUT WILL EXTEND
THE WARNING A LITTLE FURTHER TO SOUTH BASED ON THE LATEST MODELS
TRENDS. THE GFS AND THE WRF MODEL INDICATE THAT THE HEAVIEST RAIN
WILL FALL OVER CENTRAL MISSISSIPPI ALONG THE I-20 CORRIDOR. RADAR
IMAGERY INDICATES THIS ALSO WITH SHOWERS AND THUNDERSTORMS
CONTINUING TO EXTEND BACK INTO EAST TEXAS AND MOVING EAST.

SEVERE POTENTIAL HAS BEEN LIMITED TODAY WITH VERY LITTLE INSTABILITY
...BUT AS THE WARM FRONT PUSHES NORTH THE SOUTHERN PORTIONS OF THE
ARKLAMISS SOUTH OF I-20 WILL BECOME INCREASINGLY UNSTABLE TONIGHT.
THE LATEST GFS DEVELOPS A SURFACE LOW ACROSS CENTRAL ARKANSAS AND
MOVES IT INTO WESTERN TENNESSEE. A SQUALL LINE WILL DEVELOP TO THE
WEST AND MOVE EAST ACROSS THE AREA DURING THE OVERNIGHT ALONG A
STRONG COLD FRONT. INSTABILITY WILL CONTINUE TO BE MARGINAL...BUT
ACCORDING TO THE GFS ML CAPES WILL APPROACH 900 J/KG DURING THE
OVERNIGHT. THE SHEAR WILL BE PLENTIFUL WITH 0-3 STORM RELATIVE
HELICITIES RANGING FROM 350 TO 450 M2/S2 DURING THE VERY EARLY
MORNING HOURS. AGAIN THE BEST POTENTIAL FOR SEVERE LOOKS TO BE ALONG
AND SOUTH OF I-20...BUT ISOLATED SEVERE WILL BE POSSIBLE ANYWHERE AS
THE SQUALL LINE MOVES THROUGH OVERNIGHT. STORMS WILL CONTINUE TO BE
POSSIBLE OVER THE EAST AND SOUTHEAST AREAS DURING THE EARLY MORNING
BEFORE QUICKLY EXITING THE AREA BY MID TO LATE MORNING.

BY THE EARLY AFTERNOON ON FRIDAY SKIES WILL BRIEFLY CLEAR OUT...BUT
EXPECT AN INCREASE IN MAINLY LOW CLOUDS ASSOCIATED WITH SOME LOW
LEVEL MOISTURE AND THE MAIN SHORT WAVE MOVING ACROSS THE AREA FRIDAY
EVENING. STUCK PRETTY CLOSE TO GUIDANCE POPS AND TEMPERATURES
THROUGH THE PERIOD AS GUIDANCE WAS ALREADY NEAR 100 POPS FOR
TONIGHT./15/

LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...THE SURFACE LOW IS
EXPECTED TO MOVE NORTHEAST ACROSS CENTRAL TENNESSEE AND OVER
NORTHERN VIRGINIA FRIDAY NIGHT. THE GFS IS STILL MORE PROGRESSIVE
THAN THE NAM IN MOVING THE TRAILING COLD FRONT THROUGH OUR CWA
DURING THE DAY FRIDAY. EVEN THOUGH THE COLD FRONT IS EXPECTED TO BE
WELL SOUTH OF OUR CWA FRIDAY EVENING...WARP AROUND MOISTURE WITH THE
SURFACE LOW AND THE UPPER TROUGH AXIS WILL HELP KEEP LIGHT RAIN AND
DRIZZLE OVER MUCH OF THE EASTERN HALF OF OUR CWA UNTIL MIDNIGHT. WL
GO SLIGHTLY ABOVE MAV GUIDANCE POPS IN CENTRAL MISSISSIPPI. AS THE
UPPER TROUGH SHIFTS EAST SATURDAY MORNING...CLOUDS SHOULD DISSIPATE.
HIGH PRESSURE WILL BEGIN TO BUILD OVER OUR REGION FROM THE SOUTHERN
PLAINS AND LAST THROUGH MONDAY. ALTHOUGH THE AIRMASS WILL BE DRIER
THAN NORMAL...NEAR NORMAL TEMPERATURES ARE EXPECTED THROUGH THE
WEEKEND AND HAVE STUCK CLOSE TO LATEST MAV GUIDANCE. ALTHOUGH THE
SURFACE HIGH WILL MOVE EAST OF OUR CWA MONDAY NIGHT...RIDGING ALOFT
OVER THE EASTERN SEABOARD WILL SLOW THE SURFACE HIGHS SHIFT OFF THE
EAST COAST. THIS WILL RESULT IN WEDGING EAST OF THE APPALACHIANS AND
HELP KEEP US DRY INTO WEDNESDAY. A NORTHERN STREAM SHORTWAVE WILL
MOVE EAST ACROSS THE MID MISSISSIPPI VALLEY WEDNESDAY NIGHT AND HELP
TRY TO SEND A COLD FRONT TOWARD OUR REGION. LATEST MEDIUM RANGE
MODELS ARE SLOWER WITH THE PROGRESSION OF THIS FRONT AND HAVE
TRIMMED BACK POPS UNTIL THURSDAY. /22/

&&

.AVIATION...EXPECT MVFR TO IFR CONDITIONS TO CONTINUE THROUGH THE
OVERNIGHT HOURS WITH HEAVY RAIN AND FOG. CONDITIONS WILL IMPROVE
FROM WEST TO EAST TOMORROW MORNING AS A COLD FRONT MOVES THROUGH THE
AREA.

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       61  70  47  69 / 100  50  11   1
MERIDIAN      59  71  46  70 / 100  79  15   3
VICKSBURG     59  70  47  70 / 100  34  10   1
HATTIESBURG   63  74  47  71 / 100  79  11   3
NATCHEZ       61  69  46  70 / 100  34   6   1
GREENVILLE    57  65  46  70 / 100  37  11   1
GREENWOOD     61  69  46  69 / 100  51  15   1

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLOOD WATCH THROUGH FRIDAY MORNING FOR MSZ038-MSZ039-MSZ045-
     MSZ046-MSZ050-MSZ051-MSZ052-MSZ054-MSZ055-MSZ056-MSZ057-
     MSZ058-MSZ061-MSZ062-MSZ063.

     FLOOD WATCH THROUGH FRIDAY MORNING FOR MSZ030-MSZ031-MSZ032-
     MSZ033-MSZ035-MSZ036-MSZ037-MSZ040-MSZ041-MSZ042-MSZ043-
     MSZ044-MSZ047-MSZ048-MSZ049-MSZ053-MSZ059-MSZ060.

LA...FLOOD WATCH THROUGH FRIDAY MORNING FOR LAZ009-LAZ015-LAZ016-
     LAZ023-LAZ024-LAZ025-LAZ026.

AR...NONE.

&&

CAB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
705 PM CDT THU OCT 26 2006

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
280005-
ADAMS-ASHLEY-ATTALA-BOLIVAR-CARROLL-CATAHOULA-CHICOT-CHOCTAW-
CLAIBORNE-CLARKE-CLAY-CONCORDIA-COPIAH-COVINGTON-EAST CARROLL-
FORREST-FRANKLIN LA-FRANKLIN MS-GRENADA-HINDS-HOLMES-HUMPHREYS-
ISSAQUENA-JASPER-JEFFERSON-JEFFERSON DAVIS-JONES-KEMPER-LAMAR-
LAUDERDALE-LAWRENCE-LEAKE-LEFLORE-LINCOLN-LOWNDES-MADISON LA-
MADISON MS-MARION-MONTGOMERY-MOREHOUSE-NESHOBA-NEWTON-NOXUBEE-
OKTIBBEHA-RANKIN-RICHLAND-SCOTT-SHARKEY-SIMPSON-SMITH-SUNFLOWER-
TENSAS-WARREN-WASHINGTON-WEBSTER-WEST CARROLL-WINSTON-YAZOO-
705 PM CDT THU OCT 26 2006

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

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

...THUNDERSTORMS...
A RISK OF SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA
AFTER MIDNIGHT WITH A HIGHER POTENTIAL POSSIBLE ALONG AND SOUTH
OF I-20. THE PRIMARY RISK WITH THESE STORMS WILL BE DAMAGING WIND
BUT ISOLATED TORNADOES WILL ALSO BE POSSIBLE TONIGHT.

A NORTHWARD MOVING WARM FRONT WILL SERVE AS THE LEADING EDGE OF A
GULF MOISTURE PUSH THAT WILL CAUSE THE ATMOSPHERE TO DESTABILIZE
SOME AFTER MIDNIGHT. WIND FLOW WILL ALSO BEGIN TO INCREASE IN THE
WAKE OF THE WARM FRONT AND AS A STRONG UPPER LEVEL LOW HEADS
EAST. THIS WILL RESULT IN INCREASED WIND SHEAR THAT WILL ENHANCE
STRONG THUNDERSTORM DEVELOPMENT.

THE CHANCE FOR SEVERE STORMS WILL BE HIGHEST AFTER MIDNIGHT INTO
EARLY FRIDAY MORNING ESPECIALLY ALONG AND SOUTH OF I-20. AT THIS
TIME...UPPER JET FLOW WILL PRODUCE STRONG LIFT THROUGH THE
ATMOSPHERE AND THE COLD FRONT WILL MOVE INTO THE REGION. A SQUALL
LINE OF STORMS IS EXPECTED TO RAPIDLY PUSH EAST DURING THE EARLY
MORNING HOURS BRINGING THE RISK OF SMALL BOW ECHO SEGMENTS. THESE
BOW SEGMENTS WILL BRING THE POTENTIAL FOR DAMAGING WINDS AND
ISOLATED TORNADOES. THERE IS ALSO THE POTENTIAL FOR SOME SMALL
SCALE SUPERCELLS STORMS TO DEVELOP NEAR THE SQUALL LINE. ANY
SUPERCELLS THAT CAN DEVELOP WILL HAVE THE POTENTIAL FOR DAMAGING
WINDS TO 60 MPH AND ISOLATED TORNADOES.

...FLOODING...
RAINFALL WILL INCREASE IN COVERAGE AND INTENSITY OVERNIGHT AS A
WARM FRONT CONTINUES TO LIFT NORTH ACROSS THE AREA AHEAD OF AN
APPROACHING STRONG WEATHER SYSTEM.

PERIODS OF HEAVY RAIN WILL INCREASE TONIGHT AS GULF MOISTURE
SURGES NORTH AHEAD OF A COLD FRONT APPROACHING THE AREA. ANOTHER
ROUND OF HEAVY RAINFALL OVER NEARLY SATURATED SOILS WILL INCREASE
THE POTENTIAL FOR PONDING WATER AND FLASH FLOODING OVER THE
REGION TONIGHT. RAINFALL TOTALS OF 2 TO 4 INCHES WILL BE LIKELY
WITH LOCALLY HEAVIER AMOUNTS POSSIBLE. AREAS WITHIN THE CORRIDOR
OF THE NATCHEZ TRACE WILL HAVE THE HIGHEST RISK OF SEEING HEAVY
RAINFALL...ESPECIALLY ACROSS SOUTHWEST AND PORTIONS OF CENTRAL
MISSISSIPPI.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.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 LATER TONIGHT AND EARLY FRIDAY...BUT
OTHERWISE SHOULD NOT BE REQUIRED THROUGH NEXT THURSDAY.

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