Flash Flood Warning 101, NWS Jackson, MS

423 
WGUS74 KJAN 192132
FFSJAN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
432 PM CDT THU AUG 19 2010

MSC037-192138-
/O.CAN.KJAN.FF.W.0101.000000T0000Z-100819T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FRANKLIN MS-
432 PM CDT THU AUG 19 2010

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR WESTERN FRANKLIN
COUNTY...

LAT...LON 3161 9114 3161 9090 3137 9090 3136 9116

$$

MRM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1137 AM CDT THU AUG 19 2010

.UPDATE...AREA OF INTENSE RAINFALL THAT OCCURRED OVER ECNTRAL ZONES
THIS MORNING...SCOTT COUNTY IN PARTICULAR...HAS CONTINUED TO WANE IN
DAYTIME HEATING...AS TROPICAL TYPE CONVECTION USUALLY DOES. THE
ASSOCIATED CIRCULATION WILL LINGER OVER SERN ZONES TODAY AND A VERY
MOIST AIR MASS WILL PERSIST OVER MUCH OF THE FORECAST AREA. THE
EXCEPTION WILL BE NRN AND SOME CENTRAL ZONES WHERE A DRIER AIR MASS
IS FILTERING IN ON THE WRN EDGE OF THE TROUGH. WITH PWATS WELL ABOVE
2 INCHES CNTRL/S HAVE MAINTAINED POSSIBILITY OF HEAVY RAINFALL
GENERALLY ALONG AND S OF I-20. MANY AREAS HAVE SEEN 5-10 INCHES OF
RAIN OVER SRN ZONES AND THE CHANCE OF PONDING WATER/FLOODING ISSUES
WILL CONTINUE BENEATH ANY STRONGER CONVECTION THAT CAN DEVELOP TODAY.

AREAS IN HEAVIER RAINFALL THIS MORNING WILL SEE COOLER AFTERNOON
TEMPS TODAY. HOWEVER...W/NWRN ZONES REMAIN IN TRACK TO REACH THE MID
TO UPPER 90S TODAY AND THE HEAT ADVISORY REMAINS IN AFFECT.

&&

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT...A CLOSED CIRCULATION
ASSOCIATED WITH THE DECAYING REMNANTS OF TD 5 IS VERY HARD TO FIND
THIS MORNING AND WHAT IS LEFT OF THE SYSTEM SEEMS TO BE DEFINED MORE
BY A TROUGH AXIS PROGRESSING SLOWLY INTO EASTERN MS CURRENTLY. THE
EVOLUTION OF THIS DECAYING TROPICAL FEATURE APPEARS TO BE TRYING TO
FOLLOW THE MORE PROGRESSIVE ENVELOPE OF SOLUTIONS OFFERED OVER THE
PAST SEVERAL DAYS. STILL SEEING SOME EVIDENCE OF LATE NIGHT/EARLY
MORNING CONVECTION FORMING RIGHT NOW IN THE TROUGH AXIS ACROSS
CENTRAL MISSISSIPPI AND THERE IS LIKELY SOME EXTREMELY HEAVY
DOWNPOURS INVOLVED GIVEN THE VERY MOIST (2.3 TO 2.5 INCH PW VALUE)
AIRMASS. HOWEVER...THIS CONVECTION (LIKE THE TROUGH FEATURE) IS AT
LEAST SOMEWHAT PROGRESSIVE AND IS EXPECTED TO POSE MUCH LESS A FLASH
FLOODING THREAT THIS MORNING. THE PREVIOUS FLASH FLOOD WATCH IN
EFFECT FOR MY SW ZONES IS MAINLY TO THE WEST OF THE AXIS OF EXPECTED
CONVECTION THIS MORNING AND HAS THUS BEEN CANCELLED. ANOTHER WATCH
DOES NOT SEEM NECESSARY CONSIDERING POTENTIAL FOR LOCALLY HEAVY
RAINS IN CENTRAL AND EASTERN MS SHOULD NOT LAST IN ANY ONE LOCATION
TOO LONG. MAY STILL HAVE SOME ISOLATED FLOODING PROBLEMS THOUGH AS
WE GO THROUGH THE DAY...ESPECIALLY IN SOUTHEAST MS...AND THIS HAZARD
WILL BE MENTIONED IN THE HWO WITH MORNING HEAVY RAIN WORDING IN
OFFICIAL PRODUCTS.

MODEL CONSENSUS NOW GENERALLY SUGGESTS SOME VERSION OF A VERY WEAK
FRONT WILL TRY TO WORK DOWN INTO THE AREA ON THE BACKSIDE OF THE
DEPARTING TROUGH (OR TD 5 REMNANT) TODAY. THIS COULD HELP TO BE A
FOCUS FOR CONVECTION ELSEWHERE IN THE CWA LATER TODAY AS LOW LEVEL
CONVERGENCE OCCURS IN THE VERY MOIST AIRMASS PUSHED SOUTH OF I-20 ON
THE BACKSIDE OF THE SYSTEM. THIS EVOLUTION COULD BRING SOME HEAVY
DOWNPOURS AGAIN THIS AFTERNOON TO THE AREA IMPACTED BY PRODIGIOUS
RAINS FROM YESTERDAY...BUT CONFIDENCE OF HAVING ANY FURTHER FLOODING
PROBLEMS FROM THIS AFTERNOON'S ACTIVITY IS NOT HIGH ENOUGH TO
WARRANT ANOTHER FLASH FLOOD WATCH. LESS CLOUD COVER AND AND MORE
UPPER RIDGING INFLUENCE BUILDING IN BEHIND THE MENTIONED TROUGH
LATER TODAY WILL PROMOTE HOTTER TEMPS...ESPECIALLY IN NORTHWEST
ZONES (WHERE THE COMBINATION OF HEAT AND HUMIDITY HAS NECESSITATED
YET ANOTHER HEAT ADVISORY). DEFINITELY POSSIBLE THE NEED FOR HEAT
ADVISORIES WILL EXPAND FURTHER EAST INTO THE REGION OVER THE NEXT
FEW DAYS...ALTHOUGH POTENTIAL FOR CONVECTION COMPLICATES NAILING
THINGS DOWN AND THUS I HELD OFF ON ISSUING ANY ADVISORIES PAST TODAY.

THE MENTIONED WEAK BOUNDARY COMING SOUTH ON THE BACKSIDE OF THE
DEPARTING TROUGH COULD CONTINUE TO BE A FOCUS THROUGH TOMORROW AS IT
LIFTS BACK TO THE NORTH. THERE IS SLIGHT POTENTIAL AT LEAST ISOLATED
SHOWERS AND STORMS COULD PERSIST WELL INTO TONIGHT IN FAR WESTERN
ZONES NEAR THIS BOUNDARY AS SOME SEMBLANCE OF A SOUTHERLY LOW LEVEL
JET PROMOTES MOISTURE CONVERGENCE. A GENERAL INCREASE IN HEAT AND
HUMIDITY WILL DELIVER MORE INSTABILITY ACROSS THE BOARD BY TOMORROW
AFTERNOON AND SCATTERED STORMS FORMING NEAR THIS BOUNDARY (AND IN
ASSOCIATION WITH SEA-BREEZE STUFF COMING UP FROM THE SOUTH) COULD
PACK MORE PUNCH THAN HAS BEEN THE CASE LATELY. /BB/

.LONG TERM...THE EXTENDED PORTION OF THE FORECAST IS A BIT
CHALLENGING AND CONFIDENCE IS NOT OVERLY HIGH ON ANY PRIMARY
FORECAST ELEMENTS. MODELS HAVE BACKED OFF ON PUSHING A FRONT THROUGH
THE CWA...BUT IT APPEARS TO BE IN THE REGION AND ONE CAN NOT TOTALLY
RULE ITS PASSAGE OUT JUST JET. THE LATEST TREND WITH THE MED RANGE
GUID...ESPECIALLY THE EURO/GFS ENSEMBLE...IS TO TAKE SOME ENERGY
AROUND THE EASTERN EDGE OF THE SUBTROPICAL RIDGE ON MONDAY AND THEN
LEAVE A BROAD WEAKNESS OR SHEAR AXIS OVER THE SE US AND NORTHERN
GULF COAST. THE LOW LEVEL RESPONSE IS FOR A BROAD SFC TROUGH TO TAKE
SHAPE AND POSSIBLY LEAD TO SOME SFC LOW DEVELOPMENT WHICH WILL NEED
WATCHING FOR ANY TROPICAL DEVELOPMENT BY MID/LATE WEEK. EVEN IF NO
TROPICAL ENTITY DEVELOPS...THE PRESENCE OF A SFC TROUGH INVOF THE
REGION ALONG WITH A WEAKNESS IN THE MID/UPPER LEVELS WILL SUPPORT
DECENT RAIN CHANCES ACROSS MOST IF NOT ALL OF THE CWA.

THE MOST CHALLENGING ASPECT OF THE FORECAST IS WITH HIGH TEMPS. THE
LATEST GFS GUID IS QUITE WARM AND IS BASICALLY THE HIGHEST MEMBER
FOR MOST OF THE EXTENDED FORECAST PERIODS. WHAT MAKES IT SO
CHALLENGING IS THAT WE HAVE ACTUALLY ACHIEVED SUCH WARM READINGS
MOST OF THIS MONTH DESPITE BEING ABNORMALLY MOIST WITH PW'S
CONSISTENTLY 2.2 IN OR HIGHER. ADDITIONALLY...AREAS ALONG AND E/SE
OF THE TRACE HAVE SEEN ABV NORMAL RAINFALL THIS MONTH AND THAT HAS
NOT IMPACTED TEMPS THAT MUCH EITHER. CONDITIONS OVER THE AREA HAVE
BASICALLY CONTINUED TO RUN 4-6 DEGREES ABV NORMAL WITH HUMIDITY
HOLDING VERY HIGH. I SEE NO REASON FOR THIS NOT TO BE THE CASE INTO
THE WEEKEND AND THE FIRST PART OF NEXT WEEK. I ONLY ADJ HIGHS A TAD
FOR MON/TUE AS THOSE SEEMED TO BE THE PERIODS OFFERED THE BEST
OPPORTUNITY AND DID NOT FIT THE EURO OR GFS ENSEMBLE SOLUTIONS.

HEAT INDICES WILL BE QUITE HIGH FOR SAT-MON AND MOST IF NOT ALL OF
THE CWA WILL LIKELY NEED A HEAT ADV AT SOME POINT FOR THOSE FEW
DAYS. I WILL MENTION THAT POTENTIAL IN THE HWO.

ONE OTHER CONCERN WILL BE FOR THE POTENTIAL OF SOME STRONG/SVR
STORMS SAT AND SUN. AT THIS TIME...SUN LOOKS TO OFFER THE BEST
CHANCE OF SEEING SUCH ACTIVITY. HOWEVER...SAT WILL HAVE SOME
POTENTIAL. THE NW/N WILL HAVE TO BE WATCHED FOR SOME SORT OF COMPLEX
MOVING SE OUT OF AR LATE IN THE DAY. OTHER THAN THAT...ANY AREA MAY
SEE THIS ACTIVITY AS STORMS WILL LIKELY DEVELOP IN AN ENVIRONMENT
WITH 95-99 DEGREE HEAT AND SFC DEWPTS AT LEAST IN THE MID 70S. THAT
TYPICALLY RESULTS IN STRONG INSTABILITY NO MATTER WHAT THERMODYNAMIC
SETUP IS IN PLACE. I WILL SAY THAT THE MODELS ARE OFFERING STEEPER
LAPSE RATES ON SUNDAY...MAINLY DUE TO WARMER 850MB TEMPS. I WILL PUT
A BLURB ABOUT THIS STRONG/SVR POTENTIAL IN THE HWO. /CME/

&&

.AVIATION...A MIX OF VFR AND MVFR CONDITIONS ARE BEING OBSERVED AT
TAF SITES THIS AFTERNOON.  THIS WILL LIKELY CONTINUE TO BE THE
PATTERN THROUGHOUT THE PERIOD AS THE AIRMASS ACROSS THE REGION
REMAINS VERY MOIST CAUSING CEILINGS TO RANGE FROM 1500-3500 FEET
ACROSS THE AREA AND SCATTERED SHOWERS AND STORMS EXPECTED THROUGH
THE AFTERNOON AND EVENING HOURS.  TOWARD DAY BREAK FRIDAY MORNING...
MVFR/IFR VISIBILITIES WILL AGAIN BE POSSIBLE AS A RESULT OF PATCHY
FOG. /19/
&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR
MSZ018-019-025-034-035-040-041.

LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR
LAZ007>009-015-016-023-024.

AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ARZ074-075.

&&

BB/CME
03/19

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
228 PM CDT THU AUG 19 2010

ARZ074-075-LAZ007>009-015-016-023-024-MSZ018-019-025-034-035-040-
041-201930-
ASHLEY-CHICOT-MOREHOUSE-WEST CARROLL-EAST CARROLL-RICHLAND-
MADISON LA-FRANKLIN LA-CATAHOULA-BOLIVAR-SUNFLOWER-LEFLORE-
WASHINGTON-HUMPHREYS-ISSAQUENA-SHARKEY-
228 PM CDT THU AUG 19 2010

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

.DAY ONE...TONIGHT AND FRIDAY...

THE COMBINATION OF HEAT AND HIGH HUMIDITY THIS AFTERNOON AND FRIDAY
AFTERNOON WILL CAUSE HEAT INDEX VALUES TO PEAK IN THE 105 TO 110
DEGREE RANGE. A HEAT ADVISORY IS IN EFFECT THROUGH 7 PM FRIDAY.

.DAYS TWO THROUGH SEVEN...FRIDAY NIGHT THROUGH WEDNESDAY...

OPPRESSIVE HEAT WILL AGAIN BE AN ISSUE THROUGH THE WEEKEND WHEN
AFTERNOON HEAT INDEX VALUES COULD AGAIN CLIMB UP AROUND 105 DEGREES.
HEAT ADVISORIES MAY BECOME NECESSARY OR BE ONGOING DURING THIS TIME.

A SURFACE BOUNDARY MOVING SOUTH INTO A HOT AND UNSTABLE AIR MASS ON
SUNDAY HAS THE POTENTIAL TO GENERATE SCATTERED STRONG TO SEVERE
THUNDERSTORMS ACROSS THE AREA. THE MAIN CONCERN WITH THIS ACTIVITY
SHOULD BE DAMAGING WIND GUSTS.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS IS NOT EXPECTED THROUGH NEXT WEDNESDAY.

LAZ025-026-MSZ026>033-036>039-042>066-072>074-201930-
TENSAS-CONCORDIA-GRENADA-CARROLL-MONTGOMERY-WEBSTER-CLAY-LOWNDES-
CHOCTAW-OKTIBBEHA-HOLMES-ATTALA-WINSTON-NOXUBEE-YAZOO-MADISON MS-
LEAKE-NESHOBA-KEMPER-WARREN-HINDS-RANKIN-SCOTT-NEWTON-LAUDERDALE-
CLAIBORNE-COPIAH-SIMPSON-SMITH-JASPER-CLARKE-JEFFERSON-ADAMS-
FRANKLIN MS-LINCOLN-LAWRENCE-JEFFERSON DAVIS-COVINGTON-JONES-
MARION-LAMAR-FORREST-
228 PM CDT THU AUG 19 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST LOUISIANA
AND CENTRAL MISSISSIPPI.

.DAY ONE...TONIGHT AND FRIDAY...

SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON COULD
PRODUCE SOME LOCALLY TORRENTIAL DOWNPOURS ACROSS THE AREA...
PARTICULARLY ACROSS PORTIONS OF SOUTHWESTERN MISSISSIPPI AND
NORTHEAST LOUISIANA AFFECTED BY EXTREMELY HEAVY RAINS YESTERDAY.
PONDING WATER MAY OCCUR OVER ROADWAYS AND IN LOW LYING AREAS AND
THERE IS A POTENTIAL FOR ADDITIONAL FLASH FLOODING. ALSO...
DISSIPATION OF ACCUMULATED WATER WILL BE HINDERED BY ANY ADDITIONAL
HEAVY DOWNPOURS.

THIS WILL AGAIN BE THE CASE ON FRIDAY AS SCATTERED SHOWERS
AND THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY DOWNPOURS.

.DAYS TWO THROUGH SEVEN...FRIDAY NIGHT THROUGH WEDNESDAY...

OPPRESSIVE HEAT WILL AGAIN BE AN ISSUE THROUGH THE WEEKEND WHEN
AFTERNOON HEAT INDEX VALUES COULD AGAIN CLIMB UP AROUND 105 DEGREES.
HEAT ADVISORIES MAY BECOME NECESSARY OR BE ONGOING DURING THIS TIME.

A SURFACE BOUNDARY MOVING SOUTH INTO A HOT AND UNSTABLE AIR MASS ON
SUNDAY HAS THE POTENTIAL TO GENERATE SCATTERED STRONG TO SEVERE
THUNDERSTORMS ACROSS THE AREA. THE MAIN CONCERN WITH THIS ACTIVITY
SHOULD BE DAMAGING WIND GUSTS.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS IS NOT EXPECTED THROUGH NEXT WEDNESDAY.

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

19

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
920 AM CDT THU AUG 19 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0912 AM     FLASH FLOOD      FOREST                  32.36N 89.47W
08/19/2010                   SCOTT              MS   EMERGENCY MNGR

            TWO FEET OF WATER WAS REPORTED AT THE INTERSECTION OF
            HIGHWAY 80 AND 35 IN FOREST. ALSO, SEVERAL STREETS AND
            HOMES ARE FLOODED.

&&

JFAIRLY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
1004 AM CDT THU AUG 19 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     FLASH FLOOD      FOREST                  32.36N 89.47W
08/19/2010                   SCOTT              MS   EMERGENCY MNGR

            VERY HEAVY RAINFALL FLOODED AT LEAST 4 HOMES AND SEVERAL
            BUSINESSES WITH 15 PEOPLE BEING EVACUATED FROM THE RISING
            WATER. SEVERAL VEHICLES ARE TRAPPED IN FLOOD WATERS.
            NUMEROUS STREETS ARE CLOSED.

&&

FXA

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
1124 AM CDT THU AUG 19 2010

MSZ046-052-191735-
LAUDERDALE MS-KEMPER MS-
1124 AM CDT THU AUG 19 2010

...LOCAL DOWNPOURS AND ISOLATED STORMS DEVELOPING IN EAST CENTRAL
   MISSISSIPPI THROUGH 1 PM...

A SLOW MOVING CLUSTER OF HEAVY TROPICAL SHOWERS AND ISOLATED
THUNDERSTORMS WAS CENTERED ABOUT 3 MILES EAST OF MEEHAN AT 1125 AM
CDT...MOVING EAST AT 15 MPH. AS THESE DOWNPOURS MOVE INTO THE
MERIDIAN TO DEKALB AREAS THROUGH 1 PM...YOU CAN EXPECT QUICK RAINFALL
AMOUNTS OF 1 TO 2 INCHES TO OCCUR AND SOME PONDING OF WATER ON ROADS
AND IN LOW LYING AREAS.

OCCASIONAL CLOUD TO GROUND LIGHTNING STRIKES WILL ALSO BE POSSIBLE
WITH ANY STORMS ALONG WITH GUSTY WINDS OF 30 MPH.

HIGH WINDS CAN BRING DOWN TREES AND LARGE LIMBS RESULTING IN SERIOUS
INJURY OR PROPERTY DAMAGE. EXERCISE EXTREME CAUTION WHEN OUTDOORS
DURING SUCH STRONG WINDS...AND BE ESPECIALLY AWARE OF OLDER TREES.

PEOPLE IN SOUTHERN KEMPER AND LAUDERDALE COUNTIES SHOULD MONITOR THIS
STORM CLOSELY.

40

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
1144 AM CDT THU AUG 19 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 AM     HEAVY RAIN       2 SW FOREST             32.34N 89.50W
08/19/2010  M5.66 INCH       SCOTT              MS   PARK/FOREST SRVC

            6 HOUR RAINFALL TOTAL AT BIENVILLE NATIONAL FOREST RAWS
            SITE. MOST OF THIS RAIN FELL BETWEEN 6 AM AND 10 AM.

&&

GERARD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
116 PM CDT THU AUG 19 2010

LAZ024>026-191840-
TENSAS LA-CATAHOULA LA-CONCORDIA LA-
116 PM CDT THU AUG 19 2010

A SLOW MOVING CLUSTER OF THUNDERSTORMS PRODUCING HEAVY RAIN EXTENDED
FROM COOTER POINT IN TENSAS PARISH WEST TO NEAR SHERWOOD IN
CATAHOULA PARISH AT 110 PM. AS THESE DOWNPOURS MOVE SLOWLY TO THE
EAST THROUGH 2 PM...YOU CAN EXPECT QUICK RAINFALL AMOUNTS OF 1 TO 2
INCHES TO OCCUR AND SOME PONDING OF WATER ON ROADS AND IN LOW LYING
AREAS.

OCCASIONAL CLOUD TO GROUND LIGHTNING STRIKES WILL ALSO BE POSSIBLE
WITH THESE STORMS ALONG WITH GUSTY WINDS OF 30 MPH.

HIGH WINDS CAN BRING DOWN TREES AND LARGE LIMBS RESULTING IN SERIOUS
INJURY OR PROPERTY DAMAGE. EXERCISE EXTREME CAUTION WHEN OUTDOORS
DURING SUCH STRONG WINDS...AND BE ESPECIALLY AWARE OF OLDER TREES.

PEOPLE IN NORTHERN CONCORDIA...NORTHERN CATAHOULA AND SOUTHWESTERN
TENSAS PARISHES SHOULD MONITOR THIS STORM CLOSELY.

DB