Flash Flood Warning 19, NWS Memphis, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
416 AM CDT SAT APR 27 2013

.DISCUSSION...
LOTS OF RAIN ON THE RADAR THIS MORNING...BUT NOTHING APPROACHING
STRONG OR SEVERE LEVELS. IF THERE IS ANY EXISTING THREAT FROM THE
CURRENT STORMS...OTHER THAN LIGHTNING...IT WOULD BE LOCALIZED
FLOODING. PORTIONS OF NORTHWEST TENNESSEE...NORTHEAST ARKANSAS AND
THE MISSOURI BOOTHEEL HAVE ALREADY RECEIVED OVER 2.5 INCHES OF RAIN
OVER THE PAST 12 HOURS OR SO. ADDITIONAL RAINFALL COULD RESULT IN
FLOODING PROBLEMS ALONG LOW WATER CROSSINGS AND OTHER FLOOD PRONE
AREAS. THREE HOUR FLASH FLOOD GUIDANCE INDICATES THAT MOST AREAS
THAT HAVE ALREADY RECEIVED HEAVY RAINFALL CAN HANDEL ANOTHER 1-2
INCHES OF RAIN IN A 3 HOUR TIME PERIOD BEFORE ANY WIDESPREAD
PROBLEMS ARE EXPECTED. DUAL POL INSTANTANEOUS RAINFALL RATES
INDICATE RAINFALL RATES ARE UP TO 2 INCHES PER HOUR...BUT THESE
EXCESSIVE RATES SHOULD NOT LAST FOR ANY PROLONGED PERIOD OF TIME
AT ANY GIVEN LOCATION. WILL CONTINUE TO MONITOR THE FLOOD
POTENTIAL...AND ADD IT AS A THREAT IN THE HWO...BUT DO NOT ANTICIPATE
THE NEED FOR A FLASH FLOOD WATCH AT THIS TIME.

RAIN AND THUNDERSTORMS WILL CONTINUE TODAY...ALL OF THE MIDSOUTH
CAN EXPECT TO EXPERIENCE THUNDERSTORMS TODAY INTO THE OVERNIGHT
HOURS. THE SEVERE POTENTIAL LOOKS MARGINAL...GREATEST ACROSS
NORTHERN MISSISSIPPI. ALOFT...WE REMAIN IN A SPLIT FLOW PATTERN
WITH A POSITIVELY TILTED TROUGH MOVING TO THE EAST ACROSS THE
AREA. NO SIGNIFICANT DYNAMIC ENERGY IS IN PLACE TO SUPPORT
WIDESPREAD SEVERE WEATHER. ABOUT ALL WE CAN SEE IN THE UPPER
LEVELS IS 60-70 KTS OR FAIRLY UNIDIRECTIONAL FLOW AND ONLY
30-50KTS AT THE MID AND LOW LEVELS. AT THE SURFACE..A WARM FRONT
WILL LIFT TO THE NORTH ACROSS THE MIDSOUTH ALLOWING A DEEP WARM
AIRMASS TO BUILD OVER THE REGION. DEW POINTS WILL SURGE INTO THE
UPPER 50S OR LOW 60S BY THIS AFTERNOON. A SURFACE LOW IS EXPECTED
TO TRACK ACROSS EAST ARKANSAS AND ACROSS THE MISSOURI BOOTHEEL THIS
AFTERNOON...LIKELY ENHANCING SHEAR NEAR ITS TRACK...BUT OVERALL
SHEAR PROFILES DO NOT LOOK IMPRESSIVE. ADDITIONALLY...GUIDANCE
INSTABILITY PARAMETERS ARE LIKELY EXAGGERATED. IT DOES NOT LOOK
LIKELY THAT WE WILL BE ABLE TO WARM SIGNIFICANTLY TODAY UNDER
DENSE CLOUD COVER AND WITH ONGOING PRECIPITATION. NORTH
MISSISSIPPI LIKELY STANDS THE GREATEST CHANCE OF APPROACHING
GUIDANCE FORECAST CAPE VALUES IN EXCESS OF 1200J/KG...BUT THAT IS
ONLY IF THERE IS A FEW BREAKS IN THE CLOUD COVER TO ALLOW SURFACE
WARMING. WARM ADVECTION IS NOT LIKELY GOING TO BE ENOUGH TO WARM
TEMPERATURES IN THE MIDDLE 70S. WILL ADVERTISE A LOW END SLIGHT
RISK FOR SEVERE STORMS ACROSS NORTH MISSISSIPPI AND GENERAL
STRONG THUNDERSTORMS ELSEWHERE. THE ONLY FLY IN THE OINTMENT
FARTHER NORTH FOR SEVERE WEATHER WILL BE THE POTENTIAL FOR
LOCALIZED SHEAR ENHANCEMENT NEAR THE SURFACE LOW. HOWEVER...AT
THIS TIME...THINK THAT THREAT IS LOW ENOUGH TO STICK WITH ONLY
STRONG WORDING.

TONIGHT...ANY SEVERE THREAT WILL DIMINISH AND A WEAKENING COLD
FRONT WILL GRADUALLY SHIFT ACROSS THE MIDSOUTH. THE AIRMASS BEHIND
THE FRONT IS NOT A LOT DIFFERENT THAN AHEAD OF IT...BUT WINDS WILL
SHIFT FROM THE WEST TO NORTHWEST MARKING ITS PASSAGE. TEMPERATURES
SUNDAY MAY EVEN BE WARMER TOMORROW THAN TODAY AS THE RESULT OF
MORE SUNSHINE...ESPECIALLY IN EAST ARKANSAS. MUCH OF NORTH
MISSISSIPPI AND WEST TENNESSEE...NEAR THE ALABAMA STATE LINE AND
TENNESSEE RIVER WILL REMAIN CLOUDY. A FEW SHOWERS MAY ALSO LINGER
IN EASTERN PORTIONS OF NORTH MISSISSIPPI...BUT NO STORMS ARE
EXPECTED TO BE SEVERE.

MONDAY THROUGH MIDWEEK SHOULD BE MOSTLY DRY AND WARM. HIGHS WILL
APPROACH THE MIDDLE 80S BY WEDNESDAY AS RIDGE BUILDS OVER THE
MIDSOUTH AND SHIFTS TO THE EAST. BY MIDDAY WEDNESDAY RETURN FLOW
WILL SETUP ACROSS THE MIDSOUTH...AND THE CHANCE FOR A FEW SHOWERS
WILL RETURN TO THE FORECAST. GUIDANCE WINDS ARE PRETTY IMPRESSIVE
THURSDAY AFTERNOON INTO FRIDAY...FEATURING SUSTAINED SPEEDS IN THE
MIDDLE 20S AS A DEEP TROUGH DIGS OVER THE PLAINS. THERE IS
CONSIDERABLE DISAGREEMENT IN GUIDANCE THURSDAY INTO THE WEEKEND.
THE GFS HAS A MORE PROGRESSIVE SOLUTION WHILE THE ECMWF KEEPS A
DEEP CUTOFF LOW OVER THE SOUTHERN PLAINS FOR SEVERAL DAYS. BOTH
MODELS FEATURE A SIGNIFICANT TROUGH...WHICH COULD PUT US BACK IN
RECORD LOW TEMPERATURE TERRITORY TOWARD THE END OF THE FORECAST
PERIOD. PORTIONS OF THE MIDSOUTH COULD SEE A LATE SPRING/EARLY MAY
FROST FRIDAY AND OR SATURDAY MORNING.

30/SIRMON

&&

.AVIATION...

06Z TAF CYCLE

A MID LEVEL FRONTAL BOUNDARY HAS LIFTED FURTHER NORTH INTO
NORTHWEST TENNESSEE WITH MUCH OF THE CONVECTION NOW NORTH OF THE
TAF SITES. THIS BREAK SHOULD BE TEMPORARY AS ANOTHER SHORTWAVE
EMBEDDED WITHIN THE FLOW ALOFT IMPACTS THE REGION OVER THE NEXT
COUPLE OF HOURS. THIS SHOULD RESULT IN CIGS LOWERING TO MVFR/VFR...WITH
TEMPORARY IFR CIGS...AS ISENTROPIC ASCENT ASSOCIATED WITH
SHORTWAVE LEADS TO ADDITIONAL SHOWERS AND THUNDERSTORMS. WINDS
SHOULD REMAIN EAST TO NORTHEAST AT 8 KTS OR LESS OVERNIGHT.

A SURFACE WARM FRONT SHOULD LIFT NORTHWARD INTO THE AREA ON
SATURDAY MORNING WITH CONTINUED SHOWERS AND THUNDERSTORMS...ALONG
WITH REDUCED CIGS AND VSBYS. THIS ACTIVITY WILL BE ONGOING THROUGH
MUCH OF THE DAY TO THE NORTH OF THE FRONT. SOUTH OF THE
FRONT...SKIES MAY ACTUALLY IMPROVE TO VFR/MVFR WITH BREAKS IN THE
CLOUD COVER. ANOTHER SHORTWAVE WILL MOVE NORTHEAST ACROSS THE
AREA...WITH ADDITIONAL STORMS DEVELOPING OVER THE WARM SECTOR DURING
THE AFTERNOON/EVENING. WINDS WILL BE SOUTHERLY SOUTH OF THE FRONT AND
SOUTHEASTERLY TO THE NORTH.

JLH

&&

.PRELIMINARY POINT TEMPS/POPS...
MEM  71  58  72  54 / 100  60  30  10
MKL  68  57  71  50 / 100  70  30  10
JBR  68  55  70  49 / 100  50  20   0
TUP  73  62  73  54 / 100  70  60  20

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
334 AM CDT SAT APR 27 2013

ARZ008-009-017-018-026>028-035-036-048-049-058-MOZ113-115-
MSZ001>017-020>024-TNZ001>004-019>021-048>055-088>092-281030-
ALCORN-BENTON MS-CALHOUN-CARROLL-CHESTER-CHICKASAW-CLAY-COAHOMA-
CRAIGHEAD-CRITTENDEN-CROCKETT-CROSS-DESOTO-DECATUR-DUNKLIN-DYER-
FAYETTE-GIBSON-GREENE-HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-
ITAWAMBA-LAFAYETTE-LAKE-LAUDERDALE-LAWRENCE-LEE AR-LEE MS-MADISON-
MARSHALL-MCNAIRY-MISSISSIPPI-MONROE-OBION-PANOLA-PEMISCOT-
PHILLIPS-POINSETT-PONTOTOC-PRENTISS-QUITMAN-RANDOLPH-SHELBY-
ST. FRANCIS-TALLAHATCHIE-TATE-TIPPAH-TIPTON-TISHOMINGO-TUNICA-
UNION-WEAKLEY-YALOBUSHA-
334 AM CDT SAT APR 27 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST ARKANSAS...
THE MISSOURI BOOTHEEL...NORTH MISSISSIPPI...AND WEST TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

A FEW STRONG TO PERHAPS SEVERE THUNDERSTORMS ARE POSSIBLE INTO THIS
EVENING...PREDOMINANTLY SOUTH OF I-40. DAMAGING WINDS AND PERHAPS
LARGE HAIL WILL BE THE PREDOMINANT THREATS FOR ANY THUNDERSTORMS
THAT REACH SEVERE LIMITS.

IN ADDITION...LOCALIZED FLASH FLOODING FROM HEAVY RAINFALL IS ALSO
POSSIBLE. AREA RIVERS AND OTHER WATERWAYS WILL LIKELY EXPERIENCE
RISES AS AS WELL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED INTO THIS EVENING IN SUPPORT OF
SEVERE WEATHER OPERATIONS.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEMPHIS TN
617 AM CDT SAT APR 27 2013

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

0615 AM     FLASH FLOOD      BRIGHTON                35.48N 89.74W
04/27/2013                   TIPTON             TN   LAW ENFORCEMENT

            8-10 INCHES OF WATER OVER OLD HWY 51 NEAR BRIGHTON
            ELEMENTARY SCHOOL. OTHER ROADS IN TIPTON COUNTY ALSO HAVE
            SEVERAL INCHES WATER OVER THEM.

&&

CDG