572
AWUS01 KWNH 081813
FFGMPD
NCZ000-GAZ000-TNZ000-KYZ000-ALZ000-MSZ000-MOZ000-ARZ000-090000-
MESOSCALE PRECIPITATION DISCUSSION 0976
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
212 PM EDT SAT AUG 08 2026
AREAS AFFECTED...MID-SOUTH
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 081812Z - 090000Z
SUMMARY...INCREASING COVERAGE OF SHOWERS AND THUNDERSTORMS WITH
HIGH RAINFALL RATES WILL PROMOTE CONCERNS FOR AT LEAST ISOLATED
AREAS OF FLASH FLOODING GOING THROUGH THE AFTERNOON AND EARLY
EVENING HOURS.
DISCUSSION...THE LATEST GOES-E IR SATELLITE IMAGERY SHOWS COOLING
CLOUD TOPS ACROSS AREAS OF NORTHERN MS, WESTERN TN AND NORTHWEST
AL IN ASSOCIATION WITH DEVELOPING CLUSTERS OF SHOWERS AND
THUNDERSTORMS. ADDITIONAL ACTIVITY IS ALSO NOTED FARTHER EAST
ACROSS THE CUMBERLAND PLATEAU REGION OF EASTERN TN. THE ACTIVITY
IS INITIATING AND EXPANDING IN COVERAGE AS A WELL-DEFINED
MID-LEVEL VORT CENTER OVER EASTERN AR DRIFTS EAST INTO A VERY
MOIST AND UNSTABLE AIRMASS POOLED UP ACROSS THE BROADER MID-SOUTH.
FARTHER EAST, THERE IS ALSO THE INFLUENCE FROM TERRAIN AND
DIFFERENTIAL HEATING BOUNDARIES.
MLCAPE VALUES OF 2000 TO 3000 J/KG AND PWS OF 1.75 TO 2+ INCHES
ARE IN PLACE ACROSS THE REGION. THE STRONG BOUNDARY LAYER HEATING
WITH SOLAR INSOLATION WILL CONTINUE TO HELP DRIVE INCREASING
LEVELS OF INSTABILITY OVER THE NEXT FEW HOURS, AND THIS WILL
COUPLE WITH THE EVOLUTION OF SMALLER-SCALE OUTFLOW BOUNDARY
ACTIVITY FOR ADDITIONAL CONVECTION TO DEVELOP AND EXPAND IN
COVERAGE. LOCAL OROGRAPHIC ASCENT NEAR AREAS OF ELEVATION WILL
ALSO BE A KEY PLAYER IN DRIVING MORE AREAS OF CONVECTION.
THE MORNING 12Z RAOB SOUNDINGS FROM KLZK, KBNA AND KBMX CONFIRM
RATHER HIGH WBZ HEIGHTS AND PLENTY OF MOISTURE EXTENDING THROUGH
THE VERTICAL COLUMN. THIS WILL SUPPORT HIGH EFFICIENCY WITH THIS
AFTERNOON'S CONVECTION WITH HIGH RAINFALL RATES THAT WILL BE
CAPABLE OF REACHING 2 TO 3 INCHES/HOUR WITH THE STRONGER STORMS.
THE LACK OF EFFECTIVE BULK SHEAR SUGGESTS THE CONVECTIVE MODE
SHOULD MAINLY BE PULSE IN NATURE, BUT THERE MAY BE ENOUGH OUTFLOW
BOUNDARY COLLISIONS AND COLD POOL ACTIVITY TO FACILITATE SOME
LOOSELY ORGANIZED MULTI-CELL CONVECTION. THIS COUPLED WITH SLOW
CELL-MOTIONS AND SOME CELL-MERGER POTENTIAL MAY HELP YIELD SOME
LOCALIZED 3 TO 4+ INCH RAINFALL TOTALS OVER THE NEXT SEVERAL
HOURS. THIS WILL DRIVE A THREAT FOR AT LEAST ISOLATED AREAS OF
FLASH FLOODING, WITH THE MORE URBANIZED LOCATIONS AT GREATEST RISK
FOR IMPACTS.
ORRISON
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...BMX...FFC...HUN...JAN...JKL...LMK...LZK...MEG...
MRX...OHX...PAH...
ATTN...RFC...ALR...ORN...TIR...NWC...
LAT...LON 36988713 36978567 36768460 36218393 35368413
35138428 34648491 34238588 33788845 33059043
33159148 33609158 34919046 36019006 36558893
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