946
AWUS01 KWNH 122136
FFGMPD
TNZ000-KYZ000-INZ000-130300-
MESOSCALE PRECIPITATION DISCUSSION 1028
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
535 PM EDT WED AUG 12 2026
AREAS AFFECTED...FAR SOUTHWEST IND...CENTRAL
KENTUCKY...NORTH-CENTRAL MIDDLE & EASTERN TENNESSEE...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 122135Z - 130300Z
SUMMARY...PRE-CURSORY WARM FRONTAL CELLS ORIENTED FAVORABLY FOR
SHORT-TERM TRAINING WILL EVENTUALLY BE OVERRUN BY STRONGER,
CONVECTIVE LINE. STREAK OF 2-3+" TOTALS WITH QUICK SUB-HOURLY
1-1.5" MAY POSE LOCALIZED FLASH FLOODING.
DISCUSSION...21Z SURFACE ANALYSIS DENOTES OUTFLOW REINFORCED
STATIONARY FRONT CROSSES CENTRAL KY FROM CLINTON COUNTY TO HART TO
HANCOCK COUNTY AND SEPARATES HIGHLY UNSTABLE LOW 90S WITH UPPER 70
AND 80F SURFACE TDS TO SUPPORT 3500-4000 J/KG OF MLCAPE FROM
STABILIZED AIR NORTHEAST OF THE BOUNDARY. SOUTHWESTERLY SURFACE
TO 925MB IS HIGHLY CONVERGENT ALONG THE BOUNDARY AND IS CURRENTLY
SUPPORTING SCATTERED CONVECTIVE INITIATION ALONG ITS LENGTH BACK
TOWARD THE FRONT'S INTERSECTION WITH QUICKLY ADVANCING WEST TO
EAST SQUALL LINE IN S IND, CURRENTLY CROSSING THE OHIO RIVER.
WHILE THERE IS SOME MID-LEVEL DRYING IN ADVANCE OF THE SQUALL
LINE, TOTAL PWATS REMAIN OVER 1.75 TO 2" AND GIVEN 15-20KTS OF
ORTHOGONAL FLUX CONVERGENCE AND STRONG VERTICAL ASCENT SHOULD
SUPPORT 2-2.5"/HR RATES. DEEP LAYER STEERING REMAINS MORE WEST
THAN NORTHWEST, BUT GENERALLY IS SLOWED SO CELLS HAVE SOME
CAPABILITY FOR RESIDENCY TO LAY DOWN SCATTERED 1-2" TOTALS PRIOR
TO THE MAIN SQUALL SWEEPING THROUGH THE AREA.
AS FOR THE SQUALL LINE, THE INTERSECTION OF IT WITH THE FRONT IS
LIKELY TO HAVE SOME FURTHER ENHANCEMENT OF SURFACE CONVERGENCE AND
AS A RESULT LIGHTNING DENSITY AND BROADER REFLECTIVITY PATTERN WAS
NOTED EAST OF EVANSVILLE, WITH SLIGHTLY HIGHER MOISTURE AOA 2" TO
2.25" INSTANTANEOUS RATES WOULD BE GREATER WITH THIS CELL UP TO
2-3", HOWEVER, FORWARD PROGRESSION ON STRENGTH OF OUTFLOW IS
LIMITING TIME BUT OBSERVATIONS REMAIN AROUND 1.25-1.5" IN 30-45
MINUTES AS IT PASSES. THIS ALONE IS LIKELY TO RESULT IN RUNOFF
ISSUES IN URBAN LOCATIONS; HOWEVER, IT IT WILL BE THIS ADDITION OF
1-1.5" AS IT SLOWLY CATCHES THE WARM FRONTAL CELLS IN ADVANCE OF
IT THAT MAY HAVE LAID DOWN PRE-CURSORY 1-2". AS A RESULT,
SCATTERED AREAS OF 2-3+" TOTALS WILL EXIST EVEN AS THE OVERALL
LINE IS EXPECTED TO WEAKEN/REDUCE IN INTENSITY TOWARD LATE
EVENING. COMPOUND THIS WITH INCREASINGLY RUGGED TERRAIN AND
NATURALLY LOWER FFG VALUES INTO THE CUMBERLAND PLATEAU SUGGESTS
LOCALIZED FLASH FLOODING MAY CONTINUE TO BE POSSIBLE INTO
NORTHEAST MIDDLE TN AND NORTHWEST EASTERN TN.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...JKL...LMK...MRX...OHX...PAH...
ATTN...RFC...ORN...TIR...NWC...
LAT...LON 38308698 38128651 38008635 37788590 37418529
36868423 36298343 35538403 35838509 36758653
37268716 37808770 38268759
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