779
AWUS01 KWNH 111919
FFGMPD
VAZ000-WVZ000-OHZ000-KYZ000-INZ000-ILZ000-120100-
MESOSCALE PRECIPITATION DISCUSSION 1011
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
318 PM EDT TUE AUG 11 2026
AREAS AFFECTED...CENTRAL INDIANA...SOUTHERN OHIO...NORTHEAST
KENTUCKY...SOUTHERN WV...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 111920Z - 120100Z
SUMMARY...FAST MOVING SQUALL LINE WITH SUB-HOURLY 1-1.5" TOTALS
MAY RESULT IN URBAN FLOODING CONDITIONS THROUGH THIS EVENING,
UNTIL REACHING COMPROMISED SOILS IN FOOTHILLS OF CENTRAL
APPALACHIANS.
DISCUSSION...REGIONAL RADAR MOSAIC DEPICTS AN INTENSE COMPACT
SHORTWAVE/MCV CROSSING NORTHERN INDIANA AT THIS TIME. ALONG THE
FORWARD FLANK OF THE MCV/CYCLONE A MATURE SQUALL LINE EXISTS FROM
PICKWAY TO N BUTLER COUNTY OH AND ACROSS TO SHELBY, IND. SEVERE
WINDS ARE MAIN CONCERN (PLEASE REFER TO SPC MCD 1926 FOR MORE
DETAILS); YET, THE STRONG CONVERGENCE ALONG THE LEADING EDGE IS
INGESTING SOLID DEEP LAYER MOISTURE ENVIRONMENT NEAR 2" OF TPW.
FLUX CONVERGENCE WILL SUPPORT VERY HIGH RAINFALL PRODUCTION, BUT
RESIDENCY IS LIKELY TO LIMIT TOTALS TO LESS THAN 1.5". HOWEVER,
THIS MAY COME AT 15-30 MINUTE RANGE WHICH WOULD BE A PROBLEM FOR
LOCALLY PRONE FLASHY LOCATIONS AND URBAN/HYDROPHOBIC GROUND
CONDITIONS. THIS WILL CHANGE AS THE LINE REACHES THE LOWER
FOOTHILLS OF THE CENTRAL APPALACHIANS IN SOUTHERN TO SOUTHEAST
OHIO AND WV WHERE EARLIER HEAVY RAINFALL HAVE REDUCED SOIL
CAPACITY AND LOWERED FFG VALUES TO BELOW 1" FOR MUCH OF THE THE
AREA WITH SPOTS LOWER THAN .5". AS SUCH, FLASH FLOODING WILL ONCE
AGAIN BECOME POSSIBLE ACROSS THOSE AREAS AGAIN LATER THIS EVENING.
CURRENTLY, INFLOW TO THE SYSTEM IS VERY OBLIQUE, ALMOST PARALLEL
WITH VWP SHOWING NEARLY WESTERLY INFLOW FROM 925-850MB ACROSS E
IL, S IND AND N KY LIMITING THE POTENTIAL FOR FLANKING LINE
DEVELOPMENT AT THIS TIME. THERE IS SOME WEAK CONVERGENCE FOR SOME
DEVELOPMENT FROM FORD, IL TO BENTON, IND COUNTIES, THIS
CONVERGENCE TROF ALONG THE INFLOW STREAMLINES TOWARD THE MCV IN N
IND IS EXPECTING SOME WEAKER BACKING ACROSS THE OHIO VALLEY TOWARD
SW FLOW AFTER 22Z. THIS SHOULD INCREASE ORTHOGONAL ISENTROPIC
ASCENT OVER THE FLANKING OUTFLOW BOUNDARY AND INCREASE OVERALL
CONVECTION. THE UNCERTAINTY REMAINS ON LEVEL OF DEVELOPMENT WITH
SURFACE ROOTED CONVECTION LOOKING A BIT LESS LIKELY THAN ELEVATED
CONVECTION IN AN AXIS A BIT FURTHER EASTWARD. EITHER LEVEL, DEEP
LAYER STEERING WILL BE PARALLEL TO THE BOUNDARY, ORTHOGONAL TO THE
INFLOW ALLOWING FOR A HIGHER POTENTIAL FOR NW TO SE TRAINING BAND
INTO THE LATER EVENING HOURS, MORE LIKELY AT OR AFTER 00Z. IF
THE AXIS IS MORE ELEVATED, IT WOULD MORE LIKELY OVERLAP AREAS
AFFECTED WITH THE EARLIER ROUNDS OVER THE LAST FEW DAYS,
REAGGRAVATING FLASH FLOODING POTENTIAL.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...ILN...ILX...IND...IWX...JKL...LMK...LOT...RLX...
RNK...
ATTN...RFC...MSR...ORN...RHA...TIR...NWC...
LAT...LON 40718689 40488529 40098337 39748216 39368101
38837992 37938004 37258095 37168212 37538324
38448522 39458709 40098783 40558767
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