Graphic for MPD #0926

MESOSCALE PRECIPITATION DISCUSSION 0926
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
405 PM EST SUN NOV 05 2017

AREAS AFFECTED...CTRL/ERN INDIANA...OHIO...FAR NRN KENTUCKY

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 052104Z - 060300Z

SUMMARY...THE THREAT OF FLASH FLOODING IS EXPECTED TO INCREASE
THIS AFTERNOON AND INTO THE EARLY EVENING FROM CENTRAL INDIANA
INTO OHIO. TRAINING BANDS OF RAIN AND THUNDERSTORMS COULD PRODUCE
RAINFALL RATES AS HIGH AS 2.0 TO 2.5 IN/HR IN LOCALIZED MAXIMA.
ISOLATED RAIN TOTALS IN EXCESS OF 4 INCHES WILL BE POSSIBLE.

DISCUSSION...A BAND OF RAIN AND CONVECTION PRODUCING WIDESPREAD
MODERATE RAINFALL AND EMBEDDED HEAVY RAINFALL SHOULD PERSIST INTO
THE EVENING...AND BEGIN TO GRADUALLY SHIFT SOUTHEAST WITH TIME.
THE CONVECTIVE BAND HAD ADVANCED OFF THE SYNOPTIC
FRONT...PARTICULARLY ACROSS NORTHERN INDIANA AND NORTHWEST OHIO.
AN EFFECTIVE FRONT AND OUTFLOW BOUNDARY COULD BE ANALYZED FROM
NEAR TOLEDO OH...SW ALONG I-75 TO NEAR LIMA OH...TO NEAR MUNCIE
IN...TO NEAR CRAWFORDSVILLE IN. THE OUTFLOW BOUNDARY (AND ONGOING
CONVECTIVE BAND) WAS ORIENTED IN A MORE WEST-EAST FASHION IN
PORTIONS OF INDIANA...AND THIS IS AN AREA WHERE CELL TRAINING AND
MERGERS HAVE ALREADY PRODUCED AROUND 1.5 TO 3.0 INCHES OF RAIN
BASED ON RADAR ESTIMATES. AS THE NORTHERN EXTENT OF THE CONVECTIVE
LINE CONTINUES TO RAPIDLY PROGRESS EAST THROUGH NORTHERN OHIO...A
LONGER EXTENT OF THE OUTFLOW BOUNDARY MAY BECOME MORE FAVORABLY
ORIENTED FROM WEST-TO-EAST FROM CENTRAL INDIANA INTO CENTRAL OHIO.

NEAR THIS EVOLVING MESOSCALE BOUNDARY...RAP ANALYSIS AND FORECASTS
ALSO SHOW THE NOSE OF A STRONG LOW-LEVEL MOISTURE TRANSPORT
MAXIMUM AND A RELATIVE MINIMUM IN BACKBUILDING STORM MOTION
VECTORS. THEREFORE...THIS APPEARS TO BE A FAVORED AREA FOR HIGHER
RAINFALL TOTALS AND FLASH FLOODING. THE 18Z HREF BLENDED MEAN 6HR
QPF FOR 21-03Z IS IN EXCESS OF 3 INCHES OVER A LARGE PORTION OF
WEST-CENTRAL AND CENTRAL OHIO...PARTICULARLY NEAR AND JUST NORTH
OF INTERSTATE 70. LOCALIZED TOTALS COULD OBVIOUSLY BE IN EXCESS OF
AN ENSEMBLE MEAN...AND IT IS WORTH NOTING THAT 6HR FFG IS
GENERALLY BELOW 3 INCHES ACROSS A SUBSTANTIAL PORTION OF THE SAME
AREA. THEREFORE...CONFIDENCE IN FLASH FLOODING IS INCREASED GIVEN
THE STRONG SIGNAL IN HI-RES MODEL GUIDANCE...ALONG AND JUST NORTH
OF I-70 CORRIDOR FROM NEAR/JUST EAST OF INDIANAPOLIS TO PERHAPS AS
FAR EAST AS THE JUNCTION WITH I-77 IN EC OHIO.

IF THE HEAVIER RAIN RATES EXCEEDING 1 IN/HR (AND APPROACHING 2
IN/HR) CAN BE SUSTAINED IN A GIVEN AREA FOR TWO HOURS OR
MORE...THE POSSIBILITY OF A FOCUSED AREA OF MORE SUBSTANTIAL FLASH
FLOODING CANNOT BE RULED OUT. THIS WOULD ESPECIALLY BE TRUE IF IT
IS ALIGNED WITH A SIZABLE METROPOLITAN AREA.

LAMERS

ATTN...WFO...CLE...ILN...IND...IWX...LMK...PBZ...RLX...

ATTN...RFC...NCRFC...OHRFC...

LAT...LON   41698315 41538253 41598205 41668141 41378098
            40978069 40448074 39868106 39578157 39398210
            39208306 38898414 38628512 38548561 38458618
            38928653 39658685 40368646 40718566 41138487
            41628394


Last Updated: 405 PM EST SUN NOV 05 2017