MESOSCALE PRECIPITATION DISCUSSION 0654
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
352 AM EDT THU SEP 08 2016
 
AREAS AFFECTED...SOUTHEASTERN IA/NORTHWESTERN IL... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 080752Z - 081207Z
 
SUMMARY...AREA OF ORGANIZED CONVECTION SHOULD CONTINUE TO EXPAND
AS UPSTREAM DEVELOPMENT FILTERS IN FROM NORTHERN MO. THE MULTIPLE
ROUNDS OF THUNDERSTORMS ACROSS THE MPD AREA WILL INCREASE THE RISK
FOR FLASH FLOODING.

DISCUSSION...EARLY MORNING RADAR/SATELLITE IMAGERY SHOWED A
QUASI-STATIONARY BAND OF CONVECTION GENERALLY TRAINING OVER
EASTERN IA. PER MESONET OBSERVATIONS...A FEW AREAS OF 1.25 TO 1.50
INCHES OF RAINFALL HAVE BEEN REPORTED OVER CENTRAL IA DURING THE
04-05Z PERIOD. GIVEN WELL ABOVE NORMAL PRECIPITABLE WATER VALUES
IN PLACE...ON THE ORDER OF 2 TO 2.25 INCHES...COUPLED WITH
FAVORABLE UNIDIRECTIONAL FLOW REGIMES...EXPECT THE CONTINUED
THREAT FOR ADDITIONAL TRAINING BANDS THROUGH THE EARLY MORNING
HOURS. 

IT REMAINS TO BE SEEN HOW THE MORE SOUTHERN DEVELOPMENT INTERACTS
WITH THE CURRENT AXIS OF MODERATE/HEAVY RAINFALL. HOWEVER...THE
GENESIS REGION OVER NORTHERN MO REMAINS UNSTABLE AND CONTINUES TO
BE THE FOCUS FOR FURTHER CONVECTIVE INITIATION. THIS ACTIVITY HAS
GENERALLY LIFTED TOWARD THE EAST-NORTHEAST WHICH WILL CARRY IT
INTO AN AREA WHICH HAD EARLIER RECEIVED MODEST AMOUNTS OF RAIN.

THE BIGGEST LIMITING FACTOR ACROSS THE REGION IS THE THERMODYNAMIC
ENVIRONMENT WHERE MANY AREAS REMAIN FAIRLY CAPPED. IT APPEARS THE
RECENT HOURLY UPDATE HRRR/EXPERIMENTAL-HRRR HAVE CAUGHT ON TO THIS
AS THEY WEAKEN THE CONVECTION DURING THE NEXT COUPLE OF HOURS.
HOWEVER...THERE STILL REMAINS A DECENT CONSENSUS AMONG THE 00Z HRW
ARW/NMM-B AND NSSL-WRF OF 1 TO 2 INCHES THROUGH 12Z ACROSS WESTERN
IL.
 

RUBIN-OSTER

ATTN...WFO...DMX...DVN...EAX...ILX...LOT...LSX...

ATTN...RFC...MBRFC...NCRFC...

LAT...LON   42319026 41908846 40448866 40209023 39799175 
            39859259 40749313 41829178