MESOSCALE PRECIPITATION DISCUSSION 0361
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
741 PM EDT TUE SEP 09 2014
 
AREAS AFFECTED......PORTIONS OF NE/KS/IA/MO/IL... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 092340Z - 100540Z
 
SUMMARY...FLASH FLOODING WILL BECOME INCREASINGLY LIKELY ALONG THE
IA/MO BORDER BETWEEN 01-06Z AS AN MCS GRADUALLY MATURES AND
TRAINING OF CELLS INCREASES.

DISCUSSION...INTENSE DEEP CONVECTION WILL LIKELY EXPAND IN
VICINITY OF A STATIONARY FRONT AND 2 LOWS DRAPED ALONG THE
NE/KS/IA/MO BORDER THROUGH 06Z AS STORM RELATIVE INFLOW INCREASES
IN RESPONSE TO COLD POOL FORMATION...THE LOW LEVEL JET...AND
GREATER INFLUENCES FROM THE UPPER TROUGH.

THE COMBINATION OF AVERAGE MIXED LAYER CAPES OF 1500-2500 J/KG AND
PW VALUES OF 1.5 AND 2.25 INCHES SUPPORTS RAIN RATES NEAR 2 INCHES
PER HOUR..ALTHOUGH THESE RATES WILL TAKE SOME TIME TO DEVELOP ON A
LARGE SCALE EXCEPT NEAR SUPERCELLS. 

FROM 03-06Z ONWARD HOWEVER...AN INCREASING LOW LEVEL JET AND MORE
UNIDIRECTIONAL WIND PROFILES FAVOR A POTENTIAL FOR GREATER
BACK-BUILDING OF INDIVIDUAL CELLS...WITH RAIN RATES POSSIBLY
EXCEEDING 2 INCHES PER HOUR.  

ANOTHER POSSIBLE LOCATION FOR EXCEEDING FFG VALUES WILL BE ALONG
THE MO/IL BORDER MAINLY NORTH OF ST. LOUIS WHERE CONVECTIVE
OUTFLOW CONTINUES TO PROVIDE A FOCUS FOR NEW CONVECTION WHERE CAPE
VALUES REMAIN HIGH AND CIN HAS BEEN ELIMINATED.  GIVEN WEAKER
CLOUD LAYER WINDS AND MORE UNIDIRECTIONAL FLOW ACROSS THIS
AREA...FURTHER TRAINING WILL REMAIN POSSIBLE AND COULD SUSTAIN
RAIN RATES THAT EXCEED GUIDANCE. 

JAMES

ATTN...WFO...DMX...DVN...EAX...GID...ILX...LSX...OAX...TOP...

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

LAT...LON   41699398 41299159 40449029 39749064 38568990 
            38419102 39289281 39309498 39319627 39739779 
            40739789 41489679