MESOSCALE PRECIPITATION DISCUSSION 0672
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1131 PM EDT THU SEP 15 2016
 
AREAS AFFECTED...ERN NE INTO IA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 160330Z - 160800Z
 
SUMMARY...FLASH FLOODING IS LIKELY TO CONTINUE OVER THE NEXT FEW
HOURS OVER ERN NE INTO IA. LOCALLY MAJOR IMPACTS WILL BE POSSIBLE
WITH THE HEAVIEST RAIN EXPECTED JUST NORTH OF OMAHA.

DISCUSSION...SURFACE OBSERVATIONS SHOWED THAT THE WRN EDGE OF AN
OUTFLOW BOUNDARY HAS BEEN NEARLY STATIONARY OVER THE PAST HOUR OR
TWO...CROSSING THE MISSOURI RIVER JUST NORTH OF OMAHA IN NRN
DOUGLAS COUNTY. THE WRN EDGE OF THE OUTFLOW INTERSECTED A EWD
PROPAGATING MCS ALONG THE CNTRL NE/KS BORDER WITH AN MCV OBSERVED
IN BUFFALO COUNTY. RAINFALL RATES OF 2-3 IN/HR HAVE BEEN OBSERVED
FROM WEST TO EAST WITHIN A NEARLY STATIONARY AXIS OF HEAVY RAIN
ACROSS ERN NE INTO W-CNTRL IA. KOAX VAD WINDS SHOWED 30-35 KTS OF
SSWLY FLOW IN THE 850-700 MB LAYER...ADVECTING IN AN ESTIMATED
1000-2000 J/KG MLCAPE ACROSS THE OUTFLOW BOUNDARY...WITH TRAINING
OF CELLS FROM SW TO NE. 

AS THE FORWARD PROPAGATING MCS ALONG THE NE/KS BORDER CONTINUES
EWD...A CONTINUED INFLUX OF MOISTURE/INSTABILITY WILL ADVECT INTO
AND ACROSS THE NEARLY STATIONARY EAST-WEST ORIENTED OUTFLOW
BOUNDARY. ALOFT...HIGHLY DIFFLUENT FLOW AND THE RIGHT ENTRANCE
REGION OF A 90-100 KT JET STREAK WILL FOCUS OVER THE NE/IA
BORDER...HELPING SUPPORT INTENSE LIFT. ANOTHER 3-5 INCHES WILL BE
POSSIBLE FROM PLATTE...COLFAX..STANTON COUNTIES...EWD TO JUST
ACROSS THE IA BORDER. ADDITIONAL...THOUGH NOT AS SEVERE...FLASH
FLOODING WILL BE POSSIBLE FARTHER EAST INTO IA WITH CONTINUED
OVERRUNNING OF THE SLOWLY SAGGING ERN PORTION OF THE WEST-EAST
BOUNDARY.

OTTO

ATTN...WFO...ARX...DMX...DVN...FSD...GID...OAX...

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

LAT...LON   43119112 42809082 42299096 41559179 41249264 
            41179414 40619681 40569804 40969834 41649804 
            42249676 42399532 42529428 42869276 43009233 
            43079191