MESOSCALE PRECIPITATION DISCUSSION 0057
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1147 PM EDT WED MAY 06 2015
 
AREAS AFFECTED...PORTIONS OF NERN KS/SERN NE...INTO NWRN MO/SWRN
IA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 070347Z - 070747Z
 
SUMMARY...FLASH FLOODING WILL LIKELY CONTINUE OVER THE NEXT FEW
HOURS IN SERN NEBRASKA...BUT WHILE HI-RES MODELS WANT TO DISSIPATE
THE THREAT BY 06Z...SIGNS POINT TOWARD A CONTINUED FLASH FLOOD
THREAT UNTIL AT LEAST 07Z.

DISCUSSION...AN MCS CONTAINING A LINE OF TRAINING CONVECTION WITH
HOURLY RATES OF 1.5 TO 2.5 IN/HR HAS BEEN OCCURRING OVER SERN
NEBRASKA SINCE ABOUT 23Z WITH KUEX DUAL POL ESTIMATED RAINFALL
TOTALS OF 5 TO 7 INCHES FROM JEWELL COUNTY KANSAS...NEWD INTO
SALINE COUNTY NEBRASKA. LOW LEVEL INFLOW INTO THIS COMPLEX IS
40-50 KTS FROM THE SOUTHWEST...EXCEEDING MEAN STORM MOTIONS TOWARD
THE NORTHEAST BY ABOUT 10 TO 20 KTS ALLOWING REPEATING CONVECTION.
FORCING FOR ASCENT WAS INITIALLY TIED TO A NEGATIVELY MID-LEVEL
SHORTWAVE CURRENTLY PRESSING NORTHEAST OVER N-CNTRL NEBRASKA WITH
AMPLE INSTABILITY OF 1000+ J/KG FROM KANSAS INTO SERN NEBRASKA. 

AS THE SHORTWAVE CONTINUES NEWD OVER THE NEXT FEW HOURS...BETTER
MID-LEVEL SUPPORT AND ENHANCED LIFT FROM THE RIGHT ENTRANCE REGION
OF A JET STREAK OVER ERN NEBRASKA/SOUTH DAKOTA WILL BE ON THE
DECREASE. HOWEVER...THE UPPER LEVELS WILL REMAIN DIFFLUENT AND LOW
LEVEL FLOW/MOISTURE WILL CONTINUE TO FAVOR TRAINING CONVECTION
WITH BACKWARD PROPAGATION PER CORFIDI VECTORS. THIS AND SEVERAL
CONVECTIVE COMPLEXES FARTHER SOUTH IN THE PLAINS...WHICH MAY
INTERRUPT MOISTURE TRANSPORT...CREATE A MIXED SIGNAL FOR CONTINUED
FLASH FLOODING BEYOND 07Z. THE HI-RES MODELS ARE UNANIMOUS IN
DISSIPATING THE HEAVIEST RAIN FROM THE MCS BY 06Z BUT A RECENT
UPTICK IN CELLS DEVELOPING OVER HARLAN AND FRANKLIN COUNTIES ALONG
WITH A CONTINUED STRONG LOW LEVEL JET IS A CONCERN FOR
CONTINUATION. WE WILL CONTINUE TO MONITOR AND UPDATE AS NEEDED
AROUND 0730Z.

OTTO0

ATTN...WFO...EAX...GID...OAX...TOP...

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

LAT...LON   41969619 41679517 40869517 40039576 39609700 
            39349849 39929962 40659853