MESOSCALE PRECIPITATION DISCUSSION 0087
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
236 PM EDT SUN JUN 01 2014
 
AREAS AFFECTED......NORTHEAST NE/NORTHERN IA/SOUTHERN WI... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 011835Z - 020035Z
 
SUMMARY...THUNDERSTORMS DEVELOPING ALONG A SURFACE BOUNDARY SHOULD
PERSIST AS MOIST INFLOW INCREASES...

DISCUSSION...SATELLITE IMAGERY AND SURFACE OBSERVATIONS REVEAL A
REMNANT BNDRY FROM THE OUTFLOW OF FORMER THUNDERSTORMS ALONG WHICH
NEW ACTIVITY HAS DEVELOPED IN NORTHEAST NEBRASKA ACROSS PARTS OF
NORTHERN IOWA AND SOUTHWEST WI. 

MODEL FCSTS SHOW PREVAILING LOW-MID LEVEL SOUTHWEST FLOW WITH
LITTLE DIRECTIONAL SHEAR ABV 950 MB AND SLIGHT VEERING BELOW THAT.
 DAYTIME HEATING HAS COMBINED WITH INCREASING MOISTURE FLUXES AND
SFC CONVERGENCE TO TRIGGER THUNDERSTORMS.  THESE THUNDERSTORMS
WILL LIKELY PRODUCE 1-2 INCHES OF RAIN PER HOUR.

AHEAD OF THE THUNDERSTORM COMPLEX IN NEBRASKA...BNDRY LAYER
MOISTURE CONVERGENCE IS INCREASING AND IS EXPECTED TO CROSS FROM
NEBRASKA INTO IOWA...ALONG WITH FAVORABLE UPPER DIVERGENCE.  OUT
AHEAD OF THE COMPLEX...CONTINUING LOW LEVEL SOUTHERLY FLOW SHOULD
ADVECT MOISTURE INTO THE BNDRY WITH PRECIPITABLE WATER VALUES
INCREASING FROM NEAR 1.5 TO 1.75 INCHES THIS EVENING.
  
2-4" OF RAIN IS POSSIBLE WHERE THUNDERSTORMS REDEVELOP AND MOVE
OVER AREAS IMPACTED BY PRIOR CELLS. THE 12Z SPC WRF AND PARALLEL
WRF ARW ARE DEPICTING THIS ACTIVITY BETTER THAN THE HIGH RES RAPID
REFRESH...NSSL WRF...AND OPERATIONAL WRF NMM...AS WELL AS THE
OPERATIONAL GFS/NAM.

PETERSEN

ATTN...WFO...GRB...MKX...ARX...MPX...DMX...FSD...OAX...LBF...

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

LAT...LON   43489605 43779472 44209090 44278977 43738923 43119042
            42999204 42639426 42129615 41839816 42509867 43119788
            43489605