MESOSCALE PRECIPITATION DISCUSSION 0133
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
909 PM EDT TUE JUN 17 2014
 
AREAS AFFECTED...EASTERN MT, WESTERN DAKOTAS, NORTHEAST WY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 180108Z - 180608Z
 
SUMMARY...THUNDERSTORMS WITH HEAVY RAINFALL COULD CAUSE A FEW
POCKETS OF FLASH FLOODING OVER SATURATED SOILS.

DISCUSSION...A THUNDERSTORM COMPLEX COMPOSED OF SEVERAL HEAVY RAIN
CORES OF 1-1.5" HOURLY RAIN RATES STRETCHES FROM THE
MT/SASKATCHEWAN BORDER SOUTHEAST INTO NORTHEAST WY AND THE WESTERN
DAKOTAS.  THE ACTIVITY HAS SHOWN A SLOW NORTHEAST PROGRESSION
SINCE EARLIER THIS AFTERNOON, PROGRESSING WITH THE TROWAL, WITH
SEVERAL CELLS SHOWING LOCAL RAINFALL AMOUNTS OF 2-4" PER THE NSSL
QPE, WITH ONE REPORT OF 5.29" MEASURED AT THE PINE HILL MT RAWS
SITE.

THERE IS A MODERATE CONSENSUS THAT THE ACTIVITY IN THIS REGION
SHOULD MOVE EASTWARD FURTHER INTO THE WESTERN DAKOTAS THROUGH 06Z,
TAPPING INTO AN AREA OF 3000-5000 J/KG CAPES WITHIN A REGION OF 25
KTS OF 0-3 KM SHEAR.  THE ACTIVITY SHOULD MOVE SLOWLY EASTWARD
WITH THE TROWAL OVERNIGHT ACROSS AN AREA WITH FLASH FLOOD GUIDANCE
VALUES OF 1.5-2" WITHIN THREE HOURS.  THE MESOSCALE GUIDANCE
AGREES THAT LOCAL AMOUNTS OF 2-4" ARE POSSIBLE, SIMILAR TO WHAT
WAS SEEN EARLIER THIS AFTERNOON, AND THAT THE ACTIVITY SHOULD
CONTINUE PAST 06Z.  A FEW POCKETS OF FLASH FLOODING ARE POSSIBLE
WITHIN THIS AREA.

ROTH

ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...

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

LAT...LON   48990365 48190226 47540170 46870155 45480182 44320301
            44020524 44870492 45740462 47060483 47370617 47950689
            48990737 49170529 48990365