MESOSCALE PRECIPITATION DISCUSSION 0219
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1226 AM EDT TUE MAY 16 2017

AREAS AFFECTED...SERN MN INTO WRN WI

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 160422Z - 160900Z

SUMMARY...TRAINING RAINFALL WITH RATES OF 1-2 IN/HR ARE EXPECTED
TO GENERATE A FLASH FLOOD THREAT FROM SERN MN INTO WRN WI OVER THE
NEXT FEW HOURS.

DISCUSSION...04Z REGIONAL RADAR SHOWED NUMEROUS THUNDERSTORMS OVER
SERN MN...DEVELOPING NEAR A 925 MM WARM FRONT ESTIMATED TO STRETCH
FROM NWRN IA INTO SERN MN AND S-CNTRL WI. THIS ESTIMATE IS BASED
ON 00Z SOUNDINGS FROM MPX AND DVN...WITH MPX SHOWING NORTH OF THE
SURFACE WARM FRONT...CONTAINING WEAK MID-LEVEL LAPSE RATES OF 6.1
C/KM AND LITTLE TO NO INSTABILITY. MEANWHILE 700-500 MB LAPSE
RATES AT DVN WERE 8.2 C/KM AND THE SOUNDING INDICATED OVER 2000
J/KG OF CAPE. WHILE THE ATMOSPHERE OVER NERN IA HAS SINCE
STABILIZED AFTER CONVECTION FROM A FEW HOURS AGO...AMPLE
INSTABILITY REMAINS ACROSS SERN MN AND TO THE SOUTHWEST OF THE
REGION ACROSS WRN IA.

AS A 700 MB SHORTWAVE ANALYZED OVER THE CNTRL HIGH PLAINS AT 00Z
ADVANCES NORTHEASTWARD OVER THE NEXT 3-6 HOURS...LOW-MID LEVEL
MOISTURE WILL ADVECT INTO SRN MN FROM THE SOUTHWEST...ALONG WITH A
SLIGHT INCREASE IN 850-700 MB WIND SPEEDS. THIS WILL ALLOW FOR
UNIDIRECTIONAL FLOW IN THE CLOUD BEARING LAYER FROM THE WSW AND
THE POTENTIAL FOR TRAINING AND REGENERATION OF THUNDERSTORMS
CAPABLE OF 1-2 IN/HR RAINFALL RATES BENEATH MODESTLY DIFFLUENT
FLOW ALOFT. TRENDS WILL HAVE TO BE WATCHED FOR THE POSSIBILITY OF
RENEWED CONVECTION ON THE NORTHEAST SIDE OF AN ADVANCING
CONVECTIVE COMPLEX CURRENTLY PROPAGATING ACROSS E-CNTRL NE AND THE
POTENTIAL FOR THE GAP BETWEEN THE TWO AREAS OF RAINFALL TO FILL IN
TOWARD 09-10Z.

OTTO

ATTN...WFO...ARX...DMX...GRB...MKX...MPX...

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

LAT...LON   45059367 45039159 44908993 44408923 43568969
            43379163 43249380 43409430 44069481 44579465