MESOSCALE PRECIPITATION DISCUSSION 0390
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
235 AM EDT TUE JUL 03 2018

AREAS AFFECTED...CENTRAL AND SOUTHWESTERN MN...

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

VALID 030635Z - 031145Z

SUMMARY...SW-NE DEVELOPING CONVECTIVE BAND WITH SOME INTERNAL
TRAINING LEADING TO POSSIBLE FLASH FLOODING OVERNIGHT.

DISCUSSION...GOES-16 WV SUITE DEPICTS COMPACT SHORTWAVE CROSSING
SE ND SPREADING HEIGHT-FALLS OREINTED SW-NE BISECTING MN.  AT THE
SOUTHERN TRAILING EDGE OF THIS FORCING...OUTFLOW BOUNDARY FROM
CONVECTIVE COMPLEX OVER CENTRAL SD HAS NARROWED THE INFLOW FROM
STRENGTHENING SWLY FLOW INTO SW MN.  THIS HAS ALLOWED FOR RECENT
INCREASE IN CONVECTIVE COVERAGE AND INTENSITY IN RADAR AS WELL AS
COOLING IN 10.3 UM IR CHANNEL WITH OVERSHOOTING TOPS NEARING -75C
AT TIMES.  RAP ANALYSIS SUGGESTS 850MB CONFLUENCE AND LLJ
STRENGTHENING TO 50KTS SUPPORTED BY 45KT OB AT KFSD VWP.  THE
CONFLUENCE AS ALSO LEAD TO STEADY INCREASE IN TPW WITH GPS NETWORK
SHOWING VALUES OF 1.3 RAISING TO 1.6 IN THE LAST FEW HOURS IN SW
MN.  AS SUCH INFLUX OF MST HAS SEEN A STEADY INCREASE IN RAINFALL
EFFICIENCY AS WELL WITH RATES APPROACHING 2"/HR.

THE SW-NE BAND AT THE EASTERN EDGE THE SHROTWAVE'S INFLUENCE WILL
REDUCE EASTWARD PROPAGATION VECTORS AND ALLOW FOR MEAN CLOUD
BEARING FLOW FROM SW TO NE TO SUPPORT SOME TRAINING ESPECIALLY
GIVEN THE BREADTH WEST TO EAST OF THE BAND.  AS SUCH 2-4" OF RAIN
CAN BE EXPECTED ALONG THE LINE AND GIVEN THE ANTECEDENT CONDITIONS
THERE IS SOLID POSSIBLITY OF INDUCING FLASH FLOODING CONDITIONS
OVER THE NEXT FEW HOURS IN THE AREA OF CONCERN.  THIS IS
PARTICUARLY THE CASE IN SW MN WHERE FFG VALUES ARE BELOW 1.5 IN
1HR AND BELOW 2" IN 3HR. 

GALLINA

ATTN...WFO...DLH...FSD...MPX...

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

LAT...LON   46889314 46539256 45799279 44799309 43969439
            43819592 43959632 44499608 45699508 46809385