MESOSCALE PRECIPITATION DISCUSSION 0644
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1014 AM EDT TUE SEP 06 2016
AREAS AFFECTED...NORTH CENTRAL WISCONSIN TO THE UP OF MICHIGAN
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 061415Z - 061715Z
SUMMARY...ISOLATED FLASH FLOODING THREAT CONTINUES IN NORTH
CENTRAL WI TO THE UP OF MI OVER THE NEXT FEW HOURS.
DISCUSSION...RADAR/SATELLITE IMAGERY INDICATE PERSISTENT
SHOWERS/STORMS TRAINING IN ADVANCE OF AN OUTFLOW BOUNDARY IN
NORTHERN WI TO THE UP OF MI.
LOW LEVEL CONVERGENCE IS FORECAST TO PERSIST THE NEXT FEW HOURS ON
THE NOSE OF A 30-40 KT SWLY LLJ AHEAD OF THE OUTFLOW BOUNDARY.
THE LOW CONVERGENCE IS COMPLEMENTED BY UPPER DIVERGENCE MAXIMA IN
THE RIGHT ENTRANCE REGION OF THE UPPER JET ACROSS NORTHERN MN AND
WI. HIGH AVAILABLE MOISTURE REMAINS IN PLACE WITH 1.75-2 INCHES OF
PRECIPITABLE WATER ANALYZED BY THE RAP AND NAM/GFS.
OBSERVATIONS FROM THE 6 HOURS AT 12Z INDICATED AN INCH TO INCH AND
A HALF HAS FALLEN AND SIMILAR AMOUNTS ARE EXPECTED OVER THE NEXT
SEVERAL HOURS. THESE AMOUNTS ARE FORECAST BY THE LAST FEW RUNS OF
THE HIGH RES RAPID REFRESH AS WELL AS THE 00Z RUNS OF THE WRF/WRF
NMMB/WRF ARW.
WITH THE OBSERVED SOUNDING IN CENTRAL WI IN GREEN BAY SHOWING DEEP
SOUTHWEST FLOW WITH MINIMAL DIRECTIONAL SHEAR...LOCALIZED TRAINING
OF CELLS IS EXPECTED. ISOLATED 2" TO 3" TOTALS ARE POSSIBLE IN
AREAS WHERE TRAINING OCCURS.
THE STORM SCALE ENSEMBLE NEIGHBORHOOD PROBABILITIES OF EXCEEDING 3
HOUR FLASH FLOOD GUIDANCE ARE AROUND 20-25 PERCENT OVER THE NEXT
FEW HOURS AND DECREASE TO UNDER 10 PERCENT BY 21Z...SUGGESTING A
DECLINE IN RAINFALL RATES THIS AFTERNOON WITH A POSSIBLE DECLINE
IN THE STRENGTH IN THE LOW LEVEL JET.
PETERSEN
ATTN...WFO...APX...ARX...GRB...MPX...MQT...
ATTN...RFC...NCRFC...
LAT...LON 46448453 46138359 45748433 44968680 44508804
44238896 43899047 44009199 44669185 45668860
Last Updated: 1014 AM EDT TUE SEP 06 2016