Mesoscale Precipitation Discussion 0728...Corrected
NWS Weather Prediction Center College Park MD
544 AM EDT Tue Aug 28 2018

Corrected for TYPO IN SUMMARY PARAGRAPH

Areas affected...Portions of southern WI

Concerning...Heavy rainfall...Flash flooding possible

Valid 280940Z - 281240Z

Summary...The passing by of a shortwave to the north should lead
to further reduction of rainfall coverage and intensity in this
area.  Over the next few hours, hourly totals to 1.5" and local
amounts to 3" are possible.

Discussion...GOES-16 water vapor imagery shows a shortwave which
has been responsible for the prolonged heavy rainfall in southern
WI is passing to the north near the WI/western Upper Peninsula of
MI border.  Precipitable water values in the region are 1.8-2.1"
per nearby GPS values.  Inflow at 850 hPa is convergent out of the
west at 25-30 kts per VAD wind profiles, importing MU CAPE values
of 2000-3000 J/kg into the thunderstorm/rain band.

As the shortwave moves farther afield to the east, inflow at 850
hPa is expected to weaken along with upper level divergence which
should cause a further erosion to heavy rainfall over the next few
hours.  The patch of heaviest rainfall appears to be moving
eastward at 20-30 kts while individual cells move east ~40 kts. 
For this time frame, the peak hourly rain totals are likely now,
with radar estimating hourly totals locally of ~1.5".  Believe
hourly totals to 1.5" with local amounts to 3" are possible over
the next few hours over saturating soils while the band continues
to fade.

Roth

ATTN...WFO...ARX...GRB...MKX...

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

LAT...LON   44059016 43978865 43898772 43718763 43428775
            43148780 42918774 42748769 43078892 43809081