NWS-Milwaukee/Sullivan Forecast Discussion

 

						FXUS63 KMKX 210653
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
153 AM CDT Tue Aug 21 2018

.DISCUSSION...

Today and tonight...Forecast confidence is high.

The surface low will continue to shift off to the east. Look for
the wrap around rainfall to also gradually shift east, but there
is still the potential for banding precipitation resulting in more
pain for areas already soaked. It looks like the best chance for
this focused rainfall would be across the southeast through about
mid morning, mainly in the Milwaukee area and points north. It's
tough to pinpoint these areas, so remain alert for more heavy
rainfall. The flash flood watch continues for parts of the
southeast through mid morning.

A cold front will sweep south across the area later this afternoon
and evening and could trigger some showers and possible
thunderstorms across the southeast as we get into a brief period
of instability. Look for much drier air to push south across the
area tonight. We're talking dew points in the 40s vs the upper 60s
and 70s we've had for a while.

Wednesday and Thursday - Confidence...Medium High pressure will
dominate this period. A southerly return flow sets up for Thursday
as the influence of this high starts to shift off to the east.

Thursday night through Friday night - Confidence...Medium
The warm/moist return flow starts to get active with the GEM and
GFS most aggressive on bringing this activity during Thursday
night. The 12z ECMWF held it back through the night. So some pops
will be in play for Thursday night. An approaching mid level wave
expected to enhance forcing on Friday as this feature rides in
from MN into WI. So could end up seeing a couple rounds of storms
with the 850 LLJ and then with the mid level feature that moves in
for later Friday into Friday night.

Saturday through Monday - Confidence...Medium
Main story will become a fairly hot and humid airmass that arrive.
925 temps are expected to reach the mid 20s celsius. there will be
shortwaves riding through in the west/southwest mid level flow on
the periphery of the core of the mid level hot dome to our
south. So there will be some chances of storms at times in
addition to the very warm/humid airmass.

&&

.AVIATION(09Z TAFS)...Look for the showers and storms to gradually
diminish from west to east today. There could be a secondary
redevelopment late this afternoon and evening across the southeast.
The IFR and MVFR CIGS will gradually improve to VFR this afternoon.
Clearing skies arrive later tonight. Winds will back to the northeast
this morning, then north this afternoon as low pressure pushes
off to the east.

&&

.MARINE...A small craft advisory will run into Wednesday morning. Winds
will back to the north and become unseasonably strong for an August
system. Showers and storms are still possible today. We could see
some waterspouts, but this threat looks mainly out in the open
waters areas. Winds and waves will relax later Wednesday afternoon
and remain into early Friday morning.

&&

.BEACHES...Blustery east to northeast winds will become more
northerly late tonight and continue through today with a moderate
to high swim risk and high waves.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement through Wednesday afternoon for WIZ066-
     071-072.

     Flash Flood Watch until 4 AM CDT early this morning for WIZ056-
     057-062-063-067>069.

     Flash Flood Watch until 9 AM CDT this morning for WIZ051-052-
     058>060-064>066.

     Beach Hazards Statement through late tonight for WIZ052-060.

LM...Small Craft Advisory until 1 PM CDT Wednesday for LMZ645-646.

     Small Craft Advisory until 6 AM CDT Wednesday for LMZ643-644.

&&

$$
Today/Tonight/Aviation/Marine/Beaches...Davis
Wednesday through Monday...Collar