FXUS63 KMKX 152029
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
329 PM CDT Sat Jun 15 2019
.Tonight through Sunday...Forecast Confidence is Medium...
Southern WI remains sandwiched between two features, an MCV
moving across IL and a cold front moving south out of northern WI.
The lack of any real synoptic forcing between these two has
resulted in a mostly rain free day. The exception has been a band
of light showers forming along front with these clipping our far
northern counties. The lake breeze has been enhanced by cold front
nudging south and we've seen a 20 degree drop in less than an
hour for many sites near the lake. Expect this to continue pushing
inland and temps falling into the 50s and 60s.
Looking off to the west, a shortwave headed out of NE/SD and into
IA/MN has generated scattered to numerous thunderstorms. These are
forming in a more moisture rich airmass with dewpoints in the
upper 60s to lower 70s and temps in the 80s. Instability is
upwards of 3,000 J/kg in that area but quickly drops to about
500-1,000 J/kg in southern WI. So, as these storms head east into
the slightly more stable airmass they should weaken. But with
winds aloft less than 20kts, storm motions are going to be slower
and this could lead to very heavy downpours and possibly some
Overnight as the shortwave moves into the region the
shower/storm chances should continue especially in the western
portions of the area. But the cooler E/NE flow and more stable
airmass will limit the overall risk for any stronger storms. By
Sunday another shortwave moving along northern WI could generate
some additional showers/storms but confidence is low due to decent
model differences. Temperatures likely end up below 70 degrees for
much of the region and below 60 degrees for locations along the
lake. By the afternoon evening hours, the forcing aloft weakens
and drier air advecting in aloft will bring an end to rain
Sunday Night through Wednesday...Forecast confidence High.
High pressure will dominate the Upper Great Lakes, bringing light
east winds to southern Wisconsin. Monday looks dry with scattered
clouds. A few models are showing some light precip with weak surface
convergence but soundings are pretty dry and there this little
A shortwave approaches for Tuesday night. Clouds will increase ahead
of it during the day Tuesday. Some models are showing some precip
with weak surface convergence but soundings look pretty dry. The
better chance for precip comes overnight and into Wednesday. The
surface low will move across Illinois Wednesday and precip may
brush southern Wisconsin.
Thursday through Saturday...Forecast confidence Medium.
We may get between systems for a break in the precip for Thursday.
Then there are off and on showers chances for Friday and Saturday.
Cold front moving through the area has shifted winds at all but
KMSN to the NE. Lower clouds with brief dips to IFR can still be
expected this afternoon as cooler air filters into the area. A
system approaching from the west will bring chances for
showers/storms overnight but confidence in the timing and coverage
is low and have kept vicinity at sites. Cigs hold in MVFR through
the night and will be slow to clear Sunday morning.
Breezy north to northeasterly winds in the wake of a cold front
have resulted in some increase in waves in the near shore waters
to 2-3 feet. But winds and waves should start to subside
overnight. There are chances for storms overnight as a system
moves out of IA and towards southern WI.
High pressure settles in to our north with a period of lighter
winds and waves expected for much of early next week.
Tonight/Sunday and Aviation/Marine...Stumpf
Sunday Night through Saturday...Marquardt
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