Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 010827
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
327 AM CDT SAT OCT 1 2016
TODAY and TONIGHT...Forecast Confidence...High
The Mid/upper level low centered over Indiana will lift north into
southern Michigan by this evening, then slowly northeast, losing
it`s grip on our weather.
Until then expect a few more periods of light rain wrapping around
the low and into southeast and east portions of south central
Wisconsin. The low level pressure gradient weakens, along with the
low/mid level winds.
RH remains high in the lower levels, even as beginning to dry in the
mid levels later tonight. As a result expect low clouds and drizzle
especially over southeast Wisconsin through late tonight.
SUNDAY THROUGH TUESDAY...Forecast confidence is high.
Light showers associated with that closed upper low over the Great
Lakes will finally diminish Sunday morning as the low begins to
shift east. Skies will clear from west to east across all of
southern WI during the afternoon. That sunshine will help us warm
into the upper 60s inland.
Winds will be light Sunday and Monday with high pressure overhead,
so there is a good chance for some morning fog. By Tuesday, low
pressure is approaching from the northern Plains and high pressure
is sitting over the east coast, so we can expect increasing
With southerly winds comes warm air advection and increasing mid and
high clouds. Highs should be around 70 for much of southern WI
WEDNESDAY THROUGH THURSDAY... Forecast confidence is medium.
An amplified upper trough will shift from the western U.S. to the
mid section of the country. The main surface low will be over
southern Canada, but a secondary shortwave and the right entrance
region of the upper jet will create another area of low pressure
over the Midwest. The low and associated cold front will slowly
slide east through WI Wednesday afternoon through Thursday. The GFS
brings the precip with the front into southern WI earlier than the
ECMWF, but they both exit around the same time. The ECMWF takes on
more of a negative tilt than the GFS.
There is weak instability just ahead of and along the front, so kept
the mention of thunder going for this period. This is not looking
like a severe thunderstorm event.
FRIDAY THROUGH SUNDAY... Forecast confidence is medium.
Cyclonic flow aloft and surface high pressure nosing into WI will
keep us dry and cool for Friday and at least Fri night. Precip
chances for southern WI are pretty uncertain for the weekend.
A deep closed upper low will move slowly from around Indiana today
and into southern lower Michigan by this evening. A few more rounds
of light rain are expected to continue through this period. IFR/LIFR
Ceilings will persist, especially over southeast Wisconsin, with
mainly MVFR later today west of Madison.
Will let the Small Craft Advisory expire south areas, but extend a
bit north areas til 10 am cdt. Current wave observations on the
southern buoy is down to 4 feet and should lower a little more later
this morning, due to lighter northeast winds.
LM...SMALL CRAFT ADVISORY until 4 AM CDT early this morning for
SMALL CRAFT ADVISORY until 10 AM CDT this morning for LMZ643-644.
TODAY/TONIGHT AND AVIATION/MARINE...Hentz
Sunday THROUGH Friday...MRC