Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 232033
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
333 PM CDT SUN OCT 23 2016
Tonight and Monday...Forecast Confidence Is Medium.
Low pressure and the cold front will slide east southeast of the
area by early this evening. Potent 500 mb vorticity maximum over
northeast to east central Wisconsin will slide out of the area by
early evening as well. This will clip the northeastern portions of
the area. Differential cyclonic vorticity advection pushing
southeast and clipping the northeastern portions of the area should
help bring clouds in this area by early evening.
Forecast soundings continue to show a little more depth to the
moisture in the low levels. However, the mesoscale models are
continuing to keep most precipitation northeast of the area.
Synoptic models have backed off on QPF in the northeast counties
compared to their runs from yesterday. Will keep dry forecast going
in the northeast counties.
The clouds should reach about the northeast half of the area by
early evening, lingering until moving off to the east later tonight.
Tight pressure gradient in the wake of the low will continue to
bring gusty winds to the area, becoming northwest to north and
remaining gusty by early evening. These winds will weaken with a
weakening pressure gradient by later tonight.
High pressure building into the region from the northwest later
tonight into Monday should bring quiet weather, with mostly clear
skies and light winds. Cold air advection tonight into Monday will
bring cooler temperatures into the area. Lows generally in the upper
30s tonight are forecast, with middle 50s for highs on Monday.
Monday night through Wednesday night...Forecast confidence medium.
High pressure will remain over WI and Lake MI for Mon night
although middle to upper levels clouds will be increasing via warm
advection. Some frost is possible.
Low pressure and a shortwave trough over the central Great Plains
will organize on Tue and reach wrn IA by 12z Wed. Middle level
warm advection and frontogenesis will begin to focus over srn WI
on Tue and does mostly saturate the soundings above 850 mb.
Despite the lower level dry air, scattered and possibly more
widespread showers will develop Tue afternoon especially over
south central WI.
The low will then track to KDBQ around 00z Thu and ewd across far
nrn IL Wed nt. 925-700 mb q-vector convergence becomes strong
during this time thanks to a sly 45 kt low level jet and
associated strong low to middle level warm advection and
frontogenesis. PVA will also be increasing during this time as the
shortwave trough approaches, thereby aiding overall lift. PWs
around 1 inch and the aforementioned lift leads to expected
rainfall amounts of 1.25-2.00 inches via a consensus of models.
.LONG TERM...Thursday through Sunday...Forecast confidence low.
Low pressure will move away Thu am but cyclonic flow and clouds
may continue through the day. The model spread is very variable
for next weekend and is related to the evolution and track of
shortwave troughs moving from the Pacific NW and Canada into the
nrn Plains and the Great Lakes region. Small chances of rain is
forecast for much of this time with seasonal temps.
Low pressure and a cold front will exit the area by early this
evening. VFR category clouds should slide southeast into or near TAF
sites by early evening, lingering into mid evening before moving off
to the east. Any shower activity should remain northeast of the area
early this evening. Mostly clear skies are expected later tonight
Gusty west winds will veer northwest to north by early this evening.
Gusts of 20 to 25 knots are expected during this period. Winds will
weaken later this evening and overnight, as high pressure moves into
the region. Light winds are expected on Monday.
A Small Craft Advisory continues until 6 AM CDT Monday across all of
the nearshore waters of Lake Michigan. Breezy westerly winds will
veer northwest to north by early this evening, with the passage of
the cold front, and remain gusty into the evening hours. High waves
will build mainly south of North Point Lighthouse into tonight, with
3 to 5 foot waves possible. Waves will subside by later tonight.
Another Small Craft Advisory will likely be needed for Tuesday night
into Wednesday night, as low pressure moves across the region. Gusty
winds and high waves are likely during this period.
LM...SMALL CRAFT ADVISORY until 6 AM CDT Monday for LMZ643>646.
TONIGHT/Monday AND AVIATION/MARINE...Wood
Monday NIGHT THROUGH Sunday...Gehring