Scientific Forecaster Discussion
fxus63 kmkx 052310
Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
510 PM CST Thu Dec 5 2019
No change to the short range forecast.
A cold front will push across southern Wisconsin later this
evening. Winds will veer to the west then to the north at kmsn
between 03-05z Friday and at kmke/kues/kenw between 05-07z Fri.
Winds could become rather strong and gusty across the southeast in
the wake of the front. Additionally, a short period of MVFR ceilings
are also possible immediately behind the cold front. VFR
conditions should return by around 10z, then remain VFR through
the remainder of the taf period. Winds will also diminish quickly
by later Friday morning.
Previous discussion... (issued 337 PM CST Thu Dec 5 2019)
Tonight through Friday night...forecast confidence is high:
Low pressure will pass through the forecast area this evening into
early tonight, dragging a cold front across southern Wisconsin.
Dry weather will continue as this system moves through, with the
better moisture/forcing remaining north of the low. Clouds will
clear out later tonight behind the front as high pressure begins
to move in from the west.
Mostly sunny skies are likely Friday with high pressure overhead.
Temps will be colder tomorrow behind the cold front, though the
sunshine should help temps up to around normal values for early
Clouds will increase Friday night as the high departs, but
otherwise quiet weather and near normal temps will continue.
Saturday...forecast confidence high:
Quiet weather continues into the weekend as a mid-level ridge
remains across the upper Great Lakes region and a surface high
shifts eastward on Saturday. As surface highs kicks further east,
southerly flow returns to the region and warmer temperatures are
expected for Sunday with highs in the low to mid 40s.
Sunday through Thursday...forecast confidence medium:
While southern Wisconsin enjoys a quiet start to the weekend, an
upper-level trough begins to push across the Pacific northwest
Saturday night. As the trough progresses across the central
conus, a surface low develops along the Colorado Front Range. As
this system continues to traverse into the upper Midwest,
southern Wisconsin looks to be sandwiched between a right entrance
of weak jet leaving the region and a left exit/diffluent of
another, stronger 250mb jet Sunday night/Monday. This combined
with low-level warm air advection, should provide enough synoptic lift to
support increased precipitation chances beginning Sunday and
continuing into Monday. At this time, it looks to start off as
rain late Sunday and transition to snow for our northern areas and
more of a snow/rain mix for our southern areas.
However, models are not in agreement on where the surface low will
track. GFS/gefs favors a more northward track over southern
Wisconsin, while the European model (ecmwf)/CMC tracks the low further south
across northern Illinois/northwest in. Thus, depending on what solution
materializes will dictate the precipitaion type across southern
Wisconsin. Nonetheless, quantitative precipitation forecast totals for this event looks to be
light at this time and is expected to diminish Monday night as a
cold front pushes across the area.
Behind the cold front, expect frigid Arctic air to filter into
Wisconsin as the upper-level trough axis pushes east by Tuesday and
as surface high pressure builds across the northern plain/upper
Midwest on Wednesday. Tuesday night looks to be our coldest night
with overnight lows dipping into the single digits to around 0
degrees, while highs on Wednesday look to top off between 10-20
VFR conditions will persist through this afternoon. A wind shift
to the northwest is expected this evening into early tonight as
low pressure and an associated cold front move through. Winds will
become gusty for a time overnight into Friday until high pressure
begins to build in from the west during the day Friday. Low clouds
are possible behind the front late evening into the early Friday
morning hours as a colder airmass pushes in. Plenty of sunshine is
then expected Friday as the high moves overhead.
Low pressure will slide across Central Lake Michigan tonight.
Gusty north to northwest winds will develop late tonight into
Friday behind the low and associated cold front. Decided a Small
Craft Advisory will be needed overnight tonight into Friday for
the gusty winds and building waves.
Low pressure approaching from the northern plains will bring a
round of gusty southerly winds Saturday into Sunday. Gale force
gusts will be possible Saturday night into Sunday morning, with
the strongest gusts likely across the northern half of the lake.
Gusty northerly winds will develop in the wake of the system
later Monday into Tuesday, possibly approaching gale force. A
much colder airmass spreading into the region next week will lead
to freezing spray conditions.
Lm...Small Craft Advisory from midnight tonight to 3 PM CST Friday
Small Craft Advisory from midnight tonight to noon CST Friday