Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 251951

Area Forecast Discussion
National Weather Service Marquette MI
351 PM EDT Tue Oct 25 2016

.SHORT TERM...(This evening through Wednesday)
Issued at 350 PM EDT TUE OCT 25 2016

A band of low-level moisture trapped under a 4kft inversion
associated with a 850-900 hPa ridge axis combined with ample lake-
air delta T`s and some diurnal influence has allowed scattered
showers to persist from near Thunder Bay across much of the NE half
of Upper Michigan this afternoon. This band of showers will likely
continue into the early evening before diminishing to some extent
with the loss of diurnal heating.

Low pressure continuing to organize over the central high Plains
this afternoon will reach northern Iowa late tonight and far
northern Illinois late Wednesday afternoon. The corresponding
veering flow combined with relatively warm Lake MI SSTs may be
enough to maintain any lingering showers in the moisture axis and
shift them into the south-central late tonight.

Favorable forcing aloft remaining well south of the CWA combined
with a very dry antecedent air mass above the inversion will likely
slow the northward extent of precip from the surface low on
Wednesday. Do not believe any widespread precip will reach the WI
border until after daybreak Wed. There are even questions as to how
far north precip will reach during the day, with locations north of
M-28 possibly remaining dry well into the afternoon. With that said,
the aforementioned low-level moisture combined with increasing SE
upslope flow should promote at least some light showers or drizzle
for much of the central CWA during the afternoon.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 350 PM EDT TUE OCT 25 2016

Not much has changed from earlier forecast solutions with continued
periodic chances for showers and perhaps a few wet snow flakes in
the overnight hours Wed ngt/early Thur. 500mb vort max will be
pushing east across Northern Wisc late Wed ngt, with the surface low
displaced further south; however, the moist axis will extend from
Western Lake Superior southeast through much of the U.P. into
Northern Lower MI. Height rises will begin to nudge southeast
towards the U.P. by midday Thur, which could a quicker end to the
precip shield as a narrow anti-cyclonic flow covers the western half
of the forecast area by late morning Thur, then overspreads the
entire CWA by afternoon. Thick cloud cover will likely linger thru
much of the day Thur despite the arrival of anti-cyclonic flow, due
to the lack of strong mixing, thus temps could struggle to warm
beyond the lower to middle 40s.

Friday into Saturday the surface ridge will consolidate across the
Ohio Valley as the mid-lvl trough axis pivots east of the Great
Lakes, allowing warmer air to begin advecting northeast across
Northern Wisc into the U.P. and pushing temps back to the lower 50s
and possibly the mid/upr 50s in the far southern CWFA. Another
shortwave is still progged to slide southeast from the Canadian
Prairies Fri and arrive across the arrowhead of Minnesota Fri aftn,
which could re-introduce precip back to Northern U.P. The mid-lvl
ridge will begin to relax slightly Sat, but latest ensemble trends
are indicating the ridge returns Sun. Flow does remain progressive
turning towards early next week, with a return to a quasi-active
pattern of rain chances and temps generally in the upper 40s to
lower 50s, and overnight lows falling into the mid/upr 30s.

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 135 PM EDT TUE OCT 25 2016

VFR to sometimes MVFR celings and isolated showers are expected with
lake effect clouds at KSAW into early evening. Otherwise, VFR
conditions are expected at all sites overnight into Wednesday
morning before MVFR ceilings arrive late Wednesday morning and

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 350 PM EDT TUE OCT 25 2016

NE winds will increase to 15-25 knots while veering SE for much of
Lake Superior by late tonight, and continue into Wednesday. However,
winds will likely remain NE across the far western portions well
into Wednesday. There will be a trough passage on Thursday but winds
should still remain fairly light. Friday will see south winds
increase to 20 to 30 knots again over the east half of Lake Superior
as another low pressure system approaches from the Northern
Plains.The low is expected to cross over or near Lake Superior
Friday night, ushering in NW winds of 20-30 knots on Saturday. Winds
will gradually diminish to under 20 knots through the day Sunday.

Upper Michigan...
Lake Superior...
Lake Michigan...


LONG TERM...Beachler
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