Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KMQT 230900

Area Forecast Discussion
National Weather Service Marquette MI
500 AM EDT Sat Sep 23 2017

.SHORT TERM...(Today and tonight)
Issued at 419 AM EDT SAT SEP 23 2017

The main weather impact through the short-term forecast will be the
very warm and humid weather expected across the area today.

Broad ridging in place across the area will keep conditions dry
through much of the short-term forecast; however, the far western
portions of the U.P. may see some scattered showers and
thunderstorms develop this afternoon through the overnight hours.
Otherwise, temperatures just above the surface are progged to be
around 23C across much of the area, which would allow temperatures
to warm into the mid to upper 80s today. Wouldn`t be out of the
question to see a couple 90 degree readings in the favored south
wind downslope locations. The hot temperatures combined with
dewpoint values in the mid to upper 60s will produce heat index
values as high as the low 90s. The main exception will be downwind
of Lake Michigan, where highs may stay closer to the mid to upper
70s. Tonight, as disturbances slide around the western part of the
ridge and the east side of the upper-level trough, digging into the
Plains, expect scattered showers and thunderstorms to brush into the
far western portions of the U.P. and especially over far western
Lake Superior. This potential will be enhanced along a trough/weak
front, which is expected be very near the Arrowhead of MN an through
much of far western Lake Superior. Otherwise, much of the rest of
the U.P. will likely remain dry with continued unseasonbly warm
temperatures across the area. Overnight lows will be in the mid to
upper 60s.

.LONG TERM...(Sunday through Friday)
Issued at 458 AM EDT SAT SEP 23 2017

Models suggest that a slowly progressive amplified pattern will
prevail with a prominent mid/upper level ridge over the Great Lakes
this weekend giving way to troughing by the middle of next week.
Much above normal temps and dewpoints are expected into Monday with
record highs and record high mins likely for many locations.

Sunday, even with a strong subsidence inversion near the 590 DM
ridge over the cntrl/ern Great Lakes, forecast mixing through 850 mb
temps around 17C will support readings in the mid 80s over much of
the area except downwind of Lake Michigan. Adding to the discomfort
will be dewpoints lingering into the mid and upper 60s. Low temps
should also remain in the upper 60s with some downslope locations
around 70. Subsidence/capping will be strong to suppress
shra/tsra chances, keeping the pcpn to the north and west.
However, the frontal zone over ne MN into wrn Lake Superior may
allow some shra/tsra into the far west near IWD late Sunday night.

Mon-Tue, shra/tsra chances should increase by late Monday into
Monday night over the west half as the mid level trough advances
into the plains and the front approaches. The best chance for rain
is expected Tuesday as a stronger shrtwv and associated low lifts ne
near Lake Superior and drags the front through the area. The ECMWF
remained slightly faster/stronger with the mid level trough and
front and low compared to the GFS/GEFS. Although temps will remain
above normal, greater cloud cover will keep max readings around 80
Monday and the lower 60s to lower 70s Tuesday.

Wed-Fri, Cooler/drier air should finally take over with breezy wnw
winds behind the front. 850 mb temps dropping to around 3C Wed into
Thu along with wrap-around moisture will bring potential for some
sct light showers. Models have trended toward a stronger shortwave
moving in by the end of the week with even colder air (850 mb temps
to around -4C) which would bring increasing rain and lake enhanced
rain chances with brisk northerly winds. Highs during the period
will be mainly in the 50s.

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 134 AM EDT SAT SEP 23 2017

VFR conditions are expected at all TAF sites. May see some fog near
or at KCMX and KSAW, but not expected at this time. LLWS will be a
factor at all sites through the night, except possibly IWD where
winds have been steadily gusting to around 30 konts.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 419 AM EDT SAT SEP 23 2017

Low to mid 60s dewpoints sliding across Lake Superior are expected
to linger into early next week bringing patchy to areas of fog for
several days across the lake. Some of the fog could be locally dense
at times. Expect winds to generally be below 20 knots through the
early part of next week under a weak pressure gradient.

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


MARINE...KEC is the U.S. government's official web portal to all federal, state and local government web resources and services.