Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 281734

Area Forecast Discussion
National Weather Service Marquette MI
134 PM EDT SUN AUG 28 2016

.SHORT TERM...(Today and tonight)
Issued at 519 AM EDT SUN AUG 28 2016

Water vapor imagery and RAP analysis show a well-defined shortwave
over far northern Lake Superior/adjacent northern Ontario. Despite
vigorous look of wave, little pcpn is occurring s of the
international border. Shra and isold tsra did move across western
and north central Lake Superior during the night. More recently,
-shra are brushing the northern Keweenaw, and there may be a few
sprinkles over western Upper MI. A mix of stratus and stratocu
dominates the area early this morning. However, with subsidence
beginning to increase as shortwave departs, some holes are opening
up in the clouds. Upstream, the next feature of interest is
shortwave trof moving across Alberta. Increasing low-level jet ahead
of wave has generated a cluster of shra/tsra in ne SD early this

If there are a few sprinkles/isold -shra over the w half of Upper
MI, that pcpn will end around sunrise. Then, expect a gradual trend
to mostly sunny skies during the day under subsidence/drying. Based
on projected mixing heights on fcst soundings, max temps should be
mostly in the mid/upper 70s. With sfc high pres setting up over the
area this aftn, lake breezes will develop.

Tonight, as Alberta shortwave moves to Manitoba, attention turns to
the increasing low-level jet in response to the wave. Models
indicate the low-level jet will be aimed across MN into adjacent
northern Ontario during the night. Most guidance show the low-level
jet remaining w of Upper MI tonight, and while an extension of
weakening elevated instability does edge into the w overnight, the
main area of instability holds back to the w, suggesting convection
will probably remain w of Upper MI tonight. Guidance shows a wide
spread of solutions, not unusual for convection. As is often the
case, the GFS is most generous with pcpn, spreading it across the w
half of Upper MI. The Canadian models and ECMWF are dry thru 12z
while the NAM, NCEP ARW/NMM and NSSL WRF indicate pcpn nearing or
reaching far western Upper MI by 12z Mon. NCAR ensembles show quite
a spread, but a majority tend to favor the idea of pcpn reaching the
w very late tonight. At this point, will only include schc/low chc
pops spreading into western Upper MI in the 09-12z time frame. To
the e, slow moving sfc high pres ridge and axis of min precipitable
water around 2/3rds of an inch suggest leaning toward the low side
of guidance for mins tonight. Expect interior locations over the e
to fall into the 40s. Even over the central, a few spots could drop
blo 50F if clouds are slow to increase.

.LONG TERM...(Monday night through Sunday)
Issued at 134 PM EDT SUN AUG 28 2016

A low moving across Hudson Bay will drag a cold front across the
area between 00Z and 18Z Tue, with a weak shortwave possible
trailing just behind the front. Main question with the system is
potential for strong storms and coverage over the south-central CWA.
Could see some stronger storms over the west Mon evening depending
on possible morning/afternoon convection and cloud cover, but with
weak shear the overall threat is minimal. Models have slowed with
exiting the precip on Tue, with models now showing potential for
isolated to scattered showers over the southeastern CWA into Tue
afternoon. Lowest precip coverage and amounts look to be over the
south-central, with good chances of seeing measurable precip

High pressure building into the area Wed and Thu should keep mostly
dry conditions, but models now show a shortwave trough skirting the
eastern CWA on Wed as 850mb temps fall to 6-8C. This may lead to
some isolated showers and should increase cloud cover, especially
closer to Lake Superior with NNW winds. Will see some cooler nights
Tue night through Thu night.

Looks dry until later Sat at the earliest, maybe even until late
Sunday, when a low pressure system will trek northwest of the CWA
and bring a cold front in.

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 740 AM EDT SUN AUG 28 2016

With drier air and high pres building into the area today, lingering
MVFR cigs at KIWD will scatter out to VFR this morning. At
KCMX/KSAW, VFR conditions will prevail today, though brief MVFR cigs
could occur this morning. VFR conditions will then continue tonight.
However, there are a couple of items to note. Shra/tsra may approach
KIWD near the end of the fcst period, and radiation fog could
develop at KSAW overnight. Potential in either occurring is too low
right now to include a mention in fcst.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 519 AM EDT SUN AUG 28 2016

Expect winds mostly under 20kt through the middle of next week as
pres gradient remains generally weak. If stronger winds do occur,
Tue/Wed would be the time frame as a high pres ridge builds toward
the area in the wake of cold front passage Mon night/early Tue
morning. Eastern Lake Superior would be favored for the stronger

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


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