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 140927

Area Forecast Discussion
National Weather Service Marquette MI
427 AM EST Sat Jan 14 2017

.SHORT TERM...(Today and tonight)
Issued at 425 AM EST SAT JAN 14 2017

Today and tonight: High pressure shifting to the east of the Upper
Great Lakes region this morning will continue eastward to the
northeasrn U.S. today as a fast moving surface trough slides across
the U.P. Moisture and forcing will both be limited with this feature,
so the main impact will be light lake effect snow developing on the
west to west- northwest wind snow belts on the back side of the
trough. Again, overall moisture will be limited across the area, but
the increased fetch across Lake Superior will allow for a bit of
added moisture for the Keweenaw Peninsula as well as areas over the
far eastern U.P. near Lake Superior. Still not expecting much more
than an inch or so of snow accumulation as moisture depth really only
reaches up to about 3kft. Blowing snow may also be an issue near Lake
Superior as winds may gust up to 25 mph through the day today before
diminishing tonight. Temperatures today will be a little warmer with
highs reaching into the upper teens to low 20s with overnight lows
cooling back down into the single digits below zero to single digits
above zero, with the coldest readings expected over the interior

.LONG TERM...(Saturday night through Friday)
Issued at 318 PM EST FRI JAN 13 2017

Sat night thru Sun night...High pres is fcst to build over the Upper
Lakes, bringing a period of dry wx. With flow becoming more zonal
across Canada and the northern CONUS, the air mass will moderate as
850mb temps rise from around -7C Sat evening to around 0C by Mon
morning. Under light/calm wind and mostly clear skies, favored the
low end of guidance for min temps Sat night. Looks like this will be
the last night of subzero temps in the western and central interior
for quite a while as it appears the warm pattern will persist thru
late month as noted on the CPC and CFSv2 outlooks which maintain a
positive height anomaly centered in the vicinity of Hudson Bay thru
late month. Under sunny skies Sun, max temps should rise to the
mid/upper 20s, perhaps above 30F in a few spots.

Vigorous shortwave currently dropping s thru CA will lift ne in a
much weaker state early next week, reaching the Great Lakes region
on Tue. The Canadian models and especially ECMWF are more aggressive
with warming ahead of this system than the GFS, suggesting a
potential wintry mix at the onset (late Mon/Mon night) changing to
more rain on Tue. The ECMWF shows more pcpn as well, on the order of
1/3 to 3/4 of an inch. Majority of ensembles and operational model
trends support a warmer look, but probably not to the degree of the
00Z/12Z ECMWF which raises 850mb temps to +4-6C over much of the
area for Tue. At this point, plan to carry a wintry mix, spreading N
Mon aftn/night with a change over to mainly rain on Tue. Pcpn may
end as -sn or -sn/-ra mix Tue night.

Mostly dry weather and well above normal temps should prevail for
the last half of the work week as broad ridging remains in control.
Weak disturbances rippling through the ridge should have little
impact given expected dry airmass in place. If any pcpn does occur,
it should be on the light side.

Late in the week, models fairly consistent showing mid-upper trough
amplifying over the western CONUS, resulting in a deep southerly
flow and unseasonable warmth into the Great Lakes for the weekend.
Whatever shortwave emerges from the trough, it looks like the
associated sfc low will track west of the region resulting in a
period of rain for the area next weekend. Some thunder may even be
possible for next Saturday if some of the more amplified solutions
are on the right track as both the operational ECMWF and GFS
indicate negative Showalter indices.

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1221 AM EST SAT JAN 14 2017

Expect mainly VFR conditions through Saturday morning as high
pressure gradually slides off to the east with sw winds. A period of
LLWS is expected at IWD with increasing sw winds above the low level
inversion. As a weak trough moves through Saturday morning and winds
veer to the west, MVFR cigs with lake effect clouds should return to

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 425 AM EST SAT JAN 14 2017

Tighter pressure gradient across Lake Superior this morning will
slowly relax by late afternoon. Southwest winds up to 30 kts will
shift to the west following a low pressure trough passage today.
There may even be a few gale force gusts this morning; however, the
coverage and duration of these stronger gusts are expected to be
limited. High pressure will then build back into the area this
afternoon into Sunday morning, allowing winds to diminish under 20-
25 kts. The pressure gradient will tighten once again Sunday
afternoon into Sunday night as low pressure slides across central
Canada and the high pressure ridge over the Upper Great Lakes shifts
to the east. This will allow southwest winds to increase up to 30
knots once again. The next area of low pressure will approach the
Upper Great Lakes Tuesday and move through Tuesday night; however,
the system is not expected to be overly intense; therefore, winds
are expected to remain at or below 25 knots through this time period.

Upper Michigan...
Lake Superior...
  Heavy Freezing Spray Warning until 1 PM EST /noon CST/ this
     afternoon for LSZ162-242>244-263-264.

Lake Michigan...


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