Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 270031

Area Forecast Discussion
National Weather Service Marquette MI
831 PM EDT Sun Mar 26 2017

.SHORT TERM...(This evening through Monday)
Issued at 320 PM EDT SUN MAR 26 2017

Water vapor imagery and RAP analysis show a mid level low centered
over northern IL. Deep moisture associated with this feature surged
back to the n across Upper MI last night into today, bringing
periods of -ra/-fzra. Upslope e to se flow also resulted in some
patchy dense fog this morning into early afternoon over portions of
the Keweenaw Peninsula...Dickinson and southeast Marquette counties.

Models show the mid-level low and assoc trough lifting ne through
Lower Mi this evening and then into Ontario late tonight/Mon
morning. With movement of the mid-level trough the 850mb trough and
weak isentropic ascent also shifts e tonight, so expect pcpn over
mainly the central and eastern fcst area to diminish. However with
abundant moisture, developing nnw upslope flow and approaching weak
shortwave, some -ra/-fzra will remain possible over the w tonight.
Sfc temps should slip back to around freezing over the w and n
central, so there may still be a little bit of icing at some
locations late tonight. However, accumulations should be minor so no
statement will be issued at this time. Expect some fog as well.

Weak northerly flow between sfc low over eastern Ontario and sfc
high building into south central Canada will result in murky weather
conditions with some fog and possible light drizzle or freezing
drizzle Mon morning mainly over upslope locations of west and north
central U.P. Forcing from incoming northern stream shortwave could
enhance upslope pcpn turning dz/fzdz to -ra/-fzra for a time late
morning into mid aftn. NAM soundings suggest could even be brief
period of sleet or snow mixing in over west and northwest with
evaporative cooling aloft. Limited moisture depth as noted on NAM
soundings will not warrant anything more than slight chc to low chc
pops. Expect highs in the mid 30s to lower 40s, warmest e and se
under cloudy skies.

.LONG TERM...(Monday night through Sunday)
Issued at 401 PM EDT SUN MAR 26 2017

Rather benign weather is expected through much of the period as a
slow-moving mid to upper ridge is gradually replaced by a mid-level
low drifting NE from the southern plains.

Lingering low-level moisture may allow for a light wintry mix for
the higher terrain along Lake Superior, and patchy fog across most
of the CWA, Monday night. A fairly shallow and sharp inversion may
keep low clouds across the area well into Tuesday afternoon, but
gradual mixing through the day should erode most of the clouds by
the evening. Dry conditions are then expected through Wednesday with
the ridge settling over Lake Superior and northern Ontario. N to NE
winds will likely keep temps in the mid 30s both Tuesday and
Wednesday along Lake Superior.

The NW extent of a somewhat closed mid-level low will then brush
mainly the SE half of the CWA Thursday night into Friday night.
Again, precip type will be in question with cloud-layer temps aloft
only slightly below freezing. However, marginal upper-level cloud
seeding and the absence of a pronounced warm layer should limit the
amount of freezing rain.

Inconsistencies in the model guidance develop by next weekend, with
mixed signals regarding a weak mid-level trough traversing the area
Saturday night. Will maintain chance PoPs at this point.

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 822 PM EDT SUN MAR 26 2017

Abundant low-level moisture over the area should lead to prevailing
LIFR conditions at KIWD/KCMX/KSAW through tonight. Some
-FZRA is still possible but temperstures are expected to remain at
or just above freezing. Fog late tonight may be low enough to drop
vsby near landing minimums at KSAW. Drier air moving in on Monday
will result in improving conditions during the morning into the MVFR
range at KIWD and KCMX. IFR cigs should still linger at KSAW into
the afternoon.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 320 PM EDT SUN MAR 26 2017

With no signIficant weather systems affecting the Upper Great Lakes
this week, no gales are expected on Lake Superior. In fact, winds
will mostly be under 20kt.

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


LONG TERM...Kluber
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