Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 160717

Area Forecast Discussion
National Weather Service Marquette MI
317 AM EDT Wed May 16 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 329 PM EDT TUE MAY 15 2018

A quiet, cooler, and mostly cloud-free day was observed across the
area today as high pressure began to drop south across Lake Superior
and into Upper Michigan.

Tonight, high pressure will continue to move south across the area
and allow skies to remain mostly clear. From west to east across the
area, winds will become south-southwesterly overnight as low
pressure begins to track eastward across the Arrowhead of Minnesota
and Lake Superior. Temperatures will sharply drop after sunset
tonight, but then should gradually stabilize or gradually start to
slowly warm as return flow develops ahead of the approaching low.

Tomorrow, the above normal temperatures will return ahead of the
slow moving low pressure system. Expect temperatures to soar into
the upper 70s into the mid 80s across the interior west and central,
with the warmest temperatures in areas easily influenced by
downsloping west-northwest flow. Closer to the Great Lakes,
especially Lake Superior temperatures will be in the 60s. Deep
mixing ahead of and along the front will favor lower RHs during the
afternoon and then the potential for breezy winds - which may lead
to elevated wildfire concerns. With the pressure gradient ahead of
the front gradually weakening as it drops south thinking that the
sustained winds will remain less than 15 knots, but wind gusts could
approach 15 to 20 mph at times as stronger mixing taps into stronger
momentum aloft.

Not terribly impressed with precipitation chances along the trailing
front, but cannot rule out a chance for isolated showers later in
the afternoon - especially across the central and back towards the
WI/MI border where lake breezes and a subtle shortwave will locally
enhanced lift. Also, not terribly impressed with chances for thunder
given the lack of instability and steep mid-level lapse rates so
have opted to leave mentions of thunder out for now.

.LONG TERM...(Thursday through Tuesday)
Issued at 317 AM EDT WED MAY 16 2018

There will be troughing in the western U.S. and troughing in the
lower and mid Mississippi River Valley 12z Thu with a shortwave
ridge over the upper Great Lakes. This ridge will remain over the
area into Sat. It will remain fairly quiet through then and mostly
dry as moisture remains off to the west.

In the extended, GFS and ECMWF show a closed 500 mb low over Indiana
12z Sat and a trough over south central Canada with weak troughing
into the Rockies 12z Sat. A cold front will move through the area on
Sat. Upper troughing remains in the upper Great Lakes 12z Sun with a
sfc ridge moving into the area. This ridge remains into Tue over the
area. Another shortwave moves into the upper Great Lakes on Wed.
Looks pretty dry after Sat night with next chance for rain on Wed
and would only be slight chance pops then. Temperatures look to stay
above normal for this forecast period.

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 132 AM EDT WED MAY 16 2018

With a dry low-level air mass still prevailing, VFR conditions will
continue at KIWD/KCMX/KSAW thru this fcst period. In response to a
weak low pres wave moving across northern Ontario, increased winds
above nocturnal inversion will lead to LLWS overnight until an hr or
two after sunrise. Gusty winds will follow during the morning/early
aftn. Cold front associated with the low pres will settle across
Upper MI during the aftn. There is some potential of isold shra, but
potential of any terminal being affected remains too low to include
mention in fcst.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 329 PM EDT TUE MAY 15 2018

Winds will increase to 20-25 knots tonight into early Wednesday
morning as a low pressure system gradually slides south across the
region. Through the rest of the week, winds will remain between 15
and 20 knots. Friday night into Saturday, winds will increases to 20-
30 knots ahead of a cold front pushing east across the lake. Behind
the front, winds will remain between 10 and 20 knots through the
remainder of the weekend.

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


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