Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 161003

Area Forecast Discussion
National Weather Service Marquette MI
503 AM EST Mon Jan 16 2017

.SHORT TERM...(This evening through Monday)
Issued at 235 PM EST SUN JAN 15 2017

The short term will be quiet as a couple of shortwaves track across
south central Canada in a zonal flow. Best forcing and isentropic
ascent associated with the shortwaves will stay well north into
Ontario and a dry airmass will dominate over Upper Mi thru the
period. Main impact from shortwaves over our area will be pressure
falls into Ontario ahead the initial shortwave today which will lead
to increasing sw winds this afternoon into this evening mainly over
Lake Superior. A period of gales is expected between Isle Royale and
the Keweenaw Peninsula.

Under sunny skies and waa, high temps today have rebounded into the
mid 20s to mid 30s, warmest over the nw/ncntrl part of the fcst area
at locations where sw winds downslope and coolest downwind of the
mostly ice covered bay of Green Bay. Expect mins tonight to be
mostly in the teens, although some locations along Lake Superior may
not fall blo 20F. A few locations over the south central where winds
will be lightest may dip into the single digits.

Under continued mostly sunny skies through much of day, Monday`s
high temps should rise well into the 30s over much of the west half
of Upper Mi with cooler low 30s temps east, downwind of Lake Mi in a
sw flow.

.LONG TERM...(Tuesday through Sunday)
Issued at 503 AM EST MON JAN 16 2017

Challenging forecast in the early part of the extended with regards
to precipitation type and amounts.

The biggest weather impact during the extended will be early in the
extended forecast as an area of low pressure slides across lower
Michigan into Southern Ontario Tuesday. At the same time, added
support will be given from shortwave energy progged to link up with
the surface low. Model differences continue with respect to the
amount of precipitation and warm air that lifts into the area;
however, models are still trying to push the system a bit farther
south and east for the most part. This would mean that there would
be lower QPF with the system and that colder air will remain in
place. At this point, it looks like the system would only impact the
south central portion of the U.P. and areas east especially near
Lake Michigan. The precipitation will generally be in the form of
snow as it begins; however, there may be a bit of a light freezing
rain or rain mixing in throughout the day as temperatures through
the profile will be nearly isothermal along the 0C line.
Temperatures in the morning will be near freezing at the surface
before warming into the mid 30s by early afternoon, which may make
roads slippery Tuesday morning. Again, this would mainly be south
central and east. Precipitation totals will be very light as the
west half will likely see no precipitation and the east will only
see a tenth or less. The exception may be over the far south central
U.P. where liquid QPF may be closer to the 0.10 to 0.20 range. This
would yield a sleet/snow mix of up to an inch with a tenth of an
inch of ice accumulation or less expected over the south central and
east. This may still cause some travel headaches Tuesday morning,
with any ice accumulation that does occur.

The system will quickly exit Tuesday night allowing for fairly quiet
and warmer weather through the end of the work week with little to
no chance of precipitation. This will be due, in large part, to a
broad 500mb ridge building across much of the central part of the
U.S. At the surface, much of the U.P will be influenced by the
northern edge of a broad surface ridge. As the ridge slides eastward
through Friday, winds will become southerly, helping to edge
temperatures into the above normal category into the upcoming
weekend, probably reaching into the upper 30s to around 40. The next
area of low pressure is progged to slide just west or over the
western half of the U.P. Saturday, which would lead to continued
warming; however, the chances for, mainly rain, would steadily
increase for the first part of the upcoming weekend. Another system
is progged to move across the central U.S. toward the end of the
upcoming weekend into the next week, which could give chances of
precipitation; however, confidence in any one model solution is
limited at best. Have gone with a consensus of the models for this
time period.

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1208 AM EST MON JAN 16 2017

With a dry air mass associated with high pres dominating thru this
fcst period, VFR conditions will prevail at KIWD/KCMX/KSAW. As the
high moves off to the east overnight, increasing w to sw winds above
a sfc based inversion will result in LLWS at CMX and SAW.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 235 PM EST SUN JAN 15 2017

Tightening pres gradient between high pres to the s and low pres
tracking ese toward northern Ontario has led to increasing sw winds
across Lake Superior this afternoon which will continue into this
evening. Aided by max pres falls passing n of the lake, expect gale
force sw winds to 35 knots over portions of western and north
central Lake Superior this afternoon and evening. Winds will then
diminish to under 15kt Mon afternoon thru Tue as a high pres ridge
moves over the area. Winds will then be mostly 20kt or less thru the
mid and late week period as conditions become unseasonably warm over
the Upper Lakes with no significant weather features impacting the

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


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