Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 070836

Area Forecast Discussion
National Weather Service Marquette MI
336 AM EST Tue Feb 7 2023

.SHORT TERM...(This evening through Tuesday)
Issued at 134 PM EST MON FEB 6 2023

Mostly quiet weather today as surface high pressure is to the east
of us and a ridge is slowly passing through the region. This has
brought southerly flow to the area and has begun some warm
advection, bringing temperatures to above seasonal for today`s
high and tonight`s low. Lingering moisture and some slight low
level lift from the warm advection is keeping cloud cover in the
area, but some breaks in the clouds are possible especially over
the west, with the IWD vicinity clearing out by this morning.

By tonight, a shortwave will lift towards the Upper Great Lakes,
with vigorous 500mb PVA and 850mb warm advection providing the mid
to lower level support for a cold front to pass through the Upper
Peninsula tonight. While a wind shift is definitely expected, cold
air behind the front is not expected to dominate over the warm
advection and as such, warming overnight is expected. This has the
unfortunate consequence of complicating the precip type, as a
transition from mostly snow to a mix of wet snow, rain, and
depending on the area, sleet and light freezing rain is also
possible. Ice accumulations should be only around a light glaze,
particularly in areas that are expected to experience downsloping
winds that will warm the boundary layer to prevent refreezing.
HREF 24 hour FRAM accretion does not exceed the 0.01 to 0.1 inch
threshold across the UP. Snow-wise, around an inch of wet, slushy
snow is expected across the UP, as the SREF mean is 1 inch with a
couple members around 2 inches but otherwise most ensemble members
are around 1 inch. Another hazard to watch will be the winds, as
blustery winds ahead and behind the front could create a blowing
snow hazard in areas of higher terrain and areas immediately
adjacent to the Lake Superior lakeshore.

.LONG TERM...(Tonight through Monday)
Issued at 302 AM EST TUE FEB 7 2023

The last of the light LES flurries over the far east dies away this
evening as the peak of a high pressure ridge moves over the area. As
high pressure ridging remains over us tonight into Wednesday, expect
any remaining cloud cover to clear out tonight, allowing lows temps
to drop into the mid teens to low 20s across the UP. With sunny
skies remaining over us Wednesday, I wouldn`t be surprised if much
of the area gets into the low 40s as ensembles show temps in the
90th percentile; some spots, such as the downslope areas along Lake
Superior in the western half, may even get into the mid 40s for a
high Wednesday.

The clear skies won`t last long, however, as a low pressure from the
Southern Plains and a Clipper low move towards the Upper Great
Lakes. This brings cloudy skies back over the area Wednesday night.
Model guidance has converged quite a bit since yesterday morning in
regards to the track of the Southern Plains low. Now the majority of
model guidance agrees that the sfc low will track through northern
Lower MI, although the 00z NAM12km still shows the sfc low going
through the Straits of Mackinac. What does this mean? Well, it looks
like that the central and eastern UP could very well see a
significant wet snowfall event. While there is still a chance that
some sleet, freezing rain, and rain could sneak into the area
Thursday, particularly in the south central and east, odds are that
the p-type remains snow throughout the event. Now, there is still
some uncertainty with where the heaviest snowfall will occur, as the
Clipper low mentioned earlier is expected to phase with the other
low moving towards northern Lower MI at this time. However, based on
current model guidance, the heaviest snowfall looks to occur during
the day Thursday, particularly in the afternoon. In addition to the
snowfall, some breezy conditions could be seen across the area due
to the tight pressure gradient of the phasing low moving into
northern Lower MI, although the strongest winds with this system
should be far south of us via a 50+ kt LLJ streaking across southern
Lower MI. Thus travel may be hazardous in the central and east
Thursday as wet snowfall could quickly accumulate on roads, and
snowfall rates and patchy blowing snow may greatly reduce
visibilities at times. In addition, some power outages could be
possible. With CAA cycling over the region behind the phased low
Thursday night into Friday, expect some lake-enhanced snowfall to
move over the NW snow belts Thursday night, eventually becoming LES
early Friday morning; would not be surprised to see a few inches of
fluffier snowfall fall across the NW snow belts near the Lake
Superior shoreline Thursday night into Friday morning. As ridging
moves back into the region Friday, expect the LES to slowly die out,
eventually ending Friday night.

While there is quite a bit of model spread early next week in
regards to precipitation, ensemble and deterministic guidance do show
temps being well above normal late in the forecast period.

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1121 PM EST MON FEB 6 2023

Light snow will move out of the area later tonight into Tue morning.
This will lead to a gradual improvement in the TAFS with IFR
conditions at all sites going to MVFR Tue morning and to VFR Tue
afternoon into the evening.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 335 AM EST TUE FEB 7 2023

Behind a cold front that pushes through the lake this morning,
expect winds to become WNW`rly at 30 to gales of 35 knots, with the
highest winds seen over the eastern half of the lake where a Gale
Warning remains in effect until 7 PM tonight. As ridging moves in
from the west this evening, expect winds to rapidly decrease.
However, with a tight pressure gradient setting up over the western
lake late tonight, expect SW`rly winds to pick up to 20 to 30 knots
across the western half, remaining so until Wednesday morning. Light
winds of 20 knots or less are expected to remain over the lake until
Thursday night, when NW`rly winds of 25 to 30 knots move over Lake
Superior due to a shot of CAA from Canada behind a phased low; a few
gale-force gusts up to 35 knots are possible, as well as some heavy
freezing spray over the central lake Friday morning. As the CAA
weakens, expect winds to weaken as well Friday, eventually becoming
20 knots or less again by Friday night. As a Clipper moves into
northern Ontario Saturday, some SW`rly winds of 20 to 30 knots could
be seen, with the strongest winds over the western half of the lake.
With weak ridging moving back towards us Sunday, expect light winds
to move back over the area by then.

Upper Michigan...
Lake Superior...
  Gale Warning from 7 AM this morning to 7 PM EST this evening for

  Gale Warning until 7 PM EST this evening for LSZ249>251-266-267.

Lake Michigan...
  Gale Warning until 5 AM EST early this morning for LMZ248-250.



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