Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | 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 242102

Area Forecast Discussion
National Weather Service Marquette MI
402 PM EST Fri Nov 24 2017

.SHORT TERM...(This evening through Saturday)
Issued at 400 PM EST FRI NOV 24 2017

WV imagery and RAP analysis indicated a mainly zonal mid/upper level
flow across the nrn CONUS with a shortwave trough into n cntrl MN.
At the surface, a 986mb low was located just sw of James Bay with a
cold front extending into nw WI. Radars indicated some sct -shra and
virga into cntrl Upper Michigan with greater rain coverage
upstream from wrn Lake Superior and far wrn Upper Michigan into nw
WI, along and just behind the front.

Tonight, expect the band of rain showers, supported by 800-600 mb
fgen, to advance across the cwa this evening (between 21z-03z) with
the dry slot moving in overnight. Although there may a brief
period of moderate rain, overall amounts should be light,
generally a tenth of an inch or less. CAA will increase overnight
with 850 mb temps dropping to around -10C by 12z. Forecast wet-
bulb zero heights suggest that pcpn will be mainly snow by the
time any lake effect pcpn develops. Instability (water temps near
5C) will be marginal for LES by with favorable 850-750 mb moisture
and inversion heights around 5k ft, some light accumulations,
under an inch, will be possible for nw flow favored locations.

Saturday, the LES will gradually diminish as inversion heights drop
to around 3k-4k ft. However, 850 mb temps to around -13C over ern
Lake Superior will support more widespread -shsn with the potential
for accumulations around an inch. Otherwise, temps will drop closer
to seasonal averages with highs in the lower to mid 30s.

.LONG TERM...(Saturday night through Friday)
Issued at 156 PM EST FRI NOV 24 2017

...No widespread precipitation but could be breezy at times...

Strong west to east jet stream over the northern tier of the Conus
will persist through next week leading to a progressive and overall
warmer pattern. Could still be brief intrusions of cooler air this
weekend and again middle of next week with some light lake effect
but for most part a lower impact and quiet period is expected in
terms of larger scale systems. As a more stronger west to southwest
flow develops aloft next weekend downstream of deep trouging over
the western Pacific/western Conus, does appear a more prolonged
period of warmer weather could develop for the first full week of
December per CFS H5 height/H85 temp anomalies and latest 6-10/8-14
day outlooks from CPC.

To close the weekend expect broad ridge over western North America
with downstream troughing over eastern North America. Brief cold air
shot that brings lake effect early this weekend wanes Sat night but
another shot of colder air will move back in on Sun. May be a brief
period of gusty winds over 30 mph near Lk Superior as that cold air
moves in. Only shallow moisture shown in forecast soundings on Sun
but could be light lake effect over east. May end up only seeing
drizzle though as moisture only extends to temps of -8c which is
borderline to introduce ice in moist layer. Will keep it simple
with just mention of rain and snow showers attm. Any light precip
shuts down Sun night with winds shifting offshore as sfc high
brings in warmer south flow.

Sfc high moves to lower Great Lakes on Mon while stronger shortwave
over western Canada leads to deepening sfc low blo 990mb over the
Canadian prairies. South winds btwn the two sfc features will lead
to warmer conditions over Upper Michigan on Mon. Could be a lot of
mid and even lower clouds around (NAM shows more low clouds trapped
beneath inversion) but even so should see temps similar to what
occurred today (solid mid to upper 40s with even some low 50s). As
bulk of warmest air arrives late in the day on Mon maybe some light
rain could develop over the north. GEM more widespread with light
qpf compared to GFS and ECMWF. May turn breezy ahead of cold front
tied to the low. Strongest winds from southwest would be late Mon
into Mon night. Once cooler air works in Tue aftn and Tue night
could see lake effect for NW flow areas. GFS soundings are pretty
dry blo cloud base and H85 temps around -8c are marginal so any lake
effect looks very light. Gusty northwest winds over 30 mph could
develop along Lk Superior late Tue into Tue night. Temps will bounce
back quickly on Wed, then another shot of colder air moves back in
Thu-Fri of next week. Even with the changeable temps, quick moving
flow aloft looks to prohibit any big systems. However, there is a
hint especially from last few runs of ECMWF of a southern stream
rain/snow system lifting through on Thu with enough cold air behind
for light lake effect.

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1241 PM EST FRI NOV 24 2017

VFR conditions will give way to MVFR conditions this afternoon with
a lowering of ceilings under areas of rain developing along and
ahead of an approaching cold front from the west. Behind the front,
winds will become gusty at each of the TAF sites; however, CMX will
be the most exposed and could see winds gusting as high as 35 mph
from the west and northwest. Light lake effect snow will be possible
late tonight into early Saturday morning; however, ceilings and
visibility restrictions should be limited with continued MVFR

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 400 PM EST FRI NOV 24 2017

West winds 20 to 30 knots veering nw with a few gale force gusts to
35 knots are expected tonight. Additional gale force gusts of 35
knots are possible on colder northwest flow into the area late
tonight and Saturday. Winds are expected to remain in the 20 to 30
knot range through at least mid weak.

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


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