Area Forecast Discussion
Issued by NWS Marquette, MI

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 222140

Area Forecast Discussion
National Weather Service Marquette MI
440 PM EST Fri Nov 22 2019

.SHORT TERM...(This evening through Saturday)
Issued at 155 PM EST FRI NOV 22 2019

With yesterday`s system having quickly skirted off to the northeast,
visible satellite now shows clearing skies over much of the U.P. in
response to height rises aloft and surface high pressure nudging
northward through the Upper Mississippi Valley. Clear skies are
expected to continue tonight and right through the day tomorrow for
most of us. It does look fairly breezy tonight, however. This will
especially be true over the Keweenaw, and right around Marquette
where the colder air over the higher terrain accelerates downslope
and mixes down some of the 40-45 kt LLJ passing by overhead. Would
not be surprised to see some sporadic and localized 30-35 mph gusts
tonight in both of these areas.

Despite the clear skies expected tonight, hedged closer to the
warmer CONSRaw for temps tonight given that there will likely be
enough wind to prevent the PBL from decoupling - but admittedly this
is a gamble. Temps look to stay on the warm side of guidance
tomorrow as well with such clear skies and a dry WSW wind. Despite a
thermal trough dropping 850 mb temps back to about -3 C coinciding
with peak diurnal heating, it still looks like highs will be in the
upper 30s to lower 40s for just about everyone. The one exception to
the sunny skies tomorrow will be over the Keweenaw and perhaps the
immediate Lake Superior lakeshore of the east. In those areas, the
combination of lake moisture, proximity to synoptic moisture to the
north, and a little bit of lift along the aforementioned trough will
allow clouds to redevelop by afternoon. A few flurries are not out
of the question either, but they would be very isolated and brief if
they happen at all.

.LONG TERM...(Saturday night through Friday)
Issued at 437 PM EST FRI NOV 22 2019

Models suggest that a quas-zonal pattern with wnw mid/upper level
flow through the northern CONUS will give way to troughing over
the west and sw flow into the Great Lakes through the first part
of next week. The trough will settle along the Pacific Northwest
toward the end of the week with ridging through the central CONUS.
Generally mild conditions will prevail with temps at or above
seasonal averages with slight cooling from Wed-Fri.

Saturday night into Sunday, a shortwave trough is expected to slide
ese through northern Ontario, just brushing northern Lake Superior.
Since the strongest 700-300 qvector conv with this feature remains
to the north and little moisture is available in the brief WAA
pattern ahead of the shrtwv, only slight chance POPs were mentioned
for any shsn/shra Sunday.

Mon, another stronger shrtwv with stronger WAA/isentropic lift ahead
of it will move through northern Ontario. Some ra/sn will be
possible but with little or no accumulation as the stronger
forcing again remains to the north and moisture remains scarce.

Tue-Wed, the models have come into better agreement with the strong
shortwave and deepening sfc low lifting northeast from the srn/cntrl
plains. Even though the ensemble and determistic model spread has
decreased, uncertainty remains with the track/timing. The
consensus taking the low through or near srn/cntrl lower Michigan
Tue night would mainly bursh the southeast half of Upper Michigan.
Cold enough air will be pulled in for nw-n flow LES as 850 mb
temps drop to around -10C.

Thu-Fri, drier weather is likely to move in Thue with sfc and mid
level ridging building into the area. Pcpn chances increase by
Friday as a WAA pattern develops ahead of the next low developing
over the plains.

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1231 PM EST FRI NOV 22 2019

With high pressure to the south nudging into the area, skies have
mostly cleared (or at least gone to a VFR cig) and conditions will
stay VFR through the TAF period. Only concern is a period of LLWS
tonight into tomorrow morning. WS will be marginal at CMX because
sfc winds there are expected to be more westerly (thus less
directional change with height) and a few kts stronger but included
it nonetheless to err on the side of caution. Elsewhere, critical WS
threshold should be met at about 1.5 kft AGL.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 155 PM EST FRI NOV 22 2019

Gales quickly redevelop tonight on the western lake with 35-40 kt
winds expected overnight from about the Western Superior buoy to
north of the Keweenaw Peninsula. Thus, the Gale Warning remains in
place. On the eastern lake, 25-30 kt SW winds are expected. Winds
will gradually turn W and relax to about 20 kts across the lake
through the day on Saturday. Winds look to go very light Sunday
evening as slight ridging passes over the lake, but then increase
back to 20-25 kts on Monday with broad low pressure moving through
Ontario and clipping Lake Superior. The next system to watch is
Tuesday night, though right now it looks like it will pass far
enough to the south and east that only eastern Lake Superior would
be affected, and even there winds only top out in the 25-30 kt range.

Upper Michigan...
Lake Superior...
  Gale Warning until 7 AM EST Saturday for LSZ243-244-263-264.

Lake Michigan...


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