Small Craft Advisory 3, NWS Marquette, MI

Area Forecast Discussion
National Weather Service Marquette MI
638 PM EST Mon Jan 4 2021

.SHORT TERM...(This evening through Tuesday)
Issued at 407 PM EST MON JAN 4 2021

WV imagery and RAP analysis indicated a low amplitude split flow
pattern with nrn stream mid/upper level trough from northeast
Manitoba into MN/IA. At the surface, a trough extended from
northwest Ontario through western Lake Superior into northwest WI.
800-600 mb fgen ahead of the mid level trough supported a narrow
band of snow from the MN arrowhead through far western Upper
Michigan that has dropped vsby to around 1SM as it moves through.
Otherwise, southerly flow ahead of the trough as maintained low or
allowed low clouds to spread through the rest of Upper Michigan.

Tonight, expect the trough and associated area of snow to spread
west to east through Upper Michigan with snowfall amounts less than
a half inch. Over the east, there may be period of fzdz preceding
the snowband as sw low level flow off of Lake Michigan brings
additional moisture into the area. As the deeper moisture departs
late this evening and overnight, some fzdz may also develop over
northwest Upper Michigan, especially where convergent upslope wnw
flow is strongest.

Tuesday, lingering shallow moisture and 850 mb temps in the
-6C to -8C range will support continued potential for fzdz/dz in
areas favored by northwest flow over the west in the morning and in
the east into the afternoon. Under persistent clouds, temps will
still remain above normal with highs in the low to mid 30s.

.LONG TERM...(Tuesday night through Monday)
Issued at 335 PM EST MON JAN 4 2021

For winter recreation enthusiasts, this snow season has been a big
disappointment so far. Unfortunately, the outlook is bleak for
snowfall across Upper MI for at least the next 10 days. In fact,
despite being Jan, it will even be difficult to get an air mass in
here cold enough to generate any LES. The main culprit to the warm
conditions and blo normal snowfall across Upper MI since the
beginning of Nov has been the flow across the N Pacific. A strong
Pacific jet and a persistence of negative height anomalies across
the ne Pacific (and extending westward across basically all of the N
Pacific to Asia for that matter), has largely kept the Lower 48
awash in Pacific air and has prevented any sustained build up of
Arctic air to the n in Canada. This +EPO pattern has been the prime
driver of the warmth and blo normal snowfall for the last 2 months,
and has muted the responses of the AO which has been negative since
the beginning of Dec and the more recent -NAO. Often, a -AO supports
lower heights in the mid latitudes of N America and thus increased
potential for arctic air to push southward, and a -NAO is also a
colder signal as it supports lower heights across the ne portion of
the Lower 48. Not only will conditions across the ne Pacific not
change for at least the next 10 days, but there will also be an
expansive area of strong positive height anomalies at 500mb
developing over the e half of Canada. End result will be a pattern
that prevents a buildup of arctic air in Canada and even prevents
much southward push of any notably colder air at all. Split flow,
which has also been dominant across the Lower 48 and southern Canada
for the last couple of months, will also continue with the more pcpn
active southern stream way to the s of here. So, for the next 7 to
10 days, above normal temps and much blo normal pcpn will be the
rule for Upper MI...certainly, a quiet and warm pattern for Jan
standards.

Beginning Tue night, mid-level ridge will be approaching the western
Great Lakes in the wake of the shortwave passing tonight/Tue. Temps
at the base of an inversion based at 3-4kft are fcst to be near -9C,
marginal at best for any LES with Lake Superior water temps around
4C. Of course, with temps only as low as -9C, there's no guarantee
of ice nucleation to result in snowflakes if pcpn occurs. With sfc
high pres ridge arriving over western Upper MI, will leave fcst dry
in that area. Over the e, low-level flow across the e half of Lake
Superior, at least during the evening, is cyclonic, and this might
support some flurries/patchy -fzdz into the n central and ne fcst
area. Otherwise, fcst soundings suggest plenty of stratocu/stratus
will linger across the area, even over the w where high pres ridge
arrives. Leaned more toward the higher end of guidance for min
temps, but if any interior locations clear out, temps could easily
fall off toward 10F.

Mid-level ridge will then setup shop across the northern Great Lakes
on Wed/Thu and probably on into Fri. At the sfc, associated high
pres ridge will settle over Upper MI, extending from building sfc
high pres center shifting from far northern Ontario to northern
Quebec. Result will be tranquil days with light winds. Given little
advection of drier air heading into Wed, it's quite possible stratus
will dominate the area for both Wed and Thu and maybe Fri, and if
not, fog development may be an issue at night. At this point,
leaning toward low clouds dominating, especially Wed/Thu, with any
breaks mainly in areas that see some downsloping, though
downsloping will be weak with winds light. Thus, kept diurnal
ranges on the lower side with expectation of clouds holding
daytime temps down and conversely nighttime temps up. There will
be fairly big temp bust potential on the min temp side if there
is less cloud cover than anticipated right now.

Over the weekend and into early next week, a couple of northern
stream shortwaves may try to dig se into the Great Lakes region. CMC
and GFS are more aggressive with these waves into the Great Lakes
than the ECMWF has been. If the former are on track, there will be a
couple of opportunities for some -sn and maybe some LES, but even
these solutions lack any decent push of colder air for LES. The
ECMWF with support from the UKMET suggests dry weather will
prevail, and fcst will favor that idea. So, it's possible that
after some light pcpn tonight/Tue, there may be no measurable pcpn
Wed thru Mon.
&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 630 PM EST MON JAN 4 2021

At KIWD, MVFR cigs are expected through the forecast period. A few
lingering flurries are possible this evening.

At KCMX, a brief period of snow showers this evening could result
in temporary IFR vsbys, but otherwise winds veering to an upslope
west-northwest direction behind a cold front will support MVFR
cigs through the period.

At KSAW, LIFR strata deck could lift to IFR later this evening
as a low pressure trough moves across the area. A period of snow
showers could bring MVFR to IFR vsbys as well. As winds veer to
the northwest tonight, expect some improvement to at least low
end MVFR cigs.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 407 PM EST MON JAN 4 2021

SW winds of 20-30 knots late this afternoon will diminish tonight
and veer to the west as a trough moves eastward through Lake
Superior. Behind the trough, northwest winds of 15 to 25 knots are
expected late tonight into Tue morning before diminishing to less
than 20 knots.  After that, winds will remain unseasonably light
across the lake through at least the end of the week.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

SHORT TERM...JLB
LONG TERM...Rolfson
AVIATION...Voss
MARINE...JLB

Hazardous Weather Outlook
National Weather Service Marquette MI
326 PM EST Mon Jan 4 2021

MIZ001>007-009>014-084-085-051300-
Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce-
Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft-
Southern Houghton-Northern Schoolcraft-
326 PM EST Mon Jan 4 2021 /226 PM CST Mon Jan 4 2021/

This Hazardous Weather Outlook is for portions of western Upper
Michigan and central Upper Michigan.

.DAY ONE...Tonight

There is a slight chance of freezing drizzle tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

There is a slight chance of freezing drizzle Tuesday morning over
northwest Upper Michigan and also to the east of Marquette and
Escanaba. There is also a slight chance of freezing drizzle over
north central Upper Michigan Tuesday evening.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

LSZ162-240>251-263>267-051300-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-Saxon Harbor WI to Black River MI-
Black River to Ontonagon MI-
Ontonagon to Upper Entrance of Portage Canal MI-
Upper Entrance of Portage Canal to Eagle River MI-
Eagle River to Manitou Island MI-
Manitou Island to Point Isabelle MI-
Point Isabelle to Lower Entrance of Portage Canal MI-
Lower Entrance of Portage Canal To Huron Islands MI Including
Keweenaw and Huron Bays-Huron Islands to Marquette MI-
Marquette to Munising MI-Munising to Grand Marais MI-
Grand Marais to Whitefish Point MI-
Lake Superior from Saxon Harbor WI to Upper Entrance to Portage
Canal MI 5NM off shore to the US/Canadian border including Isle
Royale National Park-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
Lake Superior East of a line from Manitou Island to Marquette MI
and West of a line from Grand Marais MI to the US/Canadian Border
Beyond 5NM from shore-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
326 PM EST Mon Jan 4 2021 /226 PM CST Mon Jan 4 2021/

This Hazardous Weather Outlook is for portions of Eastern Lake
Superior...Central Lake Superior and Western Lake Superior.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

LMZ221-248-250-051300-
Green Bay North of line from Cedar River MI to Rock Island
Passage-Seul Choix Point to Point Detour MI-
5NM East of a line from Fairport MI to Rock Island Passage-
326 PM EST Mon Jan 4 2021

This Hazardous Weather Outlook is for portions of Northern Lake
Michigan.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

Rolfson