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fxus63 kmqt 141753 

Area forecast discussion
National Weather Service Marquette Michigan
1253 PM EST Thu Nov 14 2019

Short term...(today and tonight)
issued at 350 am EST Thursday Nov 14 2019

The main story this short-term will be the return of colder air
(some of US are asking "it left?") And associated wind gusts and
lake-effect snow chances tonight. First off, however, we have
widespread light, fluffy snow over about the western 2/3 of Upper
Michigan this morning. This mostly the result of low-level troughing
continuing to scoot eastward across the area (evident in msas
analysis) but also aided by westerly flow behind the trough being
both upslope and onshore. Looks like this shallow precip will be
stuck with US through mid-morning in more or less the west-northwest wind les
belts, though not amount to more than a half inch or so of new
accumulation. As heights rise and temps warm aloft today, we'll be
looking at highs in the upper 20s to low 30s, perhaps even a touch
warmer away from Lake Superior where there could even be a few hours
of sunshine this afternoon.

But by this evening, the cold air is knocking on the door once
again. A potent short wave over northern Manitoba this morning will
quickly drop southeastward through Ontario today in broader
cyclonic flow and drop 850 mb temps back to about -10 to -14 c by
late tonight. With this cold air advection and a fairly strong llj, expect to see
gales on Lake Superior and gusts on land in the 20-30 mph range
beginning late this afternoon and continuing through the night.
Winds could gust as high as 45 mph over the Keweenaw this evening,
with the strongest winds right around 00z. Because the window for
gusts this strong is so brief (a couple hours, max) and because
strong winds from the west are not uncommon up there this time of year,
will not issue a Wind Advisory but instead mention in the severe weather potential statement and on
social media.

Models hit a decent band of low to mid level Theta-E advection on
the leading edge of the cold air, likely enough for a brief burst of
snow showers or at least flurries this evening. The most persistent
snow showers will be right along the surface trough, expected to be
aligned west to east from the west through the hurons and then east
to Whitefish Point, give or take, late tonight. Some lake
enhancement is expected to the snow as well, before the air aloft
turns cold enough for pure lake-effect bands to develop into the
eastern u.P.'S northwest wind les belts. However, given dry air quickly
working in aloft and model soundings only showing saturation to
about 4-5 kft, this is not expected to be a prolific snow for
anyone. Rather, it looks like just about an inch Luce and eastern
Alger counties, and even less elsewhere.

Last thing to watch will be the (low) potential for Lakeshore
flooding. Current wave forecasts just clip advisory criteria (12
feet) on the western shore of the Keweenaw, but given the wave
direction parallel to shore, not expecting much if any impacts up
there. Waves also creep up to 12 feet tonight from Grand Marais east
to Whitefish Point. Here the wave direction is more onshore, so some
Lakeshore flooding is possible. However, since if any does occur it
would not be until after about 06z tonight, will let the day shift
take another crack at the winds (and thus waves) and let them decide
if an advisory is needed.

Long term...(friday through wednesday)
issued at 355 am EST Thursday Nov 14 2019

North to northwest les ongoing at the start of this forecast
period will taper off throughout the day on Friday as much drier
air moves into the region. Stout high pressure then takes over
Friday night into Saturday, allowing for a brief reprieve from
the precip chances, but this doesn't last long. By Saturday night,
snow chances start creeping back into Upper Michigan from the
west, with increasing chances of mixed precip by the time Sunday
morning arrives.

Speaking of temperatures, as previously discussed, temps will be
on the rise back toward normal for mid-November (mid to upper 30s
for highs), which will factor into the precip types that end up
falling through much of the long-term period. Tomorrow will be the
chilliest of the period, with highs thereafter rebounding into the
30s each day. Forties could even make an appearance early next
week, especially for locations in the south-central u.P. Lows each
night will settle into the 20s, with single digits and teens
making one last appearance tomorrow night.

Back to the precip, the entrance of these warmer temps yields a
not-straight-snow forecast from Saturday night Onward. As the
morning progresses on Sunday, increasing chances for a rain/snow
or even light freezing rain mix appears for the eastern half to
two-thirds of the u.P. But, even this is short-lived as a shot of
colder air aloft associated with a passing trough transitions most
precip back over to snow by the evening hours. From late Monday
through Wednesday, periodic mixed precip chances persist under a
fairly disorganized pattern with low confidence in the details
given the divergent solutions amongst the longer-range models.
Overall, not much signal one way or the other for accumulating
snow chances as of this forecast issuance other than it appearing
to be on the low side for this weekend.

Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 1252 PM EST Thursday Nov 14 2019

Conditions will improve to VFR briefly at kcmx/ksaw over the next
hour or two. Expect this trend to linger into the evening hours,
until a cold front drop south across the area bringing Back Lake-
effect clouds and snow showers later this evening and overnight.
Given the shallow nature of the lake-effect snow, visibilities
aren't expected to drop terribly low, but each site should see some
snow showers tonight into Friday morning.

Wind wise, all taf sites will see west-southwest winds veer
northwest during this forecast. Kcmx will feel the brunt of the
strongest winds, with a window of 30 to 40 knot winds possible this
evening along and immediately following the cold front passage.
Elsewhere, after the frontal passage, expected gusty winds to
prevail between 20 and 25 knots.

Marine...(for the 4 am Lake Superior forecast issuance)
issued at 427 am EST Thursday Nov 14 2019

Next cold front dropping southeast will Cross Lake Superior this evening
bringing a rapid increase winds, from west-northwest around 20 kts this morning
backing to west-southwest and increasing to 40 kts by late afternoon on the
Western Lake. Some 45 kt gusts are possible between the Keweenaw and
Isle Royale within about two hours either side of sunset. Gales to 35-
40kt will then expand eastward across the lake this evening as the
wind veers back to northwest behind the cold front. Have all of the lake
covered in gale warnings for this event. Despite briefly flirting
with "high-end" (40+ kt) gales, given the small area and brief
period of time (only about 4 hours) of these strongest winds, will
not issue a situation report and will instead let the gale warnings
speak for themselves. Low-end gales continue into midday Friday over
the Eastern Lake under cold air aloft. Winds will then rapidly
diminish to 15 kt or less Friday evening. 20-25 kt S winds redevelop
by Saturday morning, increasing to near 30 kts over the Eastern Lake
Saturday afternoon. Winds diminish back to less than 20 kts by
Sunday evening and then go very light on Monday with the passage of
a strong area of high pressure.

Freezing spray is expected to redevelop across the north-central
part of the lake by Friday morning (but still not warning criteria),
with light/patchy freezing spray possible throughout the lake. This
ends when winds relax Friday night.

MQT watches/warnings/advisories...
Upper Michigan...
Lake Superior...
Gale Warning from 7 PM this evening to noon EST Friday for

Gale Warning from 4 PM this afternoon to noon EST Friday for

Gale Warning until 10 PM EST /9 PM CST/ this evening for lsz162-

Gale Warning until 4 am EST Friday for lsz264.

Gale Warning from 4 PM this afternoon to 1 am EST Friday for

Gale Warning from 9 PM this evening to noon EST Friday for

Lake Michigan...


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