NWS Marquette, MI wrote its last area forecast discussion before the first event at Mar 4, 6:46 PM EST, 14 minutes earlier. Its key messages:
Area forecast discussion, Mar 4, 6:46 PM EST, 14 minutes before
Area Forecast Discussion
National Weather Service Marquette MI
646 PM EST Tue Mar 4 2025
.KEY MESSAGES...
- Rain changes to wet snow from west to east tonight into
tomorrow morning and persists through at least Wednesday
evening. Heavy snow will likely focus into the west and north-
central. Around 80% chance of at least 6" of snow over Iron
and Marquette counties and westward.
- Up to 2 ft of snow is possible in the higher terrain inland of
Lake Superior across northern Marquette county (30% chance).
- Strong winds (80% chance of 35 mph gusts, up to 55 mph along
Lake Superior shores and in the Keweenaw) will result in
additional travel hazards, possible tree damage, and potential
for power outages on Wednesday.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 255 PM EST Tue Mar 4 2025
This afternoon, deep 990mb low pressure is centered over eastern KS,
with the precip shield extending well northward into the Lower
Midwest while persistent southerly flow continues to tap into
moisture-rich Gulf air. Of note is a pretty prominent dry slot
nosing into OK and central KS. Closer to home, a frontal boundary
remains stalled out over the UP. Light rain continues mainly across
the northern UP, closer in proximity to the boundary, with patchy
fog/mist elsewhere given plenty of lower-level moisture in the wake
of earlier rain and a melting snowpack. Temperatures, meanwhile, are
rising into the mid and upper 30s across most of the UP, with warmer
temperatures cracking the 40 degree mark closer to the WI border.
Low pressure continues to track northeast into the Lower Midwest
tonight, reaching far northeastern MO by 06Z and northern IL by 12Z
Wednesday. As this happens, higher PWAT air (up to 0.75in) streams
into the Upper Peninsula while a strong southerly low level jet
streak becomes directed over the Lower Peninsula. To the north,
northeast winds will be increasing over Superior and the UP.
Steadier rainfall will spread back into the UP from the south, but
between 22-00Z, rain may already begin transitioning over to a
wintry mix with snow and perhaps sleet/freezing rain as cooler air
slowly creeps in from aloft and surface temperatures in the western
half of the UP fall to around and below freezing after sunset.
Rain continues to slowly transition over to snow from west to east
tonight into Wednesday morning, with a narrow transition zone
continuing to show a potential for some sleet or freezing rain. This
could result in some trace ice accumulations tonight where surface
temperatures are cool enough. The main concern, however, will be the
wet and heavy snow. With strengthening frontogenetical forcing over
the UP and increasingly strong NE winds as the low continues to
track northeastward into the Lower Peninsula, moderate to heavy
snowfall rates are expected to develop across the western half of
the UP especially from 06Z to at least early Wednesday afternoon.
The heaviest snowfall rates, potentially up to 1-2in/hr, are
expected across the higher terrain of northern Marquette county,
inland from Lake Superior. Across the rest of the UP, expect
snowfall rates around/in excess of 0.5in/hr are more likely.
However, with such marginal temperatures for much of the period of
heaviest precipitation, particulary nearer to Lake Superior, snow
ratios could have a pretty significant impact on snow amounts/rates.
Late Wednesday afternoon and into the evening, the aforementioned
dry slot begins to move into Lower Michigan while the surface low
tracks towards Lake Huron. This may help to cut back on PoPs across
the southern UP, while slowly weakening frontogenetical forcing and
backing winds decrease snowfall rates slightly from 18Z onward.
As far as totals: most of the western and central UP should pick up
around 6-12 in of snow, with higher totals in excess of a foot
expected where orographic lift and lake enhancement occurs due to our
strong NE flow. The highest totals in excess of 2ft will be possible
(30% chance) in the higher terrain of northern Marquette county.
This will result in a pretty tight snowfall gradient from areas
lakeside to just inland, with those lakeshore spots showing the
highest "bust" potential due to the possible moderating influence of
Lake Superior (with lake surface temperatures just above freezing).
While totals lakeside are still around a foot, there is a potential
for amounts to come in lower than that if temperatures stay warmer
than expected.
An additional area of concern will be blustery northeast to
northerly winds. Widespread gusts of 30-40mph are expected across
the UP, but stronger gusts around/in excess of 40mph are expected
along Superior and across the Keweenaw. Gusts may even exceed 50mph
(30% chance). Gusty winds will exacerbate the usual expected impacts
from a heavy, wet snowfall, with a good potential to see downed tree
limbs and power outages. Reduced visibility will also be possible in
areas of blowing snow. Thus, the Winter Storm Warnings and Winter
Weather Advisories continue for tonight through Wednesday night.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 350 PM EST Tue Mar 4 2025
The sfc low will have made it to N Lower MI near Lake Huron by 7PM
EST Wed with the trough aloft beginning to take on a negative tilt
over the Great Lakes. This pair continues NE Wed night as a trough
over Saskatchewan approaches from the NW and troughing deepens over
the Pacific Coast. 850mb temps become marginally cold enough for
lake enhanced to weak LES, quickly backing from NE to NW as the sfc
low lifts to Quebec. A few hundreths of QPF through Thu morning is
expected with upslope flow boosting values to between 0.10-0.25".
Model soundings indicate a deep DGZ with an initial period of 3-5kft
of RH>95% in the lower levels paired with inversion heights around 3-
4kft. SLRs are expected in the upper teens:1, yielding a few
additional inches of snow ahead of the Thu morning commute (1-4",
highest amounts expected in the N central highlands), but drier air
advecting in from the W will diminish snow showers from W to E at
the same time. The other expected hazard during this period will
also already be ongoing Wed night: strong winds. Nrly gusts of 30-
40mph are expected to continue into Thu with gusts up to 45-55mph
possible in the N central and near Lake Superior early (30-60%
chance after 7 PM EST). Lows are expected in the teens.
Dry weather returns on Thu as dry air quickly diminishes any
lingering snow showers over the E. Winds continue to slacken through
the morning as the pressure gradient relaxes. Highs are expected in
the upper 20s to upper 30s, warmest S central. During the day, an
embedded shortwave and associated clipper low move SE over N
Ontario. The clipper low is anticipated to remain mainly north of
the CWA, but shortwaves do graze the area Thu night into Fri and
again Sat into Sun. Another CO low tracks to the S of the CWA on
Fri. Associated system precip is not anticipated to reach the area,
but marginally cold enough 850mb temps combined with a passing
shortwave keeps 15-30% PoPs through the weekend, primarily over the
NW wind LES belts. With limited moisture and forcing, accumulations
will remain light with no expected impacts. Otherwise highs are
expected in the mid 20s to mid 30s. Lows in the teens to low 20s are
fcst save for Fri night and Sat night where the interior W
could see single digits above 0F.
Early next week, strong ridging over the W CONUS progresses E
through midweek. This favors drier and warmer weather over the
UP until late next week when troughing off the Rockies returns.
Highs reaching well into the 40s are likely with 50s not out of
the question on Tue. Spread quickly grows after Sun, so fcst
confidence is low next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1217 PM EST Tue Mar 4 2025
IFR/LIFR flight conditions are expected through the 00Z cycle as
a strong winter storm takes aim on the region. The first hazard
is fog at SAW which has resulted in near zero visibility. The
fog will likely stick around until heavier precipitation arrives
around 05Z. Rain will turn to snow at SAW around that time and
persist through the rest of the period. It will be a heavy, wet
snow through the night and into the morning hours before
becoming lighter and fluffier late morning into the afternoon.
LIFR visibility will be the rule, with occasional periods of
heavy snow bringing vis below airport mins, especially after 15Z
when blowing snow will add to the issues. IWD/CMX have already
seen snow starting, but fairly light thus far. Cigs/vis will be
borderline IFR/LIFR through much of the night before becoming
more solidly LIFR late tonight into tomorrow morning as snowfall
rates intensify. Blowing snow will also become an issue during
the morning into the afternoon hours as winds increase and snow
becomes more prone to blowing. Wind gusts of 30-40 kt from the
north-northeast will be common late tonight into much of
Wednesday.
&&
.MARINE...
Issued at 255 PM EST Tue Mar 4 2025
A strong Colorado Low approaching the Great Lakes from eastern
Kansas this afternoon ramps up winds out of the northeast to 20-30
kts. As the pressure gradient tightens tonight with the low moving
to Chicago, winds reach gales across the lake with high end gales to
40-45 kts expected over the west and north central portions of the
lake by Wednesday morning. The low then remains south of the lake,
but tracks northeast over the region reaching Quebec by Thursday
morning. As a result, high-end northeast gales across the lake to 45
kts back north by the Wednesday evening with the far western third
likely settling to 34-40 kts late. There is a 50% chance for storm
force winds to 50 kts Wednesday afternoon and evening. Although high
observing platforms could see storm force winds, widespread
conditions are not expected; opted not to upgrade any areas to Storm
Warning. North gales settle to 40 kts around midnight Wednesday
night with 34-40 kt gales continuing over the eastern two thirds of
the lake through daybreak Thursday with mainly 20-30 kts winds over
the western third. In the wake of the low, northwest backing west
winds of 20-30 kts are expected on Thursday, strongest winds are
expected earlier in the day over the east. During the gale event,
moderate to occasionally heavy freezing spray is expected with wave
heights peaking around 14-20ft, highest along the southern shores in
the east.
With weaker disturbances traversing the Upper Great Lakes and
another Colorado low remaining well south of the region on Friday,
west to northwest winds of 15-25 kts are expected Thursday
night through the weekend.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Storm Warning until 1 AM EST /midnight CST/ Thursday
for MIZ001>005-009-084.
Lakeshore Flood Advisory from 4 AM to 9 PM EST Wednesday for
MIZ001>003.
Lakeshore Flood Advisory from 7 AM Wednesday to 7 AM EST
Thursday for MIZ005-006.
Winter Storm Warning from 1 AM Wednesday to 1 AM EST Thursday
for MIZ006.
Winter Weather Advisory from 7 AM Wednesday to 1 AM EST
Thursday for MIZ007-085.
Winter Storm Warning from midnight tonight to 6 PM CST
Wednesday for MIZ010-011.
Winter Weather Advisory from 1 AM EST /midnight CST/ Wednesday
to 1 AM EST /midnight CST/ Thursday for MIZ012-013.
Lake Superior...
Gale Warning until 5 PM EST /4 PM CST/ Wednesday for LSZ162.
Gale Warning until 7 AM EST /6 AM CST/ Thursday for LSZ240>244-
263-264.
Gale Warning from 1 AM Wednesday to 7 AM EST Thursday for
LSZ245>251-265>267.
Lake Michigan...
Gale Warning from 1 PM Wednesday to 7 AM EST Thursday for
LMZ248-250.
&&
SHORT TERM...LC
LONG TERM...Jablonski
AVIATION...Thompson
MARINE...Jablonski