NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

LSZ250 737 Pm Edt Thu Oct 5 2023
.strong Thunderstorms over the waters...
the areas affected include... Grand marais to whitefish point mi... 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... Munising to grand marais mi...
at 737 pm edt, doppler radar indicated strong Thunderstorms, capable of producing winds to around 30 knots and small hail. These Thunderstorms were located along a line extending from 25 nm north of grand sable dunes to near pictured rocks national lakeshore, moving northeast at 25 knots.
locations impacted include... Grand sable dunes and pictured rocks national lakeshore.
precautionary/preparedness actions...
mariners can expect gusty winds to around 30 knots, locally higher waves, and lightning strikes. Boaters should seek safe harbor immediately until these storms pass.
this strong Thunderstorms will likely produce winds to around 30 knots, and could pose a serious hazard for boaters. A special marine warning may eventually be required when these storms reach the nearshore waters. Boaters should consider heading for shore before these storms arrive.
&&
lat...lon 4663 8615 4655 8636 4707 8636 4736 8603 4728 8584 4663 8586

LSZ200
No data

FXUS63 KMQT 301744 AFDMQT

Area Forecast Discussion National Weather Service Marquette MI 1244 PM EST Thu Nov 30 2023

SHORT TERM
(Today)
Issued at 220 AM EST THU NOV 30 2023

Key Messages: -Another warm day, but cold front may bring cooler temperatures by the middle of the day.
-Isolated light/weak lake-effect snow showers possible along the northwest wind snow belts by this afternoon.

Outside of a couple of bands of high level cloud cover remaining along the Lake Superior shore and Menominee County early this morning, GOES-16 satellite imagery shows clear skies dominating the Upper Peninsula. However, don't expect temperatures to change all that much before dawn, as warm air advection continues to move across our area into the early daylight hours. Therefore, lows this morning are expected to be in the mid 20s to low 30s; I'm thinking some spots have already hit their low already this morning. Moving into the daytime, partly to mostly cloudy skies move back over our area by the early afternoon as a cold front moves across the region.
This cold front may kick off some isolated light lake-effect snow showers across the northwest wind snow belts early this afternoon.
However, with warm temperatures remaining over our area today, no accumulations are expected; temperatures should be above freezing for much of this afternoon across the Upper Peninsula. During the early afternoon hours, there may be some very fine, light rain mixing in with the snowfall within the showers near the Lake Superior shoreline. As the temperatures fall behind the front though, expect the transition to only snow by late this afternoon near the lakeshore. Ahead of the cold front, high temperatures are expected to get up to the mid 30s to the low/mid 40s; the warmest areas look to be near the Great Lakes and the south central.

LONG TERM
(Tonight through Wednesday)
Issued at 356 AM EST THU NOV 30 2023

Key Messages:

- No widespread, significant snowfalls across Upper MI thru next week.
-Some lingering light w-nw flow LES tonight in the wake of today's clipper shortwave/front.
- After dry weather Fri/Sat, a series of shortwaves will bring periodic light snows next week, best chance on Sunday.
- Normal to above normal temps to prevail over the next 7 days with warmest conditions late next week.

Medium range models show a broad mid-level low centered over Hudson Bay rapidly weakening/lifting n Fri/Sat. Meanwhile to the w, a progression of shortwaves from the Aleutians thru the Gulf of AK into the western U.S. thru this weekend will establish a mid-level trough that will progress downstream into the eastern U.S. during the early to mid portion of next week. Farther upstream, a deepening trough over the ne Pacific/Gulf of AK Mon-Wed will force an expanding, building ridge over the western U.S. into south central Canada. This ridge will then deamplify a bit as it shifts into the eastern U.S. late next week. For Upper MI, this evolution of the flow will lead to temps around normal to above normal over the next 7 days as we first lose the influence of the mid-level low over Hudson Bay and then start the process of Pacific air masses making progressive inroads downstream across the U.S. and southern Canada.
Above normal temps should peak late next week as ridging expands to the eastern U.S. As for pcpn, a series of shortwaves moving through the trough early week will generally slide south and east of the area but could bring in periods of -sn, particularly on Sunday over the south central and east. As the western ridge begins to build eastward during the last half of the week, a few weak shortwaves rounding it could bring the potential of some waa -sn mid to late next week.

Beginning tonight, model and ensemble means indicate 850 mb temps are likely to bottom out around -11C in the wake of today's clipper shortwave/front. With Lake Superior sfc water temp averaging 5C, this will lead to lake-850 mb delta-Ts increasing to the mid teens, supporting sct lake effect -shsn tonight for the w-nw wind snowbelts. However, given the developing low-level anticyclonic flow, low inversion heights of 5 kft or less and inverted-v look of the fcst soundings below cloud base in the wake of the cold front, snow accumulations are expected to be less than 1 inch.

A sfc high pres ridge will move across the area Fri/Sat, providing quiet/dry conditions. High temps in the low/mid 30s on Fri will increase to the mid/upper 30s on Sat.

00Z models still showing little impact Sunday through Wednesday from a series of shortwaves tracking into and through the mid-level trough which progresses from the central into the eastern CONUS. The best chance of light snow would probably be Sunday over mainly the south central and eastern U.P. as a southern stream shortwave slides se through the Lower Great Lakes, but the prospects of even light snow accumulation from this shortwave is now looking less plausible than it was several model runs ago. EPS probability of 24hr snowfall of an inch or more at a 10 to 1 SLR is mainly around 10pct for central and eastern U.P. portions. The GEFS shows a higher chance of 40-50 pct for an inch or more of snow but I have less confidence in the GEFS given the high spread of model members with the fcst sfc low track on Sunday. For now, will maintain model blend fcst of 30- 50pct pops, highest s central and e, but confidence in this fcst is low and believe pops will probably trend downward as we get closer to the weekend. As the mid-level trof progresses across the area, weak caa will drop 850mb temps to around -8C, marginal for LES. As mentioned before the western ridge begins to build eastward toward the Great Lakes during the last half of the week and a few weak shortwaves rounding the ridge could bring the potential of some waa light snow into the area mid to late next week.

AVIATION
(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1244 PM EST THU NOV 30 2023

In the wake of a passing cold front, expect ocnl to prevailing MVFR cigs this aftn at IWD/CMX/SAW. Prevailing MVFR cigs are more likely at IWD/CMX than at SAW. VFR should prevail at all terminals tonight/Fri, though with a lowering inversion, cigs may end up holding at high MVFR at CMX.

MARINE
(For the 4 AM Lake Superior forecast issuance)
Issued at 356 AM EST THU NOV 30 2023

Weak ridging will give way to a cold front moving across Lake Superior later this morning as sw-w winds to 30 kts shift to nw winds gusting to 25kt, strongest across the e half of the lake.
Winds will then begin to diminish tonight as a high pres ridge builds e toward Upper MI. Expect winds mostly blo 20kt by sunrise Fri. Under high pres ridging, winds will decrease further to 15kt or less Fri into Sat. Winds will increase a little for Sun into Tue, but remain under 20kt.

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

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Marquette, MI,