Sunrise 6:38 AM   Sunset 8:55 PM Moonrise 12:00 AM   Moonset 7:17 AM

  Print   HELP   Reset   Save   Recall

LSZ249 115 Pm Edt Tue Apr 23 2024
a marine weather statement has been issued for the following areas - . 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 - . Marquette to munising mi - . Munising to grand marais mi - .
at 114 pm edt, doppler radar indicated a cluster of strong Thunderstorms, capable of producing winds to around 30 knots and small hail. The leading edge of these Thunderstorms were located over shelter bay, moving east at 20 knots.
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 this storm passes.
&&
lat - .lon 4648 8702 4647 8712 4654 8714 4669 8651 4653 8642 4640 8663 4640 8671 4643 8677 4640 8690

LSZ200
No data

FXUS63 KMQT 270906 AFDMQT

Area Forecast Discussion National Weather Service Marquette MI 506 AM EDT Sat Apr 27 2024

KEY MESSAGES

- Scattered showers and isolated thunderstorms today. A severe storm possible south central and eastern forecast area.
- Breezy today with strongest winds this afternoon south central where gusts to 35-40mph expected.
- Active pattern continues as 3-4 low pressure systems track across the region over the next week. Above normal temps/precip are expected including thunderstorm chances.
- Given the persistently dry pattern between May 2023 and March 2024, think most rainfall will be beneficial though thunderstorms may result in ponding for poor drainage areas.

SHORT TERM /THROUGH THIS AFTERNOON/
Issued at 329 AM EDT Sat Apr 27 2024

Water vapor imagery and RAP analysis show mid-level troffing over the western U.S. One vigorous shortwave is evident over the southern Rockies with a second well-defined wave lifting ne into the Upper Mississippi Valley. At the sfc, weakening low pres associated with the latter wave is over sw MN. Ahead of these features, clusters of shra are occurring across the Upper Mississippi Valley into the western Great Lakes early this morning. Thunder is mostly confined to western WI, closer to the well-defined shortwave. Current temps across Upper MI range thru the 40s F.

Low pres will continue to weaken slowly as it tracks ne, crossing western Lake Superior late morning thru the aftn and exiting northern Lake Superior by evening. Expect sct shra to continue today as this low tracks across the area. Greatest coverage of shra and some tsra will occur in association with the well-defined wave now over southern MN. This wave will reach western Lake Superior/western Upper MI this morning. The tail end of this wave could support stronger thunderstorm development early aftn into central and eastern Upper MI. Consensus of 00z CAMs, including HRRR runs since 00z, is for mlcape to reach as high as 500-1000j/kg with s central Upper MI, Menominee County in particular, at the higher end of the instability. Deep layer shear up to 50-55kt will support organized storms and a svr risk (large hail/damaging wind). However, CAMs are very muted on new storm development early this aftn, so confidence is low that any new storms will develop let alone development of any svr storms. Time period to monitor will begin around noon and end by 5pm as much of the instability will be shunted s and e of the area by that time. Breezy winds will increase this aftn, especially s central. Per mixing depth on fcst soundings, expect gusts up to 35- 40mph this aftn s central with 25-30mph fairly common elsewhere.
Will need to monitor for potential wind advy (gusts 45mph or higher)
as the day progress. If clouds break more to allow more insolation to further raise mixing height, stronger winds aloft will be tapped.
Expect high temps today mostly in the 60s F. However, s central Upper MI will reach the lwr 70s F. Also, temps over the w will begin to fall in the aftn as low pres lifting n of the area causes winds to shift wnw.

LONG TERM /TONIGHT THROUGH FRIDAY/
Issued at 506 AM EDT Sat Apr 27 2024

Three low pressure systems track across the region between today and Wednesday night with a fourth possible late next week. Upper Michigan appears to stay in the warm sector of each system preventing p-type issues and keeping skies mostly cloudy thru Tuesday morning. Mostly cloudy skies and rain chances suggest small diurnal temperature ranges with warm nights and cool days, but temps should average about 2-4F warmer than normal over the next week (warmest south and east). Ensemble means also indicate between 1.5 and 2.5 inches of rain over the next week.

The first system exits the area tonight resulting in cool/dry north winds that veer northeasterly on Sunday as the next low pressure approaches. This forecast package trended toward a slower arrival of rain chances on Sunday and it now looks like the morning will be mostly if not completely dry. Rain chances increase late in the day as a warm front surges north across the area. Guidance continues to indicate plenty of warm air advection atop a shallow frontal surface boundary that should result in a broad shield of steady rain. Robust frontogenesis on the nose of a ~45 kt southwesterly low level jet adds potential for embedded thunderstorms with this threat most likely for locations near Lake Michigan. 00Z Hi-res NAM guidance suggests potential for two rounds of embedded storms 1) associated with diurnal enhancement of LLJ during the evening and 2) Monday morning as a shortwave pivots across the area. In addition to bringing rain and storm chances, the LLJ should also result in a period of breezy winds, mainly across the east and on the Keweenaw but stable conditions should limit this hazard. The area of steady rain lifts to our north Monday morning resulting in more showery precip during the day that is focused by a cold front passage. Most deterministic model guidance tracks front across the east-central UP near peak heating indicating potential for another round of thunderstorms. Model soundings show a stout inversion and extensive stratus that prevents destabilization, but there may still be sufficient elevated instability for a few rumbles of thunder.

While surface temperatures don't change much during the day on Monday, 850 mb temps cool from ~11C to around ~0C Monday night. This CAA causes the ~1 kft stable boundary layer inversion to become unstable and deepen to 3-4 kft across the west half but wind speeds remain light. Tuesday looks like a dry day between systems with warm air advection allowing temps to increase up to around 70F across the interior. Model guidance indicates potential for mixing up to 4-5 kft and fairly dry conditions, but several days of rain should keep fire wx concerns in check. The next system moves into the area Tuesday night with a ~50 kt low level jet bringing another wave of rain with a chance for a few embedded thunderstorms. Arguably the more hazardous aspect of this system is the surge of dry air downsloping off the Rockies behind the cold front leading to potential for strong west winds on Wednesday. At this time, 10-20% of EPS members have peak wind gusts around 50 mph on Wednesday so it's a low probability hazard. However, if diurnal timing of strong mid-level winds lines up with peak heating then I'd expect those probabilities to increase. Otherwise, we're between systems on Wednesday into Thursday leading to dry weather and some potential for fire wx concerns, but recent rainfall should keep that threat in check.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
Issued at 136 AM EDT Sat Apr 27 2024

Shra will be overspreading the area overnight as low pres approaches. Might be thunder as well, but confidence is low on whether IWD/CMX/SAW will be affected, so mention was not included in fcst. Expect a transition to MVFR in the 06-09Z time frame with higher confidence now in further deterioration to IFR after 12Z. A period of LIFR also cannot be ruled out from late morning through the afternoon, but that is lower confidence. Slight improvement to MVFR will be possible by this evening, but that will be best case scenario. Meanwhile, LLWS will be a threat at all TAF sites in the 06-18Z time frame due to an associated low-level jet. And, strong southeasterly surface winds (becoming west-southwesterly) this afternoon will gust to 28 kts. Eventual wind direction will be northwesterly by this evening.

MARINE
Issued at 506 AM EDT Sat Apr 27 2024

Southeasterly winds across the eastern lake and northeasterly winds across the western lake are gusting to 20-30 kt early this morning.
A few gale force gusts to 35 kt are possible this morning near the tip of the Keweenaw and between Michipicoten Island and Whitefish Point. A low pressure tracks across western Lake Superior today resulting in generally easterly winds this morning becoming westerly behind the low. Modest pressure rises and cold air advection indicates an isallobaric component amidst good mixing leading to potential for a few northwesterly gale force gusts to 35 knots across the north-central and eastern portions of the lake. Winds back northeasterly late tonight and Sunday as the next system approaches from the southwest. Northeast gales up to 45 kt are possible across the far western lake by Sunday afternoon with easterly gales to 40 kts possible across all but the far eastern lake Sunday night and Monday morning. Gales quickly diminish Monday afternoon as the low pressure tracks across western Lake Superior Monday night. While no other gales are currently forecast, another low pressure passage Tuesday night into Wednesday could bring a period of gusty west winds approaching gale criteria.

During the gale event, waves will be highest from Duluth Harbor to the Bayfield Peninsula, with significant wave heights up to 14 ft possible Sunday evening. Wave heights will also be high Monday morning around Isle Royale at up to 13 ft. Waves across the lake fall below 8 ft Monday evening. There are also several chances of thunderstorms across portions of Lake Superior 1) through this evening, 2) on Monday, and 3) Tuesday night.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
None.
Lake Superior...
Small Craft Advisory until 8 PM EDT this evening for LSZ246- 249>251.

Gale Watch from Sunday morning through Monday morning for LSZ162.

Gale Watch from Sunday evening through Monday afternoon for LSZ242>246-264>266.

Small Craft Advisory until 11 PM EDT Sunday for LSZ244-245.

Small Craft Advisory from noon today to 8 PM EDT this evening for LSZ247.

Small Craft Advisory until 10 PM EDT this evening for LSZ248.

Gale Watch from Sunday afternoon through Monday afternoon for LSZ263.

Lake Michigan...
Small Craft Advisory until 8 PM EDT this evening for LMZ221.

Small Craft Advisory until 5 AM EDT Sunday for LMZ248-250.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


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

Marquette, MI,