Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
131 FXUS63 KMQT 182320 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 720 PM EDT Tue Jun 18 2024 .KEY MESSAGES... -Showers and thunderstorms possible tonight, particularly over the far west. Some severe weather is possible over the far west. -More showers and thunderstorms possible for the latter half of this week. -Potential heavy rain event this weekend. && .SHORT TERM /THROUGH TONIGHT/... Issued at 242 PM EDT Tue Jun 18 2024 A scattered cu deck has formed over the western half this afternoon whereas the eastern half is mostly cloud free as strong southerly winds off of Lake Michigan are helping to stabilize the air a little. Observations have already shown temperatures reaching the 80s across much of the area, with some spots such as Ontonagon and L`Anse already getting to 90+F. Meanwhile, a shortwave low moving through MN is continuing to lift along a cold front boundary over the area. As the cold front continues to move eastwards into our area tonight, expect showers and thunderstorms to move into the far west before midnight local time. We could see some severe hail and winds come this evening as the convection moves into our western area, as models show MUCAPEs in the 1k-3kJ/kg range and shearing very high in the lowest levels of the atmosphere as a low-level jet screams across our area. In addition, the hodograph and LCL levels are supportive of a very small chance (<5%) for an isolated tornado late tonight. However, with CAMs showing a lot more of the convection dying than previously anticipated, the severe weather potential looks to be relegated to the far western U.P. as the cells die and collapse (similar to how we saw the severe winds over the eastern U.P. yesterday afternoon). Given the sharp drop in precip chances as the cold front moves eastwards tonight, I`ve reduced the chances across the central and eastern U.P. to chance wording (30- 40%). However, this may need to be lowered further as the most recent CAMs seem to amplify the lack of rainfall late tonight. && .LONG TERM /WEDNESDAY THROUGH TUESDAY/... Issued at 354 PM EDT Tue Jun 18 2024 Light rain showers and maybe a stray thunderstorm or two could pop- up over the central and east Wednesday as the cold frontal boundary slowly stalls out. With CAMs showing only scattered light convective coverage continuing over the central and east on Wednesday, expect precipitation amounts to be light. By Wednesday evening, expect the rain showers and thunderstorms to generally be finished over the area. That being said, as the flow becomes zonal across our area by Wednesday night and Thursday, we get weak ridging that sets up over Lake Superior. At the same time, weak troughing looks to set up over Wisconsin. With the ridging and inverted troughing fighting one another around our south central, we could see some rain showers continue across this area, as well as a few thunderstorms. As warm frontogenesis starts to develop over our area late this week, the rain chances begin to crawl northwards across the rest of the U.P. late Thursday into this weekend. We could see some heavy rainfall come late this week into early this weekend along the strengthening warm front, as ensembles show PWATs near the max of modeled climatology (nearly 2")! With training very possible along the front given it`s slow movement northwards, we may need to keep an eye on flooding concerns across our area, particularly over the west half where the higher rainfall amounts are currently predicted. Once the low creating the warm frontogenesis moves through Lake Superior Saturday afternoon, expect a break in the rainfall before a secondary Clipper low moving over our area Saturday night and Sunday brings rainfall chances back across our area. Moving into early next week, expect ridging and finally some drier weather as a high pressure moves from the Plains through the Midwest. Overall, expect temperatures to be near normal for the extended period, with some days showing below normal high temperatures (such as Thursday, Friday, and Sunday). Outside of the rain and storm chances throughout the next week, the only other thing worth mentioning is the possibility for localized river flooding along the Chocolay River near Harvey. With much of the basin having received between 2 to 3.5 inches of rainfall over the past 24+ hours, and the Observation Program Leader having gone out to the Chocolay near Yelden (around Skandia) and seeing the river already up to the bridge, there may be some isolated spots along the river near Harvey that could see some river flooding issues that are more typical to the Spring-time (water in basements, etc.) This situation will continue to be monitored by the staff here at WFO MQT, as well as the NCRFC while the water from the recent rainfall slowly exits the Chocolay River Basin into Lake Superior. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 720 PM EDT Tue Jun 18 2024 Shra/tsra ahead of an approaching cold front will reach western Upper MI this evening then weaken thereafter. Over about a 1-2hr period, IWD/CMX will be impacted with gusty winds to 35+kt and MVFR to IFR. LLWS will follow the storms. Cigs at IWD/CMX will fall to MVFR/IFR around the time of fropa late night, then will improve to VFR early Wed aftn. At SAW, confidence is lower that any shra/tsra will reach the terminal. Only VCTS and VCSH were included in fcst. LLWS will also develop at SAW this evening. Expect a period of MVFR cigs at SAW Wed morning with VFR for the aftn. && .MARINE... Issued at 421 PM EDT Tue Jun 18 2024 Southerly winds of 20 to 30 knots across the southern nearshores and over the eastern lake this afternoon, with a few gale force gusts up to 35 knots possible along the shoreline from Marquette to Whitefish Point, weaken tonight before southwesterly winds of 20 to 30 knots moves across the western half of the lake late tonight into Wednesday morning as a LLJ passes through. Winds weaken to 20 knots or less again by Wednesday as ridging builds in over Lake Superior behind the decaying cold front boundary. The light winds look to remain over Lake Superior until possibly Saturday and again Sunday, when a Colorado low lifts through the lake in the afternoon and a secondary Clipper follows behind it, respectively. The other mentionable hazard over Lake Superior for the next several days is thunderstorms, particularly this evening over the west as some severe weather is possible. Some large hail, damaging and erratic winds, and an isolated waterspout are possible over the western lake this evening. As the thunderstorms move into the central and eastern lake late tonight, the severe weather threat dissipates, with the thunderstorm activity diminishing as well. Thunderstorms are still possible over the eastern lake Wednesday until the evening hours. Thunderstorms do become possible again Friday as a warm front lifts into the area. The thunderstorm activity could continue until after the low passes through Saturday afternoon. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ014. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...TAP LONG TERM...TAP AVIATION...Rolfson MARINE...TAP