Area Forecast Discussion
Issued by NWS Gaylord, MI
Issued by NWS Gaylord, 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
957 FXUS63 KAPX 110718 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 318 AM EDT Sat May 11 2024 .KEY MESSAGES... - Showers today, gradually diminishing w to e. Clouds somewhat slower to clear late today/tonight. - Patchy frost possible late tonight. - Rain chances increase later Sunday/Sunday night. - Some frost potential Tuesday morning? && .SHORT TERM /THROUGH TONIGHT/... Issued at 317 AM EDT Sat May 11 2024 Synopsis/pattern: A digging shortwave will close off over northern lower MI this morning. Surface cyclogenesis is underway, with a 1004mb low over nw lower MI. This system will somewhat slowly work across northern lower MI and Lk Huron into this evening. Forecast: Wet weather is expected across northern MI early today, but with slow but gradual improvement from w to e during the day and evening. Showers are gradually progressing eastward across the forecast area early this morning. Somewhat surprisingly, a few embedded t-storms developed since midnight, from the ACB-GLR area down to Rose City and Gladwin. Cold mid-level temps and reasonable forcing are able to take advantage of meager MuCape values of around 100j/kg. A few additional t-storms are possible thru midday, mainly in ne lower MI. As the mid-level low center closes off, deformation around the north flank of the low will increase. This process is resulting in the banded precip seen over the east half of upper MI. This will progress se-ward into far n central lower MI and then ne lower MI today. Sneakily healthy QPF will result; total rainfall will exceed 0.50" across a good chunk of ne lower MI, and especially near APN. Back edge of precip will make gradual eastward progress. MBL is done by mid-morning; TVC and Naubinway by early afternoon. Things slow after that; the I-75 corridor isn`t done until almost evening, and the ne lower MI coast waits until almost midnight. Highs today will be cool as a result...near 50f to the mid 50s. Clouds will also be slower to clear heading into tonight; something of considerable interest for potential aurora viewers, but also for agricultural interests. Skies may not clear in TVC until mid-late evening, and along I-75 until around or shortly after midnight. Our window for radiational cooling is thus somewhat small, as clouds will increase again into nw lower MI toward morning. In fact, a few showers could return toward dawn near Lake MI. Min temps remain progged down into the mid 30s to lower 40s. Frost (and fog) potential continues across a broad portion of the interior. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 317 AM EDT Sat May 11 2024 Pattern Forecast: Mean long wave trough across eastern North America with a train of short waves lining up back across the northern Pacific...and split flow over the western U.S. with an upper low over the Great Basin. As one short wave trough moves through the upper Great Lakes tonight/Saturday...a second currently over western Canada will propagate east as it wraps up into a small closed circulation near James Bay on Monday. By Tuesday the Great Lakes will likely be in between the northern branch upper low which will take its time passing James Bay...and the southern branch wave which as of now is expected to remain well south of Michigan. More short wave troughing may be on the way by Thursday. Northern branch short wave trough heading across Canada this weekend...while most of the main dynamics/height falls will remain well to the north...will push a cold front into the upper Midwest early Sunday and across northern Michigan Sunday night/early Monday. This front may become stationary over Lower Michigan Monday as it loses its upper level impetus (becoming the warm front for southern branch surface cyclone eventually?). High pressure expected to ridge in from the north for Tuesday/Wednesday. Primary Forecast Concerns: Rain chances increase later Sunday/Sunday night: Strong low/mid level warm advection/isentropic ascent spreads into northern Michigan Sunday morning...though accompanied by short wave ridging aloft so wondering about the vertical motion profile (is it "bottom heavy"). Strength of isentropic upglide suggests that negative PV advection and "sinking" isentropic surfaces won`t offset the upward motion much if any. The only thing this impacts is precipitation timing during the first half of the day...will nudge PoPs up a bit Sunday morning in line with the SREF guidance which bring measurable precip chances to the I-75 corridor by midday. Later Sunday afternoon/night stability weakens with arrival of low level theta-e ridge and cold front so precipitation chances expected to be more prevalent (along with thunderstorm chances). Rain may come to an end across eastern Upper after midnight. Shower chances lingering near Saginaw Bay Monday?: This all hinges on where the cold front ends up as it stalls at least in the vicinity of the US-10 corridor. Simply from a probabilistic/ uncertainty standpoint should keep some low PoPs around Gladwin/ Arenac counties (at least) as convection should bubble up along the boundary during the afternoon and could sneak into there. In addition...deformation precipitation band along the confluent northern side of the southern branch wave moving into the mid Mississippi Valley may get a little close for comfort as well again to areas adjacent to Saginaw Bay. Some frost potential Tuesday morning? Minimal probabilities for now: Just going to leave this here for now as something to consider later...cooler air settles in behind the cold front but questions about wind and extent of cloud cover across Lower Michigan. Frost probabilities right now based on temperature probability of exceedance is less than 25 percent. Dry into midweek: As long as northern edge of above mentioned precipitation shield remains south of the forecast area...high pressure ridging in from the north and resultant north/northeast boundary layer flow should result in dry weather for Tuesday and Wednesday (and temperatures generally near normal). Rain chances for Thursday and Friday. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1138 PM EDT Fri May 10 2024 Band of MVFR to IFR producing low clouds and visibility restricting showers will continue to slowly spread west to east across the taf sites this morning. Some slow improvement expected across western taf locations as we head through this afternoon, with more rapid improvement this evening. No significant wind concerns through the period. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ SHORT TERM...JZ LONG TERM...JPB AVIATION...MSB