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Office: MQT

FXUS63 KMQT 170519

Area Forecast Discussion
National Weather Service Marquette MI
119 AM EDT Wed Aug 17 2022

.SHORT TERM...(This evening through Tonight)
Issued at 139 PM EDT TUE AUG 16 2022

The GOES 16 Day Cloud Phase Distinction RGB shows a diurnal cu field
developing from east to west across UP early this afternoon as high
pressure slowly moves eastwards in the wake of a low pressure near
Angle Inlet slowly nudging towards the Upper Midwest. With high
pressure remaining over the area this afternoon, expect another
repeat of yesterday, albeit with temps a couple of degrees warmer.
Moving into the overnight hours, a cloud deck begins to slowly move
into the western UP, with a few showers and a couple of
thunderstorms becoming possible over the far west late tonight. In
addition, the central and east may see some patchy fog develop late
as high pressure remains over the eastern half, bringing another
near repeat of last night. Lows tonight should be warmer (think low
50s) in the western half as cloud cover moves in late; they should
be about the same as they were last night in the eastern half.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 319 PM EDT TUE AUG 16 2022

The pattern for the upcoming week is characterized by downstream
broad troughing and upstream ridging over the Pacific Northwest and
northern Rockies. This will position the Upper Great Lakes in
northwest flow aloft through at least Friday. At the surface,
ridging extending out of a high up near James Bay followed by a
secondary high developing over the forecast area on Wednesday will
keep the forecast area mostly dry for through mid-week. Thereafter
an upper level low will cut off from the flow, slowly meandering
through the midwest into the upcoming weekend. This will bring
precipitation chances back into the area.

Models are not very consistent with the placement and progression of
the cut off low. Diurnally driven showers and thunderstorms can be
expected into the weekend with weak instability but little in the
way of convective inhibition. Thus we should expect mainly afternoon
and evening scattered showers and non-severe thunderstorms with the
main threat being heavy rain due to weak steering flow and
precipitable water values of around 1.25". Should the low take a
more favorable track the precipitation could be a bit more
organized and widespread at times.

High temps in the period look largely to top out in the 70s, to near
80 in some spots. Overnight lows look to be mostly in the 50s away
from the lakeshores, and low 60s to upper 50s by the lakeshores.

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 119 AM EDT WED AUG 17 2022

VFR conditions and winds at or below 7 knots will prevail through
the forecast period. Dry air over the region will inhibit
precipitation development over the western Upper Peninsula later
this afternoon as BUFKIT soundings quite dry through the afternoon.
KIWD will have a chance to see some shower activity in the latter
portion of the forecast, and have pushed the initiation of the
showers back from morning to the afternoon with VCSH. A better
chance for showers will occur at KIWD after 0Z this evening. More
uncertainty with precipitation at KCMX, so will just mention VCSH
there for late afternoon and evening. KSAW being under the deeper
drier air will stay dry through the forecast.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 319 PM EDT TUE AUG 16 2022

Winds will be below 20 kts throughout the forecast period. Dense fog
and thunderstorms will be a threat from Wednesday through the
weekend as a low pressure system tracks through the Lower Midwest.
The best chances for thunderstorms will be over the western and
central portions of Lake Superior during the afternoon hours.

Upper Michigan...
Lake Superior...
Lake Michigan...



Office: DTX FXUS63 KDTX 170457 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1257 AM EDT Wed Aug 17 2022 .AVIATION... Clear-Mostly clear skies and very light winds for the rest of the night. With dew pts still hovering in the upper 50s to around 60 degrees, there is a low chance for fog development just before sunrise. Diurnal weak instability will then build through the day, but mid levels will be slightly warmer, and thus probably looking at more showers than thunderstorms. Even so, not enough confidence to mention a shower in any particular taf site tomorrow afternoon, and will even keep skies just scattered. Brief periods of BKN possible however, but cloud bases at or just above 5000 feet. .DTW THRESHOLD PROBABILITIES... * None. && .PREV DISCUSSION... Issued at 243 PM EDT Tue Aug 16 2022 DISCUSSION... Broad upper-level closed low will continue to meander across New England through Thursday while an upper-level ridge remains situated over the western CONUS. Western fringe of the upper-level low has ushered in cold temperatures aloft for mid-August standards, with h500 temperatures sitting around -15C. Rapid surface heating with much cooler temperatures aloft supports a healthy cumulus field with RAP/SPC mesoanalysis guidance suggesting around 300 J/kg MLCAPE now holds over SE MI, with localized higher amounts closer to the Thumb. Most locations are expected to remain dry today, but some pockets of better cumulus congestus remains possible with the modest CAPE, producing isolated showers or storms. This has already been observed over Tuscola and northern Genesee Counties this afternoon. Development along a lake breeze/new outflows will also be a focal point for activity through the evening. Cloud cover, and subsequently precipitation chances, will diminish after sunset where overnight lows drop into the mid to upper 50s. A persistence forecast is in play for Wednesday with temperatures again reaching into the upper 70s to lower 80s for a daytime high. Strong low-level lapse rates will promote a healthy cu field by the afternoon while some slightly better moisture brings a little higher MLCAPE values. This will bring a renewed chance for isolated showers/storms, especially along lake breezes, during the afternoon and evening hours. Rain/Thunderstorm chances will again end after sunset, with overnight lows dropping into the mid to upper 50s. An upper-level wave observed in water vapor imagery across southern British Columbia is projected to ride into the northern Plains along the periphery of the upper-level ridge which will strengthen and drop into the Midwest towards the end of the week. The upper-level closed low over New England will exit the states northeast as a result, as trough amplification takes place upstream. Upper-level flow briefly becomes more zonal across the Great Lakes late Thursday with a brief shortwave ridge setting up on Friday, pending the strength of the upstream trough. Unfavorable large-scale dynamics along with a better push of temperatures setting up a cap near h700 will limit rain chances for Thursday and Friday. Once the trough (and possible development of an upper-level low) starts to push into and move over the Great Lakes by late Saturday, rain and thunderstorm chances turn increasingly likely through early next week. MARINE... A strong area of high pressure (for Summer Standards) anchored over Eastern Canada through Wednesday will maintain light northeast winds over the Central Great Lakes, generally holding in the 10 to 15 knot range. Some gusts around 20 knots are expected through the afternoon over Saginaw Bay, as the land over southern Lower Michigan heats up to around 80 degrees. The high will weaken over the end of the work weak, allowing winds to weaken further and becoming light and variable. Isolated showers are likely both this afternoon and Wednesday afternoon with the heating of the day and some semblance of an inverted surface trough. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....SF DISCUSSION...AM MARINE.......SF/SS You can obtain your latest National Weather Service forecasts online at
Office: APX FXUS63 KAPX 170349 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 1149 PM EDT Tue Aug 16 2022 .UPDATE... Issued at 929 PM EDT Tue Aug 16 2022 The considerable amount of deep convection seen earlier (at least in the se third of the forcast area) has waned. Radar returns are gone, and what's left of the cu field in the southern zones is shriveling fast. Mainly clear skies are progged for tonight, and little change is needed there. The rain-cooled and rain-moistened airmass in s central and se portions of the CWA will be prone to fog. W Branch already has some. Will broaden/expand the mention of fog in these areas. Given surface dew points are running pretty high (50s to around 60f), have boosted min temps a smidge. && .NEAR TERM...(Through Tonight) Issued at 254 PM EDT Tue Aug 16 2022 High Impact Weather Potential: Minimal. Pattern Synopsis: Closed upper-level low over New England with broad longwave upper ridging across the western/central CONUS. High pressure east of James Bay with a ridge axis extending southwest across the northern Lakes into the Midwest. Primary Forecast Concerns: Shower and thunder chances through early evening, patchy fog development and low temperatures. Diurnal cu fields will dissipate rapidly this evening with loss of daytime heating. A few showers/thunderstorms through late afternoon or early evening across interior northern lower mainly south of M-72. This activity focused largely within a mid level theta-e ridge positioned up the spine of the higher terrain in northern lower with MUCAPES around 500 j/kg. Otherwise, a near carbon copy of last night weatherwise. Clear skies with some fog developing - especially across eastern Upper Michigan. Across northern lower, less fog but still some patchy ground fog in low lying areas. Low temperatures dropped below guidance in some areas last night and we will likely see a similar set-up tonight. This results in some mid/upper 40s across interior low lying areas with 50s elsewhere. && .SHORT TERM...(Wednesday through Friday) Issued at 254 PM EDT Tue Aug 16 2022 High Impact Weather Potential: Low Pattern Synopsis: A closed upper-level low will continue to pivot over New England through Thursday before departing up the coast on Friday. Amplified ridging will hold across the western half of the CONUS through the end of the week. A shortwave is expected to dig from Canada into the Great Plains Thursday into Friday, providing enough forcing aloft to generate a broad, relatively weak surface response across the Midwest heading into the weekend. Forecast Details: A few showers may pop up across the lower peninsula Wednesday afternoon, similar to today. Forecast soundings for Wednesday display an environment that is similar as well: dry low levels, but fumes of instability should be in place. Any healthier activity that precipitates may struggle to reach the ground with the aforementioned dry air beneath the cloud layer. The potential for a few rumbles of thunder cannot be ruled out, but is being excluded from the forecast at this time due to the lack of confidence. Additional light showers will be possible on Thursday and Friday. Otherwise, calm winds and clear skies will make for a chilly night across interior portions of the area Wednesday night as lows look to drop into the 40s away from the lakeshores. Similar lows are expected Thursday night as well. High temperatures in the low to mid 80s are expected through the end of the week. .LONG TERM...(Friday night through Tuesday) Issued at 254 PM EDT Tue Aug 16 2022 High Impact Weather Potential: Low A relatively weak wave will meander over the Midwest and Great Lakes through the weekend as broad area of low pressure follows suit. This system will bring the next main chances for rain to northern Michigan, primarily Saturday night through the end of the weekend. Heavy rainfall is not anticipated, but showers on Sunday could bring totals around a quarter to a half inch to some areas south of the bridge by Monday morning. Light rain chances may linger through Monday, but will continue to decrease through early next week. Otherwise, highs in the low to mid 80s on Saturday are expected to cool a few degrees after the system passes east of the region. Afternoon highs in the mid 70s are anticipated to start next week, which is close to average heading into the end of August. Lows in the 50s look to continue through the forecast period. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1149 PM EDT Tue Aug 16 2022 High pressure is just to our north, contributing to ne flow in the region. Mostly clear skies tonight. Some fog is possible, with the best chance for persistent fog at CIU (MVFR conditions in the TAF for now). Wednesday should be somewhat similar to today, with a chance for SHRA in the interior of northern lower MI. These are not expected to pester the TAF sites, though we will have a cu field. Light winds. && .MARINE... Issued at 254 PM EDT Tue Aug 16 2022 Winds/waves are expected to remain below Small Craft Advisory criteria as generally light northeast winds dominate through midweek. Some lake breeze development during the afternoon hours each day may turn winds more northerly in some areas. Beyond Wednesday, generally impact-free conditions continue before more active weather arrives this weekend. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JZ NEAR TERM...JK SHORT TERM...DJC LONG TERM...DJC AVIATION...JZ MARINE...JK
Office: GRR FXUS63 KGRR 170506 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 106 AM EDT Wed Aug 17 2022 LATEST UPDATE... Aviation .DISCUSSION...(This evening through next Tuesday) Issued at 244 PM EDT Tue Aug 16 2022 ...Risk for a few showers/storms this evening... Surface and 100 mb mixed layer instability has developed this afternoon...mainly east of of a line from KMOP to KJXN. A few showers and thunderstorms have developed in this region. They were drifting southwest with time. The forecast instability for the remainder of the afternoon into the evening suggests that the instability will struggle to build west. Aloft a weak shortwave was noted over eastern Lower MI. That feature is predicted to remain there through sunset. We will hold onto a low risk for showers and/or a storm mainly for eastern zones into this evening. Along the lake breeze near Little and Big Sable Points a second area of instability has developed. PWAT values are lower over the western parts of the moisture may be a limiting factor for storm development there. However...there may be enough ingredients there to lead to a shower or storm along the lake breeze. ...Increasing chances for Showers/Storms over the weekend... A series of mid level waves drop in from the northwest over the weekend. As a result we see steady height falls during this time. At the same time...PWAT values are shown to climb up to around 1.5 inches by Sunday. Down low...a warm front is indicated near Kalamazoo and Jackson during the day on Sunday. Also on Sunday...models are showing a 250 mb speed max just south of the MI border which is shown to track east during the day. Upper level diffluence is noted here in MI. So given all the above ingredients...we will feature the highest pops of the period on Sunday. Deep layer shear is not supportive of severe weather impacts if any would be hydro related. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 106 AM EDT Wed Aug 17 2022 Confidence is high for another 24-h period of VFR conditions at all terminals. Daytime cumulus development should again yield isolated SHRA after 19z, but coverage should be more limited than on Tue, as suggested by latest convection-allowing model guidance. Accordingly, have included VCSH at LAN/JXN only. Any SHRA that develop will move toward the SSW at 10-15 kts. A modest lake-breeze boundary will likely develop today along Lake Michigan and advance inland during the late afternoon into early evening, as shown in recent high-resolution guidance (namely the HRRR). The associated wind shift is accounted for in the MKG/GRR TAFs, although the timing at GRR is somewhat uncertain. Winds are expected to become light and variable at all terminals after sunset as a surface ridge axis settles over the region. && .MARINE... Issued at 244 PM EDT Tue Aug 16 2022 The pressure gradient will remain relatively weak with a general offshore flow. Thus the risk for impacts looks low into Thursday. South winds do increase Sunday...but even then the risk for winds over 20 knots looks low. As a headlines are planned through the period. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ DISCUSSION...MJS AVIATION...Kenyon MARINE...MJS