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Office: MQT

FXUS63 KMQT 180522

Area Forecast Discussion
National Weather Service Marquette MI
1222 AM EST Sun Nov 18 2018

.SHORT TERM...(This evening through Sunday)
Issued at 215 PM EST SAT NOV 17 2018

Upper air pattern consists of a 500 mb ridge off the Pacific NW
coast, a broad trough across most of the U.S. and a shortwave in the
northern Rockies this morning. This shortwave moves east into the
upper Great Lakes by Sunday morning. 850-500 mb q-vector convergence
moves into the area on Sun. With westerly winds as well and a front
moving into the area, there will be some low level convergence in
the afternoon that will help to focus a heavier lake effect snow
band somewhere across the Keweenaw Peninsula and could see up to 7
inches of snow with this for Sunday with the majority of it coming
Sunday afternoon. Hard to pin down where this will set up exactly,
so best bet right now is to put out a special weather statement to
highlight this possibility of a quick couple inches of snow Sun
afternoon across the Keweenaw. No real big changes to the going
forecast overall. Multi-lake effect snow bands will continue to
slowly wind down as the wind becomes more westerly this afternoon.

.LONG TERM...(Sunday night through Saturday)
Issued at 303 PM EST SAT NOV 17 2018

Main attention in the long term is Sun evening into Mon. Main
concerns during this time are a potentially heavy LES band over the
Keweenaw and into the far northeastern U.P. Sun evening, a shortwave
bringing a quick accumulation of snow Sun night into Mon morning,
then N-NW wind LES Mon into Mon night.

The location of that heavy LES band of the Keweenaw will be
difficult to forecast, but with W winds it should be somewhere S of
Houghton. A surface trough moves in from the W later Sun evening,
which will break up the band. SPS was issued to address concerns
with this.

A shortwave moving through Sun night into early Mon will bring
widespread light, but quick, snow accumulations. Could see around 2"
of snow in just a few hours, which will fall up to or during the
morning commute central and east. Shouldn't be too impactful, but
may need an SPS as it nears given the timing with the commute.

Cool air moves in later Mon into Mon night, but so does dry surface
high pressure from the NW. This will lead to an increase in LES in
the N-NW wind snowbelts Mon evening, but the dry air will diminish
that Mon night.

Winds turn southwesterly as LES enhances Tue afternoon and evening
as a shortwave and surface low move in from the NW. This could favor
the Keweenaw for moderate to heavy LES if winds are just right. Will
have to monitor as the event nears.

Looks like a pattern change is in the works for later next week,
with potential for warmer temps and mixed precip late in the week.
Still lots of uncertainty with many details, especially since models
have been struggling to handle pattern changes at that time frame

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1222 AM EST SUN NOV 18 2018

A band of Lake Effect snow will plague KCMX through the forecast
while KSAW will remain VFR. KIWD will stay VFR through much of the
forecast until snow moves into that area late in the forecast,
bringing periods of MVFR ceilings. But KCMX is the location with the
main impacts from this band, where periods of MVFR ceilings and
visibilities overnight and Sunday are expected. Depending upon
exactly where the most intense portion of the band sets up, KCMX
could see a period of IFR ceilings and visibilities, but at this
time any potential lower restrictions are expected to be south the

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 215 PM EST SAT NOV 17 2018
Looks like there could be a very brief gale event late tonight for
only three hours for part of western Lake Superior in zone 263 i n
the shipping lane only, but the area is small enough and brief
enough to cover with occasional gale gusts to 35 knots from the west.
This small gale event is really the only gales seen in the forecast
period with winds staying below 30 knots for the rest of the
forecast period.

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



Office: DTX FXUS63 KDTX 180430 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1130 PM EST Sat Nov 17 2018 .AVIATION... Predominant cigs to start the night should range lower VFR with occasional MVFR I-94. I-94 corridor then will see lowering cigs early Sunday morning as light snow in fgen forcing lifts just into the region. It appears mvfr/-sn will persist into late morning before shifting off the the east. While most persistent snow will focus on I-94 terminals, a period of 5-6sm -sn will be possible as far north as KPTK. Cigs will edge back up to lower VFR and even scatter out further north at KFNT and especially KMBS. For DTW...Flurries are expected to lift back into terminal with fgen by 09z-11z w/ light snow...vsbys 2-4sm...persisting Sunday morning. MVFR cigs can be expected at that time, but improve back to lower VFR by midday once the disturbance initiating the fgen forcing passes. .DTW THRESHOLD PROBABILITIES... * High for cigs aob 5kft. * High for ptype of SN Sunday morning. && .PREV DISCUSSION... Issued at 300 PM EST Sat Nov 17 2018 DISCUSSION... Unrelenting pattern characterized by well below normal temperatures and episodic light snow potential will continue right through the early week period. An inconsequential area of light snow/flurries ongoing this afternoon will gradually contract in scale across southern sections as existing forcing wanes with time through early evening. To the north, recent satellite and radar trends suggest a window remains for some pockets of light lake effect snow showers to drift into the saginaw valley and thumb through the evening hours. Little to no accumulation expected going forward through early tonight. Cold frontal boundary sags southward into the Ohio valley this evening, before stalling tonight as the frontal slope becomes parallel with the mean flow. West to east elongated axis of modest mid level fgen will emerge along the boundary in the presence of favorable right entrance region upper jet support during this time. Slight northward drift of this ascent across the 700-600 mb frontal slope residing locally will provide a brief window Sunday morning for light snow to develop across the Ohio border region. Both the placement and magnitude of this forcing still carries some uncertainty, but areas generally south of the I-94 corridor appear more favorably positioned now to witness a period of light snow. Accumulation potential within the one half to one inch range across portions of Lenawee/Monroe counties, with a much lower likelihood of seeing any accumulation up into the I-94 corridor. Conditions Sunday otherwise governed by the presence of weak high pressure, with a corresponding lack of meaningful thermal advection solidifying yet another day of well below normal daytime temperatures. Highs mid- upper 30s. Additional shortwave energy digging into the existing mean trough will provide another round of strong height falls for the early week period. Lead edge of this amplification process will drive a cold front into the region late Monday into Monday night. Brief pre- frontal window Monday for modest thermal recovery under developing low level southwest flow. The temperature response likely muted though by the high degree of cloud cover, ensuring daytime readings remain well below average. Increase in low-mid level ascent as the frontal boundary and shortwave lift through will provide at least a chance of snow Monday night. Snowfall potential carries strong reliance on defining the placement of the best mid level dynamics tied to the main pv feature and attendant upper jet axis, with current model projections suggesting a greater chance exists over northern lower MI. A strengthening thermal trough and persistent cloud cover will bring colder temperatures to Michigan by Tuesday as highs only peak in the upper 20s to lower 30s followed by lows in the 20s. Flow will turn more zonal late Tuesday into early Wednesday which will help moderate temperatures as warmer westerly flow fills in, allowing highs to peak in the mid to upper-30s as h850 temperatures climb from an average of -12C to -5C. The back edge of a second thermal trough will filter in late Wednesday to Thursday and will return h850 temperatures back down to an average of -13C, once again capping highs in the low to mid-30s. Confidence remains high regarding a pattern shift during the late- half of next week as moves across the Plains late Thursday into Friday and strengthens across northern TX/southern OK, strengthening a ridge across the eastern states. Surface high pressure centered across the Great Lakes into Ontario will bring extended periods of sunshine Thursday into Friday and will aid in increasing temperatures Friday into the weekend as anticyclonic flow takes hold when the high pressure travels east into New England. The warm-up will be marked by h850 temperatures increasing to 0-4 C Friday into the weekend and will translate to daytime highs peaking in the mid- 40s starting Friday. The ECMWF and associated MOS guidance is less aggressive with waa next weekend, so opted to not increase highs into upper-40s per yesterday's discussion. Negatively-tilted shortwave trough and weak cold front will bring the chance for precipitation throughout Saturday. If the trough moves in early enough, a chance to see a wintry mix will be possible, however, confidence is too low to at this time to discern precipitation type. MARINE... A tightening pressure gradient between high pressure and an area of low pressure tracking across southern Hudson Bay will lead to gusty winds over northern and central Lake Huron Sunday, with gusts of 20- 30 knots common. Moderate southwesterly flow will continue to linger through the early week period with broad high pressure in place. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....DG DISCUSSION...MR/AM MARINE.......JVC You can obtain your latest National Weather Service forecasts online at
Office: APX FXUS63 KAPX 180823 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 323 AM EST Sun Nov 18 2018 .NEAR TERM...(Today through Tonight) Issued at 319 AM EST Sun Nov 18 2018 High impact weather potential: Minimal. Pattern synopsis and forecast: Large/broad scale upper level troughing was seen across all but the west coast early this morning, with one sheared out shortwave pressing into the Central Plains and Southern Rockies, and another one associated with a cold front pressing into Ontario. At the sfc, high pressure in the heart of the country extended through the Great Lakes and into much of the Atlantic coast. Satellite, RUC analysis and radar all showing the dry air associated with this high pressure. Radar returns in WSW low level flow was weak to say the least (dry near sfc air and inversion heights between 3.5-4.0kft), and skies were clearing outside this flow regime. Temperatures have plummeted where it has cleared, with many areas in the single digits to teens. The sfc high pressure and dry air will sag south today, while the Ontario shortwave works it's way toward Quebec. This shove it's cold front southward and into Lake Superior. The WSW low level flow will continue to provide some very light fluffy snows into at least this morning, but fcst soundings suggest that the dry air may end the white stuff (I'll believe it when I see it). Low level winds veer more west heading into this evening, with still not much in the way of weather. However, the cold front itself will be associated with a band of snow, which drops into Chippewa county by late this evening. This could be an impressive "Snow Squall", as it does start to get enhanced by deepening moisture ahead of an incoming shortwave. Inversion heights climb to 6-6.5kft, and there is plenty of overlake instability. At the same time, hi-res data even suggesting that another area of low level convergence develops from far nrn lower Michigan through far nrn Lake Huron. The LES environment isn't as impressive as up in Chippewa county, but another band of snow is certainly possible. The shortwave and weak sfc reflection themselves will bring system snow, driven by DPVA and WAA, but the total deep layer -divQ does look to be weakening heading through the overnight hours. Minimal snowfall today, but starting late tonight (and through Monday), we may need a winter weather advisory for a handful of counties across far northern/NW lower Michigan. Can see 1-2 inches there, and around Whitefish Point in Chippewa county. Highs today will be in the upper 20s in eastern upper, to the lower half of the 30s in nrn lower. Lows tonight will probably occur in the evening, as the skies thicken in clouds through the night, stabilizing the temperature drop. Readings will generally be in the teens to lower 20s. && .SHORT TERM...(Monday through Tuesday) Issued at 319 AM EST Sun Nov 18 2018 High Impact Weather Potential: Accumulating snow Monday. Cyclonic flow within low amplitude troughing persists over the Great Lakes region with ridging continuing in the west. A clipper system drops through the northern plains sunday night and head towards the upper Great Lakes on Monday. This system drags a cold front through nrn Michigan on Monday, with a band of higher moisture and large scale life near the front supporting synoptic scale snow. Overlake instability with delta-T's of 19 C will contribute to lake enhancement through the day. Could see accumulations of 2-4" across far NW/nrn lower Michigan, and when combined with Sunday night's snowfall (see near term discussion), we could be seeing the need for a winter weather advisory. Low level winds veer through the day, focusing the snow bands from the Straits region southward through the day. By Monday evening the boundary should be south of the CWA, ushering cold dry air out of Canada on northerly winds. This will focus the best snowfall near and south of Traverse Bay overnight. Tuesday will bring high pressure sliding through the Ohio Valley and another clipper system lurking through the southeastern Canadian Plains into Ontario. Between these two, winds back to westerly then southwesterly through the day Tuesday, focusing lake bands back northward with time, ahead of the next fast moving clipper Tuesday night into Wednesday. && .LONG TERM...(Tuesday night through Saturday) Issued at 319 AM EST Sun Nov 18 2018 Forecast concerns: Minimal. Wednesday remains in cold cyclonic flow with more snow showers possible. Heights start to rise early Thursday morning as the western ridge starts to push eastward. 850 temperatures rise above freezing for Thanksgiving day, as a warm front moves northward over the area. Friday and Saturday could bring high temperatures in the low and possibly mid 40s across most of the area. Another system lifting out of the central Plains has the potential to bring some snow-melting rain on Saturday. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1154 PM EST Sat Nov 17 2018 Lake effect clouds/showers diminishing late tonight into Sunday. Strong high pressure in the northern plains is extending ridging into lower MI. Lake effect clouds and snow continues into nw and n central lower MI. The ridge will gradually work south, allowing our winds to back, and ushering in somewhat less cold air. That will erode lake effect from south to north. PLN could see periods of MVFR cigs/vsbys overnight into early Sunday. Otherwise, mainly VFR conditions. Light winds will gradually back to the w and wsw. Winds will increase and become a touch gusty by Sunday afternoon. && .MARINE... Issued at 319 AM EST Sun Nov 18 2018 Winds are starting to increase over the Great Lakes, as an axis of high pressure is sinking southward, and the pressure gradient t is tightening ahead of a cold front in Canada. Advisory speeds expected most all areas today into this evening. Winds subside with the passing of low pressure later Sunday night through Monday, but advisory level gusts are once again possible Monday night when this low pressure departs. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY until 7 PM EST this evening for LHZ345-346. SMALL CRAFT ADVISORY until midnight EST tonight for LHZ347-348. LM...SMALL CRAFT ADVISORY until 7 PM EST this evening for LMZ341. SMALL CRAFT ADVISORY until midnight EST tonight for LMZ323-342- 344>346. LS...SMALL CRAFT ADVISORY until 7 PM EST this evening for LSZ321-322. && $$ NEAR TERM...SMD SHORT TERM...STJ LONG TERM...STJ AVIATION...JZ MARINE...SMD
Office: GRR FXUS63 KGRR 180828 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 328 AM EST Sun Nov 18 2018 LATEST UPDATE... Synopsis/Discussion/Marine .SYNOPSIS... Issued at 328 AM EST Sun Nov 18 2018 Temperatures will remain below average through the Thanksgiving Day holiday this week. We will have three waves of low pressure that move through, and will bring some snow showers and lake effect to portions of the area. The first will bring some light snow to areas along I-94 this morning. The second should come through Monday night, and the third will come through Tuesday night. Significant snow accumulations are not expected, but enough snow could fall and impact the morning commute for some locations, especially near the lake. We will dry out for a few days starting on Wednesday, and likely lasting until Friday night or Saturday when the next system will affect the area. Milder temperatures will arrive ahead of the system for Friday and Saturday. && .DISCUSSION...(Today through next Saturday) Issued at 328 AM EST Sun Nov 18 2018 We have our eye on three individual features for the first portion of the forecast period, and then one at the end of the period. The three in the first portion of the forecast period will be mainly light snow with colder air holding in. The system late in the period looks to be more rain with warmer air expected to have moved in by then. The first period of light snow is from this morning, into the mid- day hours today along the I-94 corridor and areas south. This light snow is being generated from a backbuilding upper jet to our NE, with the srn portion of the area under the RRQ of the jet again like yesterday. The intensity should not be all that great, and the duration will be a few hours at worst. We are looking for up to an inch at most toward the CWFA border. This will clear out this afternoon and evening. We will see a brief break in the activity, before light snow/snow showers redevelop starting Monday afternoon, and linger through early Tuesday morning. We will see a couple of short waves aloft move through, and push a sfc boundary through the area. The system itself has limited moisture as it moves in. It expands as it encounters the warm and moist Great Lakes with colder air moving in. Areas along the lakeshore will see some accumulations with an onshore flow and delta t/s around 10-13C sufficient for enhancement. The low level flow shifts fairly quickly offshore by daybreak Tue, which will also limit accumulations. Inland areas will likely see little to no accumulations. No rest for the weary, as yet another chance of snow showers moves in Tuesday night and lingering into Wednesday. Another short wave dives SE across the nrn Great Lakes. This will drive another sfc front through, however the short wave support and polar jet core remains north of the state. This scenario has fairly low inversion heights, which will keep lake effect/enhancement from getting out of hand. This inversion is the result of warmer air aloft moving overhead. Favored areas to see some light snow will be along and west of U.S.-131. Snow showers should gradually diminish on Wed. This should not be significant enough to impact holiday travelers much, if any. The holiday itself should be dry, but rather cold. High pressure will control the weather on Thu with it being nearby. We will start the day out rather cold (in the teens), and with limited mixing we will only warm up into the lower to mid 30s at best. We will see warmer temps gradually arrive for Friday and Saturday as the srly flow increases behind the ridge. The next chance of pcpn looks to come Fri night or Sat as a srn stream system rotates out of the srn Plains. The timing and strength of this system late in the period is very much up in the air how it evolves, and in how much rain we get, and how warm we get. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1251 AM EST Sun Nov 18 2018 VFR conditions had spread across all of the terminals for a short period of time, before the lower MVFR cigs moved back north over KJXN within the last hour. We will see lower cigs move over the I-94 terminals as a band of light snow approaches from the south. As the light snow moves over the I-94 terminals, IFR will be likely, especially at KJXN which will be the most impacted. KAZO and KBTL will be close to the nrn extent of the IFR. The IFR conditions will linger into the early afternoon hours before it moves out, and clouds clear out from NW to SE. && .MARINE... Issued at 328 AM EST Sun Nov 18 2018 We will be hoisting a Small Craft Advisory for the northernmost nearshore zone from today through midnight tonight. Winds come up some, but it will be enough to build waves sufficiently to require the need for an advisory. The next period of concern for potential headlines will be Tue night into Wed in the wake of the system coming through at that time. && .HYDROLOGY... Issued at 211 PM EST Sat Nov 17 2018 There are no hydrologic concerns through the next week as episodes of rain and snow look light. The threat for ice jams remains near zero through the next week as daily average temperatures remain above 20 degrees. Warmer weather is expected towards the end of next week. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory from noon today to midnight EST tonight for LMZ849. && $$ SYNOPSIS...NJJ DISCUSSION...NJJ AVIATION...NJJ HYDROLOGY...HLO MARINE...NJJ