338 
FXUS63 KMQT 081946
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
346 PM EDT Fri Oct 8 2021

.SHORT TERM...(This evening through Saturday)
Issued at 345 PM EDT FRI OCT 8 2021

If you have gone outside today so far, you will notice that it is 
unseasonably warm, and humid outdoors. While this is certainly not 
unheard of for the first week of October in Upper Michigan, the fall 
foliage doesn't match the observed weather pattern presently. 
Satellite imagery as of 19Z this afternoon shows the low stratiform 
cloud cover beginning to wane over the west half, and even a few 
areas seeing peaks of sunshine. Dew points in the lower to middle 
60s combined with surface obs in the middle to upper 60s make a good 
case of why the low clouds and fog were present for a majority of 
the day thus far across the area. Abundant moisture advection 
continues to occur over our area as the broad surface low pressure 
over the Lower Great Lakes funnels in higher dew points from the 
southeast CONUS. GOES WV analysis shows abundant moisture aloft, 
with a narrow band of dry air remaining to the east as the stacked 
upper level low circulates over southern Lake Michigan this 
afternoon. For those that have been following the weather patterns 
over the last week or so, the present occluded ULL is the remnants 
of what we had over our area last weekend that resulted in fog, 
drizzle, and low clouds. This ULL moved from the Great Lakes to the 
Southeast CONUS, and then slowly became absorbed with the main upper 
level flow the past couple of days as it retrograded further to the 
north-northwest over the Great Lakes once again. All of that being 
said, this slow-moving weather system will slowly trek to the north 
and northeast for the short term forecast, resulting in scattered 
showers across Upper Michigan, which has been observed throughout 
the day thus far on radar. Areas that have partial clearing in sky 
coverage could see a brief heavier rain shower, and perhaps a rumble 
of thunder. Although, SPC Mesoanalysis shows very little with regard 
to instability across the area...less than 500 J/kg. Marginal lapse 
rates of 5-6 degrees C/km are present, mainly along the WI/MI 
border. Without a strong forcing mechanism, the expectation is that 
a majority of areas will see brief rain showers, and very little to 
no thunder. 

For tonight, moisture advection will continue to be funneled into 
the area courtesy of the occluded ULL. With WAA at 850mb also, the 
warm temperatures will not be disappearing. Elevated dew points 
close to surface temperatures overnight will result in very low 
cloud cigs, and patchy fog across several areas of Upper Michigan. 
Especially in locations that see rain showers. Expect overnight lows 
to drop down to the upper 50s to low 60s. It will be an unseasonable 
warm and muggy night. 

Saturday will see low clouds slowly erode as rain showers push to 
the east through morning into the early afternoon. Partly cloudy 
skies are likely for the west half as zonal to weak ridging aloft at 
H5 occurs from midday Saturday through the late afternoon. This will 
help temperatures elevate slightly into the upper 60s to lower 70s. 
Went with a conservative blend of temperatures for Saturday, but a 
couple of Hi-res members do hint at temperatures across the 
interior, and near the northern lakeshores reaching the low to 
middle 70s due to downslope effects from weak southerly winds. 
However, the expectation is that cloud cover will be slow to erode 
away, so went with highs near 70 to the lower 70s for most areas. 
With the elevated dew points remaining across the area near 60 for 
Saturday, the muggy conditions will remain across the area also. The 
break in any cloud cover will be short lived for the west half as 
the next weather system approaches from the Upper Midwest late 
Saturday evening, resulting in another round of cloud cover 
approaching Upper Michigan.

.LONG TERM...(Saturday through Thursday)
Issued at 413 AM EDT FRI OCT 8 2021

Not much change in terms of the overall expectations for this
forecast period as compared to previously. The primary 'headlines'
continue to be the unseasonable warmth along with the unsettled 
pattern already underway into next week for the U.P.

High temperatures will be well into the 60s and 70s this weekend
as ample amounts of warm, moist air continuously flows into Upper
Michigan. Some moderation in the temps can be expected early next
week behind a couple of passing lows, but ultimately, these well-
above normal temps hold steady through much of next week. By 
week's end, there are indications that cooler air (closer toward 
normal) arrives. Low temps will respond accordingly, struggling to
drop below the 50 degree mark this weekend, with 40s looking to 
reappear next week.

As previously discussed, a few disturbances crossing the Upper
Great Lakes will allow for multiple precipitation chances.
Although a weak trough will be moving through on Saturday, overall
drier conditions (just won't feel it at the surface with 50s and 
60s dewpoints hanging around, another metric of the ongoing 
unusual weather locally) will briefly pass through. The
combination of losing a lifting mechanism (the exiting trough) as
well as loss of moisture aloft yields limited PoPs for most except
for primarily portions of the eastern U.P. This won't last long
though as a more organized low quickly marches across MN on the
former weak trough's heels.

With the stronger low, instability will accompany it, as well as 
much higher shear values and the return of more supportive PWATs. 
Therefore, thunder can be anticipated, but it is additionally 
worth noting that some stronger storms may be able to develop 
given the aligning parameters, particularly under an additional 
boost diurnally-speaking, given the timing.

But, the pattern remains progressive as yet the next low 
approaches and crosses Upper Michigan, tracking further west 
according to the models as compared to runs just over 24 hours 
ago. Another slight change is that it doesn't look to weaken as 
much as prior model runs. Regardless of these slight shifts in the
forecast, precip chances remain area-wide Monday into Tuesday. 

Should see a brief break mid-week before yet another, even more 
stout-looking low approaches and crosses the region. However, 
models continue to diverge from one another, with fairly 
significant differences in tracking/their projected paths.
&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 114 PM EDT FRI OCT 8 2021

A broad surface low pressure continues to slowly move northeast into 
Lower Michigan this afternoon resulting in mostly IFR to MVFR flight 
conditions at the Upper Michigan terminals. At KSAW and KCMX, expect 
low end MVFR this afternoon, with possible fluctuations to high end 
IFR as brief VCSH to -shra occurs at times. At KIWD, expect high end 
MVFR, with fluctuations to low end VFR periods at times. Expect IFR 
cigs to return to all of the terminals tonight as moisture continues 
to be brought into the region from the surface low pressure, with 
LIFR cigs likely at KSAW.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 224 PM EDT FRI OCT 8 2021

A broad area of surface low pressure will slowly move through the 
region today and Saturday, with winds from the east and southeast of 
generally 15 kts or less through Saturday evening. The forecast 
still continues to trend this weekend toward another surface low 
pressure moving from the Central Plains to the northeast into far 
western Ontario by Sunday. The surface low is forecast to remain 
north of the lake causing wind gusts from the SE at 20-30 kts on 
Sunday, mainly on the east half. Gale force gusts may be possible on 
the east half, followed by a period of WSW winds around 20 kts 
Sunday night and Monday, mainly on the west half. Light winds should 
return for Monday night through Wednesday afternoon. Another weather 
system will approach the Great Lakes on Wednesday night, bringing 
the opportunity for wind gusts of 20-25 kts across the lake.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

$$

SHORT TERM...BW
LONG TERM...lg
AVIATION...BW
MARINE...BW