488 
FXUS63 KAPX 220356
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1156 PM EDT Thu Jul 21 2022

.UPDATE...
Issued at 1022 PM EDT Thu Jul 21 2022

So far the forecast is going according to plan. Winds have died
off over the Upper Great Lakes Region has high pressure noses in
for a bit. A few clouds are drifting down out of NW Ontario into
Lake Superior, from a shortwave trough at 500 mb. This looks to be
producing just mid-level clouds over the lake, so not expecting
much if anything with these overnight. Otherwise, things look
quiet overnight. 

&&

.NEAR TERM...(Through Tonight)
Issued at 323 PM EDT Thu Jul 21 2022

High Impact Weather Potential: Minimal.

Pattern Synopsis/Forecast: 17z surface analysis shows a 986mb 
occluded low off the southern end of James Bay along the Ontario/ 
Quebec border...cold front extends southwest from this low across 
central Upper/northwest Wisconsin/Iowa.  Brisk westerly boundary 
layer flow across the upper Lakes this afternoon.  Good bit of 
diurnal Cu across the upper Great Lakes this afternoon...with more 
vigorous convection across northwest Ontario with a couple bands of 
thunderstorms associated with a vorticity center evident in water 
vapor imagery.  A little patch of St/fog hanging on along the 
southeast shore of Lake Superior.

Northwest Ontario vorticity center expected to pass north of Lake 
Superior this evening...with a second disturbance coming in quickly 
on its heels out of Saskatchewan this afternoon and into the upper 
Lakes by Friday morning.  A frontal wave is expected to develop 
along the secondary cold front over Wisconsin and slide across 
southern Lower Michigan tonight.

Primary Forecast Concerns: Forecast concerns appear to be pretty 
minimal...diurnal clouds will fade with loss of heating but some 
residual Ac at times.  Winds will also drop off later this evening 
as pressure gradient relaxes...and with dew points having mixed out 
a bit this afternoon should have more room to cool off 
overnight...55-60 across eastern Upper and upper 50s-lower 60s 
across northern Lower.

&&

.SHORT TERM...(Friday through Sunday)
Issued at 323 PM EDT Thu Jul 21 2022

High Impact Weather Potential: Storm and heavy rain potential this 
weekend...elevated fire danger Friday...

Pattern Synopsis/Forecast: Some additional upper level energy 
diving into the general area of troughing over the Great Lakes 
this morning...left behind by yesterday's potent little shortwave 
aloft...which is currently spinning northnortheastward toward 
James Bay. A little bit of energy driving some mid-high clouds 
across southern WI as of 14z...with additional energy making its 
way toward the Upper Midwest/Great Lakes from the central Canadian
Prairies. Northwest flow through the column in the wake of this 
trough resulting in a cooler and drier airmass advecting into the 
region today...particularly behind a second cold front currently 
extending from a low near western Hudson Bay down into the central
Plains. This surface boundary quickly turns north along the high 
plains as a warm front, on the periphery of ridging that continues
to persist across the western US. For the time being, bulk of the
moisture is held across the eastern seaboard and southern US, 
south of the cold front associated with yesterday's convection 
(and driving additional convection across the TN valley into 
northern TX this morning). Further upstream...note continued 
anomalous troughing across the Bering Straits...with some general 
area of lowered heights aloft off the West Coast...and a vort max 
within this area spinning toward the Pacific Northwest attm.

Looking ahead...anticipate bulk of the northern stream energy will 
continue to sideswipe us to the north through the next 24 hours or 
so...with some additional energy attempting to scrape by Friday 
afternoon...leading to some weak surface pressure falls across the 
region...and ultimately, some semblance of a boundary/baroclinic 
zone over the region. As energy currently off the PacNW coast heads 
inland...and some additional northern stream energy swings southward 
across the central Canadian Prairies...will look for the flow to 
become a bit more zonal for a time for the end of the work week into 
the start of the weekend, with strengthening thermal gradient and 
subsequent strengthening of upper level jet across the northern half 
of the CONUS. Bermuda high off the southeast US in combination with 
the approaching lowered heights and surface pressures will result in 
increased low-level return flow across the central CONUS/MS Valley 
going into Saturday and Saturday night. Strengthening west to 
southwesterly flow should also provide transport of upstream 
capping/EMLs into this same vicinity. Some uncertainty attm in 
exact position/depth of troughing across southern Canada as it 
approaches Saturday night...and drives a cold front across the 
region through Sunday. Will certainly be keeping an eye on this 
setup for the weekend...as convection will become a concern across 
the Midwest, noting Day 3 marginal risk has been hoisted for all of 
Michigan...and even an enhanced risk across central/western WI for 
Saturday into Saturday night...with Day 3 excessive rainfall outlook 
for this region from WPC.  

Primary Forecast Concerns: Heavy rain and severe storm potential 
through the period...particularly Saturday into Sunday...non-
thunderstorm gusty wind potential as well...

Friday may not be entirely quiet...noting a niblet of energy 
swinging through during the day, which may be just enough to set off 
a few diurnal showers here and there (non-zero thunder potential), 
particularly across the eastern UP as it drops some kind of weak 
boundary into the region. This appears to also briefly increase 
winds across the area, leading to a breezy/gusty afternoon to wrap 
up the work week. Wouldn't be surprised to get some gusts into the 
30+kt range across interior northern lower as a bit of a wind max 
moves overhead and we get some good deep mixing. (Could we be 
looking at a sneaky non-thunderstorm wind event?? We'll see...)
Antecedent dry weather may preclude some precip development, 
though...particularly across northern Lower, where it looks driest 
attm...and also lead to fire danger concerns (particularly in 
combo with temps and winds), noting Great Lakes Fire and Fuels page 
has very high fire danger across a good portion of northern Lower 
attm...particularly along and south of M-72. This should only expand 
northward with time into Friday as drier conditions take hold. 

Going into Friday night, mid-level flow looks to become relatively 
parallel to this boundary over the region as nocturnal LLJ begins to 
set up to our west. Setup favors some kind of convective development 
along strengthening/approaching warm front across the Midwest late 
Friday night into Saturday, as reflected in some guidance...though 
instability gradient may be a little more nebulous (perhaps due to 
the convective development), which could make the forecast a little 
tricky on the details. Do certainly see signals of increasing deep 
moisture, along with theta-e advection, and steepening lapse rates 
aloft as upstream EMLs beneath the ridge become advected 
eastward...so will definitely have to keep an eye on this. Suspect 
that with flow parallel to lingering boundary...whatever convection 
develops Friday night/early Saturday may be a little more 
progressive with potential for cold pools to become congealed. 
Exactly where this ends up evolving is a little uncertain...though 
attm, bulk of the signals would like to keep it primarily to our 
south. So stay tuned. 

Going into Saturday...will be watching whatever convection from 
Friday night continue eastward through the morning, and its impacts 
(or lack thereof) will play a role in the setup for the rest of the 
day into Saturday night. Flow should become veered from the surface 
into the mid-levels during the daytime hours as upstream low 
strengthens and approaches. Meanwhile...instability should be on the 
increase through the day into Saturday night thanks to that 
increasing southwesterly flow...with increasingly steep mid-levels 
as EMLs and warmer temperatures advect in in advance of shortwave, 
with the warm front moving in late in the day. Warmth of the air 
mass may be able to overcome capping with enough diurnal 
heating...though this would depend on convective cloud debris from 
the overnight convection, how moist we get in the low-levels...and 
just how warm we end up getting aloft. So we may end up having to 
keep an eye out for pop-ups during the day, which could get 
interesting, noting some signals for veering flow in the low levels, 
though low-level shear doesn't currently appear too strong during 
the afternoon...likely not increasing until overnight, as the LLJ 
picks up (as do the surface winds, with the approach of that 
system). Deep-layer shear would be the greater concern...and that 
should be reasonable. Anticipated upstream convection Saturday 
afternoon will increase threat for storms and heavy rain as it heads 
into our area later in the day...and do note signals appear 
favorable attm for some kind of backbuilding/training convection 
along the warm front Saturday night. Anomalously high pwats do lend 
to further concerns for heavy rain...so will definitely have to keep 
an eye on this. Progressive nature of the system may keep things 
from sticking around too long and potentially minimize said heavy 
rain threat to some degree, as the cold front appears to slide 
through starting late Saturday night into the first part of Sunday. 
Ultimately, I expect that details will change over the next 24-48 
hrs...but the overall concern remains present for thunderstorms 
(potentially severe) and heavy rain across our region Saturday 
through Saturday night. Will definitely be a weekend to keep a close 
eye on the weather, particularly if you have outdoor plans that will 
have you out in northern Michigan's beautiful Great Outdoors... 
especially if you plan to camp Saturday night. 

Otherwise...Sunday could be another gusty day early in the day as 
the cold front moves through...noting some anomalously strong winds 
aloft...though bulk of these winds attm appear to be just to our 
south. Even so...will keep an eye on things, as it could get a bit 
blustery for a time before things eventually quiet down. May have to 
keep an eye out for some lingering showers/storms near Saginaw Bay 
depending on how warm it gets...and how quickly the front moves out 
in the afternoon Sunday...though it looks a bit dry attm for much in 
the way of convection to develop.

.LONG TERM...(Sunday night through Thursday)
Issued at 323 PM EDT Thu Jul 21 2022

High Impact Weather Potential: Minimal for now.

Temperatures look to remain pretty consistent next week as we get 
sandwiched between airmasses in the upper Great Lakes. High 
temperatures likely hold in the mid 70s to low 80s, with low 
humidity to start before dewpoints slowly creep back into the 60s 
around midweek. A longwave over Quebec will continue to meander 
slowly toward the Maritime Provinces Sunday night, forcing the 
shortwave over the Great Lakes eastward and favoring a drying trend 
into Monday as high pressure sneaks in from the west. Jet stream 
flow will turn more zonal and quite quick at that, with up to 100kt 
flow placed directly over Michigan. Convergence aloft will likely 
limit any CU field development on Monday...with any low level 
moisture eventually mixing out through the morning, yielding a good 
possibility of at least a sunny afternoon. High pressure remains in 
place for Tuesday, but as surface flow turns ever so slightly 
southerly ahead of a digging trough from the MB/ON vicinity, surface 
moisture should slowly begin to advect back into northern Michigan, 
perhaps accompanied by an isolated shower or rumble of thunder 
overnight into Wednesday. The risk for showers and perhaps some 
rumbles would likely carry into Wednesday and even Thursday as the 
pattern becomes a bit stagnant owing to an amplifying ridge across 
the western U.S. and Canada. It should be noted that there remains 
some uncertainty regarding how far south the trough will dig, which 
would have significant impacts as to how much moisture can be 
advected into the area, but model guidance has shown signs of 
backing off on this ever so slightly. In the event that a SW to NE 
jet streak from Missouri to Quebec can develop like models suggest, 
this may lead to a more widespread area of precipitation across 
portions of the Great Lakes given better divergence aloft. 
Unfortunately, given the position of this jet streak, the better 
divergence aloft will likely favor areas of eastern Ontario to the 
Ohio Valley, with the cards looking to be tilted in the favor of the 
southern Great Lakes. This would unfortunately leave us with 
"lottery showers" in northern lower and eastern upper Michigan for 
Wednesday and Thursday, because one might have to have a bit of luck 
on their side to get some jackpot rainfall. 

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1146 PM EDT Thu Jul 21 2022

Tonight, and leading into Friday morning should remain quiet, with
light winds. Friday, however, The winds will pick up again and
become gusty by the later morning. A shortwave trough will drop
into the Upper Great Lakes, and begin to kick off some showers,
and possibly thunderstorms, which would be an issue for PLN and 
APN late in the afternoon/early evening. However, it looks like 
that all of the TAF sites should remain VFR for CIGs and VSBYs 
through the period. 

&&

.MARINE...
Issued at 323 PM EDT Thu Jul 21 2022

Small Craft Advisories up for the Lake Superior and most of the
Lake Huron nearshore zones will be allowed to come down at 00z as
winds drop off for a time tonight. But another round of headlines
appears to be in the offing for Friday especially on Lake Michigan
as winds come around from the southwest.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...JSL
NEAR TERM...JPB
SHORT TERM...FEF
LONG TERM...HAD
AVIATION...JSL
MARINE...JPB