National Weather Service - Area Forecast Discussion

000
FXUS63 KAPX 300129
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
929 PM EDT Thu Sep 29 2022

.UPDATE...
Issued at 928 PM EDT Thu Sep 29 2022

High pressure is sliding east from MI into the eastern lakes.
However, significant ridging will extend back into lower MI thru
the night. This will keep low-level winds light. Just a touch of
cirrus out there, so very good radiational cooling conditions,
though we`re already bumping into the dew point in many places.
That will keep temps from plunging ridiculously low, but there
will lots of 30s out there, with near 30f/low 30s very common in
the interior of northern lower MI. Sheltered locales, and places
near bodies of water, will contend with patchy fog overnight.

Note that we have concluded frost/freeze headlines for the
season.

&&

.NEAR TERM...(Through Tonight)
Issued at 217 PM EDT Thu Sep 29 2022

...Mostly Clear and Chilly Tonight...

High Impact Weather...None expected.

1033 mb high pressure across the region will remain in control
tonight. Some lake cloudiness off of Lake Michigan currently
evident on satellite imagery should dissipate this evening as over
lake instability continues to slowly wane. This should leave
widespread mostly clear skies and when combined with light winds,
result in very good radiational cooling conditions once again.
Lows generally in the 30s inland (probably a few isolated upper
20s) and around 40 near the shorelines.

&&

.SHORT TERM...(Friday through Sunday)
Issued at 217 PM EDT Thu Sep 29 2022

High Impact Weather Potential: Minimal attm...

Pattern Synopsis/Forecast:

Longwave pattern has things largely troughing-east, ridging-
west/central. There are some shortwave exceptions to this
rule. The first is a shortwave ridge more or less overhead
this morning...with anomalous 1034mb surface high overhead as a
result, and some morning frost/radiational fog burning off across
our region. The second is a handful of niblets spinning in the flow
just upstream across the Northern Plains and Upper Mississippi
Valley...up into southern Ontario and Manitoba. A little bit of
shower activity/mid-high clouds noted with these, where there is
some weaker stability collocated with slightly deeper moisture on
the nose of a mostly meridional 40+kt low-level jet.
Additionally...the West Coast/Western US seems a little on the
troughy side behind what remains of the ridge...with vort maxima
scattered from the bowling ball in the Pac NW down into northwest
Mexico. Surface baroclinic zone extends from a low over
southern Saskatchewan/Alberta down into the southern Plains...with
additional cold fronts extending back off the coast ahead of the
cooler air aloft. Strongest jet is along/ahead of the departing
trough over New England, and baroclinic zone just offshore in
advance of it...with Ian spinning to its south along the eastern
Florida coast, south of said baroclinic zone.

Looking ahead...the upstream herd of niblets will continue to trek
through the Upper Midwest/Great Lakes Friday, though with minimal
impacts to the surface pressure pattern...as high pressure, now
centered a little more to our east, remains elongated but in
control. At the same time...a northern stream trough looks to dive
into Quebec going into the start of the weekend, becoming a little
more amplified with time...as remnants of Ian retrograde into the
southeastern US. Another anomalous surface high in the wake of this
northern stream trough should aid in a backdoor cold front sliding
into the region Saturday into Sunday...bringing an easterly feed of
dry air to the area for the start of next week...as Ian looms to our
southeast.

Primary Forecast Concerns: Rain potential (or a lack thereof),
overnight fog potential...afternoon RHs and overnight lows...

Not really much moisture to work with as those niblets come
through Friday into Saturday...so I anticipate that things should
remain pretty quiet going into the weekend. BCZ with that backdoor
cold front appears to approach the eastern UP by Saturday
morning...though it also appears deeper moisture wanes with time,
especially going into Saturday night/Sunday, thanks largely to upper
level subsidence beneath amplified shortwave ridge, and easterly
feed of low-level dry air from Canada. With some boundary layer
moisture moving through Saturday night into Sunday...do have some
concerns that we may have clouds around...but potential for things
to get wrung out of them seems quite limited attm... as forcing is
not strong, and there is not much in the way of instability to work
with, either. Anticipate things should stay largely dry.

This being said...will have to keep an eye out for overnight patchy
radiational fog Friday night as the boundary layer will likely
remain a little more moist due to the recent rainfall (as we saw
last night). Guidance derived soundings aren`t overly clear on
this...but I`m not sure they were necessarily that supportive of fog
with last night`s event. We should be somewhat drier Friday night
than we were last night or will be tonight...as we`ll have been
under the somewhat dry high pressure for a few days...but there
could still be some patches here or there. Confidence in fog beyond
Friday night is somewhat unclear as there will be some potential for
cloud cover Saturday night with the backdoor cold front, in addition
to stronger winds...and things should be much drier behind the cold
front Sunday night. Will be something to watch in the coming days.

Speaking of dry...will have to keep an eye on afternoon RHs in the
coming days, with the flow of dry air in the region through Friday
at least. Things may be slightly more moist Saturday ahead of the
backdoor cold front...and then things appear to really dry out
through the column beyond Sunday...as anomalously dry air mass
begins to advect in. This could result in overnight lows dropping to
near or below freezing again.

.LONG TERM...(Sunday night through Thursday)
Issued at 217 PM EDT Thu Sep 29 2022

High Impact Weather Potential: Minimal attm...

Pattern Synopsis/Forecast:

Easterly feed of dry air with zonally elongated surface high
centered in the vicinity/to our east indicates a dry start to the
workweek...and perhaps much of the start of the week as well...as
this should keep the baroclinic zone to our west, at least for a
time. Additionally...this will likely keep Ian`s remnants from
impacting us much at all. Exact details will of course be ironed out
as guidance gets a better handle on Ian`s remnants going
forward...as uncertainty related to this tropical system is still
playing with guidance`s head attm...even though there is some
general agreement overall in the larger scale pattern. Upstream low
over the Pac NW attm looks to get hung up in the central Plains in
the coming days because of Ian...and does not appear to get booted
eastward till late in the period...as additional energy dives down
from north central Canada toward midweek...potentially to finally
unstick the systems clogging up the CONUS. There is some uncertainty
in timing and evolution of this feature attm...so will keep an eye
on it in the coming days...as it should be our next best shot at
precip.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 713 PM EDT Thu Sep 29 2022

High pressure will provide continued quiet wx into Friday. It`s
not totally impossible for MBL/PLN to see a touch of fog
overnight. Otherwise VFR with light winds.


&&

.MARINE...
Issued at 217 PM EDT Thu Sep 29 2022

High pressure will keep fairly benign conditions across the Great
Lakes over the next few days. No headlines are planned any time
soon.


&&

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

$$

UPDATE...JZ
NEAR TERM...AJS
SHORT TERM...FEF
LONG TERM...FEF
AVIATION...JZ
MARINE...AJS

NWS APX Office Area Forecast Discussion