679
FXUS63 KAPX 151437
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1037 AM EDT Mon Jul 15 2024

.KEY MESSAGES...

- Small chances of showers and storms this morning into early
  afternoon

- Better chances of showers and marginally severe thunderstorms
  later this afternoon and evening. Primary severe weather
  threat will be damaging winds and locally heavy rainfall.

- Just a lingering isolated shower / thunder chance near Saginaw
  Bay Tuesday.

- Trending much cooler with showers Wednesday before high
  pressure takes over and we turn dry and sunny to close out the
  week.

&&

.UPDATE...
Issued at 1033 AM EDT Mon Jul 15 2024

Showers and storms continue to move out of the region this
morning, exiting to the east. Skies are clearing as the clouds
quickly recede with the rain. Warm and humid air will persist
today, and paired with sunshine will make for a hot and humid
afternoon. Isolated storm chances along afternoon Lk breezes,
however a cold front will push through later this evening and
into the night tonight. This will be the focus of the forecast
today.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 213 AM EDT Mon Jul 15 2024

     Very warm and humid today and tonight with increasing chances of
showers and storms...

High Impact Weather Potential...There is a marginal risk of severe
thunderstorms this afternoon and evening...with damaging winds the
primary threat.

Weak area of low pressure continues to make its way eastward thru
Upper Michigan and Lake Superior early this morning...with a
trailing cold front extending thru Eastern Wisconsin into Iowa. Area
of strong/svr convection/large bow that blew thru the Chicago area
continues to charge southeastward thru Northern Illinois... Northern
Indiana and SW Lower Michigan riding along a strong instability
axis. Closer to home...convection that fired over Upper Michigan
during the evening has dissipated...leaving our CWA dry with
convective debris clouds drifting overhead. A look further upstream
shows a stronger low pressure system taking shape to the lee of the
Rockies over the Northern Plains. This system will play a
significant role in our wx for tonight.

In the meantime...for today...weaker low pressure system over Upper
Michigan will slowly slide thru our CWA...providing us with small
chances of showers and thunderstorms especially as daytime
instability builds this afternoon. Better chances of showers and
storms will develop later this afternoon and evening as that
stronger Northern Plains low dives into Wisconsin by 00Z this
evening and into Lower Michigan overnight. While the stronger
convection (best chance of svr storms) will remain south of our CWA
over Illinois...Southern Wisconsin and Sw Lower Michigan where the
strongest instability will reside...a few stronger/marginally severe
storms are possible later this afternoon and evening across our CWA
along the northern periphery of the instability axis and deeper
moisture plume. Primary severe wx threat will be damaging winds...
with an outside chance of some larger hail as well.

Expect another very warm and humid day across our Northwoods to
start the work week. High temps this afternoon will warm into the
mid to upper 80s across our entire CWA...with overnight lows cooling
into the upper 50s to mid 60s tonight.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 213 AM EDT Mon Jul 15 2024

Pattern Synopsis / Forecast:

Expansive longwave troughing is set to dig into the Great Lakes
region at the start of the long term, as a robust thermal ridge
amplifies well northward into the Canadian Rockies and the western
prairies. Implications closer to home will be a surface cold frontal
boundary finally clearing the region Tuesday afternoon / evening,
effectively flushing out the ongoing heat and humidity come midweek.
As this cold front completes its passage, perhaps some returning
showers and storms may blossom Tuesday afternoon across the southern
half of the NWS Gaylord footprint as elevated surface dewpoints
contribute to a window of diurnal destabilization with the lingering
frontal forcing, while the remainder of the area holds dry in the
post-frontal stable layer. Cooler airmass dominates the rest of the
week, but dry conditions will have to wait until after Wednesday...
primary trough axis overhead and cooling temps aloft will result in
steepened lapse rates, and with diurnal heating, will likely
initiate some shallow showers across the region Wednesday. Beyond
this, surface high pressure intrudes from Minnesota and moves
overhead to close out the week, bringing a run of pleasant
temperatures, cooler nights, and dry weather into at least the
first half of the upcoming weekend.

Primary Forecast Concerns:

Tuesday: Most of the CWA is expected to hold dry in the wake of the
frontal boundary, and lowering dewpoints suppress diurnal
instability for most. Some guidance is still trying to paint a few
hundred Joules of MLCAPE near M-55 / Saginaw Bay, which could bring
about a returning shower or storm. Given the meager instability and
somewhat lackluster shear profiles, not expecting anything more than
an isolated garden variety storm, probably focused on the Saginaw
Bay breeze. Temps range from the low-to-mid 70s north of the Bridge,
mid-to-upper 70s across much of northern lower, and some lower 80s
near Saginaw Bay. Those looking to open the windows for some natural
air overnight rejoice: lows Tuesday night in the 50s basically
across the board, though wouldn`t be surprised to see some lakeshore
locales hover right around 60.

Wednesday and Beyond: Trough axis swinging through the region
coupled with diurnal heating processes should be just enough to
generate some passing showers throughout much of the CWA Wednesday,
particularly in the afternoon as we reach peak heating. Current
thoughts are that the most "widespread / frequent" showers favor
northeast lower as the primary trough axis will pass through that
general area in the afternoon, thus giving more diurnal
destabilization to contend with. By no means a washout, but by no
means a dry day as highs generally hover between 70-75 degrees
(upper 70s near Saginaw Bay). After this, surface high pressure
builds, keeping conditions dry and skies sunny as highs largely
remain confined in the 70s through Friday (perhaps near 80 in some
places Friday). Highs rise back into the low 80s for the weekend.
Overnight lows largely in the 50s... though some mid-to-upper 40s
remain well within possibility Wednesday through Friday nights
across the interior cool spots.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 645 AM EDT Mon Jul 15 2024

Low pressure will move eastward out of the Northern Plains and
into Wisconsin and Michigan later today and tonight. Chances of
showers and thunderstorms will increase around and ahead of this
system. Prevailing conditions will remain VFR thru tonight...
but will drop to MVFR/IFR within some of the heavier showers and
storms. Relatively light wind regime will allow for lake breeze
development by this afternoon.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...ELD
SHORT TERM...MLR
LONG TERM...HAD
AVIATION...MLR