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000
FXUS63 KAPX 202327
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
727 PM EDT Tue Jul 20 2021

.NEAR TERM...(Through Tonight)
Issued at 202 PM EDT Tue Jul 20 2021

...Turning a bit cooler tonight...

High impact weather potential: Minimal. A few non-severe
thunderstorms the remainder of this afternoon.

Pattern synopsis and forecast:

Amplified (at least for summer) mid and upper level pattern continues
across NOAM, with northern Michigan centered under northwest flow
between sharp Intermountain West ridge and northeast NOAM centered
troughing. Embedded shortwave trough working its way southeast
across the area early this afternoon, with its attendant cold front
also pushing southeast across lower Michigan. Detachment of best
mid and upper level support to our northeast has resulted in
mainly a dry frontal passage for most, with just some isolated
showers and storms across the northeast parts of our area as
cooler air aloft overtops a marginally unstable lower level
environment.

Mid and upper level flow regime described above continues tonight,
with prevailing northwest flow driving shortwave trough into New
England by sunrise Wednesday. Large area of Canadian high pressure
builds into the region in its wake, forcing cold front to drop into
the lower Ohio Valley by morning.

Primary forecast concerns/challenges:

Addressing lingering shower/storm potential this afternoon and
overnight temperature trends.

Details:

Still can`t rule out a few more showers and thunderstorms into very
early this evening, especially across northeast lower Michigan where
low level convergence will be maximized. Minimal cape (less than 1K
joules/kg) and less than impressive mid level lapse rates should
preclude much of a severe concern, although can`t rule out some
small hail and marginally gusty winds. High pressure builds into
the area from north to south overnight, bringing with it clearing
skies and cooler temperatures. Expect widespread lows in the
lower and middle 50s, with some of our traditional ice box
locations likely making a run into the upper 40s. Great sleeping
weather indeed.

&&

.SHORT TERM...(Wednesday through Friday)
Issued at 318 PM EDT Tue Jul 20 2021

...Low precipitation chances again...

High impact weather potential: Minimal.

A 1022mb high pressure center will be nearly directly overhead at
the beginning of the forecast period, providing mostly clear to
partly cloudy skies, warm temperatures, and fairly light winds
through at least early Thursday. Once again we have a chance of
precipitation in the forecast for Thursday as a quasi warm front
associated with a developing low pressure over the northern Plains
approaches the Great Lakes region. If we went with persistence,
there would be very spotty showers, if any at all. But to account
for the low confidence in the shower potential, there is a broad
(CWA wide) 20-30 pops. High pressure has been battling out the
precipitation the past several days, and if it wins the battle
again, there won`t be much to see at all.

Winds will be light Wednesday, with a northerly component and then
become southwesterly ahead of the aforementioned front to our west,
but remaining light. May see some gusts of 10 mph during the
afternoon hours with diurnal mixing.

Temperatures will be in the mid to upper 70s during the daytime,
with Wednesday night lows dipping into the low to mid 50s.

.LONG TERM...(Friday night through Tuesday)
Issued at 318 PM EDT Tue Jul 20 2021

High Impact Weather Potential...Minimal.

Typical summer weather for northern Michigan. There are some hints
of weak disturbances that may produce chances of showers at times,
but all in all, rain-free weather will most likely be the
predominant winner. As these disturbances become closer, timing,
duration, and intensity will be more fine tuned. One thing to watch
will be a possible very slow moving area of return flow associated
with a boundary associated with a system near Hudson Bay. If this
comes to fruition there could be a heavy rain event near the weekend
timeframe. Daytime high temperatures appear to be in the mid 70s to
low 80s, with some hints of warmer weather towards the weekend as
southerly flow advects warmer temperatures and more humidity.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 727 PM EDT Tue Jul 20 2021

Improving cigs tonight.

MVFR cigs are fairly widespread across northern lower MI. A skinny
line of showers extends from Petoskey to APX to a bit se of GOV.
As high pressure builds southward from north of Superior, drier
air will push into the region. Clouds will erode from n to s
tonight, with mainly VFR conditions after that, thru the day on
Wednesday.

Winds becoming light this evening.

&&

.MARINE...
Issued at 202 PM EDT Tue Jul 20 2021

Gusty north to northeast winds will gradually subside tonight,
with sub-advisory winds and waves expected through Wednesday night
as high pressure builds into the region. May see a few gusty
thunderstorms into early this evening across Lake Huron.
Otherwise, dry weather is expected.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 11 PM EDT this evening for LHZ349.
LM...NONE.
LS...NONE.
&&

$$

NEAR TERM...MB
SHORT TERM...TL
LONG TERM...TL
AVIATION...JZ
MARINE...MB