000
FXUS63 KAPX 240936
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
536 AM EDT Sat Jul 24 2021

.NEAR TERM...(Today through Tonight)
Issued at 232 AM EDT Sat Jul 24 2021

Impactful weather: Showers and thunderstorms. Severe storms possible
with damaging winds being the primary threat, and to a lesser
degree, large hail.

Pattern synopsis and forecast:

Shallow upper ridging was pressing east of nrn Michigan early this
morning, while shortwave troughing was working it`s way across srn
Canada and the nrn Plains. This wave was aiding in deep sfc low
pressure in far nrn Manitoba, which had a trailing cold front back
through MN/SD. A warm front extended SE of the low pressure through
the western Great Lakes. While the greatest instability was within
the warm sector east of the cold front and south of the warm front,
elevated instability off 200-600j/kg was over nrn Michigan with less
than impressive 25-30kt 0-6km effective bulk shear. Not really a
good setup for anything severe/organized, but enough for some
isolated to scattered thunderstorms in eastern upper.

The shortwave trough will press through our neck of the woods today
into this evening, with the warm front lifting through this morning,
with decent forcing (strongest in eastern upper) from upper jet
divergence and theta-e convergence, resulting in a period of showers
and some thunderstorms. Again, not looking for anything severe, and
best coverage in eastern upper. Then as typically can be the case,
things become a little more nebulous. Still looking like some fairly
extensive cloudiness will inhibit good diurnal heating (latest
guidance really wanted to bring high temperature down into the upper
half of the 70s in many places today). That said, considering it`s
late July, good a decent enough feeling that even some marginal
clearing will bring in warmer conditions, and kept high temperatures
in the lower 80s most areas. This will result in several hundred to
1500j/kg of ML/MUCAPE (greatest in the SE third of the CWA, and
least north of M-68, including eastern upper. Wind fields do
increase as well, with 0-6km effective bulk shear maybe in the 35 to
40 knot range. Much more favorable for organized storms, and we
remain in a slight chance for severe in that SE third of the CWA,
and a marginal elsewhere. The primary threat continues to be
damaging winds, and to a lesser degree, large hail, and to an even
smaller degree, maybe a tornado in nrn lower/more so NE lower.
Strongest activity is still expected this afternoon into early this
evening, before the cold front passes, and drier air/clearing and
diminishing instability arrive. Could even see some patchy fog in
low lying areas.

High temperatures will largely be in the upper 70s to lower half of
the 80s, with lows tonight in the upper 50s to lower half of the
60s.

&&

.SHORT TERM...(Sunday through Monday)
Issued at 232 AM EDT Sat Jul 24 2021

...Very Warm and Less Humid...

High impact weather: None is expected.

Weak surface high pressure and steady to slowly rising heights aloft
are expected to lead to rain free but very warm conditions through
the short term. Highs in the mid and upper 80s with lows in the
upper 50s and low 60s. Humidity levels will be down though with
dewpoints generally in the more comfortable 50s.

.LONG TERM...(Monday night through Friday)
Issued at 232 AM EDT Sat Jul 24 2021

...Continued Very Warm with Periodic Rain Chances...

High impact weather potential: Low at this time but stronger
thunderstorms are a possibility Tuesday into Wednesday.

A large upper level ridge encompassing much of the western and
central states leaves a northwest flow aloft across the Great Lakes
region. Periodic short waves moving through this flow will bring
occasional chances for showers and thunderstorms across the region,
mainly Monday night into Thursday and especially Tuesday and
Wednesday. Temperatures will continue to be well above normal
(especially as far as daytime highs) with perhaps not as warm
conditions arriving toward the end of the week.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 532 AM EDT Sat Jul 24 2021

A warm front will lift through nrn Michigan today, which will be
followed by a cold front tonight. This will bring a few rounds of
showers and thunderstorms to the airports, and a period of gusty
southerly winds this afternoon. There is also a chance for some
severe storms, with damaging winds being the primary threat, and
to a lesser degree, large hail. Winds shift more westerly tonight,
with drier air sweeping into the region, ending rainfall chances.
CIGS will lower into a period of MVFR/IFR this morning, before
returning to VFR later today through tonight.

&&

.MARINE...
Issued at 232 AM EDT Sat Jul 24 2021

A warm front will lift through nrn Michigan today, which will be
followed by a cold front tonight. This will bring showers and
thunderstorms to most nearshore waters, along with the possibility
of low end advisory southerly wind speeds today, before shifting
more westerly tonight into Sunday. Will go ahead and issue an
advisory for much of Lake Michigan and portions of Lake Huron. The
next chance of showers and storms arrives Monday night into Tuesday.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 7 PM EDT this evening for LHZ348-349.
LM...SMALL CRAFT ADVISORY until 5 PM EDT this afternoon for LMZ323-
     342-344>346.
LS...NONE.
&&

$$

NEAR TERM...SMD
SHORT TERM...AS
LONG TERM...AS
AVIATION...SMD
MARINE...SMD