FXUS63 KAPX 231446

Area Forecast Discussion
National Weather Service Gaylord MI
1046 AM EDT Fri Apr 23 2021

Issued at 1046 AM EDT Fri Apr 23 2021

Morning composite/satellite analysis reveals a fairly aggressive
short-wave working across southern Minnesota and trailing weak sfc
circulation sliding out of eastern South Dakota. Modest moisture
return axis noses up through Iowa into Minnesota with PWAT values
up to around half an inch. Enough forcing/moisture to kick off
some -RA and little -DZ across Minnesota and parts of western

Per RAP13 guidance, short-wave circulation and associated QG-
forcing for ascent will dampen out as it traverses through
Wisconsin and eventually across the U.P. later this
afternoon/tonight. But, given the degree of dry air in place
across the region and modest lower level moisture transport into
the region ahead of the wave, I have serious doubts we see much in
the way of precip this afternoon. Some CAM guidance (NAMNEST)
remain aggressive in popping off a few showers across parts of
eastern Upper Michigan this afternoon. Given RAP13 forecast
soundings up that way...I`m doubtful. So I may be removing pops up
there for the afternoon, upon collaboration with neighbors.

Otherwise, some mid and high cloud cover will be on the increase
through the afternoon. Temps are already well on their way to
forecast highs and may need some upward tweaking.


.NEAR TERM...(Today through Tonight)
Issued at 502 AM EDT Fri Apr 23 2021

Impactful weather: Minimal/none.

Pattern synopsis and forecast:

Mid level ridging and pretty dry air was over the Great Lakes region
early this morning, resulting in clear skies all around. Despite the
clear skies, a little bit of wind out there, and a good deal of low
to mid level warm advection was preventing much of a fall in
temperature. This is outside of the typically colder lower lying
locales of NE/NC lower Michigan which are protected from the wind.
Readings in these areas have dipped into the mid to upper 20s, but
otherwise, readings ranged through the 30s, with even some lower 40s
in coastal counties of Lake Michigan. There was a shortwave in the
nrn and central Plains, with stronger lower half of the atmosphere
theta-e advection/convergence out ahead of a cold front from the
western Dakotas into SW Ontario, attached to low pressure in nrn
Ontario. This was resulting in an area of light rain and drizzle as
seen on radar and sfc reports across portions of MN/IA and SD. Even
further upstream, there was more upper troughing moving through the
Rockies, with it`s own pockets of precipitation.

The mid level ridging crosses nrn Michigan this morning, while the
initial shortwave arrives this afternoon and into the evening, ahead
of the cold front that was be dropping into srn Ontario and far
western Lake Superior. There will be some thickening sky cover with
this wave, and there is a very small opportunity for a few light
showers to pop off across portions of eastern upper Michigan, within
an expected region of lake breeze convergence. This wave passes
through the remainder of the evening, and sky cover may even thin a
little, before the next upper troughing sneaks in overnight. Forcing
is rather weak ahead of this feature, with weak low to mid level
theta-e advection and DPVA. However, some light rain may get spit
out over portions of NW lower toward daybreak, with some fcst
soundings suggestive off maybe even more of a drizzly scenario.

Nothing too impactful. Better chances for rain Saturday and Saturday
evening (see below).

High temperatures are expected to climb into the mid and upper 50s
for eastern upper and NW lower, with the lower half of the 60s in
downsloping westerly flow over NE lower. Lows tonight will mostly be
in the middle 30s to lower 40s.


.SHORT TERM...(Saturday through Sunday)
Issued at 502 AM EDT Fri Apr 23 2021

High Impact Weather Potential: Freezing temps possible Saturday

Pattern Synopsis:

A potent shortwave will traverse the SE CONUS while a second
shortwave works its way into the Great Lakes on Saturday. These
features will provide favorable ascent/forcing aloft to induce
cyclogenesis/surface pressure falls as these systems trek eastward
over the weekend.


Scattered/widely scattered rain showers are expected to be working
their way into northern Michigan Saturday morning as the
aforementioned shortwave approaches the region. These lesser rain
chances will likely be off-and-on at any one location, and even
drizzly in nature at times, through the morning hours as more
favorable forcing arrives later. An uptick in precip - both
spatially and in intensity - will come in the early afternoon as a
cold front sweeps into Michigan from the northwest, providing
necessary near-surface forcing for initiation. Forecast soundings
display non-zero instability despite relatively cool surface temps
that is actually confined to the low-levels, which may result in
some heavier downpours during the afternoon/evening hours for some.
These showers formed along and ahead of this front across NW lower
are expected to work eastward into Saturday night as additional
precip is expected with a second reinforcing front moving in late
Saturday night/Sunday morning. If rain chances most of the day on a
Saturday in late April sounds fun, just wait for the lake effect
snow chances Sunday morning! Yes, a chance for some light snow will
exist Sunday morning as NW winds advect freezing low-level temps
into the area. Thus, freezing overnight temps may once again pose a
threat to sensitive agricultural areas, especially in the coastal
counties of NW lower. This will continue to be monitored over the
coming days.

Otherwise, surface high pressure will begin to build towards the
Great Lakes and bring a drier airmass to the region. This will help
end any lake effect precip by Sunday afternoon and bring partly
sunny skies to northern Michigan. Continued NW winds are expected to
keep afternoon highs on the cool side, however, as temps may
struggle to reach past the mid-40s for many.

.LONG TERM...(Sunday night through Thursday)
Issued at 502 AM EDT Fri Apr 23 2021

High Impact Weather Potential: Low for now...Monitoring middle of
next week.

A shortwave will continue to trek east of the Great Lakes Sunday
night as amplified upper-level ridging spreads across the eastern
CONUS through early next week. Subsidence aloft will help strengthen
surface high pressure over the region before being shunted eastward
by Monday night. Strong, amplified troughing is also expected work
across the heart of the CONUS through the middle of next week which
looks to bring more active weather to northern Michigan heading
towards the end of the period.

As noted in last night`s discussion, confidence is higher in a more
amplified/less progressive pattern during the middle of next week as
upper-level features become increasingly amplified. Enhanced
southerly low-level winds should advect a seasonably warm and very
moist airmass northward all the way into the Great Lakes, likely
bringing PWAT values near or exceeding climatological max values for
late April. When combined with potential instability and largely
unidirectional flow with SW/SSW orientation through the profile,
this points towards the possibility for heavy rainfall across the
region. This is still nearly a week away with many details still
blurry at this range, but consistency in guidance and pattern
recognition still make this potential noteworthy at this time -
especially since northern Michigan has been rather dry as of late.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 502 AM EDT Fri Apr 23 2021

...VFR the entire TAF period...

High pressure will cross the SE states and off into the Atlantic
today, while a cold front approaches tonight, resulting in a slight
chance for light rain across the NW lower Michigan airports. Mostly
sunny skies will start off the day, but some high-based cumulus and
increasing higher level clouds are expected through the remainder of
the day and tonight. VFR conditions expected the entire TAF period.

SW/W winds will be gusty at times this afternoon, before weakening
tonight and turning more southerly.


Issued at 502 AM EDT Fri Apr 23 2021

High pressure will cross the SE states and off into the Atlantic
today, while a cold front approaches tonight. Spotty low end
advisory gusts are possible this afternoon for Lake Michigan through
the Straits, but there`s not enough confidence to issue a headline
attm. The front crosses Saturday into Saturday evening, with lighter
and more variable winds expected across the nearshore waters. A
tighter gradient then settles in through later Saturday night, with
cold advection and growing overlake instability, likely leading to
advisory level NW winds.

There`s a slight chance for light rain across Lake Michigan late
tonight, but increasing chances for rain will be seen Saturday and
Saturday night for all nearshore waters.





NWS APX Office Area Forecast Discussion