National Weather Service - Area Forecast Discussion

FXUS63 KAPX 181035

Area Forecast Discussion
National Weather Service Gaylord MI
635 AM EDT Mon Jun 18 2018

.NEAR TERM...(Today through Tonight)
Issued at 308 AM EDT Mon Jun 18 2018

Impactful weather: Maybe a few non-severe thunderstorms with a cold
frontal passage today.

Pattern synopsis and forecast:

The mid level ridging that has been overhead was starting to get
suppressed by a shortwave trough dropping SE out of south central
Canada. This has been forcing the main channel of vort maxes
southward from the Central Plains through Wisconsin and nrn
Michigan, underneath an elongated LLJ and moisture feed axis which
was positioned ahead of a cold front. This was resulting in a large
corridor of showers and isolated thunderstorms, aided by right
entrance region upper divergence from 120+kt upper jet laid out
across the eastern half of Canada. The better winds aloft have aided
in overall bulk shear, but low to mid level lapse rates have been
gradually becoming less steep resulting in loss of MUCAPE. Behind
the Canadian shortwave, sfc high pressure was centered over srn
Alberta and Saskatchewan.

The train of individual vort maxes/shortwaves and LLJ moisture
transport axis ahead of the cold front will continue to bring rounds
of showers and isolated thunderstorms to primarily nrn lower this
morning. The aforementioned Canadian shortwave was continue to press
SE through the day and night, essentially shoving all forcing and
showers southward from later this morning through this afternoon. A
weakening LLJ and upper divergence (departing upper jet) through the
day, ought to result in a gradual decrease in areal coverage and
intensity of the convection. Maybe some remnant showers will still
be around near/along the M-55 corridor into this evening. Not
thrilled too much with thunder, as instability is expected to
continue to slowly wane through the day. The sfc high pressure with
the greatest drying/clearing will work it`s way into Lake Superior
late tonight.

There is some concern that the back end of the cold front`s
southward progress gets held up into later in the night. This due to
a closed upper low in the rockies that wants to continue to pump
more shortwave energy NE into the midwest. This could mean some
overrunning/WAA showers/clouds could possibly linger around longer
into tonight in the vicinity of Manistee.

Highs today in the mid 70s to lower 80s, with lows tonight in the
50s, coolest across eastern upper in weakest winds and best


.SHORT TERM...(Tuesday through Wednesday)
Issued at 308 AM EDT Mon Jun 18 2018

High Impact Weather Potential: None

Pattern Synopsis/Forecast: The cold front that moved through the
state Monday will continue to sag south through the eastern CONUS as
high pressure drops south out of Canada. The encroaching cooler air
behind the front will continue to dampen the ridging that has been
building over the eastern CONUS, and keep the more warm and humid
airmass suppressed to our south. A potent shortwave is expected to
develop over the Central Plains by mid-week, possibly lifting into
the Great Lakes over the weekend.

Primary Forecast Concerns: Weather will be quiet through mid-week,
and into the weekend, as high pressure settles in behind the cold
front. With a cooler and drier air mass moving in, temperatures will
run much closer to normal, though still slightly above. We should
see lake effect development, which may kick off a random shower or
two, but the next real chance for showers won`t come until the
arrival of the shortwave over the weekend.

.LONG TERM...(Wednesday night through Sunday)
Issued at 308 AM EDT Mon Jun 18 2018

With high pressure overhead until late in the week, the weather will
remain warm and quiet. The next chance of rain will come over the
weekend, as a system lifts out of the Plains and through the Great
Lakes. There is surprisingly decent agreement in long term solutions
for arrival on Saturday, considering this will a cutoff low over the
Plains. Timing may need adjustments here and there, but the blend
PoPs for Saturday look good.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 633 AM EDT Mon Jun 18 2018

...More showers and a period of MVFR/IFR...

A cold front will slowly drop south across the region into early
this afternoon. This front will bring more showers and possibly a
few non-severe thunderstorms around mainly TVC/MBL. A period of
MVFR/IFR CIGS will accompany the front at all airports, as winds
turn more westerly off Lake Michigan, and low levels further
saturate. May even see some fog across NW lower for a time this
morning. As the front continues to press southward through nrn
Michigan, CIGS will lift, and skies will decrease in cloudiness.

Westerly winds will gradually turn more northerly, then easterly
late tonight.


Issued at 308 AM EDT Mon Jun 18 2018

Still no major marine concerns for several days, outside of some
continued areas of fog through this morning, while still in a
warm/humid air mass. A cold front associated with the current
corridor of showers and isolated storms impacting Lake Michigan and
Huron will drop from north to south through the day, and skies will
gradually be decreasing in clouds later this afternoon and tonight,
mainly in the nrn nearshore waters. There is some concern that
clouds and a chance for additional showers can linger around longer
in the srn nearshores, particularly Point Betsie to Sleeping Bear
Point. This pattern looks to continue into Tuesday and Tuesday





NWS APX Office Area Forecast Discussion