523
FXUS63 KAPX 172302
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
702 PM EDT Thu Oct 17 2019

.NEAR TERM...(Through Tonight)
Issued at 307 PM EDT Thu Oct 17 2019

High Impact Weather Potential: minimal.

Ridge of high pressure is gradually advancing across IL/WI/western
upper MI. Chilly and relatively moist low-level airmass is present
along and east of the ridge. When combined with diurnal heating and
lake contributions, this is resulting in plenty of cu/stratocu.
Cloud/temp trends are the main concerns tonight.

Precip had been trending downward in nw lower MI, but another
batch of showers is making inroads into Charlevoix/Antrim Cos and
environs. In addition, ERY has been reporting rain at times,
implying some lingering showers possible in western Chip/Mack Cos.
And just this past hour, ANJ has reported a shower too. All of
this activity will diminish with a further decrease in inversion
heights, but may not entirely disappear until diurnal heating
ceases by early evening.

Clouds are still layered over portions of nw lower MI, but otherwise
are clearly trending cellular over northern MI and especially points
north. This cu field will tend to erode this evening. Sky cover
guidance has trended less cloudy tonight, and that makes sense. A
good portion of the area (northern lower MI in particular) will
still be mostly cloudy at sunset. However, clouds will erode from
that point, with partly cloudy/mostly clear conditions for
midnight and after.

With less in the way of clouds, guidance temps have not surprisingly
gone lower for tonight. Winds will diminish quickly this evening as
the ridge approaches. The main obstacle for a very cold night
(outside of clouds) is that dew points are running fairly high
thanks to limited mixing. Have lowered min temps tonight 1-2f
compared to 12Z consensus guidance. This results in a lot of
mid/upper 20s in eastern upper, n central and ne lower MI. Readings
will be around 30 into the low/mid 30s in nw lower MI. And, though
moisture will be deposited as frost as temps approach dew points
tonight, have also added a touch of fog to the overnight.

&&

.SHORT TERM...(Friday through Sunday)
Issued at 307 PM EDT Thu Oct 17 2019

High Impact Weather Potential: Minimal.

Pattern/Synopsis: Heights continue to rise Friday with shortwave
ridging building into the Great Lakes region. This ridging will be
sandwiched between a strong cut off low in the northeast, and
general troughing across the Rockies. A series of waves will rotate
around the western troughing; one with minor impacts for Saturday
evening, and the other digging in and more impactful early next
week. Temperatures through the weekend will be above normal with
east coast ridging trying to hold strong over the Great Lakes.

Details/Forecast: Friday morning the surface ridge axis will be
right overhead, leading to a chilly morning. We quickly warm up
given mostly sunny skies under general subsidence and dry low/mid
levels. Overall Friday will be mild with a lack of real sensible
weather as the high slowly moves through the Ohio Valley. In the
meantime an elongated area of low pressure pushes through the
Central Plains as its parent shortwave treks along the US-Canadian
border. As the associated front approaches Michigan southerly return
flow ramps up late Friday night into Saturday with the tightening
gradient. A moisture-starved warm front crosses us Saturday, with
mainly an increase in midlevel cloud cover through the day, as
forecast soundings saturate top-down. The narrow corridor of better
moisture doesn`t come into play until late Saturday afternoon and
into the evening, along with the passage of the weakening cold
front. Precip may be heavy at times thanks to some decent forcing
crossing our area, and PWATs nearing an inch. However, profiles
quickly dry out again closer to sunrise. Through Saturday
night/early Sunday our next system already takes shape in the
central High Plains. Over in our neck of the woods Sunday remains
tranquil thanks to transient upper level ridging and a weak surface
high behind the cold front.

Temperatures will range anywhere from 5 to 10 degrees above normal
through the weekend and into Monday, as 850mb temps range from 4 to
9 deg C, and the Canadian cold pool remains held in check by
stubborn eastern seaboard ridging.

.LONG TERM...(Sunday night through Thursday)
Issued at 307 PM EDT Thu Oct 17 2019

High Impact Weather Potential: Potential for windy/rainy period
Monday into Tuesday.

Conditions change Sunday night as the approaching surface low starts
to ramp up some gusty southeasterly winds. Guidance is still
drastically spread regarding the system strength by Monday morning,
but placement within the upper Mississippi Valley has decent
agreement. As the upper level system takes on a negative tilt some
good dynamic support overspreads the area, but the best conditions
for lift will be along and north of Lake Superior. The surface low
deepens through Tuesday across central Ontario, keeping decent rain
and wind chances going Monday through Tuesday. The best chance of
heavier rain comes Monday night, with much above normal moisture and
decent forcing along the cold front. Then a transition to more lake
effect Tuesday into Wednesday as colder air entrenches across the
upper Great Lakes. Further shower chances exist Wednesday/Thursday
due to another weak system progged to move up the mid-Mississippi
Valley. We transition back to below normal temperatures as the cold
pool sinks south behind Monday/Tuesday`s strong system.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 700 PM EDT Thu Oct 17 2019

Residual lake effect rain showers will gradually come to an end
this evening...with sct/bkn lake clouds lingering into the
overnight hours. Overall conditions will remain VFR despite the
remaining lake clouds and showers. Only some sct fair wx CU is
expected for Friday as high pressure builds into the region. North
winds AOB 10 kts tonight will become SE under 10 kts on Friday.

&&

.MARINE...
Issued at 307 PM EDT Thu Oct 17 2019

Breezy nw-n winds continue in the wake of strong low pressure well
to our east, and ahead of high pressure advancing slowly from WI.
Winds/waves will diminish rapidly later today as the high moves
in. Southerly winds will start to ramp up Friday, especially on
Lake MI, in the wake of the high. Some advisories could be needed
again, especially by late Friday into Fri night.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 8 PM EDT this evening for LHZ346-349.
     SMALL CRAFT ADVISORY until 2 AM EDT Friday for LHZ347-348.
LM...SMALL CRAFT ADVISORY until 8 PM EDT this evening for LMZ342.
LS...SMALL CRAFT ADVISORY until 8 PM EDT this evening for LSZ321-322.
&&

$$

NEAR TERM...JZ
SHORT TERM...STJ
LONG TERM...STJ
AVIATION...MR
MARINE...JZ

NWS APX Office Area Forecast Discussion