Area Forecast Discussion
Issued by NWS Gaylord, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

757
FXUS63 KAPX 211045
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
645 AM EDT Thu Sep 21 2017

.NEAR TERM...(Today through Tonight)
Issued at 342 AM EDT Thu Sep 21 2017

...Unseasonably warm and humid...

High impact weather potential...few strong t-storms possible this
afternoon/early evening northern lower MI.

Incoming cold front pushing east of MQT-ESC-GRB. Broken line of
showers/t-storms just ahead of the front is impacting portions of
northern MI. The front will lay over across central lower MI by
late today, while a trailing bubble high transits the Lk Superior/
James Bay areas. Return flow will start to get going again tonight
as the high move into Quebec, though this return flow will be much
stronger to our west. Precip trends and temps are the main concerns.

Ongoing precip is thinning out (and has been struggling for much of
the event) south of M-32. A band of stronger storms still exists
from just east of Drummond Isl to Presque Isle Co. Expect
northern activity to exit to the ne, with lingering showers to the
south continuing to dissipate. CAMs favor current convection
fading out by 12-13z, as instability fades and forcing lifts out
into Canada.

That will leave us with a warm and humid airmass, but a healthy
amount of cloud cover early on. Clouds will thin with time, with a
mostly cloudy morning giving way to a partly sunny and hazy
afternoon. Temps will climb quickly in this warm airmass, and temps
look to reach in the mid/upper 70s in the Straits area and points
north, and 80s elsewhere. Gladwin the most likely spot to take a
run at the upper 80s. (These values are generally a few degrees
short of record highs.)

Dew points in the upper 60s to around 70f (!) will support MlCape
values a bit in the 1-1.5k j/kg range. Warm temps aloft (15C at
circa 825 mb) will provide a weak cap, but lake breezes may have
enough forcing to get thru that. After pops dwindle early this
morning, will return a broad area of northern lower MI to chance
pops this afternoon, with a slight chance for redevelopment in
eastern upper. 0-6km bulk shear is anemic (10kt or less), but we
have enough instability/moisture for some strongish wet
microbursts.

Any diurnal convection here will diminish this evening. However,
with some return flow getting going overnight, the instability plume
will make northward progress tonight even as it wanes. This will be
especially notable in western/central upper MI, where return flow is
stronger. Still, pulses of deep convection could generate there
tonight, and propagate eastward into our northern sections. Chance
pops returns to far northern lower and eastern upper MI, mainly
overnight. Elsewhere, threat for some fog returns. Min temps mid 60s
to around 70f.

&&

.SHORT TERM...(Friday through Saturday)
Issued at 342 AM EDT Thu Sep 21 2017

...Dry for the Weekend...

High Impact Weather Potential...None

Pattern Synopsis/Forecast...There could be some showers left over
from the night, but for the most part the 500 mb ridge begins to
amplify and the 850 mb and 700 mb levels warm. This caps the region,
to a certain extent, and with the lack of a kicker(front or jet) the
think that the limited pops in E Upper in the morning and dry
through the afternoon looks good. The ridge continues to amp up, and
continues the dry weather through Sunday morning.

Primary Forecast concerns...If we could get any kind of kicker to
start precipitation, the MLCAPE is over 1500 J/kg. However, looking
at the ML parcels on the skew-t, there is some weak capping so don`t
think that anything gets going.

.LONG TERM...(Saturday night through Wednesday)
Issued at 342 AM EDT Thu Sep 21 2017

...Dry Early in the Week then Rain to Move in by Mid week...

Extended (Sunday through Wednesday)...Sunday through Tuesday
morning, the 500 mb Ridge continues to keep the region dry. Tuesday
afternoon, the ridge finally breaks down and the cold front begins
to move into the forecast area. There could be some thunder, but at
this point, thinking it is unlikely as we are pretty well capped as
the front moves through the region. Wednesday, there is a timing
difference in the GFS and the ECMWF 500 mb lows are placed
differently upstream. The ECMWF idea brings in LE Rain showers on
Wednesday and brisk temperatures, while the GFS is slower with the
main trough at 500 mb having yet to rotate into the region (not
until Thursday). So think that there will be some showers around,
but no confidence in this forecast for days 6 and 7.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 645 AM EDT Thu Sep 21 2017

Chance for shra/tsra this afternoon/early evening. Fog tonight.

Weak cold front will edge into lower MI today, then stall before
heading back north late tonight. Warm/humid airmass in place may
be conducive to seeing some showers/storms pop this afternoon, at
least once we get rid of the cloud cover we`re starting with this
morning. More significant aviation impacts expected tonight, when
fog develops overnight. Potential for IFR conditions at all taf
sites.

Light/variable winds.

&&

.MARINE...
Issued at 342 AM EDT Thu Sep 21 2017

Decaying cold front will slow and stall as it crosses northern
Lake MI and reaches central lower MI by early tonight. Surface
winds will be relatively light while the front is in the vicinity.
Southerly winds will ramp up into Friday and Friday night, and
some choppy conditions will develop on Lake MI, especially toward
the far north end of the Lake. Advisory-level waves are a
possibility.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

NEAR TERM...JZ
SHORT TERM...JL
LONG TERM...JL
AVIATION...JZ
MARINE...JZ



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.