Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 251950
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
350 PM EDT Fri May 25 2018

.NEAR TERM...(Through Tonight)
Issued at 340 PM EDT Fri May 25 2018

...Shower and thunderstorms possibilities...

High Impact Weather Potential...Thunderstorms will impact the
region tonight. Stronger storms will be found in eastern upper
Michigan this evening.

Pattern Synopsis/Forecast...Afternoon composite analysis reveals
a short-wave trough axis slowly pressing into the western Great
Lakes region. Surface low pressure is across south-central Canada
with a trough extending down through the Upper Midwest. Plume of
deeper moisture and best instability still resides through the
Midwest up into the western U.P. although we have managed to
generate around 1500 J/kg SBCAPE across interior northern lower
Michigan this afternoon, and a corridor showers/thunder across
north-central lower MI.

To the north, convectively induced MCV has rolled out of northern
Wisconsin and now up into the central U.P. and has sparked a few
clusters of stronger storms up that way.

Primary Forecast Concerns...convective development and trends.

Ongoing "pop-up" showers/storms across north-central lower MI will
fade away as we head through the early evening hours, and not
likely to cause too many issues other than some smaller hail and,
of course, lightning. But, will have to keep an eye on stronger
storms coming through the central U.P. and the door peninsula,
which do have the potential to produce strong-severe weather
over the next few hours.

After that, I still anticipate additional showers/storms to
develop across Wisconsin as we head into the evening hours (the
severe thunderstorm watch out there was a giveaway). Any
convection that does develop to our W/NW may try to work down into
our area later this evening and overnight. But, not overly
confident on how much actually survives the trip with diminished
instability downstream, no substantial forcing to maintain it and,
of course, the big cold body of water to cross. In fact, many
high-res guidance solutions have very low rain chances for us
through the night. I will maintain chancy pops across our area for
later this evening and overnight. But really, I would not be
surprised if hardly anyone gets rain.

&&

.SHORT TERM...(Saturday through Monday)
Issued at 340 PM EDT Fri May 25 2018

...Weekend rain chances...

High Impact Weather Potential: Scattered thunderstorms Saturday and
Sunday

Pattern Synopsis/Forecast: A pair of shortwave disturbances will
move over the region Saturday and Sunday. PWAT values over 1" will
remain overhead as well. High pressure will once again start
building into the region on Monday.

Primary Forecast Concerns: Primary concern remains the potential for
some scattered thunderstorms over the weekend. Still doesn`t look
like a washout, but some afternoon pop-up storms could cause some
inconvenience for the areas they move over. Most areas will remain
dry a majority of the time, but pop-up showers could still be a
brief annoyance with outdoor activities.

Shear still doesn`t look favorable for any kind of organized severe
threat Saturday, with  15 to 20kts of 0-6km bulk shear. There are
still a few areas Sunday with bulk shear getting into magnitudes
more supportive of organized convection, but it remains small areas
and differs across guidance. Wouldn`t be surprised to see some small
hail with storms that can get going, but again expect most to be
short lived pulse storms.

.LONG TERM...(Monday night through Friday)
Issued at 340 PM EDT Fri May 25 2018

...Lots of uncertainty next week...

The pattern remains a bit nebulous through next week, and the
differences in guidance are quite large. There is a range from
nothing all to week to rain potential almost daily. A lot of this is
likely coming from guidance struggling with a bit of a rex block
setup with what is now sub tropical storm Alberto in the Gulf and
high pressure spanning across much of the eastern CONUS. Just how
and when that breaks down, and how the remnants of the weakening
Alberto behave as they move through the Tennessee Valley will remain
details to be worked out over the coming days. For now the consensus
blends will be left.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 340 PM EDT Fri May 25 2018

Overall VFR weather is anticipated through the next 24 hours.
Pop-up showers and a few storms will continue across parts of
northern lower Michigan this afternoon, mainly impacting the APN
terminal site. Additional showers and storms are possible later
tonight and on Saturday which would produced brief MVFR
conditions. Have not explicitly included shra/tsra in taf
forecasts at this juncture given the uncertainties with
convection.


&&

.MARINE...
Issued at 349 PM EDT Fri May 25 2018

Gusty winds will persist through the early evening hours leading
to small craft advisory conditions for parts of Lake Michigan and
Lake Huron.

Otherwise, winds will lighten this evening and overnight,
remaining mostly out of the south/southwest through Sunday. The
north end of Lake Huron will be the exception, with winds Saturday
afternoon out of the southeast/east roughly as you get north of
Thunder Bay. Chances for scattered thunderstorms will continue
through the weekend, which could produce some small hail and some
localized gusty winds.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 9 PM EDT this evening for LHZ348-349.
LM...SMALL CRAFT ADVISORY until 9 PM EDT this evening for LMZ344>346.
LS...NONE.
&&

$$

NEAR TERM...BA
SHORT TERM...AM
LONG TERM...AM
AVIATION...BA
MARINE...AM



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