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

000
FXUS63 KAPX 151701
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
101 PM EDT Sat Jul 15 2017

.UPDATE...
Issued at 920 AM EDT Sat Jul 15 2017

Early morning fog/stratus succumbing to mid-July sun and slowly
strengthening southwest winds, and should be gone from the area
within the next hour or so. Scattered high based light showers in
area of relatively steep mid-level lapse rates dropping across
upper Michigan this morning. These will continue to drop
southeast, likely slowly decaying in the process. Any rain will be
light and brief for those that do experience these showers.
Otherwise, waiting on arrival of shortwave trough and attendant
cold front to ignite additional showers and thunderstorms later
this afternoon and evening. Best instability plume will remain
across Wisconsin, with instability rapidly falling off into
northern Michigan. Expect scattered/broken band of showers/storms
to develop across central upper Michigan and northern Wisconsin
later this afternoon, possibly congealing into a legitimate squall
line as they drop almost due south across Wisconsin and Lake
Michigan. This area remains within slight risk per latest SPC Day
One convective outlook, with marginal risk clipping parts of
northwest lower Michigan. While best activity does look to remain
to our west, an isolated severe wind gust is possible with any
organized convection across northwest lower and Lake Michigan
later this afternoon and early evening.

&&

.NEAR TERM...(Today through Tonight)
Issued at 231 AM EDT Sat Jul 15 2017

...Dry and warmer today with increasing chances of storms tonight...

High Impact Weather Potential...Marginal risk of severe storms for
portions of NW Lower Michigan tonight.

Pattern Synopsis/Forecast...High pressure remains centered over much
of the Upper Mississippi Valley and Wisconsin early this morning.
Skies are mostly clear across much of our CWA as a result of
subsidence and drier air building into Michigan. Some patchy fog has
developed under clear skies and light/calm winds...as temps fall
into the 50s. Meanwhile...an upstream cold front extends from
Ontario thru the Northern Plains states...generating some weak
convection over the Dakotas along this feature.

As we head into today...high pressure will slide southward thru the
Mid Mississippi Valley and into the Ohio Valley by this evening. The
upstream cold front will follow behind the surface high center...
sagging into Upper Michigan this afternoon and then thru Lower
Michigan tonight into Sunday morning. Latest short term models have
backed off on areal coverage of POPs with this feature...focusing
most of the convective development in the form of a convective line
taking shape over Central Upper Michigan and Northern Wisconsin this
evening...dropping SE and clipping our SW CWA late this evening and
into the overnight hours. Whatever convection that does develop will
likely have the capability of becoming strong/severe as it develops
along the northern periphery of the strong instability axis and
prominent 850 mb theta E ridge. Will continue to advertise highest
POPs in our SW CWA tonight...although even these POPs are chance as
strongest convection will likely slide west of our CWA.

After a couple of unseasonably cool/almost fall-like mid July
days...temps will be noticeably warmer today as afternoon highs warm
into the mid 70s to lower 80s. Low temps tonight will cool into the
mid 50s to lower 60s.

&&

.SHORT TERM...(Sunday through Monday)
Issued at 231 AM EDT Sat Jul 15 2017

...Gradually warming temperatures early next week...

High Impact Weather Potential: None.

Pattern Forecast: Slow moving mid level shortwave diving into the
northern Great Lakes gradually closes off as it spins across
northern Michigan on Sunday. Early Sunday morning cold front
progressing east across the forecast area is expected to exit by mid-
morning bringing any remaining shower/thunderstorm activity to an
end, although lingering clouds and patchy drizzle may take their
time exiting as a pocket of cooler air rotates overhead. Heights
begin to rise late Sunday afternoon as the closed low shifts
eastward into southern Ontario, ultimately being replaced with
surface high pressure and mid level ridging cutting across northern
Michigan by Monday afternoon.

Primary Forecast Concerns/Challenges: Not much in the way of
potential impacts through the short term forecast period. Main
challenge revolves around lingering clouds and perhaps areas of
drizzle as a pocket of cooler air rotates overhead associated with
the aforementioned closed upper low slowly migrating through the
northern Great Lakes. Gut feeling is that Sunday ends up a lot like
this past Thursday and Friday did with below normal temperatures,
low clouds, and patchy drizzle affecting a majority of the area for
a good chunk of the day before gradually diminishing during the
afternoon and evening.

Much more summer-like weather is anticipated for Monday with mostly
sunny skies, light winds, and high temperatures climbing back to
near normal...ranging from the mid 70s north to the upper 70s-80
degrees south.

.LONG TERM...(Monday night through Friday)
Issued at 231 AM EDT Sat Jul 15 2017

High impact weather potential: Scattered thunderstorms possible
Tuesday night through Wednesday.

Return flow ongoing Monday night-Tuesday ahead of the next system
approaching from the west, set to arrive Tuesday night-Wednesday,
will lead to climbing temperatures and increased dewpoints.  High
temps maxing out in the low-mid 80s and dew points in the low 60s
will certainly bring back more muggy air across northern Michigan on
Tuesday. Guidance continues to prog a cold front crossing the region
during the Tuesday night-Wednesday timeframe with shower and
thunderstorm development ahead of the front. Current trends suggest
modest instability may develop locally, greatest during the day
Wednesday (although much more so to our west over WI/IA/S. MN).
Combined with bulk shear values upwards of 30 kts, PWs greater than
1.75 inches, and a K-Index in the mid-30s, a conditional severe
weather threat cannot be ruled out at this juncture...and certainly
the threat for any thunderstorms to produce briefly heavy rain.

Occasional shower and thunderstorm chances continue at various times
through the remainder of the forecast period as Wednesday`s front
slowly washes out/stalls across the Great Lakes/Ohio
Valley...leaving a thermal gradient to be the focus for several mid
level perturbations emerging from the Rockies to gradually race
eastward.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1258 PM EDT Sat Jul 15 2017

Cold front will cross the taf sites from north to south overnight.
This front will bring some scattered showers and thunderstorms
along with it, although limited coverage and low confidence on
exact timing prevents nothing more than vicinity wording at this
time (and then only at KTVC and KMBL where "greatest" coverage is
anticipated). MVFR/perhaps IFR producing low clouds likely to
develop once again behind this front tonight, with this could deck
likely to stick around through Sunday morning.

&&

.MARINE...
Issued at 231 AM EDT Sat Jul 15 2017

Winds and waves will remain just below SCA criteria across our
nearshore areas thru Sunday night...although winds along Lake
Michigan may approach criteria both Saturday afternoon and Sunday
afternoon during peak mixing. After a dry and noticeably warmer day
today...chances of showers and storms will increase tonight into
Sunday morning...especially for our Lake Michigan nearshore areas as
a cold front sweeps thru the region.


&&

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

$$

UPDATE...MB
NEAR TERM...MR
SHORT TERM...MG
LONG TERM...MG
AVIATION...MB
MARINE...MR



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