Special Weather Statement, NWS Gaylord, MI

Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Mon Aug 6 2018

.UPDATE...
Issued at 949 PM EDT Mon Aug 6 2018

Approaching cold front has reached the tip of the Mitt late this
evening. Meanwhile...all convection just ahead of this front has
died with loss of diurnal instability and as focus for convective
development remains well to our south within strong instability
and moisture axes. A look at upstream radars over Wisconsin shows
remaining narrow line of shower activity near GRB along and just
ahead of the cold front has also died. Near term models suggest
some revival of shower activity over our western CWA as the cold
front drops thru Northern Lower Michigan. Radar trends certainly
do no support this idea...and given loss of diurnal instability
(which kept our weak convection alive this afternoon)...am tending
to think continued dry wx for the rest of the night is more
likely. Do expect some patchy fog development overnight into early
Tuesday...and have expanded this patchy fog into all areas of our
CWA. Temps will be noticeably cooler overnight as CAA commences
behind the cold front. Overnight lows will range from the upper
50s in Eastern Upper Michigan to the mid 60s near Saginaw Bay.

&&

.NEAR TERM...(Through Tonight)
Issued at 327 PM EDT Mon Aug 6 2018

...Showers end this evening...

High impact weather potential: Perhaps a few stronger storms through
early this evening.

Pattern synopsis/forecast: Area, for at least a bit longer yet,
remains in moisture rich southwest flow ahead of a slow moving cold
front stretching across central upper Michigan into Wisconsin.
What's left of earlier southwest Lakes convective complex bringing
some light rain across our far southern counties, along with plenty
of cloud cover across the rest of northern lower Michigan. A bit
more vigorous showers and thunderstorms firing across eastern upper
as sharp frontal-produced surface convergence axis works on a bit
more robust instability core (surface based cape in excess of 2k
joules/kg of surface based cape). These showers/storms largely
behaving, although no doubt some are producing brief periods of
heavy rain.

Cold front will continue to make slow, but steady, progress
southeast tonight, made to do so by subtle mid level wave racing
east within broader mid-level trough axis. This front is expected to
exit our southeast counties by the early morning hours of Tuesday,
ending the shower threat in the process.

Primary forecast concerns/challenges: Addressing that shower and
thunderstorm potential this evening. Overnight cloud and fog trends.

Details: Time is up for northern lower to destabilize, with much of
the action expected across eastern upper and through the Straits
later this afternoon as the front drops further south. Expect to see
a few additional showers and perhaps a rumble of thunder south of
the big bridge, with additional decaying upper Michigan activity
sliding southeast into the early evening. Per the usual, expect most
of the area and much of the time to remain dry under just mostly
cloudy skies. While not expected, an isolate severe thunderstorm
does remain possible this afternoon across eastern upper and the
Straits. Passage of front ends the shower threat from north to south
this evening and early overnight. Clouds will attempt to scatter out
for a bit as dry air advection develops. However, given lingering
low level moisture and last night's post-frontal cloud trends well
upstream, gotta believe some stratus will attempt to fill in. Have
trended the forecast at least partially to this cloudier idea. Could
also see some fog, particularly in the lower lying areas down near
Houghton Lake and West Branch.

&&

.SHORT TERM...(Tuesday through Thursday)
Issued at 327 PM EDT Mon Aug 6 2018

High Impact Weather Potential: Slight chance of thunderstorms
Tuesday afternoon and again late Wed. night-Thursday, particularly
across the southeastern portion of the forecast area.

Pattern Forecast: Broad/weak troughing is anticipated at the start
of the forecast period early Tuesday morning with nocturnal
convection associated with this afternoon's frontal boundary
expected to be well off to our south and east. Well-defined mid-
level wave is expected to trek from the plains into the mid-
Mississippi Valley Tuesday afternoon into Tuesday night, although a
weak bubble of surface high pressure across the northern Great Lakes
may keep much of the area precipitation-free. Another subtle wave
and attendant cold front is expected to trek southeast across the
forecast area Wednesday night into Thursday, providing the next
precip potential across the region.

Primary Forecast Concerns/Challenges: PoPs Tuesday afternoon and
Wednesday night-Thursday.

Weak surface high pressure is expected to gradually drift overhead
during the day Tuesday, aiding to provide partly sunny skies across
much of northern Michigan. By Tuesday afternoon, greatest deep layer
moisture across the forecast area is expected to be lingering along
and south of M-72 evident by PWs at or above 1.40 inches (tapering
quickly to the north). Aforementioned incoming mid-level wave and
developing afternoon lake breezes may be enough to kick off isolated
showers and a few thunderstorm...primarily across sections of
northeast lower. MLCAPE values upwards of 500 J/kg and bulk shear
values nearing 35-40 kts could prove to be enough for a few
sustainable updrafts and at the very least, a briefly heavy rain
threat. That said, coverage of showers/storms isn't expected to be
great with much better forcing and deeper moisture centered to our
south across southern MI into the Ohio Valley (discounted the GEM as
it remains pretty much the only outlier at this point with moisture
shifted north across the CWA and a much deeper area of low pressure
trekking downstate).

By Tuesday night, dry conditions are expected across the forecast
area with mostly sunny skies prevailing for Wednesday. Focus then
shifts to a secondary weak incoming wave and attendant cold front
expected to slowly press southeastward across the CWA. This will
renew shower chances over eastern upper MI Wednesday evening/
overnight before sagging southward Thursday morning and eventually
stalling out further south toward central lower by Thursday
afternoon.

High temperatures coolest on Tuesday ranging from the low-mid 70s
across eastern upper and northeast lower to near 80 near Saginaw
Bay. A few degrees warmer area-wide Wednesday-Thursday...ranging
from the upper 70s to low 80s.

.LONG TERM...(Thursday night through Monday)
Issued at 327 PM EDT Mon Aug 6 2018

High Impact Weather Potential: Diurnally driven thunderstorms
possible Friday; otherwise, minimal for now.

Troughing over the Great Lakes will continue to support additional
chances of precipitation through Friday...especially diurnally
driven showers and thunderstorms during the afternoon/early evening
hours. The upcoming weekend appears to be mostly quiet at this
juncture with cutoff upper level low pressure spinning across the
Tennessee/Ohio Valleys and surface high pressure anchored across the
Great Lakes.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 1145 PM EDT Mon Aug 6 2018

A cold front will continue to drop SE through Northern Lower
Michigan overnight. Majority of the precipitation ahead of this
front has ended across our area. Some patchy fog/stratus will
develop overnight into early Tuesday...dropping conditions to
MVFR...and possibly IFR in some locations. Light/variable winds
overnight will become N/NW at around 10 kts on Tuesday.

&&

.MARINE...
Issued at 327 PM EDT Mon Aug 6 2018

Sub-advisory southwest winds will gradually veer northwest
overnight as a cold front crosses the regions. A few showers and
thunderstorms are expected with this front, some of which could
bring some brief gusty winds and heavy rain. Northwest to north
winds continue Tuesday, with winds becoming light and variable
Tuesday night. Current trends support a continuation of sub-advisory
winds right through the remainder of the week.

&&

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

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

Hazardous Weather Outlook
National Weather Service Gaylord MI
907 PM EDT Mon Aug 6 2018

LHZ345>349-LMZ323-341-342-344>346-LSZ321-322-MIZ008-015>036-041-
042-071200-
Straits of Mackinac within 5 nm of Mackinac Bridge including
Mackinac Island-St Ignace to False Detour Channel-
5NM East of Mackinac Bridge to Presque Isle Light MI including
Bois Blanc Island-
Presque Isle Light to Sturgeon Pt MI Including Thunder Bay
National Marine Sanctuary-Sturgeon Pt to Alabaster MI-
Grand Traverse Bay south of a line Grand Traverse Light to
Norwood MI-Seul Choix Point to 5NM West of Mackinac Bridge-
Norwood MI to 5NM West of Mackinac Bridge including Little
Traverse Bay-Sleeping Bear Point to Grand Traverse Light MI-
Point Betsie to Sleeping Bear Point MI-
Manistee to Point Betsie MI-
Whitefish Bay (U.S. Portion)/Whitefish Point to Point Iroquois MI-
St. Marys River Point Iroquois to E. Potagannissing Bay-Chippewa-
Mackinac-Emmet-Cheboygan-Presque Isle-Charlevoix-Leelanau-Antrim-
Otsego-Montmorency-Alpena-Benzie-Grand Traverse-Kalkaska-Crawford-
Oscoda-Alcona-Manistee-Wexford-Missaukee-Roscommon-Ogemaw-Iosco-
Gladwin-Arenac-
907 PM EDT Mon Aug 6 2018

This hazardous weather outlook is for northern Lower Michigan...
eastern Upper Michigan...and adjacent nearshore waters of Lake
Michigan...Lake Huron and Lake Superior.

.DAY ONE...Overnight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

There is a slight chance of thunderstorms across parts of northern
lower Michigan Tuesday afternoon, and across the entire outlook
area late Wednesday night into Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report any significant weather and
rainfall amounts to the National Weather Service. Reports may be
made one of three ways:

Online:   weather.gov/gaylord
Facebook: facebook.com/nwsgaylord
Twitter:  twitter.com/nwsgaylord

&&

For more information visit http://weather.gov/gaylord.

Special Weather Statement
National Weather Service Gaylord MI
1202 AM EDT TUE AUG 7 2018

MIZ020-026-070500-
Leelanau-Grand Traverse-
1202 AM EDT TUE AUG 7 2018

...A STRONG SLOW MOVING THUNDERSTORM WILL AFFECT SOUTH CENTRAL
LEELANAU AND CENTRAL GRAND TRAVERSE COUNTIES...

At 1159 PM EDT, a strong slow moving thunderstorm was located over
Fouch, or near Traverse City, moving east at 20 mph.

Winds in excess of 30 mph and very heavy rainfall is possible with
this storm.

Locations impacted include...
Traverse City, Bingham, Cedar, Traverse City State Park,
Greilickville, Spider Lake, Fouch, Grawn and Bates.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4490 8580 4489 8565 4478 8564 4477 8561
      4485 8555 4487 8558 4488 8550 4481 8556
      4476 8557 4475 8555 4477 8550 4479 8551
      4487 8544 4487 8538 4461 8544 4470 8582
      4477 8581 4478 8583
TIME...MOT...LOC 0359Z 281DEG 17KT 4479 8572

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