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 111701
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
101 PM EDT Fri Aug 11 2017

.UPDATE...
Issued at 1001 AM EDT Fri Aug 11 2017

Surface low center has reached the Straits area late this morning...
with the associated cold front currently sliding eastward thru
Lower Michigan. Narrow dry slot just ahead of the cold front
continues to steadily fill in with developing low clouds. Upper
level trough axis is following right behind the surface low and
cold front...marking the leading edge of a more uniform OVC low
cloud area thanks to wrap-around moisture and stronger CAA. Temps
will only warm a few degrees today...if at all for some
locations...as CAA continues to strengthen in the wake of the cold
front. Greatest potential for surface heating...and thus
destabilization and thunder chances...will be across our SE CWA
during peak heating this afternoon/early evening. Modest bulk
shear of around 30 kts in the vcnty may lend to the development of
some stronger storms...but severe storms are still not expected.

&&

.NEAR TERM...(Today through Tonight)
Issued at 356 AM EDT Fri Aug 11 2017

...Cooler with lingering showers/thunder today...

High Impact Weather Potential...A few thunderstorms are possible
today...mainly eastern upper and northeast lower Michigan. Severe
storms are not expected.

Pattern Synopsis/Forecast...As has been stated repeatedly in
recent times...long wave troughing remains across much of eastern
NOAM with long wave ridging along the west coast/Rockies. Another
well defined short wave is rolling through northern Michigan this
morning. Associated surface low pressure is nearly overhead with a
cold front just pushing into the western reaches of the CWA.
Narrow axis of instability...showers and storms well ahead of the
front have pushed on off to the N/E with a nice dry slot sliding
through lower Michigan. There are some showers lingering across
the U.P...part of the "wrap around" deformation side of the
system.

Primary Forecast Concerns...are relatively minimal today. Will
have a period of quieter weather with some sunshine across
northern lower Michigan...at least to start the day as the dry
slot slides through the region. Lingering showers/thunder for
eastern upper Michigan. Surface cold front slips through the CWA
during the course of the day with post-frontal wrap around
moisture/stratus/increasing shower chances overspreading the
region...diminishing but lingering through tonight.

With higher dewpoint air still in place and the opportunity to
heat up ahead of the front...anticipate additional thunderstorms
today... particularly this afternoon across NE lower Michigan
where temps/dewpoints/instability will be better. But...given
relatively lighter winds aloft/modest instability with MLCAPE
values under 1000 J/Kg...severe threat looks low overall. That
said...some stronger updrafts/modest storm organization will be
possible over the SE counties toward Saginaw Bay and may present a
low end hail threat.

&&

.SHORT TERM...(Saturday through Sunday)
Issued at 356 AM EDT Fri Aug 11 2017

...Slowly improving Saturday followed by nice weather Sunday...

Saturday...Surface low pressure/upper level trough will continue to
depart off to our northeast. Lingering showers (mainly in the
morning) should diminish. Model soundings (especially the nam)
indicates that low clouds will be slow to clear out from northwest
to southeast due to lingering over lake instability (lake/850 mb
delta ts around 12). Cool with highs only ranging from around 70 to
the lower 70s.

Saturday night into Sunday...Slowly increasing heights aloft as well
as weak surface high pressure building in should make for clear to
partly cloudy skies. Cool Saturday night with lows ranging from the
middle 40s to the lower 50s. Highs Sunday moderating into the middle
and upper 70s.

.LONG TERM...(Sunday night through Thursday)
Issued at 356 AM EDT Fri Aug 11 2017

Slowly building heights continue into midweek resulting in mainly
dry and warm conditions. Lowering heights from the north and a
possible surface cold front will increase pops Wednesday night into
Thursday (though extended models vary on the timing). Highs
generally in the middle 70s to lower 80s (perhaps even the middle
80s Wednesday) and lows mainly in the comfortable 50s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 101 PM EDT Fri Aug 11 2017

Showers will increase in areal coverage and intensity this
afternoon into early evening thanks to increasing diurnal
instability and low pressure tracking thru the Straits.
Thunderstorms are also possible...mainly across NE lower Michigan
(APN). Areal coverage and intensity of precip will diminish with
sunset and loss of diurnal enhancement...leaving a few showers
lingering into Saturday morning. Winds will become NW in the wake
of the surface low and cold front...and will strengthen by midday
Saturday...with gusts of 15 to 25 kts expected.

&&

.MARINE...
Issued at 254 PM EDT Thu Aug 10 2017

Tonight through Saturday...Winds will pick up for a bit as the
gradient tightens before the cold front moves into the area, but
the gradient relaxes as the sfc low moves into Lake Michigan and
winds remain below small craft through 00z/Fri. After 00z, the
winds diminish and remain around 5 knots overnight. The sfc low
should be moves into Lake Huron and then Ontario by 18z/Fri. The
pressure graident will tighten up on the back side of the low and
winds will increase and probably get to small craft conditions on
Lake Michigan by 00z/Sat, and last through 12z/Sat. Winds diminish
on Saturday as the sfc high begins to builds into the region.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY from 5 PM this afternoon to 6 PM EDT
     Saturday for LMZ342-344>346.
LS...NONE.
&&

$$

UPDATE...MR
NEAR TERM...BA
SHORT TERM...AS
LONG TERM...AS
AVIATION...MR
MARINE...JL



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