Area Forecast Discussion
Issued by NWS Gaylord, MI

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421
FXUS63 KAPX 251504
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1104 AM EDT WED MAY 25 2016

.UPDATE...
Issued at 1050 AM EDT Wed May 25 2016

Strong May sun starting to work its magic, with a noticeable decrease
in fog across the tip of the mitt in the last few hours. Stratus
deck starting to succumb too, although may take several more hours
to complete that process, especially up across the straits region.
South of M-68, sun is plentiful, and temperatures are definitely
responding accordingly, with widespread readings in the lower 70s.
These will only continue to trend upward, with afternoon
temperatures topping 80 degrees for much of the interior of
northern lower. Somewhat "cooler" for those tip of the mitt
counties and eastern upper, but readings in the 70s there are still
several degrees above normal.

As for rain chances...that will be tied to expected instability
development as larger scale forcing mechanisms are largely non-
existent. Per modification of local 12z sounding and high res
instability progs, several hundred joules/kg of mean layer cape
will develop this afternoon, just enough for parcels to scrap by
h6 centered cap. Wind fields are light, with background light east
synoptic flow butting up against lake Michigan induced stable
layer and forced ascent through the highlands likely being the
triggers to drive shower and storm development. Coverage will
remain scattered, and centered largely south of M-32. No severe
weather anticipated given marginal instability and shear values.

All in all, inherited forecast has above handled well, with
changes relegated to real-time temperature and cloud trends.

&&

.SHORT TERM...(Today and tonight)
Issued at 356 AM EDT Wed May 25 2016

High impact weather potential: t-storms returning this afternoon
and especially tonight.

Weak cold front is somewhat difficult to pick out, but appears to
have settled a bit south of TVC/APN. The front will drift south into
central lower MI before stalling this morning. It will return north
tonight, before getting caught and absorbed by a warm front now in
KS/southern MO. Lingering shra activity is moving out across Lake
Huron, giving us a lull in precip for the morning and early
afternoon. There are two possible sources of precip after that:
any chance that deep convection can fire this afternoon, and then
a true surge of warm/moist air arriving tonight.

Today...post-frontal band of fog/stratus has settled into the
straits region and eastern upper mi. Some fog has also formed
ahead of this across far northern lower, thanks to a rain-cooled
and -moistened airmass. Fog south of CVX/Petoskey/Rogers is thin
and will erode quickly this morning...with little to limit strong
late May sunshine. Straits/upper MI cloud cover is thicker and
will be considerably more stubborn (marine influences will help
maintain it). But do expect that cloud deck to break down around
midday.

Meanwhile, despite being in the /cool/ sector, northern lower will
be baking away. There is a touch of cirrus wafting in from the sw
now, and will become more prevalent with time as the day proceeds.
But with plenty of sunshine otherwise and a mild start to the
morning, highs will be somewhat toasty again today. A tendency
toward a light se synoptic wind will keep the Lake Huron
coastline cooler in the 70s (even cooler yet along the immediate
beaches). Same applies for eastern upper. But the rest of northern
lower will reach the lower and perhaps mid 80s again.

Dew points have finally jumped dramatically thanks to the nighttime
SHRA activity. Outside of marine-influenced locales, surface dew
points in the mid 50s will be common. This results in reasonable
instability building this afternoon near/south of M-72. Mlcapes
should approach 1k j/kg by late in the afternoon. Model soundings
do portray a touch of capping trying to arise this afternoon at
about 625mb. Said soundings suggest this cap will not hold, but
worth noting that model soundings generally underforecast capping.
Background se synoptic wind will be weak enough to permit lake
breezes, so suspect we will have the trigger needed to get past
capping aloft.

So, after a dry morning, will advertise a chance of pm t-storms in
southern sections, away from the coastlines. This is largely in
agreement with the going forecast. Shear is unimpressive, with less
than 15kt of wind up thru 700mb, and 0-6km bulk shear around 20kt.
Not much in the way of a svr threat, though if instability ends up
toward the high end of estimates, something brief/marginal is not
completely out of the question.

Tonight...warm front will charge into northern lower MI overnight.
850mb dew points will increase into the lower teens, and surface dew
points behind the warm front will push 60f overnight. This airmass
enters the region on 25-35kt 850mb winds. Outside of lingering
daytime convection, the mid-evening hours look largely dry. But that
lingering convection will stay healthier than one would otherwise
expect as better 850mb theta-e advection kicks in. More widespread
precip is likely late evening and overnight as the surface and 850mb
warm fronts race in. Not quite ready to kick pops to categorical
(this is convection we/re dealing with), but 70 pops at least will
suffice for overnight. Qpf totals of 0.25-0.50 look most likely. Min
temps lower 50s to lower 60s.

.LONG TERM...(Thursday through Tuesday)
Issued at 356 AM EDT Wed May 25 2016

...Warm and muggy with showers and storms into the holiday weekend...

The pattern over the next few days still looks unsettled at times
with climbing humidity levels along with decent chances for rounds
of showers and thunderstorms. This will be the result of numerous
pieces of energy ejecting out of a broad long wave trough which will
continue to stretch from the Pacific Northwest into the northern
Plains through early next week. There still could be some strong to
severe storms across northern Michigan Thursday as a wing of forcing
sweeps across the region. The best shot for any stronger storms to
form looks like it`s over north central and northeast lower Michigan
as models generate 0-1 km ML Cape of between 1500 and 2500 j/kg and
little convective inhibition. Wind fields are decent Thursday
afternoon with 0-6 km bulk shear of 35 to 40 knots (strongest north)
but generally under 30 knots for the remainder of the period as the
main jet stream remains focused north and west of the region.
Moisture is on the increase with PW/s generally increasing to
between 1.25 and 1.50 inches so we could get into some heavy
rainers. A more widespread area of showers with embedded
thunderstorms is likely late Friday into Saturday as energy/moisture
advect into the region. Besides the system driven showers, expect
diurnally induced showers and storms to fire with a limited
potential for isolated severe storms over the coming days.
Temperatures through the period are still expected to run a few
degrees above normal for the end of May.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 644 AM EDT Wed May 25 2016

IFR/LIFR early this morning at PLN. MVFR returns to MBL/TVC/APN
late tonight.

Stratus/fog deck has settled in over PLN, behind a cold front
moving into central lower MI. Clouds/fog will burn off by late
morning. VFR elsewhere thru this evening. SHRA/TSRA move in from
the sw tonight, mainly after midnight. MVFR cigs/vsbys expected
at MBL/TVC/PLN late.

Light southeast surface winds.


&&

.MARINE...
Issued at 356 AM EDT Wed May 25 2016

Somewhat more humid airmass is already in place thanks to last
nights rain. That is contributing to fog, especially north of Gd
Trav Bay and Rogers City, including around eastern upper MI. An
even more humid airmass invades late tonight as a warm front
moves in. Marine fog/stratus will be an occasional issue thru the
forecast. Winds/waves will generally be light...from the se
today...becoming s to sw tonight.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...MSB
SHORT TERM...JZ
LONG TERM...Sullivan
AVIATION...JZ
MARINE...JZ



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