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Area forecast discussion
National Weather Service Gaylord Michigan
942 PM EDT Thu Jun 21 2018

issued at 942 PM EDT Thu Jun 21 2018

High pressure looms just north of this forecast area, over and
east of Superior. This is providing dry and somewhat cool low-
level air. Some thin cirrus continued over parts of northern lower
mi, spawned by slow-moving low pressure to our SW. Main concern
for tonight is temps. Pressure gradient will remain on the tight
side in central and southern lower mi, but for most of northern Michigan
will pose little obstacle to decoupling. This is effectively the
shortest night of the year, but with dew points mixing out into
the 30s in many areas, expect US to have enough time for temps to
take a decent tumble. Will tweak temps down very slightly,
allowing for a few upper 30s, primarily in the Au Sable valley.


Near term...(through tonight)
issued at 410 PM EDT Thu Jun 21 2018

..chilly night ahead...

High impact weather potential: none.

Pattern synopsis/forecast: surface high pressure centered over
eastern Ontario remains ridged over northern Michigan providing yet
another afternoon of seasonable weather. Said high pressure is
holding the high clouds associated with a low pressure system over
the upper Mississippi River valley to our south...besides a few
strands of cirrus here and there across northern lower. Winds will
decouple again tonight with mostly clear skies, radiational cooling
will provide for a chilly night, especially for the inland low lying
areas of northern lower and eastern Upper Michigan. Some locales may
even see temperatures of 10+ degrees below normal tonight.

Lows will be in the upper 30s to mid 40s...with a bit warmer
temperatures along the Lake Huron shoreline.


Short term...(friday through sunday)
issued at 410 PM EDT Thu Jun 21 2018

High impact weather potential: minimal.

Pattern synopsis/forecast:

Overall flow remains split over the conus, with the northern flow
arcing well north into western Canada before dipping south into a
trough over New England. The southern branch is moving through The
Four Corners region over to the Gulf. Between these two a strong (2
sd) upper closed off low is currently sitting over the mid-
Mississippi Valley. There is an 80 knot jet diving south out of the
Hudson Bay region toward Lake Ontario.

The upper level low is supporting a 1002 mb surface low over western
Iowa, which has already become stacked. An occluded/warm front
extends from this low to the eastern Ohio Valley. Visible and water
vapor imagery shows mid-level drying and subsidence, with clouds
dissipating in southern Ontario down through northern lower. A mid-
level moisture axis extends through the Ohio Valley into Iowa where
it wraps back around the low on its northwest.

The main low will dig southward toward southern Illinois tonight
before pivoting northeastward toward the lower Great
Lakes...weakening and opening up into a wave Friday night into
Saturday morning. As the deformation axis sits just to our south on
Friday the mid-levels will become much more dry due to cool dry flow
out of Canada.

Primary forecast concerns: rain and cloud cover for our southeast
counties late Friday night into Saturday

Mid-level moisture returns late Friday night into early Saturday as
the low pulls closer to southern Michigan. A Theta-E gradient pushes
north over US Friday night as this occurs as well higher pwats
pushing into the area. Saturday looks like it could have scattered
showers through the southeast as this low slides to our east. A
short wave will start to approach the region from northern Ontario
on Saturday morning along with the right entrance region of an upper
level jet. Moisture tries to increase just ahead of this keeping
rain chances in the forecast through Sunday.

Long term...(sunday night through thursday)
issued at 410 PM EDT Thu Jun 21 2018

Monday and Tuesday remain dry with high pressure dominating the
area. The next chance for rain moves in on Wednesday with a short
wave moving into the region from the northern plains, however the
timing and intensity of this system is still in question.


Aviation...(for the 00z tafs through 00z Friday evening)
issued at 708 PM EDT Thu Jun 21 2018


High pressure over and east of Superior is providing plenty of dry
low-level air to the region. Some cirrus is overhead, spawned by
slow-moving low pressure in the mid-MS valley. This general trend
will persist into Friday evening.

Easterly winds will relax somewhat tonight, then get a little
breezy again on Friday, especially in the afternoon.


issued at 410 PM EDT Thu Jun 21 2018

Low pressure will move to near Southern Lower Michigan by Friday
night, maintaining easterly winds. Winds will remain from an
easterly direction through Saturday, head line criteria is not


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