Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 270531

Area Forecast Discussion
National Weather Service Marquette MI
131 AM EDT WED JUL 27 2016

.SHORT TERM...(This evening through Wednesday)
Issued at 250 PM EDT TUE JUL 26 2016

Upper air pattern consists of a shortwave across MN and the ern
Dakotas this morning that will move across the area this afternoon
into early evening. Nam shows some 850-500 mb q-vector convergence
over the area through 00z Thu with another shortwave affecting
mainly the southern cwa on Wed.

Couple things going against the convection for this afternoon. KMPX
and KGRB 12z soundings show dry mid levels and also the possibility
with sfc heating this afternoon mixing out the dew points in the
lower levels in the afternoon with sfc dew points falling in the
afternoon. This appears to be the case as sfc dew points have been
slowly falling and mixing out this afternoon which will tend to cut
down the instability this afternoon and because of this, have cut
the pops down a bit and delayed them a bit as well. Models also show
the strongest shear to the northeast with less instability and more
instability with less shear to the southwest of area. We cannot seem
to get everything to come together, so this argues for cutting pops
a bit. Still have chance pops in though for late this afternoon into
this evening in case some convection gets going on the lake breeze
boundaries which would be a possibility with lake breeze
convergence. Still kept in some chance pops in for Wed across the
south as well as a shortwave goes by to the south of the area and
have it dry to the north. Overall, did not make too many changes to
the going forecast for temperatures or weather.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 446 PM EDT TUE JUL 26 2016

Beginning Wednesday night: The cold front moving through Upper
Michigan on Wednesday will stall just south of Upper Mi Wed evening.
Models advertise a shortwave tracking along a the frontal boundary
which will likely enhance convective development along the front.
Some showers could brush south central Upper Mi mainly in the
evening in environment of a few hundred j/kg of MLCAPE so wl keep
some higher chc pops over far south central to cover this
possibility. With much greater instability fcst to stay south expect
bulk of convection to stay well south of CWA into Wi.  N-NE winds
ahead of building sfc high pressure will bring much drier dewpoints
into area which will allow clearing from the north through
evening/overnight hours. Clearing and PWATs dropping blo .5 inch
will also allow for min temps Wed night to drop near 50F over some
of colder interior west half locations.

Thursday through Tuesday...Models now indicating sfc high pressure
building over area from the northwest on Thu will persist over the
region into early next week. This will result in generally dry
conditions through the period. Increasing southerly flow beginning
on Sunday as sfc high pressure center moves east will allow for
increasing moisture and advection of higher dewpoints into the Upper
Great Lakes. Expect increasingly more humid and warmer conditions
beginning Sunday and continuing into Tuesday, but influence of high
pressure and anticyclonic flow should maintain dry conditions into
at least Monday. As mid-level ridge axis pushes east of the region
on Tuesday and shortwave energy lifts up its backside into the Upper
Lakes, there could some shra/tsra Tuesday at least over the west
half of the CWA.

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 131 AM EDT WED JUL 27 2016

VFR conditions continue through the forecast. There remains a slight
chance for showers and possibly thunderstorms late tonight into
Wednesday morning at KIWD and possibly a few showers at KSAW with
the passage of a disturbance to the south of the area. KIWD has the
higher probability for TSRA there but even this is quite low, so
included only VCTS in forecast there and included a few hours of
VCSH at KSAW. KCMX deeper into the drier air so do not expect any
precipitation there.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 250 PM EDT TUE JUL 26 2016

Winds across Lake Superior for the remainder of the week should be
mostly 15kt or less as the pressure gradient remains on the weak
side across the Upper Great Lakes.

Upper Michigan...
Lake Superior...
Lake Michigan...


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