Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 262058

Area Forecast Discussion
National Weather Service Marquette MI
458 PM EDT Mon Jun 26 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 355 PM EDT MON JUN 26 2017

Finally some dry weather in the short-term forecast after showers
end over the far eastern U.P. late this afternoon into this evening.

As the shortwave that brought all of the rain over the past 24 hours
shifts east of the U.P., heights will begin to rise from west to
east. This ridging aloft along with a surface high building into the
Upper Great Lakes region, will allow the precipitation to come to an
end and allow for clear skies across the area. This will allow
temperatures to cool off tonight, with many locations inland cooling
to the low 40s tonight. Actually, with ideal radiational cooling,
its not out of the question that a few of the typically cooler
locations may see a few upper 30 degree readings. The dry weather
and clear skies will continue into Tuesday; however, there is a very
small chance that some isolated rain showers may develop over the
eastern U.P. during afternoon heating/lake breeze boundaries. The
increased sunshine will help temperatures to rebound closer to
normal for this time of year with many locations warming into the
mid 70s.

.LONG TERM...(Tuesday night through Monday)
Issued at 456 PM EDT MON JUN 26 2017

Models suggest a slowly progressive pattern will prevail with a
transition toward zonal flow during the middle of the week and
troughing through the north cntrl CONUS this weekend as a mid level
low moves from Alberta to the nrn Great Lakes.

Wednesday into Thursday, a shortwave trough moving out of the nrn
Rockies will move through the wrn Great Lakes. Strong moisture
advection will accompany this system, as the sfc low moves into the
Upper MS valley, pushing PWAT values into the 1.5-1.75 inch range.
Although the models suggest a period of stronger 305k-310k
isentropic lift(800-700mb) will bring a period of moderate to heavy
pcpn through most of the cwa, expect that the strongest convection
and heaviest rain will remain closer to the 850 mb front and
strongest 850mb theta-e advection through nrn WI. With fcst
MUCAPE values only in the 500-1000 J/Kg range and thickening cloud
cover, the severe tsra risk will be minimal. Although the
progressive system may limit potential for heavier cells over any
locations for a longer period, rainfall amounts in the 1-2 inch
range will be possible, especially over the srn cwa. As the shrtwv
and sfc low depart some wrap-around pcpn may linger through
Thursday morning.

Friday-Monday, Uncertainty is greater with the evolution of the mid
level low and impacts on weather over the cwa. Pcpn associated with
a shrtwv moving out of the cntrl plains Friday are expected to
remain mainly south of Upper Michigan although some lighter pcpn may
develop. As the mid level low drops into the region during the
weekend, expect a better chance of rain Saturday with a few diurnal
tsra similar to what developed last weekend. GEFS/GFS/ECMWF suggest
pcpn chances will diminish Sunday. Confidence is low by Monday with
models handling of another significiant shrtwv moving out of the
plains. Initial indications are that the higher pcpn chances and
heavier pcpn will remain to the south.

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 355 PM EDT MON JUN 26 2017

All TAF sites will see improving conditions to VFR through this
evening. KSAW will see some lingering low clouds early this
afternoon before drier air moves in from the northwest and the main
area of moisture shifts to the southeast. Skies will clear tonight
and wouldn`t expect too much more than some fair weather clouds to
pop up tomorrow afternoon with daytime heating.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 355 PM EDT MON JUN 26 2017

Winds of 10 to 15 knots are expected to continue through the first
half of next week as the pressure gradient decreases and high
pressure builds into the area. Towards the middle of the week, winds
will start to increase to around 20 to 25 knots as a low pressure
system lifts across the Upper Great Lakes. Winds will then decrease
to around or less than 15 knots towards the end of the week and next
weekend as the pressure gradient relaxes once again.

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


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