Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 220750

Area Forecast Discussion
National Weather Service Marquette MI
350 AM EDT Sat Oct 22 2016

.SHORT TERM...(This evening through Saturday)
Issued at 328 PM EDT FRI OCT 21 2016

A ridge of high pressure currently over the western CWA will
continue to diminish lake effect rain and snow showers that are
mainly over central Upper MI. Last precip should be around 00Z this
evening. The upper trough over the Great Lakes right now will shift
east while an upper ridge moving in behind it. Between those two
features, the upper jet will arc into the area tonight, which will
force some precipitation aloft. That precip is not expected to reach
the ground over land and only maybe over the western lake due to dry
low levels. This should lead to cloud cover that will cover much of
the area tomorrow morning before slowly dissipating/moving out.

Lows tonight will be in the 20s away from the shores. Since cloud
cover will move in from the west, the coldest area will be interior
central Upper MI in the low 20s.

.LONG TERM...(Sunday through Friday)
Issued at 342 AM EDT SAT OCT 22 2016

Upper level trough over New England and Quebec stays near stationary
into early this week while ridging aloft slowly moves from the
western Conus to the central Conus. Result will be northwest flow
aloft with seasonably cool airmass across the Great Lakes Sun-Tue.
Stronger upper level disturbance is expected to slide out of mean
trough over far western Conus early next week and this will reach the
Great Lakes by midweek as the downstream ridge lifts across Northern
Ontario to Hudson Bay. Weak shortwave moving through in the nw flow
aloft crosses on Sun. The upper level support along with associated
sfc low could bring some light rain showers across Upper Michigan on
Sun, especially from late morning into the aftn.

Behind this system a push of cooler air arrives Sun night into Mon
with h85 to h8 temps dropping to as low as -6c across eastern Lk
Superior and the eastern cwa. With Lk Superior water temps 10-13c,
resulting delta t/s 16-19c will be sufficient for lake effect
precipitation. Wbzero heights aoa 1kft should keep ptype rain.
Limited low-level convergence forecast and lack of larger scale lift
aloft should keep coverage and instensity of any lake effect on the
lower side. Best chance of measureable precip will be late Sun night
into Mon to the east of Munising. Despite nw flow across Lk Superior
appears chances for lake effect over west and north central will be
minimal due to warmer temps aloft (h85 temps only down to -2c) and
with as those areas are closer to sfc ridge/drier low-levels.

Since that sfc ridge eventually becomes main feature in low-levels
on into Tue and Wed, low pressure system crossing the central Plains
will probably experience difficulty in bringing rain farther north
into Upper Michigan by midweek but the southern portions of cwa could
see some rain on Wed into Wed night. Does not appear to be as high of
a chance as it looked previously, though model consistency here is
lacking. Only main change to forecast was to lower min temps on Tue
night over east half into the upper 20s as clouds/precip likely stay
west through daybreak on Wed.

Pretty big differences from the models by late next week and into
next weekend mainly dealing with whether upper level ridging or
troughing will be dominant and the associated warmth that makes it
to the sfc. Left the consensus alone attm with the big differences.

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 117 AM EDT SAT OCT 22 2016

VFR conditions will prevail at KIWD/KCMX/KSAW thru this evening with
cloud bases no lower than 4000-5000ft at times thru the morning hrs.
Sfc high pres ridge will mostly dominate, resulting in light winds.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 328 PM EDT FRI OCT 21 2016

No significant low pressure systems are expected to move through the
Upper Great Lakes in the next several days. Winds will remain below
gales through the period. A tightening gradient between a deep low
pressure system moving through Quebec and a high pressure ridge
building into the Plains could lead to a period of NW winds to 30
knots over north central and eastern Lake Superior late Sunday into

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


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