Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 020505

Area Forecast Discussion
National Weather Service Marquette MI
105 AM EDT SAT JUL 2 2016

.SHORT TERM...(This evening through Saturday)
Issued at 347 PM EDT FRI JUL 1 2016

Very quiet in the short term. A few showers and possibly some
thunderstorms may skirt far northeastern Lake Superior this evening
as a shortwave drops southeast out of Ontario. Can not completely
rule out a shower over Isle Royale this evening, but was not
confident enough to put in the forecast.

Sat looks a bit warmer, with sunny skies and light winds. Minimum RH
values will fall to 30-40 percent inland. May see additional showers
N/NE of Lake Superior and a couple high-res models show a blip or
two of QPF inland, but did not include that in the forecast.

.LONG TERM...(Saturday night through Friday)
Issued at 407 PM EDT FRI JUL 1 2016

Over the next 7 days, the western Canada positive height anomaly is
forecast to shift ne and dominate northern Canada by the middle of
next week. This western Canada positive height anomaly/ridge has
been a common feature so far this warm season and has supported a
mean eastern N America trof. Thus, the Upper Great Lakes have
avoided any sustained periods of above/well above normal temps. With
this height anomaly shifting to northern Canada, flow will begin to
undercut it across the northern CONUS/southern Canada in the coming
days, leading to some progression of shortwaves roughly along the
international border and causing the current eastern N America trof
to lift ne. As a result, a slow trend to warmer weather/above normal
temps will occur over the next several days. Could become quite warm
for a couple of days during the middle portion of next week as flow
becomes wsw downstream of a modest trof developing into the nw
CONUS. Farther down the line, Canadian ensembles tend to suggest the
positive height anomaly over northern Canada may drift back to the w
a little, possibly leading to renewed mean eastern Canada troffing
which would keep temps overall close to normal out into mid July. In
contrast, recent days CFSv2 runs are indicating a definite
warm/above normal temps signal for the Great Lakes region for much
of this month. As for pcpn over the next 7 days, dry weather will
prevail thru the weekend under slowly rising heights as the eastern
trof lifts ne. Development of wsw flow early next week and the
accompanying progression of shortwave energy should then lead to
periodic shra/tsra chances for much of next week, but not until
after the long holiday weekend. Right now, there is no clear
indication of what day or days will have the best chc of pcpn, but
there is some signal for perhaps a more important shortwave to
affect the area late in the week.

Beginning Sat night thru Sun night, with sfc high pres dominating
the area, dry weather will prevail. However, with very weak
shortwaves embedded in the relaxing nw flow, a few models generate
isold pcpn. At this point, don`t see sufficient low-level
moisture/instability to support any shra development. May see a
little more vigorous cu development along lake breeze boundaries on
Sun. Low temps will dip into the mid/upper 40s in the interior Sat
night and around 50F Sun night. On Sun, expect high temps in the
upper 70s/lwr 80s with local cooling near the Great Lakes during the

On the 4th, recent days model runs have indicated some potential for
pcpn as a shortwave moves across northern Ontario in developing wsw
flow. With theta-e advection and stronger 850mb flow ahead of wave
aimed nw and n of Upper MI, convection associated with the wave
should also pass by to the n. Will continue to carry a dry fcst for
4th, including into the night. So right now, it appears that
communities with fireworks displays should have no weather issues.
High temps on the 4th will be a couple of degrees higher than Sun.
Again, expect local cooling near the Great Lakes in the aftn.

Tue looks like a similar setup to Mon with indications that wsw flow
will carry shortwave energy thru northern Ontario with dry weather
most likely to prevail to the s across Upper MI. Stronger low-level
s to sw winds should prevent any cooling near Lake Superior on Tue.
Away from Lake Michigan, temps will push well into the 80s.

Wed thru Fri, although troffing to some degree will likely persist
over the nw CONUS, stronger mid level low over Hudson Bay will drift
s a little, helping to suppress shortwaves ejecting from the nw
CONUS trof on a track slightly farther s with time. As a result, a
frontal boundary will sag s into the Great Lakes, bringing an
increasing potential of shra/tsra. Given the increase in heat and
substantial build up of instability by that time just ahead of the
southward drifting front, a svr storm risk could certainly arise in
addition to heavy rainfall potential. Conditions will likely become
uncomfortably humid until the front passes.

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 105 AM EDT SAT JUL 2 2016

VFR conditions are expected through the period.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 347 PM EDT FRI JUL 1 2016

NW winds of 15 to 25 knots will continue into this evening before
persistent high pressure brings winds generally under 15 knots late
tonight through Independence Day. Winds will then become SW to 20
knots across western Lake Superior on Tuesday as a trough approaches
from the west.

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


LONG TERM...Rolfson
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