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fxus63 kmqt 291130 

Area forecast discussion
National Weather Service Marquette Michigan
730 am EDT Thu Jun 29 2017

Short term...(today and tonight)
issued at 411 am EDT Thursday Jun 29 2017

Water vapor imagery this morning showers shortwave activity lifting
northeast towards the area, allowing the surface low to lift into
western portions of Lake Superior. Two main areas of rainfall were
observed across the area this morning, one associated with lingering
warm air advection and moisture transport across the east, and then
more rain shower activity back across the west around the main
surface low. Areas of fog have developed ahead of the surface low
pressure where dew points remain in the low 60s. With drizzle
accompanying the fog in some locations this morning, visibilities
have been flucuating a bit this morning so think the dense fog
should remain rather patchy through the early morning hours.

Today, expect the cloudy conditions to linger across much of the
area. As the surface low tracks across the area today, southerly
winds will eventually become westerly with a bit drier air mass.
This westerly flow should allow cloud cover to gradually diminish
across the south central portions of the area, where downsloping
will increase. As a result, temperature are expected to be warmest
across the south central, around 70 degrees, and then in the 60s
elsewhere. As the main upper-level trough moves overhead and surface
low tracks east through the day, a transient band of light rain
should move across the area; elsewhere drizzle will be possible
especially through the morning and early afternoon hours.

Through the first part of the evening and overnight hours, weak
ridging is progged to move into the area and should allow any
lingering precipitation over land to weaken/diminish. However, into
the early morning hours on Friday another shortwave is expected to
lift across the area bringing back chances for rain showers,
especially across the east.

Long term...(friday through wednesday)
issued at 534 am EDT Thursday Jun 29 2017

Models indicate a slowly progressive pattern will prevail with zonal
flow giving way to troughing through the north central Continental U.S. This
weekend as a mid level low moves from Alberta into the upper Great
Lakes. A ridge will then build from the northern plains into the
upper Great Lakes for the first half of next week. Temperatures will
remain below normal with moderation closer to seasonal averages
early next week.

Beginning Friday, as the larger scale mid level trough begins to
deepen from the northern plains into the upper Great Lakes, a
shortwave trough is expected to lift NE into the western Great
Lakes. 00z models have trended weaker and farther se with this
feature and thus with weaker forcing are showing more isolated to
scattered coverage with showers. Diurnal instability of nearly 500
j/kg MLCAPE will support greatest coverage south central with
isolated T-storms.

Saturday-Sunday, with the mid-level trough deepening over the
northern Great Lakes, rain chances will continue Saturday into
Sunday, especially inland during peak heating. Isolated to scattered
T-storms will also be possible central as MLCAPE values range FM 500-
1000 j/kg. Enough moisture/instability will linger into Sunday with
cyclonic mid level WNW flow and models suggest another vigorous
shortwave moving through the region during peak heating to warrant
low chc pops for mainly afternoon isold to scattered showers. GFS
soundings suggest there might even be enough instability for a
rumble of thunder se.

Monday-Wednesday, models and ensembles in good agreement with the
drying trend expected at least for the first half of next week with
rising mid-level ridge heights and sfc ridging building into the
area. Sunshine should push temps well into the 70s with a gradual
warming trend for the 4th of July into Wednesday. Could even see a
few lower 80s readings over the western interior on Wednesday if
warmer Canadian model verifies with 5h ridge heights building to 582-
585 decameters.

Aviation...(for the 12z tafs through 12z Friday morning)
issued at 730 am EDT Thursday Jun 29 2017

LIFR ceilings continue to impact ksaw and kcmx this morning with
visibilities below 1/4sm at times and. Expect these visibilities to
hold on longer this morning at kcmx given the persistent upslope
winds. At ksaw, winds will switch around to the west-southwest later
this morning and will allow the current upslope flow to transition
to more downslope. Visibilities should begin to improve after this
transition occurs later this morning. Ceilings will also
improve at ksaw through the day up into the MVFR category. Kiwd has
been the last to see ceilings lower, but expect the IFR/LIFR
ceilings to linger through much of the day as winds become
more onshore. Scattered showers will be possible through morning
hours at kiwd/ksaw, but chances will linger through the day at kcmx.
Therefore, have included mentions of vcsh for now.

Marine...(for the 4 am Lake Superior forecast issuance)
issued at 411 am EDT Thursday Jun 29 2017

As low pressure tracks across Upper Michigan today, winds across the
lake will remain a bit enhanced at around 15 to 25 knots. Patchy to
areas of fog are possible this morning, and into tomorrow. In some
locations fog may be locally dense, in fact on ship north of the
Keweenaw peninsula this morning reported reduced visibilities due to
fog. As this point, no plans for issuing a dense fog advisory over
the lake, but is something that will need to be monitored this

Into Friday morning, winds will relax to around 10 to 15 knots as
the surface pressure gradient weakens with low pressure exiting the
region. Winds through the weekend and much of next week are expected
to remain 15 knots or less.

MQT watches/warnings/advisories...
Upper Michigan...
beach hazards statement through this evening for miz014.

Lake Superior...
Lake Michigan...


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