Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 201916

Area Forecast Discussion
National Weather Service Marquette MI
316 PM EDT Tue Mar 20 2018

.SHORT TERM...(Today and tonight)
Issued at 457 AM EDT TUE MAR 20 2018

WV imagery and RAP analysis indicated confluent mid/upper level flow
through nrn Ontario into the nrn Great Lakes between a trough over
Quebec and a ridge through northwest Ontario. This supported a sfc
ridge from nrn Ontario into the northern Great Lakes which was
bringing cool dry air into Upper Michigan on ene low level winds.
An area of lake effect clouds and a few flurries has spread into
north centrl Upper Michigan. Otherwise, IR loop showed an area of
mid clouds spreading from MN and nw WI into portions of western
Upper Michigan.

Today, continued ene with min temps to -12C at the top of the
shallow cold layer to 2k-3k ft will provide only marginal
instability for any LES. So, mainly just a few flurries at most are
expected early. The very dry low level air with dewpoints around 10F
will also be unfavorable for any diurnal -shsn development. In
addition, increasing mid clouds will also limit sfc heating. High
temps, similar or slightly lower than Monday, will only climb into
the mid 20s north to around 30 south.

Tonight, mid/high clouds remaning over the region will limit
radiational cooling. However, temps in the cold airmass will still
drop into the single digits inland with teens near the Great Lakes.
Additional dryning and lowering inversion heights with winds
veering easterly will be unfavorable for any additional light LES
or flurries.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 316 PM EDT TUE MAR 20 2018

There will be troughing off the Pacific NW coast 00z Thu with a
ridge over the Rockies and a trough over the ern U.S. and a
shortwave over the upper Great Lakes. The shortwave slowly moves to
New England by 00z Sat while the ridge moves into the plains. Should
be pretty quiet for this forecast period and did not make too many

In the extended, GFS and ECMWF show a 500 mb shortwave over the
central plains 12z Sat with a broad 500 mb ridge over the upper
Great Lakes. This ridge moves to the lower Great Lakes 12z Sun and
to the eastern U.S. 12z Mon. A broad trough moves into the Rockies
12z Mon. Troughing moves into the northern plains 12z Tue. Pretty
quiet this forecast period with systems staying away from the area.
Temperatures will be near normal.

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 129 PM EDT TUE MAR 20 2018

Under a dry low-level air mass, VFR conditions will prevail at
KIWD/KSAW thru this fcst period. On easterly winds, lake effect
clouds are currently affecting KCMX, resulting in MVFR cigs and some
flurries. These MVFR cigs should clear out toward evening as drier
air advects across the lake. VFR conditions should then prevail
tonight thru Wed morning.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 457 AM EDT TUE MAR 20 2018

High pressure building in from Ontario will produce ne winds around
25 knots over western Lake Superior today and over the east tonight.
Otherwise no significant winds are expected through the forecast
period, with winds generally staying at or below 20 knots.

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


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