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Area forecast discussion 
National Weather Service Marquette Michigan
533 am EST Wednesday Feb 10 2016

Short term...(today and tonight)
issued at 530 am EST Wednesday Feb 10 2016

..lake effect snow warnings continue for Marquette and Alger
counties with lake effect snow advisories stretching from Ironwood
through the Keweenaw peninsula...

Satellite imagery this morning is showing fairly extensive cloud
cover across a good portion of the u.P. With colder cloud tops
showing up over the heavier bands of snow over the west and north
central u.P. Radar is showing several bands of moderate to heavy
snow across a good portion of the eastern half of the u.P. With an
estimated one inch per hour or better snowfall rates. Winds are
gusty as well with north to northwest winds gusting around 15 to 25
miles per hour and as high as 30 miles per hour along the Lake Superior shoreline.

Today...the broad 500mb trough will remain in place over the eastern
Continental U.S. With continued ridging over the west. The shortwave that slid
through the western u.P. Last night will continue to traverse the
central and eastern u.P. This morning before sliding east of the
area this afternoon. At the surface...the low pressure system over
Lake Huron this morning will slide to the New England states by this
afternoon. This along with a lake induced thermal trough lingering
over the area will keep most of the u.P. In the continued north to
north-northwesterly flow. The deeper moisture will slowly exit to
the east of the area by late afternoon with the shortwave. 850mb
temperatures are prognosticated to be between -20c and -23c across the
entire u.P. Throughout the Day. Lake induced inversion heights will
be around 5-6kft over the western u.P. Through the
day...however...moisture is prognosticated to diminish above 4kft this
morning and above 3kft by this afternoon.

Central and eastern portions of the u.P. Will See Lake induced
inversion heights around6-8kft through the day with the layer
staying fairly moist through about 5-6kft. This will keep the more
focused snow over the central and eastern u.P. Due in part to the
closer proximity to the shortwave axis. Only a small...very shallow
layer of the convective cloud layer will be in the dgz over the
western u.P. Through the day which will keep snow-to-liquid ratios
much lower and snowfall much lighter. Over the central and eastern
u.P. The convective cloud layer will be a deeper into the
dgz...thanks largely to the increased fetch and lake modification of
the airmass...which will help to make the snow ratios increase a bit
and help the snow to accumulate at a faster rate. Hi-res models are
showing winds veering this morning which will help to shift the
focus of the heavier snow bands farther west over the high terrain
of Marquette County through early afternoon. By middle afternoon...the
winds back more northwesterly allowing the bands to focus farther
east over Alger County once again. Low level convergence is also
focused strongly along the Marquette-Alger County area through this
afternoon. The western u.P. Along Lake Superior will see additional
low level convergence...a little weaker...along the high terrain of
the west this morning before becoming evening weaker this afternoon
allowing snow showers to diminish in intensity. Generally expecting
an additional 3 to 7 inches today over northern and eastern
Marquette County. Western Alger County could see an additonal 4 to 8
inches through this afternoon with a localized 10 inch report not
out of the question...again the highest totals are expected over the
higher terrain.

Tonight...much drier air is prognosticated to slide into the area as the
upper level trough axis slides ever so slowly to the east and a
ridge of high pressure slowly approaches the far west from central
Canada and the northern plains. Again...the longer fetch over the
eastern u.P. Along with north to northwesterly flow will help to
modify the airmass a bit...keeping deeper moisture around at
slightly warmer temperatures to create continued moderate snow
showers through tonight. Convergence continues to be enhanced over
the eastern U... Lake Superior...in the low levels as seen
via the hi-res models. This along with a little deeper moisture
lingering in the favored dgz in the convective cloud will also allow
for enhanced snowfall over Alger County. This should allow for at
least additional advisory level snow for Alger County tonight. The
dry air along with reduced fetch with northwesterly winds over the
western u.P. Will allow snowfall rates to diminish to very light
snow over the Keweenaw peninsula and possibly only flurries closer
to Ironwood...therefore there should be no need for the lake effect
Snow Advisory to be extended into the evening hours.

Long term...(thursday through tuesday)
issued at 530 am EST Wednesday Feb 10 2016

Models indicated the amplified pattern with intrusions of very cold
Arctic air into the northern lakes will become more zonal next week with
milder Pacific air and above normal temperatures returning to the
region.

Thursday...with backing winds from northwest to west ahead of the next clipper
shortwave...les will shift into the Keweenaw and near Lake Superior
east or Munising. Despite 850 mb temperatures around -22c...inversion
heights of 4k-5k feet will limit les intensity and keep additional
accumulations to 1 to 2 inches northwest and from 2 to 4 inches over the NE
County Warning Area. Temperatures will rebound slightly with highs from 12 to 17.

Thursday night into Friday...a clipper shortwave moving through northern Ontario
will drag an Arctic cold front into the northern lakes with winds veering
from west to northwest...mainly after 06z/Fri. Although a heavier snowband
associated with low level conv along the front will move in
overnight...it should move through fast enough to limit accumulations
to an inch or two. Moderate to occasionally heavy les for northwest wind snow belts
will develop for Friday as inversion heights climb to 6-8k feet with 850
mb temperatures into the -25c to -30c range. The best chance for more
signficant accumulations will be over the east...downstream of the
longer fetch. A limiting factor will be the shallow dgz nearthe surface
in the very cold airmass leading to mainly smaller snowflakes and
lower slr values. The combination of winds and smaller snowflakes
that will be effective in reduicing visibility require an les advisory even
with lower end snow amounts.

Friday night into Sat...moderate northwest flow les will continue. Wind chill
values across most of the County Warning Area are expected to drop to advisory levels
(around -25) with temperatures from -5 to -10 and winds to near 10 miles per hour.
Highs Sat will remain in the 4 to 10 degree range.

Sun-Tue...winds shifting to the south ahead of a plains shortwave and
surface trough will bring an end to the les by Sun morning. The
GFS/European model (ecmwf) were in reasonable agreement bringing potential for light
snow into Upper Michigan late sun into Sun night with a strengthening warm air advection
pattern. There is more uncertainty early next week with a faster west-northwest
flow developing with the potential for embedded weak shortwaves that
could produce some light snow.
&&

Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 1159 PM EST Tuesday Feb 9 2016

Under a north-northwest flow of Arctic air across Lake Superior...lake effect
snow showers will be the rule at kiwd/kcmx/ksaw through this forecast
period...and typical for lake effect snow...conditions will be
highly variable. Prevailing conditions will likely be IFR...but
expect periods of LIFR and MVFR. LIFR conditions should be more
likely to occur at ksaw late overnight/early this morning as slightly
veering winds shift heavier snow showers westward to ksaw. Somewhat
drier air and a falling inversion should lead to improving conditions
this afternoon with a trend to prevailing MVFR.
&&

Marine...(for the 4 am Lake Superior forecast issuance)
issued at 530 am EST Wednesday Feb 10 2016

There may be a few gale force gusts this morning over Eastern Lake
Superior. Another round of gales are possible Thursday night and
Friday across Lake Superior as next shot of cold air move in and
pressure gradient tightens up again. Freezing spray will also
increase with the heaviest freezing spray expected through tonight
and again Thursday night into Friday.
&&

MQT watches/warnings/advisories...
Upper Michigan...
lake effect Snow Advisory until 7 PM EST /6 PM CST/ this evening
for miz001>003-009.

Lake effect snow warning until 7 PM EST this evening for miz005.

Lake effect snow warning until 7 am EST Thursday for miz006.

Lake Superior...
heavy freezing spray warning until 7 am EST Thursday for
lsz265>267.

Heavy freezing spray warning until 4 PM EST /3 PM CST/ this
afternoon for lsz162-263-264.

Lake Michigan...
none.
&&

$$

Short term...kec
long term...jlb
aviation...rolfson
marine...kec

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