Mesoscale Discussion 0010
NWS Storm Prediction Center Norman OK
0215 AM CST Mon Jan 07 2019
Areas affected...Eastern part of the MN Arrowhead
Valid 070815Z - 071315Z
SUMMARY...Snowfall rates are expected to increase overnight to 1-2
inches per hour across northeast portions of the Minnesota Arrowhead
region (the North Shore) from southern Lake to southern and eastern
Cook Counties. These rates should develop by 3 AM and persist until
around 7 AM, at which time heavier intensities should begin to
decrease from the south.
DISCUSSION...A mean trough will shift east from Plains states into
this morning. Meanwhile, an embedded shortwave trough, currently
located across the Dakotas into western NE per satellite imagery,
should pivot toward the northeast, reaching north of the
international border into northwest Ontario by 18Z. Models remain
in good agreement suggesting a surface wind shift, which currently
extended from eastern ND to western IA, will advance east across
much of the discussion area by late morning. Strong forcing for
ascent attendant to the Dakotas trough will maintain height falls to
sustain the presence of a strong southerly low-level jet translating
from west-east across the upper Great Lakes and northern Ontario.
Surface observations indicated light to moderate snowfall ongoing
across the MN Arrowhead. Strong warm advection along the low-level
jet combined with an onshore upslope component to the surface winds
will promote favorable conditions for increased snowfall rates, as
deeper forcing for ascent with the shortwave trough spreads across
the region. Given the progressiveness of this storm system, the
strongest low-level warm advection along the 850-mb jet is expected
to shift poleward away from the MN North Shore after 14-15Z,
resulting in a subsequent decrease in snowfall rates.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 47419176 48049047 48018940 47639058 47089169 47419176