FXUS63 KDLH 250930
Area Forecast Discussion
National Weather Service Duluth MN
330 AM CST Sun Feb 25 2018
.SHORT TERM...(Today through Monday)
Issued at 330 AM CST Sun Feb 25 2018
The latest winter storm to affect the Northland will wind down
this morning for most locales with light snow showers or flurries
lingering into this afternoon.
Light to moderate snow continued across the Northland early this
morning. A compact but deep shortwave trough stretched from
northwest Ontario southeastward toward southern Lake Michigan. A
secondary shortwave with a compact ribbon of vorticity was found
farther west from central Manitoba south into the Red River
Valley. The latest MSAS surface analysis indicates the center of a
994 mb low over western Upper Michigan with a secondary center
over northern Lake Michigan. An inverted trough extended to the
northwest over northern Minnesota and into southeast Manitoba. The
storm system will continue its fast east-northeastward trajectory
into northeast Ontario by noon today. The secondary shortwave
aloft is forecast to rotate eastward across our northern zones
during the day. The bulk of the snow with the surface low will
taper off this morning from southwest to northeast. The secondary
trough, overall cyclonic flow, and cold air advection should be
able to wring out some lingering snow showers and flurries through
this afternoon. Have held onto some low chance POPs and flurries
to the forecast with this update.
Have adjusted the end times of the current suite of headlines.
Snow has all but ended from Cass and S. Itasca through Pine
County, so have cancelled the Winter Storm Warnings for those
locales. The next tier of zones from S. St. Louis/Carlton south to
Price County will end at 12Z and everything else is slated to go
at 15Z. Given the speed with which snow is tapering off to light
snow showers and flurries, earlier expiration times seemed
appropriate. Still think light snow showers and flurries will
continue this morning into the afternoon, but additional
accumulation from those contributions will be negligible.
Another fast-moving clipper will advance eastward across the
Canadian Prairies and into northwest Ontario tonight and Monday.
The clipper will back winds from westerly to southwesterly keeping
temperatures elevated tonight and trending warmer for Monday. The
southerly flow aloft and warm air advection should yield
additional cloud cover over northern Minnesota tomorrow. Think we
may see some snow showers or flurries along the International
Border, but kept POPs below 15% for this update cycle. The ECMWF
is the only deterministic model which brings QPF near the
Northland, so while POPs were increased above the consensus blend,
still opted for a dry forecast. Highs will reach the upper 30s to
near 40 for most locales.
.LONG TERM...(Monday night through Saturday)
Issued at 330 AM CST Sun Feb 25 2018
The early part of the week will see the upper air pattern to be
in a split flow regime with the Northland mainly out of the
general path of either the northern branch or southern branch.
This also puts the Northland in a nearly Pacific flow which will
bring a milder period with above normal temperatures by 5 to 10
degrees. The next chance for any precipitation will be Thursday
when the northern stream merges with the southern stream and
brings the upper trough through the region. At this point the
resultant lee cyclone will be moving up through the mid
Mississippi Valley then into Ohio. That will put mainly the
southern portion of our forecast area in any precipitation
chances, with the northern extent into the Twin Ports. A stronger
trough will dig into the southwest U. S. next weekend, bringing a
chance of precipitation for later next weekend.
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1130 PM CST Sat Feb 24 2018
An upper level trof was moving over the terminals at the start of
the forecast. This resulted in light to moderate snow affecting
all locations, accompanied by IFR/LIFR cigs and vsbys. As the trof
moves east of the terminals after 12Z, the snow will end from
southwest to northeast through the morning. Cigs and vsbys will
improve to MVFR, with scattered VFR. Gusty surface winds are
expected to affect the terminals from mid morning through the
afternoon, diminishing around sunset.
.PRELIMINARY POINT TEMPS/POPS...
DLH 29 14 36 19 / 30 10 0 0
INL 28 14 39 16 / 100 20 10 0
BRD 29 13 36 16 / 20 0 0 0
HYR 29 15 39 20 / 20 10 0 0
ASX 31 19 39 24 / 40 10 0 0
WI...Winter Storm Warning until 6 AM CST early this morning for
Winter Storm Warning until 9 AM CST this morning for WIZ002>004.
MN...Winter Storm Warning until 6 AM CST early this morning for
Winter Weather Advisory until 9 AM CST this morning for MNZ010-
Winter Storm Warning until 9 AM CST this morning for MNZ011-012-