Area Forecast Discussion
Issued by NWS Duluth, MN
FXUS63 KDLH 181456 AAB
Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
856 AM CST Sat Feb 18 2017
.SHORT TERM...(Today through Sunday)
Issued at 246 AM CST Sat Feb 18 2017
The dry and well-above average temperatures look to continue
through the short-term forecast period. Mostly clear skies
continued this morning across much of the region as a dry air mass
remains situated overhead, along with mid- to upper-level
ridging. The 18.00Z GFS/NAM models are indicating another sunny
day across the Northland Saturday, although some high clouds could
develop, especially in the afternoon. Much like Friday, high
temperatures are expected to be well above normal again for
Saturday. Much of the latest guidance seems much too low for
temperatures, so bumped up highs Saturday quite a bit higher, with
highs in the upper 40s and lower 50s expected for much of the
Northland. Conditions should remain dry as a surface high pressure
ridge advances through the region this evening and overnight.
With another day of additional melting of the snow pack, model
soundings are indicating a shallow moist boundary layer developing
tonight. With dewpoint depressions near zero, and decreasing
winds due to the surface high pressure ridge passage, areas of fog
are expected to develop late Saturday night, persisting through
Sunday morning. Some of the guidance is progging visibilities for
portions of the Northland as low as one- quarter of a mile, but
other guidance doesn`t seem quite as bullish on dropping that low.
For now, will maintain areas of fog across the Northland.
Another above-average temperature day is expected for Sunday as
mid-level ridging continues. Any fog that develops early Sunday
morning should dissipate by mid to late morning as temperatures
increase. Model soundings indicating mid to high clouds to
develop. This could prohibit temperatures from getting warmer than
Saturday`s temperatures, despite slightly warmer 925 mb
temperatures progged for Sunday. Still, highs in the upper 40s to
lower 50s are looking likely.
.LONG TERM...(Sunday night through Friday)
Issued at 237 AM CST Sat Feb 18 2017
An upper-level ridge will be over the forecast area Sunday night
while high pressure over the western Great Lakes drifts off to the
east. Meanwhile, an upper level long wave trof will be crossing
the Rockies, with a surface low organizing in the western Dakotas.
With the tightening pressure gradient, mixing will occur to the
surface and preclude any fog formation and have removed. Model
differences in the onset of the rain into the western portion of
the area shows up overnight. The ECMWF is dry, the NAM/GEM are too
fast and wet, the GFS is pointing toward some light QPF
developing. Went with a blend and have small POPs over the
western third of the region. On Monday, the long wave trough
moves into the eastern Dakotas, while the surface low lifts north
into southern Manitoba. The rain overspreads the forecast area
through the day. Models have backed off on the amount of CAPE
available and have removed the mention of thunder as a result.
There is a chance of some light freezing rain Monday morning east
of Ely and through the Arrowhead. The surface low continues on
its northerly trek through Manitoba Monday night. Meanwhile, the
long wave trough pushes into the forecast area. Temperatures will
be warm enough for rain, which will begin to diminish late Monday
night. The long wave trough and surface low finally exit the
region on Tuesday. Model differences show up Tuesday night with
the approach of a low pressure system that will move along the
Canadian border. This signals a change in the overall pattern from
warm to cold and the return of a winter pattern. POPs will be
aligned along the northern third of the forecast area Tuesday
night through Wednesday evening as the surface low moves along the
border. A rain/snow mix is expected with the diurnal fluctuation
in temps. A break from the precipitation comes late Wednesday
night through Thursday morning as high pressure moves nearby.
Model differences with the timing of the next round of
precipitation and the overall coverage begins Thursday afternoon
through Friday. Regardless, a good size weather maker is due to
affect the region. Will see mixed rain and snow Thursday afternoon
and evening before changing to all snow overnight. Overall QPF
coverage and amounts are in question this far out and have used a
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 523 AM CST Sat Feb 18 2017
High pressure will be nearby through the forecast. VFR at the
outset. Look for fog with MVFR vsbys around sunset lingering
through the end of the forecast.
Issued at 850 AM CST Sat Feb 18 2017
Record Highs for February 18...
Duluth................ 53 in 1981
International Falls... 49 in 1954
Record Warmest Lows for February 19...
Duluth................ 35 in 1930
International Falls... 32 in 2016
Record Highs for February 19...
Duluth................ 51 in 1930
International Falls... 47 in 1994
Record Warmest Lows for February 20...
Duluth................ 33 in 1954
International Falls... 32 in 1915
Record Highs for February 20...
Duluth................ 54 in 1877
International Falls... 48 in 1990
Record Warmest Lows for February 21...
Duluth................ 33 in 1878
International Falls... 29 in 1981
Record Highs for February 21...
Duluth................ 57 in 1877
International Falls... 50 in 2000
Record Warmest Lows for February 22...
Duluth................ 35 in 1930
International Falls... 32 in 1998
.PRELIMINARY POINT TEMPS/POPS...
DLH 51 29 47 35 / 0 0 0 10
INL 45 25 45 35 / 0 0 0 10
BRD 50 29 52 41 / 0 0 10 20
HYR 51 28 50 38 / 0 0 0 10
ASX 52 30 50 35 / 0 0 0 10