Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 181123
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
523 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 fcst 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 sfc 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
sfc 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 trof 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 trof pushes into the forecast area.
Temperatures will be warm enough for rain, which will begin to
diminish late Monday night. The long wave trof 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
blend.

&&

.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.

&&

.CLIMATE...
Issued at 520 AM CST Sat Feb 18 2017

Record Highs for February 18...

Duluth................53 in 1981
International Falls...49 in 1954

&&

.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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...JTS
LONG TERM...GSF
AVIATION...GSF


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