Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 211147

Area Forecast Discussion
National Weather Service Duluth MN
647 AM CDT Fri Oct 21 2016

.SHORT TERM...(Today through Saturday)
Issued at 446 AM CDT Fri Oct 21 2016

Two areas of low stratus were located over the area early this
morning; one over the Arrowhead and the other stretching from
Lower Red Lake across much of my western and southern zones. A
high cirrus deck was moving eastward into northwest Minnesota
associated with the first push of warm advection and frontogenesis
marking the approaching warm front. A mid-level ridge axis was
found just behind the leading edge of the mid-level cirrus and a
shortwave trough was located farther upstream over Saskatchewan
and southern Alberta. Temperatures at 4 AM ranged from the low 20s
over portions of Koochiching County to the middle 30s under the
low stratus across my south.

The low stratus layer will slowly move eastward this morning, but
should linger until late morning when it should mix out. The mid-
level ridge will quickly push across northern Minnesota and
northwest Wisconsin by this afternoon as the shortwave deepens and
moves into northwest Minnesota. Ahead of the trough, the warm
front will advance across the Dakotas and into my western zones
tonight. Forcing for ascent will accompany the warm advection
aloft bringing the mid and high clouds over North Dakota and the
Canadian Prairies into my western areas around 12Z, and farther
eastward through the rest of the day. Think there will be enough
lift to create showers across northern Minnesota. A few sprinkles
may fall over the remainder of the CWA this afternoon into this
evening. The showers will push across the Arrowhead tonight and
should be clear of the area by sunrise Saturday morning.

As the shortwave moves east into eastern Ontario Saturday
morning, longwave ridging will build across the region. Skies will
begin to clear overnight tonight leading to mainly sunny to partly
cloudy skies across the CWA by late morning. Mid-level warm air
advection will increase once again over my western zones by
afternoon Saturday, leading to gradually increasing cloud cover
once again.

Temperatures will remain near to slightly below normal for today
as the surface warm front remains west of the Northland.
Southwesterly flow and warm advection will lead to slightly above
normal temperatures tonight and Saturday. Look for highs today in
the low 40s in the high terrain of northeast Minnesota and around
50 degrees in my southwest. Lows tonight will be in the middle to
upper 30s. Temperatures Saturday will climb into the upper 40s to
upper 50s.

.LONG TERM...(Saturday night through Thursday)
Issued at 446 AM CDT Fri Oct 21 2016

The models are still having a difficult time resolving the
surface low center Saturday night and the position and strength of
an upper level short wave trof. They all differ in surface low
location and QPF as well. Used a blended approach to POPs/QPF
which favors no QPf in the evening, then a chance of showers over
the northwest quadrant of the forecast area overnight. Warm air
advection is underway and in varying strengths, which results in
an all rain forecast. The models agree on pushing the surface low
east of the area on Sunday as the upper trof drops through the
western Great Lakes. Varying amounts and locations of QPF are
noted and maintained the blended approach to resolve the
differences. Upper level and surface ridging move over the region
Sunday night. On Monday, the surface ridge begins to move off to
the east, while some mid to upper level ridging is nearby. A warm
air advection pattern begins late in the afternoon to varying
degrees. Monday night and Tuesday features more model
discrepancies. The ECMWF has a northwest flow over the area. The
GFS has upper ridging, the GEM has the upper ridge flattening.
Used a compromise solution which resulted in a shift of the
previous forecast of POPs over the entire area, to just the
southern third as as the best forcing will be over southern
Minnesota nearest a warm front that will be near the
Iowa/Minnesota border. Models try to come into better agreement
Tuesday night with a surface low center somewhere over Iowa.
However, their handling of an upper level trof and closed off mid
level circulation are different. These issues become exceedingly
large Wednesday through Thursday and will use a blend of solutions
to attempt to resolve the differences.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 647 AM CDT Fri Oct 21 2016

High pressure was overhead at the start of the forecast. This will
move east today with a warm front moving past the terminals
tonight. Some showers or sprinkles may occur in the vicinity of
the front and have VCSH mentions as confidence is low in actual
timing of rain. VFR expected through the forecast, although a
brief period of MVFR ceilings is possible as the front gets


DLH  47  36  55  40 /  10  10   0  10
INL  47  37  51  38 /  30  20  10  30
BRD  51  36  59  40 /  10   0   0  10
HYR  48  37  58  38 /  10  10   0   0
ASX  49  38  57  39 /  10  10   0   0




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