Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 250520

Area Forecast Discussion
National Weather Service Duluth MN
1220 AM CDT Tue Oct 25 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 322 PM CDT Mon Oct 24 2016

High pressure over the Northland will result in another night of
mostly clear skies and light wind speeds, so it will be another
cold night. The relatively low humidity, with dew point
temperatures in the 20s and low 30s as of this afternoon, suggest
temperatures will plummet after sunset. However, a little
concerned about increasing upper-level cloud cover later in the
night associated with blow off from low pressure and shortwaves in
the western US, which will be moving into the Plains overnight
into Tuesday. Therefore, refrained from the coldest model
guidance. May need to lower temperatures, with an update this
evening, if it looks like it will take longer for the upper-level
cloud cover to spread over the Northland. There be enough
relatively humidity amidst the strong radiational cooling later
tonight, and light enough wind speeds, to result in patchy fog for
the lower-lying areas of northwest Wisconsin and the
Arrowhead and Iron Range.

Otherwise, easterly flow will develop overnight with the passing
high pressure, and the flow will pick up in speed during the day
Tuesday. Increasing cloud cover will limit highs to the middle 40s
to low 50s. Strong east to northeast flow will develop over
western Lake Superior during the afternoon and going into the
evening, in response to the approaching low pressure, and that
wind will translate to the Twin Ports area. There could be gusts
of 20 to 25 mph by the late afternoon.

This area of low pressure will be bringing our next round of rain.
However, it will take some time for the rain to move into our
territory because of the relatively dry east to east-southeast
flow. Some of the rain will go into saturating the atmosphere. It
may reach the far southwest forecast area by evening.

.LONG TERM...(Tuesday night through Monday)
Issued at 322 PM CDT Mon Oct 24 2016

A shortwave trough will dig across the Northern Plains into
northern Minnesota at the beginning of the extended. This feature
will move into the central Great Lakes by Wednesday evening. Still
some differences between the latest guidance, with most notably
the ECMWF coming in with a weaker shortwave. At the surface, this
will develop an area of low pressure across Iowa, which will move
eastward into southern Wisconsin by Wednesday evening. This will
bring rain to much of the Northland Tuesday evening through
Wednesday. Tuesday night lows will generally be in the 30s
throughout the Northland. Highs on Wednesday will top out in the
low to mid 40s.

Rain will taper off across much of the forecast area Wednesday
evening into early Thursday morning. Light precipitation chances
will continue across northern Minnesota and eastern Wisconsin
Wednesday evening into Thursday morning as another shortwave
trough dives southeastward from Saskatchewan into western Lake
Superior. Behind the shortwave, weak high will gradually build
into the area. On the western side of the ridge, will see a
gradual warm up for Thursday and Friday as southwesterly warm
advection occurs at 850 hPa.

Will see another shortwave eject from the Pacific Northwest and
late on Thursday and into the Northern Plains by Friday. The
latest ECMWF again features a more subtle shortwave in comparison
to the GFS/GEM. Will see 850 hPa temps between 0C to +5C, so
expecting mainly rain Friday. As the system exits on Saturday will
see cooler northwest flow bringing -5C to 0C air into the
Northland. With the cool northwest flow behind low, kept some
lingering low chances of light precipitation into Saturday morning
as hinted by the latest GFS. Late in the weekend and early next
week a ridge of high pressure will build into the Northern Plains.
The latest GFS/ECWMF bring another round of warm air advection due
to southwesterly flow at 850 hPa. Once again it appears there will
another brief warm up Sunday/Monday before the next system moves
in on Tuesday.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1220 AM CDT Tue Oct 25 2016

High pressure will gradually lose its grip on the Northland
throughout the TAF period, as a low pressure system rapidly moves
into the region from the west. Overnight we may see some scattered
MVFR CIG`s and VSBY`s, but the main threat to aviation would push in
from southwest to northeast later in the TAF period. The first to
see a rapid onset of low clouds and rain will be KBRD in the late
afternoon on Tuesday. The rain will then spread to KDLH and KHYR
just before the end of the TAF period. It should stay out of the
KHIB and KINL areas through that time period, but arrive shortly
after the end of the TAF period.


DLH  30  47  38  43 /   0  10  70  70
INL  28  48  37  44 /   0   0  40  60
BRD  35  49  40  45 /   0  50  80  60
HYR  30  50  40  44 /   0  10  80  70
ASX  29  50  38  45 /   0  10  60  70




SHORT TERM...Grochocinski
AVIATION...DAP is the U.S. government's official web portal to all federal, state and local government web resources and services.