Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 210836

Area Forecast Discussion
National Weather Service Duluth MN
336 AM CDT Sat Oct 21 2017

.SHORT TERM...(Today through Saturday)
Issued at 335 AM CDT Fri Oct 20 2017

An area of low pressure was located over south central Canada at
07Z. A cold front extended south from the low through the central
Dakotas, while a quasi-stationary front was north of the
Minnesota/Canada border. A stiff southerly flow of air/moisture was
working its way into the area ahead of the low on a strong low level
jet. Some sprinkles were dotting the forecast area, even though the
radar indicates there may be some better rain in northwest
Wisconsin. However, the very dry airmass that has been over the
region for the past week, is proving to be tough to overcome as
cloud bases are greater than 10K feet. After this initial surge of
sprinkles, there will be a break in the action as the potential
vorticity advection that is helping to initiate these sprinkles
moves off to the north. Next round of more robust showers is
expected to arrive later this morning as the next shot of vorticity
arrives from the South. The showers will overspread the region by
noon with some isolated thunder as well. Not expecting any severe
storms as MUCAPE remains below 1000 J/kg for most of the day. 0-6 km
shear is 25 to 30 knots in the afternoon. The best shear however
lags the MUCAPE axis. Expect the showers and isolated storms through
the afternoon.

The cold front begins to move into the western third of the forecast
area by 00Z, and reaches the far eastern edge of the region by 12Z
Sunday. Showers and a few thunderstorms will percolate across the
area tonight with the thunderstorms occurring ahead of the front.
The rain will end gradually from west to east through the night,
except for the far eastern edge where some showers may linger in the
vicinity of the front.

The front pushes out of the region Sunday morning accompanied by a
sharp upper level trof. Some rain will linger from the Arrowhead
into the Hayward Lakes area and points east in the morning due to
their proximity to the departing front and the upper trof. The rain
departs by the afternoon as the best forcing exits. No rain
elsewhere as a drier airmass works into the area from the West.

.LONG TERM...(Saturday night through Thursday)
Issued at 335 AM CDT Fri Oct 20 2017

Not a whole lot of change to the previous discussion as model
continuity continues giving a tad more confidence to the forecast.
Precipitation will slowly progress east out of the area on Sunday
morning with the remainder of the day remaining dry. The dry
weather will be short- lived as another shortwave pushes across
the region from the Dakotas into the Lake Superior region Sunday
night and Monday. An upper level trough will amplify across the
western Great Lakes Monday and Monday night, with upper level
shortwave energy bringing unsettled weather to the Northland. Some
snow showers will even be possible Monday night and early
Tuesday, as colder air pours into the area from Canada. This upper
level low and amplifying trough will dominate the weather across
the Great Lakes region at least into midweek.

The best chance of precipitation throughout the long term period
will be Thursday night. Temperatures drop considerably to below
seasonable norms by Tuesday morning. A slight warm up on Thursday.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1221 AM CDT Fri Oct 20 2017

VFR conditions expected through the TAF period. The main concern
is with winds, with strong southwest winds aloft in the 40-45knot
range as depicted on radar wind profiles. These winds will
continue until 09-11z in the morning, so have included LLWS groups
in the TAF forecast. Surface winds increase in the 15z-18z time
range to 10- 15kts with gusts of 15-25kts, with the strongest
gusts near KBRD. These strong winds aloft increase once again
around 03z, and have included LLWS for the terminals beginning at


DLH  71  56  64  46 /   0  40 100  80
INL  74  58  66  42 /   0  40  80  60
BRD  73  60  65  42 /  10  50 100  60
HYR  75  58  67  47 /   0  30  70  80
ASX  77  58  70  50 /   0  30  70  80




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