Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 150524
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1224 AM CDT Tue Oct 15 2019

.UPDATE...
Issued at 1224 AM CDT Tue Oct 15 2019

Updated for the 06Z Aviation discussion.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 328 PM CDT Mon Oct 14 2019

Upper level and surface ridging covered the forecast area this
afternoon. Drier air over the southern half of the region has led
to some clearing. Clouds were hanging on over the north where
more moisture was available and an embedded upper level impulse
was moving through and helping to generate these clouds. Even with
the cloud cover, temps have warmed into the 40s, except along the
Borderland and into the Arrowhead where upper 30s were found at
2pm.

The ridging prevails through this evening. Late tonight, a closed
upper low arrives in the Red River Valley of the North, while its
surface low drifts into southern Minnesota. A fairly potent
vorticity maxima will reach western Minnesota overnight. Showers
will develop/spread into the southern portion of the region before
09Z/4am, then continue north to the international border. Colder
temps just off the surface will lead to some snow mixing in with
the rain north of MN Highway 210. No snow accumulation tonight.

The closed upper low moves into Wisconsin Tuesday, while the surface
low reaches Green Bay by late afternoon. The aforementioned vort max
intensifies as it moves just ahead of the closed low. Cold air
advection on the backside of the upper/surface lows will work
together with the vort max to keep the precipitation going,
especially over the southern half of the area nearest the low track.
The mixed precip types will continue until noon, then switch to all
rain. In northwest Wisconisn Tuesday afternoon, some colder air
coming off of Lake Superior, will lead to a rain/snow mix in the
high terrain areas through the rest of the afternoon. A light
accumulation of snow is possible from southern Bayfield east through
central and southern Iron counties, but less than one inch.

Tuesday night finds the closed low reaching lower Michigan, while
the surface low moves to the eastern Great Lakes region. Additional
impulses will work over the area as well. The showers will persist
through the evening, ending from west to east overnight as high
pressure approaches. The rain/snow mix will switch to all rain as
boundary layer temps remain above freezing and is supported by
latest short term models.

.LONG TERM...(Wednesday through Monday)
Issued at 314 PM CDT Mon Oct 14 2019

High pressure will be the main weather feature from Wednesday
through early Friday morning across the Upper Midwest. A period
of quiet weather is expected. Temperatures will trend warmer
Thursday  and Friday, and remain warm through the weekend.

An upper-level ridge is forecast to build across the region on
Wednesday and will amplify further on Thursday. Northwest flow in
the low-levels will support a chance of lake effect rain or snow
showers in the northwest Wisconsin snowbelt areas Wednesday
morning. A weak shortwave trough and associated vorticity
advection will move across Minnesota and Wisconsin Wednesday
night and Thursday morning. With limited moisture, expect a
slight increase in cloud cover to mark its passage. Precipitation
is unlikely with the passing shortwave trough. Winds in the low-
levels will turn westerly Wednesday afternoon and southwesterly
for Thursday ushering in a surge of 850 mb warm air advection.
The strongest warm air advection is expected Thursday night into
Friday morning before the next shortwave trough moves through the
region Friday afternoon and evening. Have raised low temps
Thursday and Friday morning and high temps during the afternoon
hours both days. Temperatures will be near normal on Thursday
with readings in the middle 40s in the Arrowhead to the middle
50s in central and north-central Minnesota as well as much of
northwest Wisconsin. Friday will trend above normal with highs in
the low 50s to low 60s.

The shortwave trough of Friday and Saturday morning will bring a
weak cool front through the region. There is a chance of light
rain with the system. Conditions dry out again for Saturday
afternoon through Sunday evening in response to weak ridging
aloft. Temperatures will remain a few degrees above normal
through the weekend. A more organized storm system will take
shape in the Central Plains Sunday afternoon and evening and will
bring a chance of precipitation to the Northland by late Sunday
night. The system will continue to affect the region Monday and
Tuesday of next week.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1224 AM CDT Tue Oct 15 2019

Initial VFR conditions are expected to begin deteriorating around
09z as an incoming, fairly fast moving upper level low pressure
system moves across central Minnesota and southern Wisconsin through
the TAF period.  Conditions should lower to MVFR for most sites by
13z, then to IFR by 17z for a 3 to 6 hour period before improving
again to MVFR beginning around 19z and spreading from west to east
through 02z.  Do not expect any sites to return to VFR until after
the end of the TAF period.

&&

.MARINE...
Issued at 1224 AM CDT Tue Oct 15 2019

A ridge of high pressure over western Lake Superior will retreat
off to the east tonight as a low pressure system develops over
southern minnesota and moves across Wisconsin on Tuesday. This
will cause winds to become northeast overnight tonight and
strengthen during the morning hours. These winds will cause
building waves, especially for the south shore of Lake Superior. A
Small Craft Advisory has been issued for much of Tuesday and
Tuesday night for the South shore due to these gusty winds and
building waves. The winds and waves will diminish again late
Tuesday night and early Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  36  41  36  44 /  50  90  10   0
INL  36  42  36  44 /  50  70  20   0
BRD  36  42  37  45 /  60  80  10   0
HYR  34  41  36  46 /  70 100  40   0
ASX  34  42  39  48 /  50 100  60  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory from 10 AM this morning to 10 PM CDT this
     evening for LSZ121-144>147.

     Small Craft Advisory from 10 AM this morning to 4 AM CDT
     Wednesday for LSZ148.

&&

$$

UPDATE...LE
SHORT TERM...GSF
LONG TERM...Huyck
AVIATION...LE
MARINE...LE


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