Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 270526
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1226 AM CDT TUE SEP 27 2016

.UPDATE...
Issued at 723 PM CDT Mon Sep 26 2016

Boundary layer has decoupled and the gusty winds are not as strong
as earlier. Adjusted the wind speeds and gusts for this change.
Otherwise, with the occluded system over northern Lake Superior,
will continue to see waves of rain affecting the area. Only some
minor tweaks were made.

&&

.SHORT TERM...(This evening through Tuesday)
Issued at 238 PM CDT Mon Sep 26 2016

A slow moving stacked low, centered over northern Lake Superior,
will allow for the below normal temperatures and gusty northwest
winds to prevail overnight through Tuesday. The cyclonic flow and
steep lapse rates will continue to produce gusty northwest winds
overnight. Rain showers will also continue overnight across the
Minnesota Arrowhead and northern wisconsin zones near the low
center where instability is the greatest.

The core of coolest mid level air, with 850hPa temperatures around
zero C, dives over northern MInnesota and into Wisconsin Tuesday.
Latest NAM/GFS BUFR soundings are in good agreement that the
combination of deep moisture and sufficient instability will
bring increasing shower activity across the Northland through the
afternoon.

.LONG TERM...(Tuesday night through Monday)
Issued at 238 PM CDT Mon Sep 26 2016

Summary: A large area of low pressure will dig from the Great Lakes
to the central Appalachians, only to then retrograde or lift back
north to the central or eastern Great Lakes over the weekend. The
low will help maintain easterly flow across the Northland through
the weekend, but temperatures will be slightly warmer than normal
with highs primarily in the lower 60s and low temperatures in the
low to middle 40s.

Tuesday night and Wednesday...A large, vertically stacked area of
low pressure over southern Lake Superior will dig south to
Indiana/Ohio. The cool and relatively humid northeast flow will
result in lingering overcast/broken low-level cloud cover and rain
showers Tuesday night into early Wednesday, especially across
downwind of Lake Superior across northwest Wisconsin, and over the
Arrowhead. A ridge of high pressure will begin to build into the
region from the west Wednesday, but there looks to be enough
lingering moisture in the cyclonic flow to pop scattered/broken
cumulus midday Wednesday. The cloudiest conditions Wednesday will be
downwind of Lake Superior, where there could be light rain showers.

Wednesday night...The low will approach the central Appalachian
Mountains near West Virginia and eastern Kentucky, while the ridge
of high pressure will move into northern and western Minnesota. The
Northland should see clearing skies and negligible winds by the wee
hours of the morning, promoting radiational cooling. Leaned on the
cooler Consensus-MOS guidance for temperatures, with widespread
lower 40s. Some parts of the Borderland of far northern Minnesota
could get down to the upper 30s.

Thursday through Sunday...The Northland will likely have several
days of relatively similar weather. The area of low pressure over
the central Appalachians will then retrograde (per the ECMWF) or
lift north (GFS/Canadian) north to the central or eastern Great
Lakes over the rest of the week and into the weekend. This will
maintain light easterly flow across the Northland, but the upper low
should be far enough east to stave off the associated heavier cloud
cover with the low.

Early next week...The next best chance of for showers will when a
cold front approaches the region sometime early next week. The GFS
and ECMWF are trending later in time with this feature, so the pcpn
might not quite come until Tuesday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1226 AM CDT Tue Sep 27 2016

With the occluded low nearby, will continue to have periods of rain
showers, gusty winds and MVFR through the forecast. The exception
will be BRD/HYR which begin with VFR, gradually having MVFR ceilings
return through the overnight.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  47  60  44  63 /   0   0   0   0
INL  41  60  39  63 /   0   0   0   0
BRD  45  60  42  64 /   0   0   0   0
HYR  46  59  43  64 /  30  20   0   0
ASX  49  59  46  63 /  50  20   0   0

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...Small Craft Advisory until 10 AM CDT this morning for LSZ121-
     140>148.

&&

$$

UPDATE...GSF
SHORT TERM...Graning
AVIATION...GSF



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