Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 011737
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1237 PM CDT SAT OCT 1 2016

.UPDATE...
Issued at 1237 PM CDT Sat Oct 1 2016

Updated for the new 18Z Aviation Discussion below.



UPDATE Issued at 720 AM CDT Sat Oct 1 2016

Please see the updated 12Z Aviation Discussion below...

&&

.SHORT TERM...(Today through Sunday)
Issued at 419 AM CDT Sat Oct 1 2016

The cut off upper low over the Lower Ohio river valley early this
morning, along with a weak ridge axis extending over northern
Minnesota will remain in control of  weather for the Northland
through the weekend.  The upper low will gradually move north across
Indiana today, then slowly ease northeast into far southeast Ontario
by Sunday afternoon. This low is going to do little more than
bring some mid and high clouds to the eastern sections of the
forecast area through Sunday, with some small rain chances for
Price county. Stratus that has developed over the area downstream
of Lake Superior the last few mornings is here once again, with
the relatively warmer -mid 50s- lake modifying the airmass that is
in the mid 40s where the clouds are clear. Expect this behavior
once again tonight, with stratus developing over the head of the
lake and over the Bayfield Peninsula in the lee of the light east
to northeast flow over the lake. The signal is not as strong as it
was the last two nights, but the pattern is about the same, and
there really hasn`t been significant change in the airmass, so it
seems best to assume the stratus will form again. The similar
airmass and only small changes in cloud cover should favor a
persistence forecast in temperatures, with highs both days getting
into the middle and upper 60s and upper 50s/low 60s near the lake.
Onshore flow is weaker on Sunday so it should be a little warmer
near the lake then. Lows to be very similar as well, dipping into
the low 40s where it clears out, with mid and upper 40s under the
cloud cover.

.LONG TERM...(Sunday night through Friday)
Issued at 419 AM CDT Sat Oct 1 2016

Sunday evening continues the long-awaited departure of the
stagnant cut-off low. By 03.00Z, that feature is forecast to be
over the eastern Great Lakes and progressing eastward with time.
Farther to the west, a high pressure ridge will be positioned over
the Plains and the Upper Midwest. A weak shortwave trough is
forecast to move across the northern Canadian Prairie Provinces
overnight and early Monday. Surface high pressure over the western
Great Lakes, with the transient low to the north, will continue
the development of a southerly return flow across the region
Sunday night into Monday.

The upper-level ridge will advance eastward ahead of a deepening
longwave trough digging across the western United States by Monday
night. A cold front will push across the Dakotas and into western
Minnesota overnight with increasing cloud cover and rain showers
spreading east toward the Northland. Tuesday afternoon through
Wednesday evening appear quite soggy with and area of rain, and a
few embedded thunderstorms, slowly moving eastward ahead of the
decelerating cool front. Twenty-four hour rainfall of 1 to 2
inches seems likely for the eastern two-thirds of my CWA.

Differences in the deterministic and ensemble guidance increase
after Wednesday. The variety of solutions for the track and
intensity of Hurricane Matthew, and the resultant quasi-Rex Block,
produce a wide spread of sensible weather for the area. The
deterministic GFS brings the closed upper low slowly northeastward
into southern Manitoba by Thursday morning with most of the GEFS
members farther west. The ECMWF and GEM both feature a more
progressive solution with the ECMWF opening the low back into a
trough. Prefer the slower GFS solution and nudged the consensus in
that direction.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1237 PM CDT Sat Oct 1 2016

Low stratus and fog had developed across large portions of
northwest Wisconsin and northeast Minnesota last night and early
this morning from light easterly flow from Lake Superior. The low
stratus has eroded today, but there is a threat of some more
stratus and fog developing again tonight. While the stratus may
begin near Lake Superior and move inland, think KDLH may narrowly
avoid it. The wind direction at KDLH will more likely be
northeast, not east, so the stratus may sneak just to the south.
The KBRD is probably the most likely area to get at least IFR/MVFR
conditions by later tonight. The KINL/KHIB/KHYR could also get
lower visibility and ceilings, but the chances are not as high as
KBRD.

Any stratus and fog that develops by early Sunday will linger a
bit into the morning, but should lift and dissipate to bring back
VFR conditions by the late morning or early afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  63  45  65  46 /  10   0   0   0
INL  66  49  69  48 /   0   0   0   0
BRD  68  46  69  49 /   0   0   0   0
HYR  69  44  67  44 /   0   0   0   0
ASX  62  47  64  44 /   0   0   0  10

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...None.
&&

$$

UPDATE...Grochocinski
SHORT TERM...LE
LONG TERM...Huyck
AVIATION...Grochocinski


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