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Area forecast discussion...updated 
National Weather Service Duluth Minnesota
1234 am CDT Tuesday Sep 16 2014

issued at 1234 am CDT Tuesday Sep 16 2014

Updated aviation discussion for 06z taf issuance below.


Short term...(this evening through tuesday)
issued at 257 PM CDT Monday Sep 15 2014

High pressure will be centered over SW Iowa tonight. Meanwhile...a
surface low will be in northern Manitoba. The pressure gradient between
the two will be the most pronounced over the northern two thirds of
the forecast area. As a result...the wind...what little there is...will keep
min temperatures up a bit over the north. Cooler min temperatures will occur over northwest
WI to near the twin ports and the eastern Iron Range. Patchy frost
is expected once again in these areas with more frost in northwest WI. Will
keep the headline in place.

The center of the high drifts over the southern Great Lakes on
Tuesday. This allows for weak warm air advection through the day. Expect more
clouds along the international border region than today as short
wave energy moves into northwest Ontario just north of the border. Models are
hinting at some light quantitative precipitation forecast right at the border...but not enough of a
consensus for probability of precipitation. Did add a mention of sprinkles in the late
afternoon however.

Long term...(tuesday night through monday)
issued at 257 PM CDT Monday Sep 15 2014

As of Tuesday evening...there will be an upper level low centered
over Hudson Bay...and the broad trough will extend south through the
eastern United States. An upper level ridge will be over the western
United States. Surface high pressure will be centered near Illinois.
There will be a surface low in central Quebec with a trailing cold
front through Ontario and Manitoba.

The models are in decent agreement early on. The cold front in
Canada will gradually shift into the Northland Tuesday night and
Wednesday. This will bring low chances of showers to parts of the
forecast area...mainly the northern forecast area Tuesday night.

The front will stall over the Northland region late Wednesday.
Southerly flow will then kick in Thursday as the upper level ridge
over the western United States shifts into the central United
States. This will bring a warming trend through the latter half of
the week.

Chances of showers and storms will increase Thursday night due to a
strong low level jet and increasing moisture transport ahead of an
approaching trough in the Dakotas. The precipitation chances will continue to
increase Friday and Friday night as the trough moves into the upper
Midwest. The GFS/ECMWF/Gem are in decent agreement as far as
indicating this could be a wet and stormy period and with the timing
of the trough/cold front...but the models have very different
indications of where ideas of where the surface low pressure system
will be.

There will likely be a cooling trend late this weekend and early
next week as northerly flow filters down cooler air in the wake of
the passing trough/front. There are low chances of showers...mostly
over The Arrowhead.


Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1234 am CDT Tuesday Sep 16 2014

VFR conditions are expected for the most part at all taf sites for
the next 24 hours. The only exception to this will be the
potential for radiation fog temporarily reducing visibility to 1
to 3 miles at the two favored locations of khib/khyr during
roughly the first 6 hours of this valid taf period. Otherwise..we
expect a period of scattered-broken 050-070 ceilings during the day Tuesday
associated with sustained low level warm advection. However..the
lower atmosphere is too dry to support any precipitation. A fast-moving
disturbance and associated surface cold front will approach the
international border from the north during the last 6 to 8 hours
of this period..but at this time it appears that any MVFR ceilings
and/or precipitation will remain north of kinl through 17/06z.


Preliminary point temps/pops...
dlh 45 59 42 59 / 10 20 0 10
inl 41 60 40 64 / 20 20 0 10
brd 44 68 45 67 / 0 0 0 10
hyr 42 66 43 66 / 0 10 0 10
asx 45 60 42 62 / 10 10 0 10


Dlh watches/warnings/advisories...
WI...frost advisory until 8 am CDT this morning for wiz002>004-

Ls...Small Craft Advisory from 4 am early this morning to 4 PM CDT
this afternoon for lsz146-147.



Short term...gsf
long term...grochocinski

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