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Area forecast discussion 
National Weather Service Duluth Minnesota
327 PM CDT Wednesday Aug 27 2014

Synopsis...
issued at 323 PM CDT Wednesday Aug 27 2014

Surface high pressure overs the region this afternoon underneath a
progressive middle level ridge. Extensive area of scattered/broken cumulus developed
with diurnal heating today...especially over southwestern County Warning Area where a
925/850 moisture axis remains from previous frontal boundary. Expect a
dissipation of this cloud field once diurnal warming decreases this
evening.

&&

Short term...(this evening through thursday)
issued at 323 PM CDT Wednesday Aug 27 2014

Tonight...surface high will shift to eastern Great Lakes by early morning with
weak return flow setting up over decoupled boundary layer. Areas of fog
are expected again...this time over the eastern County Warning Area where forecast surface conditions
press deficits.

Tomorrow...active weather pattern organizes over the ctrl plains as
significant middle level trough advects east into neb/KS. A low level jet impinging
on a strong low level thermal boundary will setup a large area of
convection south of the region. Although 850 mb moisture transport does
increase over the County Warning Area...it appears that any precipitation development will
be slower to occur than originally anticipated. Large anticyclonic
boundary layer flow combined with antecedent drier air will maintain a
wedge of relatively drier air over the northern and eastern County Warning Area.
Will keep thunder out of forecast through the period as limited
instability forecast...with support from sref cloud physics thunder
parameter.



Long term...(thursday night through wednesday)
issued at 323 PM CDT Wednesday Aug 27 2014

After a couple dry days...we will once again be entering a pattern
that is more unsettled and wet. There are some pretty serious model
differences with respect to the system moving in from the southwest
Thursday night and Friday. Surface low pressure is expected to move
into Minnesota Thursday night...with moisture spreading northward into the
Lake Superior region. The European model (ecmwf) and NAM generally keep the bulk of
the precipitation over northern Wisconsin with the twin ports being
on the edge of the majority of the precipitation. The GFS and Gem
bring a big batch of precipitation further north into the Brainerd
lakes and into the Minnesota arrowhead. At this point we feel the European model (ecmwf) and
NAM solutions make the most sense...and have trended our forecast
for Thursday night and Friday in that direction. This system will
then trend to the south and east later Friday and Friday
night...while a weak frontal boundary drops across northern Minnesota
Friday and Friday night. In general we are looking at lighter quantitative precipitation forecast
Saturday and Saturday night...although the chances look to be enough
to mention a warrant of a slight/chance for much of the County Warning Area. A
fairly major system is expected to wrap up Sunday night into
Monday...as a broad trough develops in the upper Midwest and south
central Canada. A north to south frontal boundary is expected to
develop across the upper Midwest from Sunday night into Monday with
abundant moisture expected to reach our area. This trough will
continue to affect the area through midweek...with a few weak
systems bringing a chance of precipitation. Otherwise it should be a
bit on the cool side.




&&

Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1242 PM CDT Wednesday Aug 27 2014

A widespread cumulus field had developed as of midday and it will
continue to be an issue throughout the afternoon and into early
evening. For a short time...we will see some local MVFR ceilings but
with daytime heating we should see cloud bases rise to VFR. Some
local fog will then develop overnight...with some local IFR
cigs/vsbys. Conditions will then improve on Thursday.



&&

Preliminary point temps/pops...
dlh 51 69 57 70 / 0 10 40 20
inl 45 75 55 74 / 0 10 10 40
brd 53 69 59 76 / 0 40 20 20
hyr 47 70 59 73 / 0 40 70 30
asx 48 72 58 69 / 0 10 60 30

&&

Dlh watches/warnings/advisories...
Minnesota...none.
WI...none.
Ls...none.
&&

$$

Synopsis...Cannon
short term...Cannon
long term...dap
aviation...dap

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