Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 141825

Area Forecast Discussion
National Weather Service Grand Forks ND
1225 PM CST Tue Nov 14 2017

Issued at 1220 PM CST Tue Nov 14 2017

fog and low clouds hanging on as anticipated hallock to near
grafton to cooperstown. Western edge of dense fog moved into
Hallock and Cooperstown so did add those areas and extended dense
fog advisory for portions of the RRV and NW MN thru 21z. Models
doing reasonably good with showing most dense fog hanging out on
the western fringe of low level moisture from Valley City to Grand
Forks/TVF region. Fargo area and east to Bemidji/Park Rapids low
clouds but vsbys in fog improved to aoa 1sm. West wind shift with
front will be entering DVL region nr 20z and this will move into
the RRV 00z or so pushing the fog and low clouds east.


.SHORT TERM...(Today and Wednesday)
Issued at 303 AM CST Tue Nov 14 2017

Dense fog will be the initial concern. The dense fog advisory from
earlier (northern Red River Valley) is still valid with
observations remaining 1/4sm or less. The other area of concern is
the low level moisture advecting northward into the FA. This has
led to visibilities dropping through the night. 1/4sm visibility
has developed across eastern South Dakota and adjacent portions of
Minnesota, which is also advecting northward. Some of the model
guidance actually has a decent handle on the situation, and
indicates this trend to continue. Timed the dense fog northward
until sunrise and went with this area for a dense fog advisory.
There are some sites that are not yet dense, but figured it would
be best to get ahead of the game. Most road sfc temperatures are
above freezing, or rising, so do not any additional impacts from
freezing mist on roadways.

Thinking clouds/fog will move into much of the FA by mid-
afternoon before the SFC trough pushes the low level moisture
east. As the SFC trough interacts with the low level moisture,
forcing may be enough for patchy drizzle to develop this evening.
Otherwise, best precip chances will be late tonight into early
Wednesday across NW MN with the passage of a stronger upper level
wave. This precip should be all snow, with amounts remaining very
light. High pressure builds into the region by later Wednesday
afternoon. Kept some very low pops for later aftn GFK-JMS region
some weak returns on BIS radar.  If anything just sprinkles.

.LONG TERM...(Thursday through Monday)
Issued at 357 AM CST Tue Nov 14 2017

Upper level ridge over the western Dakotas will shift east over the
area Wed night. Another upper level trough will move across southern
Canada Thu night with the GFS a faster solution than most of the
models. Warm advection precip is forecast for Thu night into Fri.
Also the right entrance region of the jet will be over the area.
Precip is expected to be light.

Main upper trough over the northeast Pacific will move through the
Northern Plains Fri night. The GFS remains the faster model and
farther south than the ECMWF. The ECMWF was trending a little slower
while the GFS was trending faster and farther north except for the
latest run. Precipitation also is expected to remain light. The
ECMWF and the GFS were 180 degrees out of phase by Mon.

The long wave pattern amplifies through the extended period with an
upper level ridge over the Rockies and a long wave trough over
eastern North America.

High temperatures were generally increased zero to two degrees for
Fri. High temps were increased one to three degree for Sat, and
increased five degrees for Sun and Mon from yesterdays forecast.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1220 PM CST Tue Nov 14 2017

Poor flying conditions with LIFR, IFR conditions to continue in
vsby or cigs in the RRV and NW MN thru late aftn. This evening
will see a west wind shift and improvement in the cigs/vsbys from
west to east. However lower cigs likely to return in the cold
advection overnight with northwest winds.


ND...Dense Fog Advisory until 3 PM CST this afternoon for NDZ027>030-

MN...Dense Fog Advisory until 3 PM CST this afternoon for MNZ001-004-



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