Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 211534

Area Forecast Discussion
National Weather Service Grand Forks ND
934 AM CST Sun Jan 21 2018

Issued at 934 AM CST Sun Jan 21 2018

Patchy dense fog will persist through the forenoon across portions
of eastern ND and northwest MN... mainly along and north of the
Highway 200 corridor. Middle to higher level clouds are building
into the FA from the south as winter storm moves into the central
plains... while a low cloud deck and increasing north winds are
spreading southward into the FA from Manitoba. The patchy dense
fog is mainly in the steadily shrinking, more stable airmass
between these two features.

UPDATE Issued at 705 AM CST Sun Jan 21 2018

Areas of fog moving around the far they haven`t
stayed in any one spot for a long time. Hodgepodge of vsby and
cloud cover. Main question from a few hours ago was stratocu in
Manitoba and that has been surging much faster southward now down
the Red River valley and there is a pressure rise into the RRV due
to high pressure to our north and a more noticeable north
direction shift has been observed. Overall not much change to
grids but patchy fog and cloud cover were tweaked a bit.


.SHORT TERM...(Today and tonight)
Issued at 346 AM CST Sun Jan 21 2018

Fog this morning and cloud cover the main issues today. Light
winds have favored ground fog formation over parts of NW
MN...mainly in the Crookston to Bemidji area. Obs still indicate
up and down vsbys...and webcams dont indicate widespread fog. Will
keep mention of patchy fog in NW MN and also into NE ND though no
fog has formed. An area of stratocu is advancing southeast and
clipping far NE ND and far NW MN at 09z. No one model has this
area progged well, but seems likely these clouds will continue to
move SE and be over parts of NE ND/far NW MN thru much of the day.
How far south they go is ??. There is a weak sfc high in Manitoba
nosing down the RRV with colder air the lower clouds are advancing
south in this colder airmass.

High/mid clouds over SE ND into WC MN should remain there most of
the day.  No precip will occur.

Tonight cloud cover remains an issue. Would expect some higher
clouds SE fcst area near the storm system but also may well have
stratocu over parts of the area as there is extensive cloud cover
upstream thru Manitoba. Unless clear, fog formation would be

.LONG TERM...(Monday through Saturday)
Issued at 346 AM CST Sun Jan 21 2018


A relatively quiet period expected. Upper level trough forecast to
move across IA and keep precipitation south of the forecast area for
today and tonight. Upper level trough off the BC coast will move
across the Northern Plains Tue and may produce very light snow for
the area.


Longwave ridge over western North America builds slightly through
the period. Longwave trough over eastern US weakens a bit through
the period. The GFS was a little faster than the ECMWF but overall
in reasonably good agreement.

Upper air pattern remains relatively progressive.  Next upper level
trough is forecast to move through the Northern Plains Fri into Sat.
Upper level ridge moves over the area Thu. Mild weather is expected
for Thu and Fri with highs in the twenties and thirties.

High temperatures were increased a degree or so for Wed, increased
two degrees on Thu, and increased one to three degrees for Fri and


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
updated at 934 AM CST Sun Jan 21 2018

Along and south of the Highway 200 corridor... expect generally
VFR conditions with patchy ground fog though 17z. AFter 17z...
expect MVFR CIGS to overspread the area. North of the Highway 200
corridor... expect widespread MVFR CIGS with patchy IFR CIGS and
VSBYS in fog. After 17z...expect areas of MVFR CIGS in low




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