Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 201832

Area Forecast Discussion
National Weather Service Grand Forks ND
1232 PM CST Mon Feb 20 2017

Issued at 1232 PM CST Mon Feb 20 2017

Narrow band of heavy fog has moved to just east of the Red in the
northern Valley, but with more rain moving in shortly and winds
shifting to the west think that this will be short lived. Adjusted
POPs for current radar trends, extending the mention of rain
across the eastern counties into this evening. Lowered temps a
couple of degrees as rain has kept temps from rising too much
early this afternoon and some spots already saw their highs for
the day.


.SHORT TERM...(Today and tonight)
Issued at 250 AM CST Mon Feb 20 2017

Plenty of forecast challenges today, namely dense fog/pcpn
chances/thunder/pcpn amounts and record high temps. So far,
showers with embedded thunder have been moving quickly NNE out of
eastern SD and western MN. Models have shown a ribbon of mid
level instability with a low level jet, working through the Red
River Valley into the northwest quarter of MN today, so that has
been consistent. However, the latest model runs have shown the
instability arriving sooner and ending sooner, so kept the thunder
mentioned this morning and removed it for the afternoon. The pcpn
has developed a little further east than the latest high
resolution models showed, so basically the entire FA has pcpn
chances today. Pcpn amounts so far have been spotty and fairly

The spottiness is always a function of convection, so amounts
will stay on the variable side. Overall, thinking most areas will
probably be lower than a tenth to a quarter of an inch, but if
several rounds of stronger echoes move over the same area, some
quarter to half inch amounts are possible. This would mainly be
over the southern Red River Valley up into NW MN. Dense fog
developed over the Devils Lake region, where the low level
moisture moving northward has encountered the coolest sfc temps.
Went with a dense fog advisory for several counties around Devils
Lake through mid Monday morning. Will keep an eye on visibilities
in that area and adjust as need be. Finally, forecasting a record
high at Fargo, but it appears the Grand Forks records will be
safe. High resolution models show any pcpn moving off to the NE by
late this afternoon, so kept tonight dry.

.LONG TERM...(Tuesday through Sunday)
Issued at 250 AM CST Mon Feb 20 2017

Tuesday will be the last very mild day, and are currently
forecasting highs just below records. Models continue to show some
light pcpn developing as well, but the details remain quite
sketchy. There is much better agreement by late Tuesday night
into Wednesday, in showing pcpn developing mainly across the
northern half of the FA. Low level temps during this time frame
are borderline for rain or snow, depending on the time of day and
location. The day 2 winter weather map shows an inch or two of
snow possible across the north, but mainly over the Devils Lake
region. Even a hint for freezing rain on the southern fringe of
the pcpn band is indicated. So this system will also bear
watching. Models also differ quite a bit on how fast it will exit
off to the east, but it looks to be by Wednesday evening.

Longer range models are currently in fairly close agreement on
developing a broad trof across northcentral Canada NOAM and
extending southwestward across the western half of the CONUS. This
leaves the path opened for a series of fairly wet systems to work
through the intermountain west and to produce some winter-like
activity into the Great Plains states.

Thursday and Friday... The GFS and ECMWF have been most consistent
in developing a Colorado Low type system across the central plains
...with heavier snow indicated across portions of SD and southern MN
...and only a brush of snow across far southern Red River Valley and
adjacent portions of west-central MN. This most of our area should
stay under a mainly dry northerly flow... with temperatures still
ranging a bit above long term seasonal normals even on Friday.

Saturday and Sunday... though a muddy H5 trof axis persists just
west of the FA into the coming weekend there is no indication of any
well organized storms brewing. Only a scattered snow shower or two
is in the current forecast package for the Red River Basin... with a
hint additional snow possible along the South Dakota.. southern
Minnesota belt. Meanwhile... temperatures continue to linger a good
five degrees above long term normals.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1232 PM CST Mon Feb 20 2017

Complex situation today with several rounds of rain moving through
with fog at times between. Vis down to 1/4SM over KGFK an hour ago
has moved east, with KTVF seeing visibility in the tank currently.
Rain moving through and winds shifting to the west have improved
visibility somewhat, but most locations are still 2-5SM with
ceilings ranging from over 3000 ft to around 300. Rain will move
off to the east during the afternoon and into the evening,
eventually exiting the area. Some clearing behind the rain for a
time overnight, but may have to watch for fog formation or more
clouds moving in from the west. For now have locations like KGFK
and KBJI going down to IFR or lower tonight and tomorrow morning
with KFAR and KDVL staying VFR. All sites should improve to VFR by
the tail end of the period. West winds will shift back to the
southwest by tomorrow morning.




LONG TERM...Godon/Gust
AVIATION...JR is the U.S. government's official web portal to all federal, state and local government web resources and services.