Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 042120

Area Forecast Discussion
National Weather Service Grand Forks ND
320 PM CST Sun Dec 4 2016

.SHORT TERM...(This evening through Monday)
Issued at 318 PM CST Sun Dec 4 2016

Challenge for the next 24 hours includes cloud trends tonight
and their impact on temperatures then arrival of snow tomorrow.
SFC trough with the light snow continues to slowly make its way
west into NW MN. Light snow will end this afternoon and early
evening with winds turning to the south overnight in response to
developing low pressure across western ND. Clearing line near
Minot to Jamestown to Forman ND is expected to make it to around
the Fargo area and into west central MN before filling back in.

During the day tomorrow a leading short wave on the long wave
pattern changing 500mb trough will propagate along the
international border increasing in strength with time. As a result
SFC features remain in flux with their evolution wrt 12Z model
solns. There is a signal for some mid level frontogensis on the
NAM/GFS solns so there is potential for a narrow band of heavier
snow fall rates to develop. Placement of that band tomorrow
afternoon will need to be monitored and refined. Current forecast
has the heaviest snowfall in the Devils Lake basin and northern
valley through tomorrow afternoon. Winds will remain light during
the snowfall and unimpactful during the day Monday.

.LONG TERM...(Monday night through Sunday)
Issued at 318 PM CST Sun Dec 4 2016

The weather system that begins in the short term and continues into
the early part of this period will be the main forecast challenge.
The six hour period with the most snow in the forecast is 00-06z Tue
mainly centered over the northern Red River Valley. Thereafter,
snow amounts already begin to taper off. Do not have a high degree
of confidence in where and how much snow is going to fall. The
American models would tend to favor the northern Red River Valley
into northwest MN, while the ECMWF would favor the Devils Lake
region up into northeast ND. The ECMWF has trended weaker now with
the sfc low and all models still seem to struggle with how to
resolve pcpn amounts around several distinct sfc lows. However,
this does appear to be a hybrid low and should not have as much
moisture to work with as a much stronger Colorado Low.

With the apparently weaker sfc low and the uncertainty in where/how
much snow falls, deciding where to show any blowing snow is harder
than it was yesterday. Guidance has backed off on wind speeds a bit
and keeps the stronger winds more across the Devils Lake basin into
northeast ND. Therefore have restricted any blowing snow mention to
that area for now. Have much more uncertainty in any light snow and
blowing snow beyond Wednesday morning, so did not include it beyond
then. However, models do show a potential for gusty winds into
Thursday with some light snow too. Will monitor later model runs and
adjust this as need be. Cold air becomes entrenched over the region
throughout the long term, finally bringing below normal temperatures
with it. Friday looks dry with quite a bit of uncertainty by next
Sat/Sun. Guidance keeps a potential for light snow Sat/Sun so will
keep it for now.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1231 PM CST Sun Dec 4 2016

GFK and FAR currently at MVFR with DVL and TVF expected to improve
this afternoon as BR lifts. MVFR conditions expected to persist
overnight with clearing line from the west approaching. Current
thinking is that it will reach only FAR overnight. VFR at FAR and
MVFR elsewhere except IFR at BJI overnight.




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