Area Forecast Discussion
Issued by NWS Grand Forks, ND

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
538
FXUS63 KFGF 230340
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
940 PM CST Thu Feb 22 2018

.UPDATE...
Issued at 940 PM CST Thu Feb 22 2018

Light to moderate snow continues to move north into the forecast
area. Regional radar shows the heavier bands have so far been
staying to our south and east, although some heavier returns
developing over northeastern SD could impact our southeastern
counties in the next few hours. The 00Z run of the RAP has some
pretty strong frontogenesis developing right over the southern
counties by 05Z or so, recent runs have backed off on that and the
negative EPV values stay mostly southeast of the CWA. Several of
the high resolution models have been pretty good about matching
current radar trends, so blended them in with the current QPF.
This lowered the evening totals a bit but bumped them up after
midnight, leaving adjusted totals fairly similar to what we had
going. Will continue to leave headlines as they are for now and
take another look in the next few hours.

&&

.SHORT TERM...(This evening through Friday)
Issued at 325 PM CST Thu Feb 22 2018

The snow is expanding on radars to the south, but is still down
and south of Watertown SD. It will lift up into the far southern
FA in the next 2 to 3 hours, then continue to expand slowly
northward tonight. The initial onset of the snow is slower than
yesterday, and also lingers a little later into Friday morning.
However, general snow totals look about the same, with areas
within the advisory expected to pick up 3-5 or 3-6 inches, with
less outside the advisory. Like the previous shift noted, there
may be a sharper northward border to the snow, which is a little
further south than the models showed yesterday. The Grand Forks to
Baudette MN corridor is along this line, so these areas may pick
up a dusting or maybe not much at all. Wind speeds still look
pretty light throughout this event, so blowing and drifting snow
are not expected to be an impact. With the slower onset and
departure times, did make some adjustments to the timing on the
winter weather advisory. The snow should exit out of the eastern
FA by late Friday morning, with Friday afternoon looking dry.

.LONG TERM...(Friday night through Thursday)
Issued at 325 PM CST Thu Feb 22 2018

The main focus for the extended outlook centers around a strong
Colorado low that is expected to develop in the central Plains
Saturday and propagate into the Great Lakes region Saturday night
and into Sunday morning. As a robust upper level trough moves out
over the Plains Saturday, lee cyclogenesis and upper level ascent
along a baroclinic zone will result in a strong surface low that is
expected to propagate to the northeast. While most deterministic
guidance agree with the development of this storm, timing and track
differences add uncertainty to the forecast. Long and medium range
ensemble guidance, along with analog guidance, suggest the greatest
risk area lies from northeast South Dakota through central/south
central Minnesota. Frontogenetical and upper level forcing signals
suggest the potential for snow banding to occur Saturday night
through Sunday across the risk area.

At this time, accumulating snowfall appears to be the biggest winter
weather threat to the FGF CWA with the best chance for accumulation
across western Minnesota and far southeastern North Dakota. Light
snow will be possible further north across northwest Minnesota and
northeast North Dakota, though there is much less confidence in
accumulation for these regions. Winds are forecast to be relatively
light until mid day Sunday when wind gusts of 20 to 25 knots will be
possible on the backside of the low in response to moderate pressure
rises.

Beyond this weekend, relatively quiet and calmer weather is
anticipated as a surface high builds over the northern Plains.
Southerly return flow should return by early next week and allow for
seasonal temperatures with highs in the mid to upper twenties and
overnight lows in the single digits and low teens.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 646 PM CST Thu Feb 22 2018

VFR across the forecast area as mid level clouds spread
northward, but conditions will deteriorate as snow and lower
stratus moves in from the south later tonight. Think snow will be
in KFAR and KBJI by mid to late evening, then move into KGFK and
KTVF around 06Z. KDVL will be spared and should be VFR throughout
the period. The other TAF sites will see ceilings drop to the
1500-4000 ft range with visibility down to 1SM, although some
2-5SM is possible on the northern fringes. The lowered vis will
continue to around 12Z before snow moves off to the east,
lingering at KBJI just a bit longer. All sites should return to
VFR conditions by afternoon, with the west and central sites
seeing the most clearing. Winds will remain fairly light, shifting
from the south to the northwest and then west, staying below 10
kts.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Winter Weather Advisory until 3 AM CST Friday for NDZ052-053.

MN...Winter Weather Advisory until 6 AM CST Friday for MNZ024-028-
     030>032-040.

     Winter Weather Advisory until 3 AM CST Friday for MNZ029.

&&

$$

UPDATE...JR
SHORT TERM...Godon
LONG TERM...AM
AVIATION...JR



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.