Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 250007

Area Forecast Discussion
National Weather Service Grand Forks ND
707 PM CDT Sat Mar 24 2018

Issued at 703 PM CDT Sat Mar 24 2018

Large clearing area expanding north-northwest into the RRV and
thru NW MN the last few hours so lowered sky cover greatly this
area for first half of the night. Narrow band of precipitation
psbl into the DVL basin after 06z as main short wave lifts
northeast into SE Saskatchewan. Did tweek some prob ice grids Sun
night-Mon for a bit less straight fzra and to have more
mix...soundings would show if precipitation enough for
accumulation mainly snow.


.SHORT TERM...(This evening through Sunday)
Issued at 313 PM CDT Sat Mar 24 2018

Shortwave ridging aloft is transitioning over western Minnesota,
with southwest diffluent flow in the mid-upper levels over the
Dakotas. An axis of subsident/dry air is in place over much of our
CWA. The next shortwave trough is currently near western Montana.

Tonight-Sunday: Main upper trough moves from Saskatchewan across
Manitoba Sunday, with increasing southerly flow keeping decent
moisture advection in place over our CWA. In this pattern the window
for large scale ascent is mainly limited to the later part of Sunday
afternoon, with weaker lift overspread the CWA early Sunday. We
should see snow increase in coverage relatively quickly, and models
are showing a strong signal on at least measurable snowfall. There
is a signal in model QPF and model frontogensis  for possible
banded precipitation embedded. There could also be enough instability
to support a narrowing of any bands that develop. Location of one or
more narrow bands of moderate to heavy snow is uncertain.

Most locations would tend to have 1-3", and only localized/narrow
areas exceeding this. Consensus of higher resolution guidance has
favored locations north of I-94 in North Dakota, however these types
of bands will be hard to anticipate with a level of confidence
necessary for advisory consideration at this range. Plan is to
message this with SPS (Special Weather Statement) and graphics for

.LONG TERM...(Sunday night through Saturday)
Issued at 313 PM CDT Sat Mar 24 2018

Banded snow event should be ending by sunset
Sun. There is likely to be a break in the action for a time Sun
night before the next wave affects us overnight into Mon. Examined
various ops models for ice probabilities and good agreement among
them for lower ice potential leads to FZRA chances mostly along and
southeast of a Baudette to Fargo line. Mon morning commute icing
impacts would be possible. By afternoon, warming boundary layer
temps should lead to mainly rain pcpn types, ending as some snow at
night. Weak high pressure to follow for the daylight hours on Tue.

Wed through Sat...

Northwest to zonal flow will dominate during this period. A series
of clippers would be the featured weather makers with Wed and Fri
the targeted times. On Wed with projected high temps above freezing
some periods of rain or mixed may occur. Colder air moving in behind
this system will drop temps to below (if not well) normal to end the
week into the weekend. Ensembles feature strong signals for a
significantly below average temp regime during this time as 850 mb
numbers fall to 15 to 20 below zero C.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 703 PM CDT Sat Mar 24 2018

VFR conditions expected all but DVL basin into Sunday morning.
Therafter chances for wintry mix of precip spreads in with vsbys
lowering to IFR levels in snow at GFK. But as bands of
precipitation move through Sunday mid to late morning and aftn a
variety of ceilings and vsbys can be expected. Gusty south-
southeast winds continue into Sunday.




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