Scientific Forecaster Discussion
fxus63 kfgf 160916
Area forecast discussion
National Weather Service Grand Forks ND
316 am CST Sat Dec 16 2017
Short term...(today and tonight)
issued at 316 am CST Sat Dec 16 2017
In the short term...there are a couple of concerns. The first is
dense fog in the Valley City area. Local law enforcement reported
dense fog in Barnes County, primarily in the north. Also had mping
report of dense fog from Steele co and the Cooperstown AWOS has
been reporting <0.25 mi. Hrrr model points toward the fog
affecting areas south of Valley City toward Gwinner and perhaps
western Cass co. Otherwise, not expecting much more coverage than
that overnight as surface trough will be switching winds to the
northwest eventually in this area. So we may see some dissipation
from the west.
The second concern is the freezing drizzle potential in northwest Minnesota
later this morning. Although the likelihood may be small...it does
appear the chance does exist as models are producing precip in
area of low level isentropic lift. NAM shows lift in the 850 to
750 mb layer with temps in temps of -5 to -10c. Since no temps
colder than -10 in the column...it looks like it would likely be
liquid reaching the ground. Mainly from Crookston to Bemidji and
perhaps as far north as Roseau. Will monitor and remove it in the
next few hrs if it doesn't look like its materializing.
Mid level wave will also bring some rain to south central ND this
morning. Believe it will mostly stay to the west of Ransom and
Sargent...but will monitor this area as well, as freezing rain
could be possible. The large scale wave will push through the
forecast area this morning...ending any precip by midday in the
Lake of The Woods area. Clouds will start to decrease late in the
day from the northwest as well. Temps will be a little warmer
today as surface trough/warm frontal boundary will shift eastward.
Tonight, clouds continue to decrease from northwest toward the
southeast...with winds switching to the south ahead of another
Long term...(sunday through friday)
issued at 316 am CST Sat Dec 16 2017
Sunday through Tuesday... Sunday surface high pressure will lead
to a dry day with above normal highs. The above normal highs
continue Monday and Tuesday with highs in the 20s and 30s while
normals highs are in the 10s and 20s in mid December. Monday looks
to be the warmest with highs reaching into the low 40s in the
southern valley. Stronger winds will be possible on Tuesday from
the Red River Valley West to central North Dakota. The strongest
winds should be in the morning as the pressure gradient lessens
later in the day.
Wednesday and Thursday... the next system looks to arrive late
Wednesday into Thursday and brings another chance for snow. The main
factor with the impacts of this system will be the track of the
surface low. This has lead to a range of solutions in the ensembles
such as the gefs plumes. Once model guidance has less variability in
the low track confidence in this forecast will increase. Colder air
is expected to arrive on Wednesday bringing temperatures back down
near seasonable normals. Thursday could even fall below normal
temperatures with highs in the single digits and teens.
Friday and Saturday... moving later in the week a clipper is heading
down towards US on Friday. Precipitation chances for this clipper
are still low as the track is uncertain at this point.
Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1155 PM CST Fri Dec 15 2017
Most sites are MVFR or IFR, although kfar has briefly gone VFR.
The airports will stay stay steady or deteriorate later tonight
and most ceilings will be in the 500-1000 ft range by morning.
Snow has been gradually diminishing, but lingers at kgfk and the
Minnesota taf sites. Vis will be in the 3-5sm range through the next few
hours and should improve by morning. Some fog has been developing
west of kfar but think it should stay away from the taf sites.
Conditions will gradually improve to MVFR and then VFR during the
day tomorrow. Winds will shift around from the southeast to
northwest but remain under 12 kts.
ND...dense fog advisory until 9 am CST this morning for ndz028-029-