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Area forecast discussion 
National Weather Service Grand Forks ND
656 PM CST Monday Nov 24 2014

issued at 656 PM CST Monday Nov 24 2014

Weak upper shortwave producing radar returns across southwest
Manitoba into north central and northwest North Dakota. A few ob
sites indicating -sn with visibility in the 2sm-5sm range. Will keep the
schc probability of precipitation for later this evening into the overnight hours for the
far western forecast area. The rap and hrrr also indicate quantitative precipitation forecast here...albeit
very light. The main concern with this quantitative precipitation forecast is that a dry layer
aloft will be moving into this region after midnight...and with
the low-level moist layer mean temperatures around -5c to
-8c...supercooled water droplets are possible. Inserted patchy
freezing drizzle into the forecast for the Devils Lake basin and

Will also issue a Special Weather Statement for the snowfall potential Tuesday
evening/overnight. Weather forecast office bis has a statement issued...and it would
be best to keep the message within North Dakota consistent.
Plus...a few indications for mesoscale-scale banding (steep middle-level
lapse rate...frontogenesis...possible conditional
instability)...and higher resolution models indicating a narrow
band of quantitative precipitation forecast up to around 0.4 inches (so could be a narrow band of
3-5 inches...but location of this band could be anywhere).


Short term...(this evening through Tuesday night)
issued at 333 PM CST Monday Nov 24 2014

Forecast challenge is low temperatures tonight and then snow threat Tuesday
night. For tonight...skies generally clear over much of eastern/central
ND with lingering clouds roughly Roseau to Fargo to Forman east.
Clouds in the east will slowly diminish as low pressure moves
into Upper Michigan. Expect a period of clear sky this evening in
eastern ND and as winds lighten temperatures could fall quickly in some
spots. Variable snow cover will make low temperatures tough...but
generally expect single digits. There is a short wave in
Saskatchewan that will move southeast. There has been some very
light with this on Canadian radar but models indicate precipitation will
dry out more as it moves east into surface high. Did keep 20 pop for
any light snow that may make it into western forecast area toward midnight
or a bit after. Clouds coming into the west should make temperature fall
stop and temperatures rise a bit.

Alberta clipper system for later Tuesday handled a bit better now
with consensus is to take surface low through southwestern ND into
eastern South Dakota with band of 2-3 inch snowfall Williston to Carrington
to about Wahpeton-Forman area. Lesser amounts east of this but
still expect enough moisture into the colder airmass northeast of
the low to squeeze out some light snow Tuesday night. Look for a
period of wind (20-25 kts) southern valley late Tuesday night so will need
to watch that for any blowing snow issues if forecast pans out.

Long term...(wednesday through monday)
issued at 333 PM CST Monday Nov 24 2014

Blustery and cold Wednesday as high drops south. Next short wave
due to move east from southern b.C. Into Montana and northwestern
North Dakota Thanksgiving day with light snow reaching dvl basin
Thursday late afternoon. This is a more Pacific hybrid type system and
models typically have a hard time with these and with thermal
boundary in place track of system may change.

Thursday night to Monday...models in fair agreement with the long
Holiday weekend weather. Chance of snow Thursday night through Saturday
night as 500mb flow becomes nearly zonal and a baroclinic zone sets
up across the northern plains. Best chance will be Thursday night
across the entire County warning forecast area as warm air advection occurs and temperatures rise overnight.
Lesser chances continuing into the weekend especially across the
northern tier. The baroclinic zone will be pushed south of the area
as 1036mb high pressure moves into the region Sunday...ending the
precipitation threat. Maximum temperatures will be below end of November normals with 20s
Friday falling into the teens and single digits Saturday through
Monday with Sunday being the coldest day.


Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 656 PM CST Monday Nov 24 2014

VFR conditions to start...but an area of MVFR ceilings approaching the
region from the northwest...and should affect all taf sites
tonight or early Tuesday morning. These ceilings will likely continue
through much of the day on Tuesday.


Fgf watches/warnings/advisories...

short term...Riddle
long term...Riddle

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