Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Grand Forks ND
1012 am CST Sat Feb 28 2015

issued at 1010 am CST Sat Feb 28 2015

We will increase winds a bit along and east of the valley...with
about 30-35kt near 925mb through 18z. Winds should slowly subside
by late afternoon. changes needed this morning.


Short term...(today through sunday)
issued at 315 am CST Sat Feb 28 2015

Forecast challenges concern temperatures and low end snow chances.
Main model differences will be -sn potential with weak wave
passages and will use a blend.

Several weak waves will rotate through base of northern stream middle
level trough this weekend. First of these features and associated
surface trough moving into western ND will propagate east across
forecast area later today and tonight. European model (ecmwf) continues to be weakest with -sn
potential. At this point it looks to be the odd model out as
GFS/Gem/NAM all showing better snow potential albeit light mainly
this evening. RUC also developing -sn from valley eastward late
this afternoon into the evening. With rucs spotty nature of
possible -sn hesitant to raise probability of precipitation too far and kept within chance
range. Low level warm advection will continue ahead of trough and
will be starting out about 10 degrees warmer than yesterday.
Satellite imagery/surface observation indicating broken SC deck across central-
western ND which should move in today which may have an impact on
degree of warming. For this was conservative on maximum
temperatures. Any -sn this evening over northwest Minnesota should exit forecast area to
the east after midnight. Overall looking a half inch or so of
potential accumulation. Clouds will also have a bearing on minimum
temperatures tonight.

A weaker wave will affect forecast area on Sunday. Surface features also
weaker so likely looking at mainly flurries but did introduce some
low probability of precipitation over northwest Minnesota late in the afternoon. Followed persistence
with temperatures as clouds and how cold we start out in the morning
will impact maximum temperatures.

Long term...(sunday night through friday)
issued at 315 am CST Sat Feb 28 2015

High pressure will shift across Central Plains Sunday night. With
high center to our South West-SW surface flow and warm advection will
limit temperature drop and should see mins a few degrees either
side of zero.

Brisk southerly flow and continued warm advection Monday should
allow temperatures to finally approach seasonal averages.

Maintained low probability of precipitation Monday night with approach of next wave and
cold front although models not in very good agreement. Based on
timing of cold front boundary looks to be through all but the far
southeast by morning. This could set up respectable temperature contrast
across the forecast area with coldest minimums across the northwest deeper in the
colder air.

A breezy to windy extended period looks to be shaping up as Arctic
boundary pushes through the forecast area early Tuesday swinging
winds from SW to north-northwest. Cold air advection behind boundary will make Wednesday the
coldest of the bunch with area wide highs only in the positive
single integers. GFS/European model (ecmwf) are close with 850 mb temperatures pegging a
core of -20 to near -30c into and through the northern valley. Aside
from a period of light snow/snow showers for wc Minnesota Tuesday afternoon the
entirety of the extended is essentially pop free. Upper flow becomes
more zonal Thursday into Friday and as surface high drifts south and
southeast expect thermal recovery to near average values by
Friday...maxes from the upper 20s to low 30s.


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 658 am CST Sat Feb 28 2015

Off and on VFR ceilings expected across the region today ahead of a
weak frontal boundary.


Fgf watches/warnings/advisories...

short term...voelker
long term...wjb/voelker

National Weather Service Glossary of Abbreviations