597 
fxus63 kfgf 071555 aaa 
afdfgf 


Area forecast discussion...updated 
National Weather Service Grand Forks ND 
955 am CST Wednesday Jan 7 2009 


Discussion... 
high temperatures pose a slight challenge today...otherwise most 
of the forecast through this evening is in good shape. Much of the 
region this morning is falling behind schedule in the rise in 
temperatures...so today is expected to be a bit cooler than 
previously thought. High temperatures were therefore cooled a 
couple degrees. There also seemed to be potential for a bit 
stronger northerly winds today...in particular the southern Red 
River valley and west central Minnesota...through this afternoon. 
For now bumping those winds up a few knots seemed good. 
Lastly...stuck in some minimal probability of precipitation to cover the potential for 
lingering very light snow across the Baudette...Bemidji...and Park 
Rapids areas through this afternoon. 


&& 


Aviation... 
a variety of cloud coverage and cloud bases today. Some clearing 
north of Winnipeg may drop into northern valley and northwest Minnesota and affect 
gfk-tvf sites by late morning and afternoon. Band of thicker and lower 
clouds (mvfr) from dvl into southeast Saskatchewan may hold on well into the day 
and this may affect Fargo as well. Bji to see some lower ceilings through 
middle morning with some breaks later today. Confidence in timing any 
ceilings or clearing lower than usual today. Winds will remain 
northwest mostly near 10 to 12 kts. 


&& 


Previous discussion... /issued 335 am CST Wednesday Jan 7 2009/ 


Short term... 
immediate challenge will be storm system for Thursday night-Friday and 
headlines and snow potential. Models remain in a bit of 
disagreement with regards to exact placement of low and how warm 
to get at 925-850 mb layer. UKMET/Gem/ECMWF are a bit farther 
south with surface low and thus a bit colder while GFS/NAM are a bit 
farthern north with 00z NAM the farthest north and warmest. Per 
discussion with HPC winter desk a blend of European model (ecmwf)/GFS/Gem was used 
with quantitative precipitation forecast and surface low track most closely resembling the 00z GFS. 


Another of these storm systems from the Pacific northwest and 
British Columbia will move through southern Alberta into northwest 
North Dakota Thursday evening and then southeast into far 
northeast South Dakota by Friday morning and then toward Chicago 
by Friday evening. 


As mentioned above...blend of models would bring a heavy snow band 
from near Regina to Estevan then toward Devils Lake the southeast 
toward Grand Forks or Fargo. Grand Forks cross section from 00z 
GFS shows pretty good Omega in the middle layers 00z Friday to 06z Friday 
period throughout the entire column. With precipitable waters  over 0.50 inch and 
a period of strong isentropic lift along with 1000-850 mb 
frontogenesis it would appear reasonable to expect a 6-7 inch 
band of snow to fall from dvl into the middle section of the Red 
River valley. Frontogenesis and lift weakens a bit as you go into 
Minnesota thus confidence in 6 inches of snow is weaker. Also maximum winds 
on the backside of the low will hit North Dakota into South Dakota 
much more than east of the valley. The far southwestern County Warning Area along 
the South Dakota border does stand a chance of mixed freezing rain 
and snow for a time...but consensus is for the majority of the 
precipitation to remain just north of bis-jms-Wahpeton line. Thus based on 
the above and coordinate with weather forecast office bis issued a Winter Storm Watch valid 
00z Friday to 00z Sat for NE and ecntrl ND and the Red River 
valley...from Valley City to Fargo northward. 


Before this sytem...today's issue is cloud cover. Some clearing 
noted north of Winnipeg at this time and RUC does bring some drier air 
from this area southward into northern valley and northwest Minnesota by 15z. 
Meanwhile band of MVFR ceilings from central Saskatchewan into Estevan and dvl 
moving southeast and this band of clouds may hold on well into the 
day. Temperatures will not rise a whole lot today as weak cold advection 
continues with northwest winds. High pressure moving over the area 
tonight should bring some clearing and those areas that clear will 
see temperatures drop into the teens below zero. Increasing clouds from 
west to east on Thursday as winds turn east. 


Long term... 
made a few tweeks to temperatures Sat-sun for a bit warmer airmass moving 
into central ND but kept the valley and northwest Minnesota cold. Did add low probability of precipitation 
Sunday as next short wave prognosticated to drop south into the area. 00z 
GFS on board along with European model (ecmwf) of a major Arctic cool down middle week 
next week as 1050 high drops southeast into Alberta/sask. 




&& 


Fgf watches/warnings/advisories... 
ND...Winter Storm Watch from Thursday evening through Friday 
afternoon for ndz006>008-014>016-024-026>030-038-039-054. 


Minnesota...Winter Storm Watch from Thursday evening through Friday 
afternoon for mnz001>004-007. 


&& 


$$ 
Grochocinski/Hopkins