Weather

662 
fxus63 kbis 110228 
afdbis 


Area forecast discussion 
National Weather Service Bismarck ND 
928 PM CDT Friday Oct 10 2008 


Update... 
latest regional radar showing an area of rain from near 
Bismarck...south and east. Persistent area continues to develop 
and move northeast. Have increased probability of precipitation and wording to likely 
category this evening...tapering off to chance in some sections 
after midnight. 00z NAM just coming in and this supports the 
current trends in the radar. Heaviest precipitation still slated for 
Saturday night/Sunday morning...with a dry slot punching up into southern 
sections during the afternoon. Current forecast handles this well. 
Current Winter Storm Watch still on track given the colder 850 mb temperatures 
of -2c to -4c in the west and plethora of moisture. Latest zones 
have been sent. Rest of forecast after tonight on track. 


Kansas 


&& 


Previous discussion... /issued 352 PM CDT Friday Oct 10 2008/ 


Synopsis...storm system continues to dig across the southwest US 
and is expected to turn the corner and move into the northern 
plains on Saturday night and Sunday. The main issues with this 
forecast will include the rains now line in western North Dakota 
.The dry slot which will lower the precipitation amounts and the 
possibility of sleet and snow together with strong winds across 
the southwest. 


Short term...tonight through Monday night... 
I have kept the Winter Storm Watch going for Saturday afternoon 
through Sunday. The main threat for severe winter weather 
continues to be Saturday evening through Sunday. Expect only rain 
from a Bismarck to Minot line and east. There will likely be a 
mix of rain and snow between Bismarck and Dickinson...with some 
accumulations across the west Missouri River counties. But the 
significant snow accumulations will occur along and west of a line 
from Hettinger to Dickinson to the Canadian border south of 
Estevan. 


As the upper low kicks out of the southwest there is some evidence 
it will pick up high level moisture from Hurricane Norbert in the 
eastern Pacific and track it into the plains. Model guidance from 
NAM suggests a stronger dry slot into central North Dakota on 
Sunday. Have tried to scale back moisture a bit there Sunday 
afternoon. Otherwise the trend continues to be a strong push of 
moisture into west and central North Dakota Saturday night and 
Sunday morning. 


I am concerned about the combination of winds...the possibility of 
sleet and or freezing rain and snow southwest after midnight 
Saturday. At this time will mention snow and blowing snow and 
highlight these sleet and freezing rain concerns in my winter weather 
statement. 


Long term...Tuesday through Friday night... 
a return to dry mild weather can be expected on Tuesday...extending 
through Friday as the flow aloft turns zonal then ridging develops 
over The Rockies. 


Aviation...conditions will continue to deteriorate from the south 
over the next 24 hours as a winter storm moves into the plains. IFR 
conditions in southwest North Dakota will spread across the state by 
Saturday evening. 


&& 


Bis watches/warnings/advisories... 
Winter Storm Watch from Saturday afternoon through Sunday 
evening for ndz001-009-017-018-031>033-040-041-043-044. 


&& 


$$ 


Warm air advection/thunderstorm with snow showers