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fxus63 kbis 210902 
afdbis 


Area forecast discussion 
National Weather Service Bismarck ND 
402 am CDT sun Mar 21 2010 


Short term...today through Tuesday night... 
currently...an upper level ridge over The Rockies and troughing from 
Hudson Bay to the south central US resulted in northwest flow aloft 
over North Dakota. At the surface a low pressure center was over 
southern Alberta with a frontal boundary extending eastward from the 
low across south central Canada and towards Hudson Bay. North Dakota 
will remain on the warm side of this frontal boundary today as the 
upper level ridge over The Rockies moves eastward - but begins to 
flatten and become more zonal as the next upper level trough begins 
moving eastward across The Rockies Sunday night. Surface winds today 
should be southwest at 10 to 15 miles per hour and bring warm advection to the 
region. Expecting highs today from the lower 40s in the Devils Lake 
basin to the middle 50s in the far west. 


Tonight the surface low in Alberta develops/moves southeast to the 
Montana/North Dakota border by Monday morning as the upper level 
trough and embedded shortwave energy reaches western North Dakota. 
As this occurs...the aforementioned surface frontal boundary sags 
southward into northern North Dakota. 


The low and accompanying frontal boundary moves southeast across the 
state on Monday along with the upper level trough and shortwave 
energy. Monday night winds will have shifted to northwesterly across 
the region with cold advection moving into the state. Residual upper 
level shortwave energy impulses also continue across the state 
Monday night and Tuesday. Will keep a chance of rain showers 
Monday...and rain or snow showers Monday night and Tuesday. 


The best chance for precipitation on Monday will be in the west and 
north...along the west-east frontal boundary across northern North 
Dakota and in the west where the best upper level energy with the 
upper trough enhances lifting. Precipitation amounts up to 0.15 
inches are possible across the north Monday/Monday night. 


Long term...Wednesday through Saturday... 
not much in the way of significant weather is expected during the 
extended period. Medium range models still indicate a rather weak 
short wave trough flattening the upper ridge...impacting the 
forecast area mainly Thursday night into Friday. Have left slight 
chance probability of precipitation going. The main challenge will be temperatures. 
Wednesday will likely be the warmest day of the extended period with 
upper ridging and southwest surface flow. However...Wednesday night 
into Thursday...there is good model consensus that another shot of 
colder air will drop south through the region. This will set up a 
northeast to southwest temperature contrast. Expect temperatures in the 
lower 30s northeast sections...with readings in the low to middle 40s 
southwest. Overnight lows will be generally sub-freezing. 


&& 


Aviation...21/12z 
VFR conditions will continue through the period with increasing 
southwest winds this morning. 


&& 


Hydrology... 
temperatures anticipated in the 40s in the Devils Lake basin to the 
middle 50s far west today...and 40s north to low/middle 50s south Monday. 
These warmer temperatures will increase snowmelt runoff...especially across 
the southwest half of the state...where many locations still have a 
significant snow pack. This will raise flood concerns during the 
coming week...for both river and overland flooding. Colder 
conditions are expected Tuesday...with a slight recovery on 
Wednesday...followed by another cool down on Thursday and Friday. 


A Flood Warning for overland flooding from melting snow remains in 
effect through Tuesday afternoon for Dickey...LaMoure...Logan and 
McIntosh counties. 


A Flood Watch for ice jams and resulting overland flooding from 
melting snow remains in effect through Sunday evening along the 
little Missouri River from Marmarth through Medora and north into 
McKenzie County. 


Point forecasts for river flooding continuing for LaMoure on the 
James...Ludden dam on the James and near Pingree on the Pipestem 
creek. 


Colder temperatures have reduced overland flooding but Beaver Creek 
at Linton and Apple Creek near Menoken remain above flood stage. 


&& 


Bis watches/warnings/advisories... 
Flood Watch through late Sunday night for ndz017-031-032-040-043. 
Flood Warning for Dickey...LaMoure...Logan...McIntosh counties 
through Tuesday afternoon. 


&& 


$$ 


Short term/hydrology...jv 
long term/aviation...Kinney