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fxus63 kfgf 181528 
afdfgf 


Area forecast discussion 
National Weather Service Grand Forks ND 
1028 am CDT Friday Jul 18 2008 


Discussion... 


15 UTC water vapor loop shows shortwave moving to the east across 
western Ontario with weak upper level ridge building across the 
forecast area. Corresponding surface analysis depicts high pressure 
axis extending from Rolla to Wahpeton. Both GFS and NAM show this 
surface feature moving slowly to the east through the day. As 
such...today will be dry with light wind. Expect partly to mostly 
sunny skies today with cirrus blow off from convective complex 
across South Dakota/Nebraska border combining with afternoon fair 
weather cumulus. With less cloud cover than yesterday...maximum 
temperatures will rebound to near 80 degrees most spots. Current 
forecast looks good with no significant updates required. 


Main forecast challenge for the afternoon forecast package will be 
precipitation chances and severe potential Saturday and Saturday 
night with approaching upper level short wave currently over 
British Columbia. Will wait for 12 UTC GFS before finalizing 
forecast. 


&& 


Aviation... 


Expect VFR conditions at all taf sites through at least 06 UTC 
tonight as surface high pressure moves across the region. Cirrus 
blow off from convective complex across South Dakota will combine 
with afternoon fair weather cumulus...but any ceilings to develop 
are expected to remain at or above 4000 to 5000 feet. Wind will 
remain light the next 24 hours. 


&& 


Previous discussion... /issued 430 am CDT Friday Jul 18 2008/ 


Discussion...today through Sunday night 
upper level ridge was over the southwestern US while progressive 
northern stream was over the northern states. Water vapor loop shows 
a short wave along the southern mb/Ontario border. Another upper low 
was over British Columbia and another jet streak/short wave over or. All short 
waves were moving east. Models having typical timing problems with 
fast flow. British Columbia trough to move through Sun morning. 


Areas VAD winds indicate the NAM may be a little fast returning 
moisture northward today and tonight. So will use the GFS. Model 
showing precipitation over western South Dakota to move across the southern 
zones. Will go higher probability of precipitation in the southern zones tonight. 


Ridge building forecast to occur late in the period to the west. 


Extended...Monday and Tuesday 
upper trough moves east of the area Monday with a higher amplitude 
upper ridge moving into the northern plains Tuesday. 


&& 


Fgf watches/warnings/advisories... 
ND...none. 
Minnesota...none. 
&& 


$$ 
Rogers