Weather

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afdfgf 


Area forecast discussion 
National Weather Service Grand Forks ND 
252 PM CDT Sat Oct 11 2008 


Short term... 
obvious concerns are precipitation amounts through Sunday evening with current 
system. For tonight into this evening coverage of precipitation will be 
more scattered in nature as area in very broad but intense 850 mb 
temperature/moist advection with precipitable waters  increasing to 1.50 by 06z sun. 
Water vapor shows stream of upper level deep moisture from 
hurrican/ts off Baja California California up into southeast South Dakota now and this 
moisture will continue to feed north-northeast this evening. Lots 
of scattered convection in this moisture feed from eastern South Dakota into New 
Mexico and with southerly 850 mb flow increasing overnight will 
continue to see feed of moisture and scattered convection into the forecast 
area. Soundings show very moist profile with only real instability 
in eastern ND/northwest Minnesota rooted at 700-750 mb and even that is marginal. 
Despite this have been getting 50-55dbz cores close to severe 
limits with earlier reports of pea to one half inch size hail in 
NE South Dakota with storms earlier this morning. Think similar in our area 
too. 


Overnight into Sunday...a piece of the 500 mb low over Utah moves 
northeast toward eastern Montana and surface low now in Kansas moves north into 
southern South Dakota and then into southern North Dakota just 
northwest of Aberdeen by 18z Sunday. This track will allow 850 mb 
warm front to move northward and lie near a bis-gfk-Rox-bde line 
Sunday morning with surface warm front entering southeastern forecast on 
Sunday. Thus looking at more def zone widespread rains of 1-2 
inches with locally more more over the dvl basin and the northern 
valley overnight into Sunday with this main wave with scattered 
convection in warm sector. How much convection is not known at this time. 
If widespread convection rainfall rates then could be hefty totals 
again in the southern valley and west-central Minnesota where ground is most 
saturated. Just not sure yet of convection and rainfall rates so 
at this time will continue hitting rainfall in severe weather potential statement/weather story graphic but no 
flash flood advisory headline at this time. 


Surface low will be just west of gfk 00z Monday and then move north into 
Canada sun evening with cold front moving into western Minnesota sun evening. Models 
showing potential heavy rain and convection along front into west-central 
Minnesota sun evening (00z-06z mon) and this will have to watched. 


As for probability of precipitation went likely to categorical all areas through Sunday and 
in Minnesota County Warning Area through Sunday evening. 12z models want to slow movement of 
front eastward Monday over parts of southeast South Dakota/Minnesota and thus chance of 
showers may linger in parts of west-central Minnesota past 12z Monday. Otherwise 
upper low will drift northeast into southern Manitoba. Position of upper 
low not real good for showers Monday over area but will maintain 
20 pop although models do show dry slot over area Monday. 




Long term (wed-sat)... 
models in fairly good agreement so will go with blended solution at this time. 
Pattern is expected to be more zonal thus will see systems move 
across the area a little quicker. Surface high pressure on days 4 and 5 
over the NC plains will keep the weather cool and quiet. Return flow 
on days 6 and 7 with increasing thickness values on the back side of 
the ridge will keep temperatures near seasonal normals. The next 
system expected to affect the forecast area will be after the end of the period. 


&& 


Aviation... 
mainly IFR conditions expected to remain over the forecast area as abundant 
moisture combines with overrunning associated with warm boundary. Little 
shift of the front is expected through the period so will stay with 
continuity. Winds will remain NE and gusty as gradient remains 
fairly tight with the system. Some thunder is expected to be 
embedded early in area of marginal instability. 


$$ 


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


$$ 
Riddle/Hopkins