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FXUS63 KFGF 290800

Area Forecast Discussion
National Weather Service Grand Forks ND
300 AM CDT Thu Jun 29 2017

.SHORT TERM...(Today and tonight)
Issued at 300 AM CDT Thu Jun 29 2017

Main concerns will be fog this morning, and then shower/thunder
potential this afternoon/evening.

The recent rain adding low level moisture combined with light
winds leads to the potential for fog early this morning. Dense fog
has developed from Valley City northward to the International
border, and eastward into the northern Red River Valley. This area
is basically in the area that has cleared (on the edge of the low
stratus clouds). Phone calls to the affected area indicates that
the fog is indeed dense, but coverage is more or less limited to
lower areas. GOES-16 nighttime microphysics RGB shows the
developing fog well, with coverage increasing over the past couple
hours. Have issued a special weather statement, and will need to
consider a dense fog advisory if current trends continue. The low
stratus clouds should prevent dense fog across the central and
southern valley. 

The next upper level wave will approach the region today, and move
through tonight. As such, expect scattered showers/thunder across
eastern North Dakota by this afternoon, with precip chances slowly
moving eastward through the overnight hours. Deep layer shear and
instability are weak and strong storms are not expected. PWATS
remain just over 1.00-1.25 inches, and given the expected slow 
storm movement (@10 knots) anticipate isolated heavy rain the 
main impact. 

.LONG TERM...(Friday through Wednesday)
Issued at 300 AM CDT Thu Jun 29 2017

Friday...The upper low will continue to slowly propagate eastward
leading to scattered showers, slowly ending from west to east
through the day. Again, with PWATS 1.00-1.25 inches and slow storm
movement, isolated heavy rain the main impact. 

Saturday-Sunday...Northwest flow aloft with an upper low tracking
to the northeast of the region. Showers possible across northwest

Monday-Wednesday...Upper level ridging builds into the region and
most ensemble guidance indicates a strong potential for warmer
temperatures (near to slightly above normal values). The ECMWF is
stronger than the GFS with this ridging, and thus keep all thunder
activity north of the region. Still lots of uncertainty with the
strength of this ridging, which will determine thunderstorm
chances (and severe potential). 


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1135 PM CDT Wed Jun 28 2017

Fog and low cigs main challenge. Guidance continues to indicate
potential for fog overnight with LIFR cigs/and vsby. Seems best
potential will be areas which have cleared out along and west of
the valley. GFK and FAR on edge of cloud shield but still have
some degree of fog mentioned. Conditions should improve mid
morning with most areas vfr by afternoon. 




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