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Area forecast discussion 
National Weather Service Grand Forks ND
627 PM CDT Wednesday Aug 20 2014

issued at 627 PM CDT Wednesday Aug 20 2014

No changes at this point. Updated aviation discussion below.


Short term...(this evening through Thursday night)
issued at 338 PM CDT Wednesday Aug 20 2014

Water vapor loop indicates a short wave trough over central/western
Montana. Trough forecast to rotate across southern man and northern ND
tonight and Thursday. Deep Theta-E advection expected east of upper
trough for tonight and Thursday. Low level jet to nose into eastern South Dakota
this evening, then shift to states south of the forecast area
through Friday. Thereafter low level jet develops over the High
Plains with entrance region in the western Dakotas. Precipitable
water rises to around an inch and three quarter late tonight and
Thursday. Bulk shear under 35 knots. Should storms develop, locally
heavy rain may be possible.

Some residual instability to remain over parts of the northern zones
Thursday night...will add low probability of precipitation north.

Will trim back probability of precipitation northeast and southwest zones Friday.

Water vapor loop indicated a second short wave over Washington/British Columbia border.
The short wave is forecast to move across southern man and northern
ND Friday. Will have probability of precipitation mainly over the west and north.

Short wave over the Desert Southwest to affect the area Sat and so a
higher threat for precipitation.

Long term...(friday through wednesday)
issued at 338 PM CDT Wednesday Aug 20 2014

Unsettled period as upper low over the northern rockies lifts NE
into mb remainder of the weekend. Unfortunately models showing
significant differences in precipitation placement so targeting specific
areas for rain difficult. Will see a brief break Monday before long
wave trough moves across the forecast area towards midweek. Temperatures to
remain well below average through the period.


Aviation...(for the 00z tafs through 00z Thursday evening)
issued at 627 PM CDT Wednesday Aug 20 2014

Evolution of the precipitation into our forecast area tonight seems a tad slower than
expected. Models not in the best of agreement on when the onset
will be so kind of going with a blend for the tafs. Will start out
with just cirrus blowoff from convection out west but should see
some middle level clouds by later in the evening...especially at
kdvl. Kdvl should also see the precipitation arrive first...then probably
at kfar followed by kgfk/ktvf. Kbji may not see much of anything
until Thursday morning. Once the precipitation rolls in it looks like it
will stay through the rest of the taf duration. Kept ceilings VFR
for now but they likely will drop down into the MVFR range with
any heavier rain.


Fgf watches/warnings/advisories...


short term...hoppes
long term...voelker

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