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Area forecast discussion 
National Weather Service Hastings NE
558 PM CDT Thursday Apr 17 2014

Short term...(this evening through friday)
issued at 359 PM CDT Thursday Apr 17 2014

Expect a transient ridge of high pressure across the northern
rockies this afternoon...to cross the plains on Friday...with dry
weather anticipated locally through the short term forecast periods.
Some middle and high level clouds spilling over the top of the ridge
will begin to spread across the local area overnight...which
combined with light but steady southerly winds...should help keep up
low temperatures a few degrees above this mornings unseasonably cold
readings...albeit still on the cool side for middle April.

Through the short term periods...winds and temperatures have been
the primary focus this afternoon as the pressure gradient is
forecast to tighten across the local area overnight as a surface low
deepens across Montana. This will act to generate a light southerly
wind at the surface overnight...which should keep temperatures
elevated a few degrees. Then as the aforementioned low tracks
further east on Friday...expect the pressure gradient to really
tighten...and for windy conditions to develop across the local area.
Contemplated a Wind Advisory for tomorrow...but with latest guidance
coming in just a bit lower than previous guidance with slower
progression of surface trough...so opted for just a mention in the
severe weather potential statement and will leave to evening/overnight shifts to decide if an
advisory will become necessary. That said...still expect sustained
winds around 25 miles per hour most areas on Friday...making for a pretty windy
day across the local area. Other than winds...temperatures are
expected to jump back up above seasonal norms as warm air advects in
from the south tomorrow...and upped temperatures a couple of degrees
as a result.

Long term...(friday night through thursday)
issued at 359 PM CDT Thursday Apr 17 2014

Weekend and middle week thunderstorm chances remain the primary
forecast concerns through the long term period.

The start of the forecast period hasnt seen much change...models
still in good agreement showing upper level ridging in place through
the central Continental U.S....primarily driven by low pressure systems in
place near the Gulf Coast and over Southern California...but another upper low
sits over the Montana/Canada border. During the overnight
hours...the Main Ridge axis starts sliding east...allowing for
southwesterly flow to build in as both disturbances to the west
creep closer. At the surface...low pressure and accompanying trough axis
remain just west of the County Warning Area...with srly winds remaining in the 15 to
20 miles per hour and higher gusts. By 12z Saturday...an approaching cold
front is expected to be draped through the sandhills. At this
point...any precipitation chances still look to remain off to the west...so
kept the dry forecast in place.

The weekend period is still looking to be an active one...with the
position of the surface front being the feature of interest. The upper
level low over the Mont/can border slides east Sat...while a piece
of shortwave energy ejected out ahead of the main system in the
desert SW is moving NE toward the region. The push from the northern
system along with the deepening of surface low pressure over southeastern Colorado is
expected to push the main surface cold front further southeast into the
area...with the general idea that it will be draped from SW/NE
through the County Warning Area. Models still vary a little with the exact
details...the NAM/sref are a touch further into the County Warning Area /the
middle/southeastern third/...vs the GFS/ECMWF/Gem which hang it up over the
northwestern corner of the County Warning Area. Forecast timing remains a blend at this
point...but any model you look at shows it being a concern. Added a
little more detail to timing of precipitation...trimmed back probability of precipitation a bit Sat
morning...and totally removed from 12-15z. If model trends
hold...doubtful there will be anything prior to 18z. During the
afternoon...the better chances continue to be advertised by models
to occur during the middle/late afternoon...with the best chances then
in the evening Post 00z as the disturbance moves in and a S/southwesterly
low level jet increases to around 40-50kts. Models continue to show dewpoints
climbing into the Lower/Middle 50s across the southeastern half of the
County Warning Area...with instability values in excess of 1000 j/kg /NAM showing
values closer to 2000 j/kg/. While overall deep layer shear isnt the
greatest...roughly in the 15 to 30 knots range depending on the
model...certainly cant rule out some strong to potentially severe
thunderstorms during the evening hours /instability tapers off some
overnight/...and have decided to insert that mention in the severe weather potential statement.

Had thought 24 hours ago that for Sunday...precipitation would be tapering
off during morning...with not much going on through the afternoon.
The latest runs have continued a trend from the 00z runs of a slower
passage of the main upper level trough axis...so could be more
precipitation for your Easter. Confidence is not high for the forecast for
Sunday...because it will also be dependent on how Saturday plays
out...and where the surface boundary ends up. Question with whether it
will linger across southern portions of the County Warning Area during the day like many
of the models are showing...which could be a focus for more
thunderstorm development for the afternoon/evening hours...though the
main axis of instability /should/ be just off to the east/southeast of the
County Warning Area. Lot of details to be ironed out...for both days.

As far as temperatures go...did bump up highs on Saturday...mainly for
locations ahead of the front which should see better mixing with
gusty srly winds...forecast highs range from near 70 near Ord...to
near 80 across NC Kansas. Sunday is cooler behind the front...with highs
in the middle 60 to near 70.

Kept the first part of the work week dry...though some models would
suggest that some precipitation could linger even into the first part of
the day Monday across the east...confidence just not high enough to
mention at this point. Otherwise...upper level shortwave ridging is
expected to amplify over The Rockies on Monday in between this
latest system and another approaching the West Coast...with a ridge
axis once again sliding east onto and then through the plains by the
end of the day Tuesday. Surface high pressure looks to keep winds on
the lighter side for Monday...and gradually transitioning from the
north to southeasterly by 12z Tuesday. Low pressure again becoming
organized over the High Plains on Tuesday will result in increasing
S/southeasterly winds across the County Warning Area...and temperatures by Tuesday are expected to
rebound back into the middle 70s.

Wednesday/Thursday has the potential to be another active period for the
County Warning Area...but lot of questions linger in this day 6/7 timeframe. By the
time 12z Wednesday rolls around...models arent in too bad of agreement
showing an upper level low pressure system having moved into the Pacific
northwest region...with troughing through the rest of the western Continental U.S. And
southwesterly flow in place over the plains. Though it may be closer to the
end of the work week before this main low slides east across the northern
Continental U.S....pieces of shortwave energy ejected out ahead of it could
bring periodic thunderstorm chances to the County Warning Area. Kept probability of precipitation on the low
side...until timing/location of the disturbances...frontal positions
and other feature details can be worked out...but it is a period
Worth keeping an eye on.

&&

Aviation...(for the 00z tafs through 00z Friday evening)
issued at 548 PM CDT Thursday Apr 17 2014

An upper level ridge of high pressure will build onto the Central
Plains through Friday...with warmer and windy conditions
developing. Surface high pressure will continue to slide east
tonight with low pressure deepening along the High Plains region.
In a tightening pressure gradient south winds will be on the
increase on Friday...strengthening to 25 miles per hour with gusts to 30 miles per hour.

&&

Gid watches/warnings/advisories...
NE...none.
Kansas...none.

&&

$$

Short term...Rossi
long term...ado
aviation...Fay