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Area forecast discussion 
National Weather Service Hastings NE
1227 am CDT Wednesday Apr 1 2015

Short term...(this evening through Wednesday night)
issued at 314 PM CDT Tuesday Mar 31 2015

After a beautiful day across the region expect changes to encompass
the local area tomorrow afternoon and evening as an approaching cold
front helps to trigger some potentially severe thunderstorm
activity during the afternoon and evening hours.

Ahead of this cold front...despite the light winds and mainly cloud
free skies expected overnight...anticipate a very mild start to the
day on Wednesday as increased moisture from the south will help hold
up overnight low temperatures well above normal. With this
increasing moisture...the only significant change to the first
period was to add the chance for some patchy fog to start the day on
Wednesday primarily south of Highway 6...as sref probs and other
guidance hinting at this possibility.

That said...this increasing moisture will then become one of the
main ingredients for the potential of strong to severe storms with
the approaching front later in the day...which should provide a nice
trigger for convection. Thanks to the mild start to the day...expect
afternoon temperatures to also climb well above normal before the
front arrives...and several degrees above this afternoons
readings...so maintained lower to middle 80s for most
locations...which is several degrees above guidance.

Otherwise...with this warm and relatively moist airmass in place
across the region to start the day Wednesday...expect instability to
build by early afternoon...on the order of 2000-3000 j/kg...with
the approaching front providing the necessary trigger for fairly
widespread convection across the local area. As mentioned in the
morning discussion from Storm Prediction Center...thanks to ample deep-layer
sheer...expect initial storm development to be generally
supercellular in nature...with the potential for large hail
associated with the stronger cells being a real possibility. As
these storms then mature and become more linear along the
front...damaging winds will also be a threat. Continue to agree
with this thinking...and no significant changes were made to the
severe weather potential statement.

With both the 12z WRF/NAM coming in with the front reaching the Tri
Cities in the 00z-03z time frame...which is arguably just a tad
slower than previous model data...expect nearly the entire
forecast area to see a fairly good shot for some beneficial
rainfall tomorrow....with the widespread convection expected to
develop just northwest of the Tri-Cities during the late afternoon
hours. That said...once this front clear the area...the focus of
convection will shift further southeast and become more elevated
near the nose of the low level jet...resulting in an end to the chance for
rainfall across the local area during the overnight/early morning
hours.

Model spread is quite high with precipitation amounts for this
system...which is not surprising given its convective nature...but
think previous mention of a narrow corridor or 1-2 inches in the severe weather potential statement
is definitely possible...with areas outside of this corridor
expected to receive around a half an inch of rainfall...with the
lowest rainfall amounts expected across our extreme northwest.

Long term...(thursday through tuesday) issued at 314 PM CDT Tuesday
Mar 31 2015

This period starts cooler and then warms through the weekend and
early next week. The best shot for precipitation appears to be
Thursday night across the southern forecast area...but that could
be limited in scope and amount.

Thursday is cooler...but still above normal temperature wise and
probably a pretty nice day. Late in the day...clouds will increase
from the west as a short wave approaches. Good jet dynamics teamed
with the wave riding along middle level baroclinic zone has the
potential for a narrow axis of light precipitation. Its probably too
broad brush in the forecast...area wise...and will want to be
tightened up with time. With temperatures potentially dipping into
the middle 30s...to close not to mention some rain and snow but no
snow accumulation is expected. This system will move likely impact
north central Kansas and far southern Nebraska...and will quickly
die out/move on by middle morning Friday. The rest of the day Friday
will be colder...roughly about normal...and brisk across the area.
Likely the coolest day in the next 7 days.

Easter weekend looks good...at least in terms of dry...mild weather
conditions. Of concern is increasing wind on Saturday afternoon
and forecast relative humidity values near 20 percent west of
Highway 281. Winds may/may not reach 20 miles per hour criteria...but the
area of concern isn/T likely to see much rain with the front...so
they would be more prone to fire weather impacts.

Easter Sunday itself will have low relative humidity...but lighter
winds and should be really pleasant.

After the shortwave ridging over the weekend...the flow turns more
southwest early next week...a wave nudges into The Rockies and we
see just a small risk for showers/isolated storms. Too early to nail
down any specifics of much more than a small risk for precipitation.

&&

Aviation...(for the 06z kgri/kear tafs through 06z Wednesday night)
issued at 1221 am CDT Wednesday Apr 1 2015

Winds just off the surface are strong this morning and have
introduced wind shear through day break. With low level moisture
increasing across the area there could be a few lower clouds this
morning. A cold front will move through the area late this
afternoon. Thunderstorms are expected to develop along and behind
the front.

&&

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

$$

Short term...Rossi
long term...Moritz
aviation...jcb

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