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Area forecast discussion...updated 
National Weather Service North Platte NE
706 PM CDT sun Aug 2 2015

Synopsis...
issued at 419 PM CDT sun Aug 2 2015

Stalled boundary stretched east west across central Nebraska this
afternoon. Warm moist are south of the boundary combining with shear
of 30 to 40 kts and cape of around 2000 j/kg to produce scattered
thunderstorms. Upper level ridge remains across southwest Continental U.S. With
northwest flow across the High Plains.

&&

Short term...(this evening through monday)
issued at 419 PM CDT sun Aug 2 2015

Isolated to scattered thunderstorms continue to develop along and
south of a stalled middle level front. Moisture is decent and shear is
marginal but enough for a few strong thunderstorms this evening.
Storms will drift southeast and expect them to diminish after
sunset. Overnight a wave will move across northern Nebraska and the
latest rap brings some quantitative precipitation forecast through the region. This activity may
keep temperatures up...however expect showers to be scattered to isolated with
breaks to allow for temperatures to cool down and went with guidance.

Tomorrow cooler conditions with highs in the 80s to lower 90s.
Another disturbance will bring additional chances for isolated
thunderstorms.

Long term...(monday night through sunday)
issued at 419 PM CDT sun Aug 2 2015

Forecast challenges in the days 2 and 3 period involve precipitation
chances associated with the weak southward advancing front currently which
stalls and retreats slowly northward through this period. Upper pattern
influenced by upper low over Hudson Bay with an upper jet and
associated pv anomalies moving across the upper Midwest and Great
Lakes area. As the jet rounds the base of the upper low...upper
forcing wanes and transitions eastward and surface high slides southeastward.
Meanwhile significant lead pv anomaly associated with an upper
trough off the California coast will move across the central rockies
continuing its negative tilt. As this occurs surface troughing will develop
along the Lee of The Rockies allowing a return to strong srly low
level flow which pushes the boundary northward through Tuesday night. This
lead pv anomaly will enter the High Plains Monday into Tuesday though
the models diff significantly on timing and eventual location. This
will obviously have an impact on where low level convergence can
maximize along the retreating front. So confidence on timing is only
average...however southeasterly flow level flow initially will bring
additional moisture back into the area with much better large
scale forcing should see better precipitation chances Monday night into
Tuesday than of late.

For Thursday through the weekend...deepening low pressure near the
Aleutian Islands and downstream troughing along the Pacific northwest will
flatten the transitory Central Plains ridge leading to quasi-zonal
flow across western and north central Nebraska. This will be associated
with quicker moving subtle pv anomalies /short waves/ helping to
generate thunderstorms along pre-existing boundaries...and generally
diurnally driven into the weekend. Temperatures in this type of
pattern will typically be moderate and generally at or slightly
below average for this time of year.

&&

Aviation...(for the 00z tafs through 00z Monday evening)
issued at 703 PM CDT sun Aug 2 2015

Isolated thunderstorms over western Nebraska will dissipate this
evening. Other isolated storms from kvtn to konl are expected
after 03/09z. Skies will continue with VFR ceilings with areas of
bkn070 and ovc250. Winds will be less than 10kts over western
Nebraska through Monday except in the vicinity of thunderstorms.

&&

Lbf watches/warnings/advisories...
none.
&&

$$

Synopsis...masek
short term...masek
long term...jws
aviation...power

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