Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Hastings NE
1258 am CDT Sat Mar 28 2015
Short term...(this evening through saturday)
issued at 343 PM CDT Friday Mar 27 2015
Aloft: a highly amplified western USA ridge/eastern USA trough was in place
with north-northwest over the plains. However...this configuration will be
progressive and deampify through tomorrow as a shortwave trough off the
Pacific northwest moves onshore and into the northern rockies. By late Sat a
shortwave ridge will be overhead.
Surface: high pressure will slide from the MS valley and settle over
the eastern USA. A stationary front extended from the Canadian
prairiess down to the Colorado-Kansas border. This front will move little.
A weak low was moving south-southeast down the front and was producing warm air advection
clouds and spotty very light precipitation. In the meantime...the next
Pacific cool front will move onshore and through the northern rockies and
intermountain west. More westerly flow aloft will also strengthen the
Rest of this afternoon: cloudy. Precipitation has been highly variable
on radar...blossoming and decaying with very little organization.
Overall believe sprinkles or flurries will handle it...but there
could be a burst of light rain or snow. We saw it earlier.
Ord did briefly drop to 3sm in -sn at 2 PM. Gri was down to 4sm
around 230 PM.
Tonight: this band of warm air advection-driven cloudiness will shift east of the
region as heights rise. Cumulus fields have developed over the
Panhandle this afternoon. Some hi-res models suggest some isolate
showers will develop and head southeast into the forecast area early this
evening. They will fade with loss of heating. Played it as
sprinkles. Decreasing clouds from the west.
Low temperatures are largely continuity with the previous forecast just with
a bias correction applied.
Sat: probably some scattered clouds linger to start the day from
Highway 281 east...but overall a nice improvement over today with temperatures
rebounding nearly 30f. Great for being outside!
Long term...(saturday night through friday)
issued at 358 PM CDT Friday Mar 27 2015
Warmer temperatures will return and then persist through next week
with above normal to well above normal high temperatures in the
forecast. Little to no measurable precipitation is forecast until
Wednesday afternoon when thunderstorms may then be possible
depending on the timing of a frontal passage.
Sunday...an upper shortwave will track southeast just to the north
of our forecast area with an accompanying surface trough that will track
through our forecast area resulting in stronger winds and turning
the wind to northwest. Most of the precipitation with the upper
shortwave will be to the north and east of our forecast area and
thus we will be going with a dry forecast for all of our zones.
The bigger concern will be the drier air moving in behind the surface
trough along with the breezy winds combining to create near
critical fire danger. Fire weather headlines may eventually be
needed Sunday afternoon if confidence increases in low relative humidity and
gusty winds. Highs will generally be in the middle 60s to around 70.
Monday and Tuesday...an upper ridge will gradually nose into the High
Plains from the west with warmer air moving in both aloft and at
the surface. These will be some of the nicest days of the week with
highs well into the 70s and maybe even a few 80s across our
southern zones on Tuesday.
Wednesday...this also appears to be a continued warm day with highs
in the 70s and increasing moisture as dewpoints climb with a gusty
south wind. There should be a cold frontal passage at some point on
Wednesday but timing is sketchy this far out and is a critical
component when it comes to thunderstorm chances.
Therefore...confidence in thunderstorms is still fairly low as an
earlier frontal passage would send most all of the thunderstorms
east and south of our forecast area. However...a slower frontal
passage will increase our chances of seeing afternoon and evening
thunderstorms allowing our area to be more unstable beneath
dewpoints that should be in the 50s south of the cold front.
Thursday and Friday...temperatures will cool back down behind the
Wednesday cold front...but the air does not appear overly cool and
highs could still be in the 60s...which continues to be above the
normal of the middle 50s. Uncertainty is high in rain chances...but
there is at least some chance of rain with an upper trough trying to
develop over The Rockies.
Aviation...(for the 06z kgri/kear tafs through 06z Saturday night)
issued at 1255 am CDT Sat Mar 28 2015
The biggest issue will be potential low-level wind shear toward
late Saturday evening. Wind could also become a bit gusty by
Saturday afternoon as well. Some numerical models are indicating
some reduced visibility overnight...but latest observations do not