Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Hastings NE
339 PM CST Monday Nov 24 2014

Short term...(this evening through tuesday)
issued at 338 PM CST Monday Nov 24 2014

A northwest flow pattern will be in place across the Central Plains
during the short term periods. In a tight pressure gradient in
between a surface high over the central rockies and low pressure to
the east...northwest winds have been steady/gusty today with gusts
around 35 miles per hour.

The upper trough will lift out to the Great Lakes region tonight and
as the low moves wind speeds will decrease as the gradient relaxes.
Dry conditions are forecast tonight but cloud cover will increase as
an upper jet noses south along the Front Range...and models suggest
a hit or miss chance for light precipitation along the High Plains...to our
West.

Heights rise Tuesday and temperatures trend up in rising heights/warm air advection
ahead of another approaching trough and cold frontal boundary.
Westerly downslope flow will aid in the warming but temperatures will also
be dependent on varying cloud cover...and readings in the 40s to
around 50 degrees still look to be in the ballpark. The middle level
shortwave trough translates southeast into central Nebraska during
the afternoon...along with the associated cold frontal boundary. Lift is
also enhanced in favorable jet dynamics toward evening as 160kt 300 mb
jet noses onto the plains from the northern rockies. Models are
suggesting the potential for light precipitation to develop
beginning late afternoon on Tuesday...with the WRF model the most
aggressive. It is hard to discount the WRF as it performed well with
the Sunday rain event. Have introduced low probability of precipitation across our north for
Tuesday afternoon and will need to keep an eye on timing. Forecast
soundings are fairly dry below 850 mb and it may be more of a sprinkle
potential at the onset before things saturate. The low level temperature
profile remains above freezing through the afternoon and precipitation type will
remain as liquid.

Long term...(tuesday night through monday)
issued at 338 PM CST Monday Nov 24 2014

At the start of the long term period Tuesday night...main change
made to the forecast was to add some slight chance probability of precipitation across northestern
portions of the County Warning Area. Models show the area under continued
northwesterly flow aloft...with ridging extending well north along
the West Coast. They are in decent agreement showing another
shortwave disturbance sliding southeast out of central Canada into the
Dakotas...clipping the northestern corner of NE and into western/southern Iowa by
sunrise Wednesday. 12z run of models have shown more support with
the northern portions of County Warning Area at least see a chance of being affected by
the southern edge of the disturbance...so have probability of precipitation along/east of a Loup
City to Hebron line. Models also showing a hefty upper level jet
streak nosing in from the northwest...thinking that precipitation chances
associated with it should remain to the west of the County Warning Area...but it may
come close to the western edge of the County Warning Area. A surface cold front
accompanies this disturbance through the region...with models in
good agreement showing it through the County Warning Area by early morning
Wednesday. Will start seeing cooler air building in...thus the rain/snow
mention...but the coldest air looks to lag a bit behind the
precipitation.

As we get into Wednesday...currently have the forecast dry as that
disturbance continues moving east...but am a little concerned about
the need for maybe some flurries into the first half of the day or
so as that upper level jet streak slides east. Should be seeing some
drier air moving in...so kept the mention out for now. Expecting it
to be a breezy day...with a tightened pressure gradient in the
morning and increased mixing potential...northwest winds of 15 to 25 miles per hour
are currently forecast. High temperatures for Wednesday expected to drop
into the middle 30s NE to low/middle 40s SW.

For Thanksgiving day...overall no significant changes were made.
Still looking at a dry Holiday...with models continuing to show
northwesterly flow in place in the upper levels...and no notable
disturbances expected to move through. At the surface...start the day out
with lighter winds as high pressure is sliding east of the
area...which will then turn to the south as a trough of low pressure
becomes better established over the High Plains. Models remain in
good agreement showing moderating temperatures aloft sliding in from the
west...so expect a bump up in temperatures...current forecast highs are in
the upper 30s NE to upper 40s SW.

Friday and Saturday...latest run of models still showing another
nice rebound in temperatures. The upper level flow is becoming more
zonal...with very broad ridging moving onto the central/Southern Plains
and warming temperatures aloft continuing to build in. 850mb temperatures from 00z
Friday to 18z Saturday rise from the single digits above zero to
near 10c...to the middle/upper teens. Combine that with the downsloping
west/southwesterly winds that are expected to be in place and not too much in
the way of clouds...lead to the highs for both days being trended
up...and some models suggest it wasnt enough. 50s/60s currently
going...but possible that Saturday may have more widespread
60s...with increased mixing ahead of an surface cold front approaching
from the northwest. Saturday highs alone were raised around 8 degrees. Look
to be a real nice couple of days.

Then comes the cold front. Models not in too bad of agreement with
the timing of the front...ushering in nearly winds to the entire County Warning Area
by sunrise Sunday. The disturbance pushing this front south looks to
remain well north of the area...so no precipitation currently
forecast. Surface high pressure building in /but remaining centered to
the north/NE of the County Warning Area/ will bring diminishing winds along with the
colder air...which will linger around into Monday. Have 20s/30s
going for highs on Sunday...with the potential for a slight bump up
for Monday into the 30s/low 40s.

&&

Aviation...(for the 18z kgri/kear tafs through 18z Tuesday afternoon)
issued at 1125 am CST Monday Nov 24 2014

Gusty northwest will be the main concern for the taf period
through the afternoon hours. Northwest winds of 20 to 25kts and
gusts of 30kts are forecast until the gradient relaxes this
evening. Cloud cover is expected to thicken toward Tuesday morning
and have kept ceilings at VFR.

&&

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

&&

$$

Short term...Fay
long term...adp
aviation...Fay

National Weather Service Glossary of Abbreviations