Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Hastings NE
546 am CDT Thursday Jul 24 2014

Short term...(today and tonight)
issued at 422 am CDT Thursday Jul 24 2014

Upper air and satellite data show a continued amplified pattern
across mainly the central and western thirds of the Continental U.S....with an
area of high pressure anchored over co/nm...while an area of low
pressure spins over the Pacific northwest with a trough extending south along
the West Coast. At the surface...a frontal boundary is draped to
the west and south of the County Warning Area...while high pressure is centered
over MN/WI. The resulting winds are S/serly...but with a weaker
pressure gradient the speeds are generally in the 5 to 10 miles per hour

Through the early to middle morning hours today...main questions is
whether the County Warning Area will see any precipitation. Even at this point
models show plenty of differences...but hires/short term models
show the potential of mainly the northestern third or so of the County Warning Area
being a weak upper level wave rides the edge of the
ridge and an increased low level jet lingers across the area. Seeing a few
showers have developed over southwestern South this point will keep probability of precipitation
in the 20- 30 percent range...and will see how things evolve over
the next few there is also the suggestion the County Warning Area wont
see anything.

Should thunderstorms affect the County Warning Area this is currently
expected to shift off to the east by midday. Left the afternoon
hours dry...with additional thunderstorm activity expected to
develop late in the afternoon over the High Plains along a surface
boundary as another weak upper level wave on the edge of the ridge
moves out of The Rockies. These thunderstorms look to remain west
of the County Warning Area prior to 00z...with some question between models with
just how far east the activity will get. Kept the low chance probability of precipitation
going across western and northern portions of the County Warning Area between 00-06z with
the hours following dry...though confidence in that is not high.
Cant completely rule out a few strong thunderstorms with any
activity that develops.

Otherwise...expecting a breezy day across the County Warning Area as surface low
pressure becomes better organized to the west/northwest of the
County Warning Area...tightening the pressure gradient across the region. Srly
winds of 15 to 25 miles per hour and higher gusts are expected. Models in
good agreement showing increased temperatures aloft...with a bump up in
highs expected. Current forecast highs range from the upper 80s in
the far east to middle/upper 90s in the W/SW.

Long term...(friday through wednesday)
issued at 422 am CDT Thursday Jul 24 2014

Biggest challenge will be determining thunderstorm/severe chances
Friday night into Saturday night. Also...high temperatures on

A subtropical high will dominate our weather at the beginning of
the long term. There is some high base convection that could
develop with a wave along the Front Range of the northern rockies
Friday afternoon...but this convection should remain north of the
County Warning Area as the convection moves east. We should be capped as well.
Temperatures will be tough to determine as a cold front slides
south. It really looks like this could be a sleeper for very hot
temperatures in north central Kansas as the peak heating of the
day will probably occur before the cold front can clear north
central Kansas...allowing temperatures to soar well above 100 with
the help of compressional warming.

A low-level jet will develop Friday night with the nose focused
north of the County Warning Area. I included a slight chance of showers and
thunderstorms in the far northern County Warning Area. There could be enough
support for a strong storm late Friday night into Saturday
morning...but focused north...possibly helping to support earlier
high-based convection that may have developed farther west earlier
in the day. This could linger into Saturday morning...but with a
strong cap expected...this should die out in the morning.

The aforementioned cold front should have cleared the County Warning Area by
then...but will eventually stall at some point. The strong cap
would deter convection from developing until evening...and by
this time...the boundary should be far enough away to keep
convection focused east/southeast of the County Warning Area. Any storm that
develop along this boundary could become severe...but again...the
current thinking is that we should remain far enough
west/northwest to keep US out of this area. Most numerical model
solutions indicate that the front should have well cleared our County Warning Area
by early Saturday evening.

Surface high pressure and capping will help keep things dry Sunday
night through Monday. Return flow will allow a small chance of
showers and thunderstorms to creep into the west/southwestern County Warning Area
by Monday night...and creep east for the rest of the long term
as the high continues to move east.

We will have below normal temperatures for Monday through Wednesday
as much cooler air moves out of Canada. Most model solutions place
US well west of the main thrust of colder air...much like the last
time this happened earlier in the month. Highs are still forecast
in the lower to middle 80s early next week...but this may have to
be lowered a bit as long range numerical models tend to rely more
on climatology in later periods.


Aviation...(for the 12z tafs through 12z Friday morning)
issued at 543 am CDT Thursday Jul 24 2014

No significant changes made for this taf period...still enough
uncertainty due to model differences with regard to precipitation
chances this morning to leave the mention out at this point. Will
see how things evolve over next hour or so and adjust as
necessary. Otherwise...VFR conditions remain in the
forecast...with any cloud cover at this point expected to remain
in the middle/upper levels. Still expecting a breezy day...especially as we
get into the late morning/afternoon hours...with southerly winds
of 15 to 25 miles per hour and higher gusts forecast.


Gid watches/warnings/advisories...


Short term...ado
long term...heinlein

National Weather Service Glossary of Abbreviations