Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
1222 PM CDT Tue Oct 25 2016
issued at 956 am CDT Tuesday Oct 25 2016
Have updated temperatures and dewpoints to try and tighten the
gradient across the forecast area with the stationary front expected
to lift north as a warm front later today. Have also scaled back pops
to just the far northern forecast area through the day and then this
evening and tonight as the cold front pushes through. There may be a
few sprinkles/light showers further south today but the coverage
looks too low to mention at the moment given weak forcing.
issued at 349 am CDT Tuesday Oct 25 2016
Short range (today through Wednesday night):
There are a few challenges in the short range. The first will be the
chance for drizzle this morning and the second will be the chance for
thunderstorms tonight into Wednesday.
This morning, a stratus deck is blossoming over eastern Kansas which
was forecasted well by hi-res short term models. This cloud deck
will continue to expand into the local area this morning allowing
for the potential for drizzle. This cloud cover should begin to
scatter as we move into the afternoon and conditions should remain
dry for most of the County Warning Area with capping in place. The exception will be
across the northeastern County Warning Area where a warm front will be in the
vicinity and few shower may be possible. There will be a drastic
temperature gradient across the County Warning Area as well due to this warm front.
The northeastern County Warning Area will only reach the upper 50s whereas the
southwestern County Warning Area will rise into the mid to perhaps even upper 70s.
As we move into the evening a shortwave trough will move into the
northern and Central Plains. Surface cyclogenesis will occur in
response to the short wave with a surface low developing across
central Nebraska and a cold front extending southwest from there.
Thunderstorms are expect to develop north of the area by late
afternoon/evening north of the area on the nose of a developing low level jet.
Storms are then expected to develop further south across eastern
Nebraska and northeastern Kansas along the cold front. Instability
will be modest with MUCAPE values around 1000j/kg, 0-1km shear will
also be sufficient between 25-30kts, steep mid-level lapse rates
will be present, and a tongue of low to mid 60s dewpoint are
expected to extend into northwestern MO. These parameters would
suggest at least the potential for a few strong to possibly isolated
severe storm across the northwestern County Warning Area. The recent trend has been
to have the cold front lag across the area as we move into Wednesday
morning as the best forcing remains well north of the area.
Consequently, thunderstorm chances are expected to continue into
Wednesday. In fact, model now depict instability of 1000-1500j/kg of
MUCAPE ahead of the front on Wednesday across the South County warning area...this
again would provide the potential for another round of strong
storms. The cold front should finally push east of the area by
Wednesday evening with surface high pressure building into the area
Extended range (thursday through monday):
The extended period continues to look dry and mild. Surface high
pressure will be in control on Thursday with highs in the mid 60s to
near 70s. Friday will be the warmest day of the forecast period with
warm air advection and upper level ridging building into the area. Highs will be in
the mid 70s to near 80. A weak cold front will move through on
Saturday however temperatures will still remain above normal with
highs in the upper 60s to mid 70. Another weak cold front moves
through Saturday night and highs will fall into the mid 60s to near
70 on Sunday. Temperatures, however, push well above normal again as
we move into Monday as warm air advection drives high temperatures into the low to
Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 1219 PM CDT Tuesday Oct 25 2016
VFR conditions are expected through this afternoon and this evening.
A cold front will move through the area late tonight into tomorrow
morning and spread showers and storms to the area. Timing this into
the terminals yields the predawn hours, likely between 8z and 12z.
Behind the front there will likely be a period of low MVFR ceilings
which may then persist into the afternoon.