Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
330 am CST Wed Nov 26 2014
issued at 326 am CST Wednesday Nov 26 2014
Today/tonight: forecast looks on track for the next 12 hours.
Currently, water vapor and radar imagery shows a well-defined
clipper system centered over western Iowa. With increasing ascent,
radar returns have blossomed over the past couple of hours, with
precipitation spreading into much of northwest Missouri and Iowa. As
anticipated, temperature profiles along the I-29 corridor have
yielded a mix of rain and snow, with surface observations reporting
light snow over much of Iowa stretching into north central Missouri.
Through mid-morning, portions of eastern Kansas and far western
Missouri should expect a rain-snow mix, whereas areas further east
in the cold air over north central and northeast Missouri should see
primarily snow. For areas in the colder air of north central and
northeast Missouri, total snowfall accumulations should average
between 0.5" to 1" of snow before noon. Little to no accumulation is
expected outside of those geographical areas, thanks in part to
relatively warm surface temperatures. As the upper disturbance moves
through the region, a suite of models suggest light precipitation
may redevelop late this morning into the afternoon over the eastern
half of the County Warning Area. With slightly warmer air in the lowest couple
thousand feet by this afternoon along with some loss in ice
introduction in the cloud layer, higher uncertainty exists with
precipitation type, with a rain-snow mix the most likely scenario.
Regardless, little to no additional accumulation is anticipated upon
the exit of the initial wave of precipitation this morning.
Precipitation should quickly exit the forecast area by late this
afternoon or early evening, with some cloud cover thinning over
eastern Kansas and western Missouri. Lows tonight will be chilly,
with temperatures in the middle teens to middle 20s.
Thursday: one final shot of cold air is projected to move through
the region on Thursday as surface high pressure builds into the
region and the pesky longwave trough slowly shifts east.
Thanksgiving day will be chilly with highs in the upper 20s
northeast to near 40 southwestern cwa, with dry weather prevailing.
Lows Thursday night will fall into the 20s areawide.
Friday/saturday: on Friday, weak upper ridging across the western
two-thirds of the Continental U.S. Will provide a large and fairly aggressive
warm air advection regime over much of the Great Plains, spreading
eastward. With surface high pressure sliding off to the east,
southerly winds will return early on Friday. The end result is a
quick warmup Friday into Saturday, with afternoon temperatures in
the upper 40s to upper 50s on Friday. The warmest day is expected on
Saturday with highs reaching the middle 50s to lower 60s across the
forecast area. Precipitation is not expected during this multi-day
period of warm weather, making for an optimal time for any outdoor
Extended: models diverge on the speed of a cold front projected to
move through the area on Sunday. This will have potential affects on
forecast high temperatures. Currently went closer to the European model (ecmwf)
solution, but any slower trend may yield a slightly warmer day on
Sunday. Similar model challenges continue into early next week.
While Monday looks quite cold with below normal temperatures,
tuesdays temperatures remain in question depending on the frontal
progression southward as well as the aggressiveness of warm air
advection across the plains in the wake of surface high pressure and
in advance of the next upper disturbance. Carried some chances of
showers Tuesday night into Wednesday with aforementioned warm air
advection regime, but overall confidence on a particular scenario
remains low at this time.
Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 1129 PM CST Tuesday Nov 25 2014
Mid lvl clouds have filtered into the terminals tonight ahead of a
cold front. Top down saturation will allow precipitation to form at
the terminals in the form of rain mixing with snow. No accumulation
is expected at the terminals as pcpn will be lgt and temps will
remain abv freezing. Pcpn will begin at the terminals btn 08z-09z
with a ovc cloud deck btn 3-4kft. A cold front will pass thru the
terminals btn 12z-14z veering winds from the south-southwest around 10kts to the
west-northwest as MVFR cigs build in behind the front. MVFR cigs will persist
thru the day before lifting out to around 5kft around 00z. Winds will
also pick up out of the northwest late this morning btn 15-20kts with gusts
up to 30kts until around sunset when it will diminish to around