National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KTOP 040548
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1148 PM CST Tue Mar 3 2015

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Wednesday)
Issued at 330 PM CST TUE MAR 3 2015

Today the mid-level trough continued to deepen, with the trough axis
extending from the Northern Plains into the southwestern U.S.  At
the surface, the cold front had exited the forecast area by mid
afternoon with surface high pressure advancing into the area behind
the front. With the frontal passage, winds shifted to the northwest
resulting in cold air advection and falling temperatures for most
locations through this afternoon. These northerly winds will support
cold air advection overnight through tomorrow with lows in the
mid/upper teens and Wednesday highs only reaching into the upper
20s/low 30s.

The main focus of the short-term forecast (as well as the biggest
adjustment from the previous forecast) is the increased potential
for precipitation late tonight through Wednesday morning. Several
short-range models are showing increased forcing and lift as the
trough axis advances into the Central Plains. In fact, models show
one decent band of precipitation setting up along and behind the
cold front that exited the area today, but some of the associated
precipitation may extend as far north as our far southern portions
of the forecast area.  A second batch of moisture seems to be
associated with the enhanced forcing noted ahead of the advancing
trough axis. We have seen very light reflectivity returns on radar
across far east central Kansas for much of the day and model
soundings show that low-level saturation may increase enough this
evening to produce some very light rain showers or drizzle.
Precipitation chances increase late evening into the overnight hours
as the 2 regions of moisture try to converge near the forecast area.
While the better chances for precipitation look to be along and
south of I-70, portions of north central and far northern Kansas may
get clipped by the western wave overnight. Drier air from the
advancing surface high pressure should help to end the precipitation
from north to south during the morning hours with some light
lingering precipitation possible over far east central Kansas during
the afternoon. Temperatures across the entire outlook area should
drop below freezing by mid evening. Soundings have temperatures
aloft cooling as well, so do not anticipate a warm nose above
freezing as the column saturates. As a result, a majority of the
precipitation should be in the form of snow. While the best forcing
and lift looks to be centered over southern Kansas, some models are
suggesting that modest forcing/lift could extend as far north as the
I-70 corridor. Additionally, there are signs of some elevated
instability extending northward into the area overnight into
Wednesday morning as well, which could enhance precipitation totals.
Due to this recent shift in the forecast models, confidence is on
the low side with regards to possible snow accumulations. At this
time, have snowfall accumulations of around 1 to 1.5 inches along
and south of a line stretching from Minneapolis to Abilene to
Garnett with lesser amounts north of this line. However, it`s worth
noting that if any enforced snow bands develop across east central
Kansas then some slightly higher snowfall totals will be possible.
We will continue to monitor the short-term model trends and adjust
the forecast as needed this evening.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 330 PM CST TUE MAR 3 2015

Lower to middle levels continue to dry Wednesday night as cold high
pressure builds in. This should end any precip ending by the early
evening. There remains some wind aloft and high cloud looks to
remain into the evening so don`t expect a prime radiational cooling
setup, but lows still should drop to around 10. Warm advection
becomes the rule under persistent west-northwest flow aloft for good
insolation. Westerly winds around 850mb should yield noticeable
temperature gradients from west to east Thursday and Friday with
highs back to near to even slightly above normal values for Friday.
Models are similar in a few weak fronts passing over the weekend
bringing minor uncertainty in temps, but mid to upper 50s expected
to dominate. Upper trough in the eastern Pacific makes eastward
progress to near the West Coast into early next week for warmer
temps by Tuesday.

&&

.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1147 PM CST TUE MAR 3 2015

VFR to mvfr cigs will be common through 10Z then predominately
MVFR through 15Z then becoming VFR by 17Z. Snow will be possible
at the terminals in the 10Z-15Z period with mvfr vsbys at times. North
winds around 10 kts with gusts near 18 kts through 13Z then north
at 10 kts before decreasing to less than 10 kts after 00Z.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Hennecke
LONG TERM...65
AVIATION...53