000
FXUS63 KTOP 152030
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
330 PM CDT Sat Mar 15 2014

.SHORT TERM...(This Evening through Sunday)
Issued at 327 PM CDT SAT MAR 15 2014

An upper level trough over eastern NM and west TX will be phasing
with an upper trough digging south-southeast across western NE and
CO. The upper level trough will dig southeast and take on a more
positive tilt as it moves southeastward towards the mid MS river
valley, extending southwest across eastern TX by late Sunday
afternoon.

The cold front was pushing southeast across western Kansas this
afternoon and will move across the CWA this evening. The colder air
was lagging behind the initial wind shift. A tight surface pressure
gradient northwest of the cold front will cause northerly winds to
increase to 25 to 35 MPH with gusts up to 45 MPH. Therefore, I will
keep the wind advisory going Tonight into Sunday morning. The strong
winds will spread from northwest to southeast across the CWA through
the evening hours. The northwest winds will gradually diminish from
northwest to southeast across the CWA during the mid morning hours
and into the early afternoon hours of Sunday.

Deeper moisture was being transported northeast from central and
northeast OK into southeast KS. Dewpoints across eastern OK were in
the mid to upper 50s. As a result of isentropic lift, a line of
showers and isolated thunderstorms heave develop from ICT to south
of Independence, KS. This line of showers and thunderstorms will
move north into east central KS late this afternoon and early this
evening. The short-term models continue to show about 200 to 500
J/kg of MLCAPE late this afternoon and early evening south of the KS
turnpike. So, I would not be surprised to here a rumble of
thunder early this evening across portions of east central KS. Light
rain will also develop as the stronger ascent ahead of the H5 trough
spreads across the CWA.

Low-level CAA behind the cold front will gradually cool the low
boundary layer and forecast soundings show vertical temperatures
profiles cooling below freezing across much of the CWA through the
early morning hours. The rain should mix with and turn to light snow
across the north central KS late this evening and then across the
remainder of the CWA through the early morning hours of Sunday. The
new run of the NAM does not show as much QPF developing in the
colder air than what previous runs were showing. I suppose the
northeast counties of the CWA could see up to an inch of wet snow
through the early morning hours of Sunday. Everyone else will only
see a trace to a half inch of snow. Overnight lows will reach the
mid to upper 20s across north central and northeast Kansas. Lows
across east central KS will be in the upper 20s to lower 30s.

As the H5 trough shifts east into MO, the precip should end during
the mid and late morning hours. Skies will be mostly cloudy with a
north wind. Temperatures will be much colder on Sunday. Highs across
the eastern portions of the CWA may only reach the upper 30s. There
may be some afternoon sunshine across north central KS which will
allow highs to warm into the lower to mid 40s. The strong north
winds will diminish through the afternoon hours, though wind chills
may make it feel like highs are only in the 20s.


.LONG TERM...(Sunday Night through Saturday)
Issued at 327 PM CDT SAT MAR 15 2014

The mid-level trough associated with the passing storm system will
have progressed east of the area by Sunday night with a nose of
surface high pressure centered over the region. As a result, dry
conditions are expected by Sunday night with mostly clear skies. This
surface high will shift south of the area overnight with winds
becoming out of the south. The switch to southerly flow will limit
the amount of cold air advection overnight, however low temperatures
Monday morning are still expected to be 5-10F degrees below normal
in the low/mid 20s.

Models show another mid-level trough moving into the Pacific
Northwest on Monday, tracking eastward into the Northern and Central
Plains Monday night through Tuesday. This approaching trough will
help to push another area of low pressure centered over the Northern
Rockies Monday morning southeastward toward the region with a cold
front expected to track across the area on Tuesday. Models show the
pressure gradient increasing over the area on Monday ahead of this
system, resulting in breezy southerly winds that may gust upwards of
20 to 30 mph. These southerly winds combined with mostly sunny skies
will aid in decent warm air advection into the region. A weak
mid-level ridge should stretch from the southwestern U.S.
northeastward into the Central Plains, and it`s within this ridge
that models show a nice thermal ridge present over the eastern
Rockies and into the western half of Kansas with high temperatures
expected to range from the upper 50s to upper 60s east to west on
Monday. Dewpoints through the day are expected to be fairly low in
the 20s to low 30s, resulting in RH values generally dropping into
the mid to upper 20 percent range with the driest conditions focused
across north central Kansas. These low RH values combined with gusty
winds during the afternoon may result in a heightened fire danger
concern across that area, so we will need to continue to closely monitor
these conditions over the next couple of days.

There are still some minor model discrepancies with regards to just
how quickly the front passes through the region on Tuesday. There is
fairly good agreement in the north-to-south oriented front entering
central Kansas Tuesday morning, but then should exit east of the
area anytime from early afternoon to early evening. This uncertainty
in the timing of the frontal passage leads to uncertainty in the
temperature forecast for Tuesday, but at this time have a range of
upper 50s to middle 60s. Expect a period of breezy northwesterly
winds behind this front Tuesday afternoon and evening before
weakening overnight as surface high pressure advances into the area.
These west/northwesterly winds will remain in place on Wednesday,
resulting in slightly cooler temperatures with highs in the 50s.
However, the surface high pressure should shift southeast of the
area Wednesday night, with southwesterly winds on Thursday helping
to develop another thermal ridge across much of Kansas. As a result,
expect high temperatures to rebound back into at least the low/mid
60s. Models show another cold front moving through on Friday as
another mid-level trough skims eastward across the Northern Plains.
The GFS continues to be the only model developing precipitation over
the forecast area on Friday with the ECMWF keeping us dry, however
the 12Z ECMWF does develop precipitation just east of the area
across Missouri, so will need to see if it trends further west in
future runs. At this time, have a dry forecast for the end of the
week into the weekend with temperatures dropping a bit into the
mid/upper 50s by Saturday.


&&

.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1236 PM CDT SAT MAR 15 2014

Expect VFR conditions through the early evening hours. A strong
cold front will move southward across the terminals between 2Z and
4Z SUN. North winds will increase to 20 to 26 KTS with gusts of 28
to 35 KTS possible after 4Z. Periods of light rain will mix with
snow and sleet after midnight and last through the mid morning
hours of Sunday. Stratus ceilings will decrease to MVFR levels
with some periods of IFR ceilings. Visibilities will drop to 2 to
4 miles with some lower visibilities in areas of sleet and snow.


&&

.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY from 7 PM this evening to 7 AM CDT Sunday FOR
KSZ008>012-020>024-034.

WIND ADVISORY from 10 PM this evening to Noon CDT Sunday FOR
KSZ026-035>040-054>056-058-059.

&&

$$

SHORT TERM...Gargan
LONG TERM...Hennecke
AVIATION...Gargan