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000
FXUS63 KTOP 091708
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1208 PM CDT Sun Mar 9 2014

...AVIATION UPDATE...

.SHORT TERM...(Today and Tonight)
Issued at 420 AM CDT SUN MAR 9 2014

The highlight of the Sunday and Sunday night period will be a return
to warmth. Warm advection throughout the day will pull 850 hPa temps
to around +12C while sunshine and southwest winds promote mixing and
plenty of warming at the surface. Do expect a gradient across the
area with temps 8 to 10 degrees warmer in north central KS than east
central KS, but much of the area should climb to 60 or above.

With the warm temperatures and gusty winds come fire weather
concerns. North central KS in particular appears to have a fair
chance of RH dropping to around 20 percent with some small potential
of strong mixing allowing very dry air to reach the surface in which
case RH could approach 15 percent or so. Winds will gust mainly in
the 20 to 25 mph range, but could see an hour or two of winds
greater than 25 mph. Will need to keep an eye on moisture profiles
and mixing efficiency this afternoon as potential high cloud cover
could limit the mixing of dry air to the surface, but again the
potential does exist for rather dry conditions.

Winds will continue at 8 to 15 mph overnight across the entire area,
and should keep low temps above freezing, likely in the middle to
upper 30s under mostly clear skies.

.LONG TERM...(Monday through Saturday)
Issued at 420 AM CDT SUN MAR 9 2014

By Monday morning, a more zonal mid-level flow will be in place
across much of the northern CONUS with surface high pressure over
the southeastern U.S. With this pattern in place, southwesterly
surface winds are expected across the region, which will aid in good
warm air advection into the region. Models show a westerly flow to
the low and mid-level jets on Monday, which will help to spread the
thermal ridge which develops over western Kansas today further east
across the state on Monday, with 900MB temperatures reaching upwards
of 14C to 16C. Guidance has continued to trend a few degrees warmer
for Monday highs, so generally have low to mid 70s in the forecast.
Models are still showing a weak backdoor front stretching near the
Kansas/Nebraska border on Monday, which could potentially result in
a wind shift and slightly cooler temperatures, but at this time the
boundary looks to remain just north and west of the area.

A mid-level trough looks to advance into the Pacific Northwest on
Monday and progress southeastward toward the Central Plains Monday
night through Tuesday. This advancing trough will help to push a
cold front southward across the area on Tuesday. Models are starting
to come into better agreement with the timing and tracking of this
cold front. The general model consensus shows the front moving
southward through the morning and early/mid afternoon hours. The NAM
is the fastest solution in having the front well southeast of the
area by 18z Tuesday while the ECMWF is the slowest in having the
front bisecting the CWA at that time. Have trended more with a blend
of the GFS/GEM/ECMWF in having the winds veering to the north by
late morning across far northern Kansas. As a result, have increased
the spread in high temperatures for Tuesday, ranging from the
low/mid 50s over far northern Kansas to the mid/upper 60s over east
central Kansas where winds should remain out of the south through
much of the day. With this in mind, have gone with a non-diurnal
temperature trend for Tuesday. A tight pressure gradient looks to
set up over the area behind this front as surface high pressure over the
northern Rockies quickly advances into the Central Plains. As a
result, breezy northerly winds area expected Tuesday night, which
will aid in CAA into the region. With increased cloud cover, low
temperatures should drop into the upper 20s/low 30s. As for the
potential for post-frontal precipitation, the GFS has started to
come into better agreement with the ECMWF in having better
saturation occur over much of the area late Tuesday afternoon
through Tuesday night. There is still some uncertainty with just how
much moisture will be available with this system, but expect
precipitation to start off in the form of rain due to the warmer
daytime temperatures. With temperatures dropping off near the
freezing mark overnight, could see a transition over to snow before
quickly exiting east of the area by Wednesday morning. With
northerly flow in place through the day, Wednesday looks to be the
coolest day of the week with high temperatures in the upper 40s/low
50s. As surface high pressure shifts south of the area Wednesday
into Wednesday night, expect southwesterly surface winds to return
by Thursday and Friday with temperatures quickly rebounding back
into the upper 50s/low 60s. On Saturday, models are showing a
mid-level trough developing over the northern Rockies and
progressing into the Central Plains Saturday night, however there
are some model discrepancies with the surface features ahead of this
system that ultimately impact the wind/temperature forecast, so
stayed with a consensus model blend since that system is still
several days away.

&&

.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1208 PM CDT SUN MAR 9 2014

A dry airmass will allow VFR conditions to persist into Monday.
There is some concern for low level wind shear due to an increasing
low level jet. However forecast soundings do not indicate a sharp
discontinuity in wind speeds between the boundary layer and the
low level jet. Therefore will not include wind shear at this time.

&&

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

&&

$$

SHORT TERM...Barjenbruch
LONG TERM...Hennecke
AVIATION...Wolters