Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 212348
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
548 PM CST Tue Feb 21 2017

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Wednesday)
Issued at 230 PM CST Tue Feb 21 2017

As of 20z, a surface ridge was slowly pushing east across the
forecast area. Winds beneath the ridge are near 5 knots resulting
in a beautiful afternoon with temperatures near 70! The light
winds and reduced BL mixing has allowed RH values to remain in the
mid to upper 30s across the eastern half of the area, thus
reducing the fire danger. North-central KS continues to receive
weak dry air advection behind the surface ridge, resulting in RH
values in the upper 20s. These RH`s coupled with southwesterly
winds near 10 knots have resulted in high to very high fire
danger.

The high to very high fire danger continues into Wednesday ahead of
a weak surface trough. South to southwest winds will increase midday
Wednesday mainly along and SE of the KS Turnpike with sustained 10-
15 mph and gusts 20-25 mph. Have reduced dew points a few degrees
from guidance Wednesday afternoon, as most guidance is only mixing
BL to ~900mb. Based on NAM and GFS soundings, a well mixed
environment exists above 900mb, therefore think BL will mix beyond
900mb. The lower Td`s have equated to minimum RH values in the mid
to upper 20s Wednesday afternoon. High temperatures are expected to
reach the middle to upper 70s! We are on record watch for Topeka and
Concordia as their record high temperatures for February 22nd are 75
and 76 respectively.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 230 PM CST Tue Feb 21 2017

Surface front will bisect the CWA at the onset of the period on
Wednesday evening and settle over central Kansas overnight. As a
broad shortwave moves across the northern Rockies, a surface low
will develop along this baroclinic zone and eject northeastward
across Kansas late in the week. There remains considerable
disagreement amongst the 12Z deterministic guidance with respect to
the timing of the low`s passage, but there remains less variability
in the track of the cyclone through Kansas. This projected track
would take the center of the low through the CWA and used a blend of
the GFS/EC in the timing of the low passage. There may be some
elevated showers attendant to the lifting warm front/theta-e
advection on Thursday, but thermodynamic profiles are not terribly
supportive of convection. There may be window of opportunity across
the eastern/northeastern CWA Thursday afternoon and evening for
thunderstorms as the surface low nears and MUCAPE/CINH values are
more favorable.

Winds on Friday behind the departing cyclone will increase to around
15 to 20 kts, with good differential CAA through the boundary layer
steepening low level lapse rates and increasing the potential for
gusts of 30 to 40 kts. Latest trends also are pushing the potential
for snow north of the CWA and have removed mention of accumulating
snow from the grids and HWO (though kept light snow mentioned in the
wx grids for the far NW CWA). Temperatures for Friday and Saturday
will fall to near "normal" upstream of an approaching ridge. An
omega block over the NE Pacific will facilitate the
reestablishment of a WSW flow pattern for early next week, with
850 temps once again in the +10 to +15 C range by Tuesday and
surface temps returning to the 50s and 60s for highs.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 538 PM CST Tue Feb 21 2017

Expect VFR conditions for the next 24 hour. After 10Z the low-
level jet at about 1500 feet may increase to around 30 KTS which
will produce moderate low-level windshear at the terminals from
10Z through 14Z MON.

&&

.CLIMATE...
Issued at 230 PM CST Mon Feb 20 2017

Record Highest Maximum Temperatures:

...for February 21...

Topeka......76, set in 1977
Concordia...75, set in 1977

...for February 22...

Topeka......74, set in 1995
Concordia...76, set in 1982

&&

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

$$

SHORT TERM...Baerg
LONG TERM...Skow
AVIATION...Gargan
CLIMATE...Skow



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