Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 220550
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1150 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.

Wednesday, 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 06Z TAFS through 06Z Wednesday night)
Issued at 1144 PM CST Tue Feb 21 2017

Expect VFR conditions for the next 24 hours. The low-level jet
will increase to 35 to 40 KTS after 10Z as surface winds remain
below 5 KTS...thus there will be low-level wind shear within 2,000
feet above the surface, at the terminals between 10Z and 15Z.

&&

.FIRE WEATHER...
Issued at 629 PM CST Tue Feb 21 2017

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.

&&

.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
FIRE WEATHER...Baerg
CLIMATE...Skow



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