Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 102331
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
531 PM CST Sun Dec 10 2017

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday)
Issued at 347 PM CST Sun Dec 10 2017

As of 20Z Sunday afternoon, stagnant mid-level pattern continues
across the CONUS with a large trough in the eastern US and a
highly amplified ridge in the west. Weak surface trough moved
across the CWA last night, veering surface winds to the northwest.
Winds have remained sustained near 15 MPH with occasional gusts
upwards of 25 MPH. A very dry boundary layer noted by relative
humidity values in the mid to upper teens across portions of
central and north central KS. The combination of dry conditions
and strong wind speeds has resulted in a Red Flag Warning being
issued for areas along and west of a Washington to Manhattan to
Emporia line. Conditions are expected to improve after sunset as
the surface trough pushes eastward, weakening the pressure
gradient. Boundary layer cooling will also increase relative
humidity values. The decreasing winds and mostly clear skies will
yield low temperatures near 30 degrees.

Monday: We then turn our attention to the shortwave trough
currently positioned from central Canada into northern Montana.
Short range solutions bring the mid-level feature and associated
surface trough through the region near dawn Monday morning. As a
result, a strengthening pressure gradient will setup across the
CWA. Northwesterly winds look to remain sustained between 20 and
25 MPH with gusts upwards of 35 MPH. With a very dry boundary
layer remaining in place, another day of fire danger is expected.
At this point, have held off on any headlines as minimum RH values
look to remain in upper 20s to lower 30s percent. Cloud cover is
expected to arrive during the afternoon hours as moisture
associated with the mid-level wave overspreads the area. High
temperatures look to range from the low 50s along the KS/NE
border, where cloud cover overspreads slightly sooner, to the mid
50s in central KS.

.LONG TERM...(Monday night through Sunday)
Issued at 347 PM CST Sun Dec 10 2017

The stubborn mid-level pattern looks to continue through much of
the extended period. A secondary mid-level shortwave looks to
translate down the western periphery of the trough on Wednesday. A
brief cool down is expected Thursday behind the aforementioned
shortwave. Highs look to remain in the 40s Thursday afternoon.
Otherwise, temperatures look to remain in the 50s for much of the
extended period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 517 PM CST Sun Dec 10 2017

With this issuance will go ahead and add a few hours of LLWS for
transition before the boundary layer mixes out in the morning.
Once it does so, winds increase enough for a second bump up in
wind speeds by mid day. Winds should diminish toward the evening
hours.

&&

.FIRE WEATHER...
Issued at 347 PM CST Sun Dec 10 2017

Another day of very high to potentially extreme fire weather
conditions is expected Monday. Minimum relative humidity values
look to reach the upper 20s to lower 30s percent. Northwesterly
winds are expected to be much stronger than today with sustained
winds near 20-25 MPH with gusts upwards of 35 MPH. These
conditions coupled with very dry fuels could yield extreme fire
danger. Have held off on any associated headlines as exact timing
of cloud cover will play a role in high temperatures and resultant
minimum relative humidities.

&&

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

$$

SHORT TERM...Baerg
LONG TERM...Baerg
AVIATION...67
FIRE WEATHER...Baerg



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