Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KTOP 240449
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1149 PM CDT Mon Oct 23 2017

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday)
Issued at 253 PM CDT Mon Oct 23 2017

Mid/upper level low pressure is currently diving southeastward over
south central Canada and the upper Midwest. This will keep the tight
pressure gradient across the region, which is responsible for the
gusty winds today. Some locations are experiencing sustained speeds
near 30 mph and gusts close to 45 mph especially in central KS. The
lowest relative humidity values have remained above 20 percent, but
low enough to cause very high fire danger this afternoon. The loss
of surface heating should allow the boundary layer to begin
decoupling and therefore a decrease in wind speeds. There may be an
occasional gust overnight, but not as high as during the day. There
is not much change in the overall pattern as the mid/upper low digs
over the Midwest, which means that wind speeds will be similar for
tomorrow. Cool air advecting from the north result in the minimum
relative humidity values slightly higher for tomorrow. This means
very high fire danger is the most likely scenario.

.LONG TERM...(Tuesday night through Monday)
Issued at 253 PM CDT Mon Oct 23 2017

Northerly sfc flow begins to back to the southwest into Wednesday as
the Midwest upper low gradually lifts northeast. Another strong
clipper shortwave trough is quick to follow entering the northern
plains by Thursday 00Z. Pressure gradient in the lower levels
tightens in response off the western high plains as the cold front
quickly translates southeast through Wednesday evening. All guidance
is trending towards stronger winds not only during the day Wednesday
but also behind the front as it enters north central Kansas Thursday
morning. Increased winds Thursday afternoon with an average of 20 to
30 mph sustained with gusts 35 to 40 mph, ushering the coldest
airmass we have seen thus far for the weekend. H85 temps are on
average 6-8C below zero Friday afternoon as temps struggle into the
40s. Freeze headlines will likely be needed Friday through Sunday
mornings as well with forecast lows trending in the upper 20s to
lower 30s. Fortunately, ample dry advection with this system will
keep any mention of precip out of the forecast through the extended
period.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1149 PM CDT Mon Oct 23 2017

With surface winds recently backing and weakening, will continue
LLWS. Overnight cold air advection leads to gusts returning
quickly after sunrise and gusts in the 25-35KT range through
around 23Z.

&&

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

$$

SHORT TERM...Sanders
LONG TERM...Prieto
AVIATION...65


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.