Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Graphics & Text | 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
FXUS63 KTOP 200439

National Weather Service Topeka KS
1139 PM CDT MON SEP 19 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM CDT Mon Sep 19 2016

Strong westerlies observed on the water vapor imagery this
afternoon from the northern Plains towards the Midwest regions.
Upper ridge controls the southern half of the CONUS, including
northeast Kansas where sunny skies reside. At the sfc, trough axis
stretches from the Texas panhandles northeast through Iowa and
Wisconsin. Warm southerly air mass ahead of the boundary has
resulted in highs in the upper 80s to lower 90s. Moisture lifting
and pooling near and ahead of the boundary has caused heat indices
to reach from 99 to 102 degrees. These should only last for the
next hour or two as peak heating wanes aft 23Z. For tonight, there
may be a few passing high clouds from thunderstorms dropping south
over central MO, otherwise should be a mostly clear evening. Temps
do not cool much in the upper 60s as winds become light and
variable in the vicinity of the boundary. A decent sfc inversion
with ample low level moisture may form patchy fog towards sunrise,
especially towards far northeast Kansas.

Little changes made for Tuesday afternoon as a sfc high pressure
shifts east, washing out the boundary tomorrow afternoon while
troughing develops over southeast CO. Winds veer to southerly
throughout the CWA reaching 10 to 15 mph in the afternoon. Similar
airmass in place will lead to another afternoon of warm and humid
conditions with readings in the lower 90s. Heat indices once again
hover around 100 degrees.

.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM CDT Mon Sep 19 2016

Precip chances for Tuesday night through Friday appear to be
limited to Wednesday night and possibly into Thursday morning as a
shortwave lifts out from the southern Rockies across the central
plains. Although POPs are only in the 30 to 50 percent range for
Wednesday night for a couple reasons. First the models are not
that excited about moisture. The stronger PVA may actually move
across the region during the day Wednesday. However forecast
soundings show the boundary layer remaining capped through the day
even with highs expected to be around 90 once again. So models
seem to be focusing on the potential for elevated storms Wednesday
night with the potential for some speed convergence with the low
level jet. But forecast soundings show pretty dry low levels with
marginal moisture advection while mid level lapse rates become
closer to the moist adiabat. The GFS/ECMWF in particular keep
some light QPF over northern KS into Thursday morning. By this
time, any large scale forcing has moved off to the northeast.
Second, the models seem to keep any low level convergence to the
west and north of the forecast area for Wednesday and Wednesday
night, keeping any surface boundary from moving into the forecast
area. So there is some signal from the models to maintain a chance
POP but there are also some less than favorable signs for precip.
Temps look to remain above normal through Friday as the thermal
ridge remains over the area with no real cold air advection
progged. Models do show heights and thicknesses diminishing
towards the end of the work week. Because of this have highs
trending cooler for Thursday and Friday, but still in the mid and
upper 80s. Lows should also remain above normal with readings
forecast to be in the lower 70s Wednesday and Thursday and the 60s
for Friday.

For Friday night through Monday, the forecast becomes a little
more uncertain as another cutoff low moves into the inter-mountain
west and towards the plains. There seems to be good agreement in
the models synoptic patterns for energy to move into the Rockies
and then split as the upper low gradually retrogrades to the south
and southwest and energy lifts over the northern plains.
Eventually the models prog another pacific front to move into the
region by the end of the weekend. Overall there is no clear signal
that there will be precip, but with the proximity to the upper
low to the west and the boundary moving in late in the weekend,
will stick close to the model consensus and maintain a chance for
precip. Temps are forecast to trend cooler through the weekend as
much for the anticipated cloud cover and precip chances. The
coolest temps are expected to occur Monday with a high pressure
system building into the plains.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1139 PM CDT Mon Sep 19 2016

VFR conditions are expected through 09Z then some mvfr vsbys which
may for a brief period around sunrise slip down to IFR at TOP.
Winds light northeast to east becoming south after 18Z to around
10 kts from the south.


.TOP Watches/Warnings/Advisories...NONE.



LONG TERM...Wolters
AVIATION...53 is the U.S. government's official web portal to all federal, state and local government web resources and services.