Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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

000
FXUS63 KTOP 010815
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
315 AM CDT SAT OCT 1 2016

.SHORT TERM...(Today and tonight)
Issued at 315 AM CDT Sat Oct 1 2016

Main questions through tonight are cloud and fog trends. Upper low
in the Ohio Valley has moved little in recent hours and taking a
more north-northeast turn per water vapor imagery. Cirrus has been
more prevalent than anticipated with RAP 1.5 PV analysis indicating
a weak disturbance moving east across western Kansas likely one
factor for this cloud. Stratus was nearing the northeastern corner
of the state from the east though with the high cloud being somewhat
persistent, there is little evidence of anything more than patchy
and shallow ground fog so far this morning. Latest upstream low-
level VAD winds showing winds near the surface backing from
northeast to north.

Pattern changes little today and tonight with very weak low level
flow and Ohio Valley system nudging northeast. Stratus may push into
northeastern areas early this morning, and increased moisture will
liekly lead to a diurnal cumulus field here in the late morning and
afternoon, but anticipate slow clearing of the cirrus as the PV
anomaly pushes on southeast across the state. As for fog, will opt
to keep a patchy mention nearer the deeper moisture and less
persistent cirrus this morning, but a widespread dense event is
becoming increasingly unlikely. Could see some of the lower cumulus
linger into the evening and am not confident enough in fog for
inclusion tonight as the airmass continues to modify. Weak
isentropic upglide around 700mb/305K ensues late tonight in central
Kansas but very limited moisture quality as this level should keep
any measurable precip in check. Have highs for all but northeastern
areas a bit warmer but cloud trends will of course need to be
watched watched. Lows tonight should again in the upper 40s to lower
50s.

.LONG TERM...(Sunday through Friday)
Issued at 315 AM CDT Sat Oct 1 2016

Sunday a mid and upper level ridge will build across the Plains as
an upper level trough moves off the Eastern Pacific and into the
western CONUS and the upper level low in the Ohio Valley moves
eastward. Soundings show mixing down from around 850 mb on Sunday
yielding highs in the mid and upper 70s. Negative tilt upper trough
rotates out into the Northern Plains Monday and Tuesday. Southerly
flow will bring moisture northward into the Plains ahead of the
upper trough. Forcing will increase across the Central Plains late
Monday and Tuesday as the as the main upper trough translates
eastward. Showers and thunderstorms are possible Monday night mainly
in north central Kansas then across the rest of the area Tuesday
through Wednesday. Shear and instability will be sufficient for a
few strong to severe storms Tuesday evening in western and central
Kansas and on Wednesday ahead of the cold front. Upper level jet
will provide additional lift with northeast Kansas in the right
entrance region on Wednesday. Morning convection will play a role in
later development across the area both days. The upper trough axis
looks to move east of the cwa by early Thursday which should bring
an end to the precipitation. The GFS and ECMWF differ with timing
and the GFS brings additional energy across Kansas on Thursday which
may linger precipitation through the morning hours or into the
afternoon. A frontal boundary will move through on Wednesday and
will usher in cooler air for the last half of the week. Highs
generally around 80 on Monday will cool off back into the lower 70s
for the end of the week.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1143 PM CDT Fri Sep 30 2016

Prospects for dense fog continue to diminish as cirrus has
overspread the forecast area and nearly calm surface winds make
any moisture advection negligible. So have continue to back off on
VSBY restrictions at TOP and FOE. Stratus over northern MO is
progged by the NAM and GFS to remain mainly east of the MO river
and the RAP appears to initialize the clouds to far west. So in
general think a VFR forecast is likely to persist. Have kept a
tempo for some MVFR VSBY around sunrise in case a break in the
cirrus allows enough radiational cooling for some ground fog.


&&

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

&&

$$

SHORT TERM...65
LONG TERM...53
AVIATION...Wolters



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