848
FXUS63 KTOP 130854
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
354 AM CDT Tue Aug 13 2013
.SHORT TERM...(Today and Tonight)
Issued at 324 AM CDT TUE AUG 13 2013
A ridge of surface high pressure had worked its way into northern
Kansas early this morning, bringing with it a rather stable
airmass. While yet another short wave trough was moving east across
southern Kansas this morning, thunderstorm activity has been confined
south of the forecast area. Between 2 and 4 AM, the thunderstorm
complex has attempted to make a run to the northeast as it pushed
out weak outflow, and has come close to Dickinson and Morris
counties, but the airmass just seems to increase in stability to the
north and the forecast area has remained dry thus far. Another short
wave trough of interest, well defined in water vapor imagery, was
diving south out of the Dakotas and has aided in development of a
thunderstorm complex over north central Nebraska.
This morning, there is still some small chance for the complex over
southern Kansas to send a few storms into the far southern parts of
the forecast area, and have maintained small chances for
thunderstorms in these areas accordingly. This potential may even
linger into the early afternoon hours as the center of the short
wave passes over eastern Kansas. The activity over Nebraska is
forecast to track generally to the south with the bulk of convection
favored on the western flank where it has greater instability to
work with. This should keep this system west of the forecast area,
but included a slight chance for precip generally near and west of
Highway 81 in case it should clip the area. Temperatures will be
similar to, or even a bit cooler than Monday with highs in the lower
80s. Kept the forecast for tonight dry as the surface high would
seem to maintain a hold on the area with a stable airmass, and the
stronger deep forcing and upper support looks to remain south and
west of the forecast area.
Barjenbruch
.LONG TERM...(Wednesday through Monday)
Issued at 324 AM CDT TUE AUG 13 2013
On Wednesday, expansive area of surface high pressure centered
over the Mississippi Valley begins to shift eastward leaving
another dry and pleasant day for the area. Edged high temperatures
during the afternoon into the lower 80s with weak low level winds
and peaks of sunshine expected by the late afternoon period.
Focus returns to the northwest flow aloft on Thursday as another
wave is progged to deepen as it enters the northern plains and dives
southeast. The recent runs of the NAM, GFS, and ECWMF have varying
timing and intensity differences with the GFS being the most
amplified of the group. Almost all solutions have agreed on slight
chances of sct thunderstorms developing ahead of the trough on
Thursday afternoon over north central KS. Otherwise was not
confident to increase rain chances Thursday evening as the main
piece of energy may center just north or east of the area. Continued
the trend from the afternoon package by assuming increasing cloud
cover could leave highs Thursday near the 80 degree mark. Depending
on timing with the main upper level system could still see some
lingering showers and thunderstorms Friday afternoon especially over
east central and northeast portions of KS. Models are beginning to
trend subsidence filling in behind the wave which would bring dry
conditions over north central areas. Will see if this trend
continues in upcoming days.
Looking at the extended period, the weekend continues to look dry
and pleasantly warm as the upper ridge builds into the plains
region. With the weak flow pattern in place, highs in the low 80s
and lows near 60 degrees still appear to be reasonable. Another
shortwave trough entering over the Pacific Northwest suppresses the
ridge as it shifts into the plains region as we head into Monday.
Continued with a dry forecast at this time as low confidence
exists in timing and how deep the wave is progged to be.
Temperatures will greatly depend on the scenario with highs at
this time trying to rise closer to normal values in the middle 80s
and lows in the 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1116 PM CDT MON AUG 12 2013
High level clouds are currently working into the area which may
limit the fog potential later tonight. There could be breaks in
the cirrus allowing temporary fog development, although not
expecting the visibilities to drop below MVFR. The fog potential
will last until sunrise with VFR conditions expect the rest of the
period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Bowen
AVIATION...Sanders