Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 260451

Area Forecast Discussion
National Weather Service Topeka KS
1151 PM CDT Sun Jun 25 2017

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday)
Issued at 304 PM CDT Sun Jun 25 2017

As of 20z, a broad upper level trough was positioned across the
upper midwest. The central and northern plains continue to reside
within the mid level northwest flow. Water vapor reveals a subtle
700MB wave traversing the area, contributing to the scattered
showers and thunderstorms across portions of Kansas. As the wave
exits the area this evening, the bulk of showers will push eastward
of the area. At the surface, a cold front was located along Highway
400. As high pressure and dry air advection continues to build in,
the front will continue to be shunted southward. To the north of
the surface boundary, weak isentropic lift will remain over the
southern counties and may contribute to a few rain showers through
the overnight hours.

Shower and thunderstorm chances will once again increase by
midday on Monday. A secondary embedded wave within the northwest
flow will traverse the central and northern plains, sparking
showers and thunderstorms along a secondary weak surface boundary.
Modest mid level lapse rates (5-6 C/KM) and dew points in the
upper 50s to near 60 will contribute to MUcape between 500 and
1000 J/KG. Effective shear will remain near 30 knots. Due to the
limited instability and shear, the potential for strong to severe
storms appears low. High temperatures tomorrow afternoon will
remain ~10 degrees below normal with highs in the upper 70s.

.LONG TERM...(Monday night through Sunday)
Issued at 304 PM CDT Sun Jun 25 2017

Isolated showers/tstorms may linger into Monday evening but shift
to the west of the area for much of the day on Tuesday, under the
influence of surface high pressure for much of the day. It should
also bring one more day with highs in the low 80s. Southerly winds
return to the boundary layer and the LLJ also returns over the
state Tuesday night, which advects moisture and instability back
into the Central Plains. Strength of the overnight convection
Tuesday night into Wednesday will depend on how much return there
is, and the timing of the northern plains shortwave, but at this
time may see enough instability and shear for some strong storms
in the northern counties.

Front potentially stalls out over eastern Kansas late Wednesday
into early Friday and could remain the focus for repeated rounds
of convection, before the stronger shortwave dislodges it to the
south late Friday. Overall the period is unsettled, with chances
for strong storms, and with potential for repeated rounds of heavy
rainfall. Recent runs of the EC and GFS suggesting front may move
south and west of the area for much of the weekend, but with an
active progressive pattern, timing could certainly change between
now and then.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1151 PM CDT Sun Jun 25 2017

VFR conditions are expected through the period outside of
convection. Some patchy fog is possible through 08Z but clouds
moving back over the terminals will keep it from lowering to mvfr.
Some afternoon tsra is possible after 20Z and have added vcts.




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