Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 220500

Area Forecast Discussion
National Weather Service Topeka KS
1200 AM CDT Mon May 22 2017

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday)
Issued at 309 PM CDT Sun May 21 2017

Batch of afternoon showers over southwestern Kansas tracking to the
east at this hour, with northeast Kansas currently in the clear.
Highs expected to rise to near 70 through the afternoon with west
northwest winds.

Upper low over the northern US continues to rotate pieces of
shortwave energy around the base and into the Central Plains.
Impulse over southern Kansas looks to stay to the south, with the
next shortwave noted over Northern Nebraska the next in line to aid
in bringing a chance of rain overnight into Monday.  Better moisture
is slow to return around the western periphery of the surface high,
but has a little help from the LLJ overnight, and appears to work in
concert with this next wave enough to generate showers and embedded
thunder to move across the area after midnight and through the early
afternoon hours.  This will hold high temperatures down a few
degrees, with overnight lows around 50 rising to possibly 70 by
later Monday afternoon.  Storms in the morning and early afternoon
are not anticipated to be severe, with CAPE less than 600 j/kg and
15-25kts of bulk shear. If NC Kansas can get a chance to destabilize
later in the afternoon after the first round, its possible
atmosphere could gain additional instability for the stronger front
in the evening.

.LONG TERM...(Monday night through Sunday)
Issued at 309 PM CDT Sun May 21 2017

Primary focus for convection Monday evening into the overnight
relies on the frontal boundary entering north central Kansas by 00Z.
Convergence near the boundary is decent with upwards of 2000 J/KG of
elevated Cape. Effective shear is not particularly strong however
adequate for a few rotating updrafts around 35 kts, becoming a bit
stronger as the upper trough axis dips southward into eastern KS. As
mentioned previously, main determent for severe weather will be the
timing and duration of earlier convection. Residual showers and
thunderstorms are likely to spread southeast overnight into
Tuesday with localized heavy rainfall possible.

Vorticity lobes rotating around the main upper low Tuesday and far
eastern KS Wednesday afternoon may continue to provide light showers
and isolated thunderstorms. Severe weather is not expected during
this period. Temperatures appear well below normal given the precip
and weak, cool advection behind the cool front. Highs in the 60s
with overnight lows in the 40s are likely.

Broad troughing builds over the western CONUS mid week with an
embedded trough ejecting eastward into the CWA Thursday evening. A
few strong thunderstorms are possible with the frontal boundary once
again while dewpoints recover back into the 60s. With the series of
waves coming through Friday into the weekend, models are having
difficulties discerning the optimal precipitation chances. However,
believe it to be a decent bet for thunderstorms in the region Friday
night and Saturday evening somewhere within the region.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1135 PM CDT Sun May 21 2017

For the 06Z forecast period, expect that some potential will exist
for VCTS, so have inserted into the forecast. Timing is still
uncertain and saturation may be slow to occur, so have pushed back
KTOP/KFOE to begin showers or storms around 15Z time frame. LLWS
shouldn`t be a concern, but there could be a short time near the
12Z time frame where some concern exits as the upper wave
encroaches further on the region.




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