Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 250439

Area Forecast Discussion
National Weather Service Topeka KS
1139 PM CDT Sat Mar 24 2018

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Sunday)
Issued at 258 PM CDT Sat Mar 24 2018

The upper low center is currently centered over Iowa this afternoon.
The associated low stratus downstream of the wave has resulted in a
blustery, cool afternoon over northeast Kansas. While clouds may
attempt to break towards the Emporia area by late afternoon, the
stratus is expected to fill back in overnight as the system exits
eastward and ridging amplifies across the central plains. Low level
flow veers towards the southwest after midnight as a poignant
shortwave trough deepens over the west coast. A weak embedded vort
max quickly lifts northeast through the mean flow towards central
Kansas by Sunday morning. Forecast soundings have limited moisture
to work with as much of the isentropic ascent is below 875 mb so
confidence is not high for widespread precip to occur through Sunday
morning. We are still not anticipating frozen precip in north
central areas with all high resolution guidance depicting temps in
the middle 30s by the onset. Have a slight chance for drizzle along
and west of highway 75, with chances for scattered showers
increasing during the afternoon and evening hours as lee
cyclogenesis commences to the west as the upper system approaches.
Persistent cloud cover and cool air advection from the east will
limit highs once again to the upper 40s to lower 50s.

.LONG TERM...(Sunday night through Saturday)
Issued at 258 PM CDT Sat Mar 24 2018

Surface trough quickly deepens over the highs plains Sunday night as
a stronger shortwave trough ejects into the central plains. Sfc
dewpoints in the 50s, possibly 60, advects northward towards the
CWA, while a stout 850 mb jet overruns a warm front bisecting the
CWA west to east. Showers are likely with scattered thunderstorms
expected after midnight. Steep midlevel lapse rates with 0-6 km bulk
shear values in excess of 50 kts spell the potential for a few
strong or low end severe storms. Profilers suggest a strong capping
inversion layer throughout the day with convection initializing
above this layer. Main hazards with these storms would be
marginally severe hail and gusty winds. As the cold front tracks
southeast through the CWA Monday afternoon, uncertainty increases as
to if there will be any clearing and the possibility of
destabilizing the capping inversion. Latest sweep of the model
guidance leans more towards a slower trend in precipitation clearing
eastward by late afternoon with the GFS being the more robust and
slower with the front, increasing instability and initiating
convection over the CWA. Most other guidance focuses the stronger,
surface based convection towards southeast Kansas. Will maintain the
chance for thunderstorms during the afternoon and early evening,
however many factors still unclear in the severity and mode of
convection, especially in the late afternoon.

Post frontal showers linger through Tuesday morning before cool and
gusty northwest air filters into the area, dropping temps from the
upper 60s Monday to the lower 50s Tuesday. The elongated, slow
moving shortwave trough is gradually phased with the northern stream
series of waves, bringing additional shower chances Wednesday night
and Thursday. The lack of strong temperature advection should keep
temperatures fairly similar Wednesday onward with highs around 60
and overnight lows in the 30s. Much of the area unfortunately
remains dry through Saturday.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1135 PM CDT Sat Mar 24 2018

MVFR ceilings remain over the area and are expected to continue
through 20-21Z this afternoon. Light rain is expected to develop
this morning and move across northeast Kansas through the
afternoon. Have included VCSH at this point as models vary
considerably on coverage of any precipitation. Ceilings will lift
briefly to VFR during the late afternoon and early evening before
an approaching wave may drop ceilings back down to MVFR at the
very end of the period.




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