Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 231739
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1239 PM CDT Thu Mar 23 2017

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 233 AM CDT Thu Mar 23 2017

Water vapor imagery showing upper ridge in eastern portions of the
region with upper trough sliding east across the Great Basin. Lower
cloud enveloped the area this evening, though much of Oklahoma
clearing out despite rising dewpoints. Latest KEMP observation
confirming KTWX radar imagery of light precip recently developing
where dewpoint depressions were nearing 10F.

Model soundings continue to be consistent in capping inversion
around 8 kft on top of 3-5 kft of saturation where good veering
profiles exist. This keeps precip in drizzle form, with drying
evident to the south of the state end any mention by midday. With
faster clearing anticipated, have raised highs in the mid to upper
70s. A few lower 80s not out of the question but records in the
upper 80s should be safe. Winds will continue to veer at the surface
with mixing depths increasing. Sustained speeds could approach 30
mph with gusts to around 40 mph in best mixing this afternoon and
again this evening as low level jet returns but Advisory levels look
hard to come by per surface pressure gradient. Will keep small
precip chances going for northwestern areas tonight with convection
likely to fire in far western Kansas late this afternoon and
trajectories giving some chance for this to reach the local area,
and with upper trough emerging into the state late in the night.
Breezy south winds and some cloud should keep lows in the mid 50s to
lower 60s.

.LONG TERM...(Friday through Wednesday)
Issued at 233 AM CDT Thu Mar 23 2017

Potential for showers and thunderstorms on Friday morning add to
uncertainty for severe potential with this system. Despite low
instability, morning storms still have considerable wind in the
column and wouldn`t be surprised for strong gusts to mix down with
the morning activity. If this area can get pushed to the east and
allow some clearing/heating for a little better instability to
develop over the eastern counties before the dryline moves into
south central Kansas, then the potential for all modes of severe
weather will increase. At this time, both the GFS and the EC have
the surface low farther to the south, and keep better instability
to the south of the area. If the NAM solution is more on track and
lifts the surface low across the area along I70, then this would
also bump up chances for severe weather. Ample shear is in place
to work with what does develop, so still a bit of a wait and see
for coverage and strength of storms given placement of the low and
northward progress of the instability. Have tracked decreasing
thunder chances west to east through the later evening and
overnight hours. Highs should still reach into the low 70s. Kept
rain chances into Saturday morning and mostly out of our area by
the afternoon save the far eastern counties for precipitation
wrapping around behind the departing low. Highs cool down into the
50s for Saturday.

Remainder of the extended continues to look optimistic for some
rainfall in our area, as another wave moves toward the forecast
area by late Sunday, and another forecast for mid to late week
although timing and strength differences remain. Highs are
forecast near normals in the 60s with overnight lows in the 40s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1236 PM CDT Thu Mar 23 2017

VFR conditions are expected throughout the period. Southerly winds
will remain strong through much of period with sustained near 20
knots and gusts approaching 35 to 40 knots. LLWS is also expected
during the overnight as a 50-60 knot LLJ overspreads the area. A
few showers are possible during the late morning hours at the
Topeka terminals. The best chance for thunderstorms impacting the
terminals looks to hold off until Friday afternoon and evening.

&&

.FIRE WEATHER...
Issued at 1105 AM CDT Thu Mar 23 2017

A Red Flag Warning has been issued for the entire outlook area
through 04Z this evening. With the sunny skies that continue to
persist over much of the area, BL mixing heights have increased,
allowing stronger winds to reach the surface. Minimum RH values
are only expected to reach the middle 30 percent range this
afternoon. However, the combination of dry fuels and southerly
wind gusts in the 35-45 MPH range with result in extreme fire
danger conditions through the evening hours. These dangerous fire
conditions may continue into the overnight as wind gusts are
expected to remain in the 35-45 MPH and possibly stronger. As the
surface low across eastern Colorado continues to deepening this
evening, the surface pressure gradient will continue to increase
to near 8 MB from east to west across the CWA. This tight
pressure gradient in of itself will keep surface winds in the
20-30 MPH range. Short term guidance continues to suggest a LLJ
of 65-75 knots. With the surface winds remaining strong, a weak BL
inversion should not preclude the mechanical mixing of LLJ winds
to the surface.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 11 PM CDT this evening for KSZ008>012-
020>024-026-034>040-054>056-058-059.

&&

$$

SHORT TERM...65
LONG TERM...67
AVIATION...Baerg
FIRE WEATHER...Baerg



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