Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 181120
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
620 AM CDT Wed Apr 18 2018

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 353 AM CDT Wed Apr 18 2018

Early this morning an upper level trough was located over north
central Nebraska and moving to the east. At the surface an deepening
low pressure was located over Lawrence Kansas at 08Z while a cold
front was moving through the cwa on the back side of the low.
Earlier very high wind gusts up to 66 mph were observed over central
Kansas behind the front as strong winds aloft translated down to the
surface. Nighttime microphysics satellite images showing ongoing
fires across parts of the cwa this morning and the wind shift was
flaring some of them up and showing some that have reignited.

Models early this morning were not handling the winds very well, but
were showing improvement in the latest runs at 06Z. Main concern for
today will be the winds as the pressure gradient remains tight over
eastern Kansas and we mix stronger winds down from aloft through the
mid afternoon hours. Have increased the winds and gusts over
guidance, but speeds preclude the issuance of a wind advisory at
this time. Clouds are expected to move into north central and
northeast Kansas this morning then gradually decrease from southwest
to northeast as the upper system and surface low move off to the
east. Highs today will range from the upper 40s in far northeast
kansas to around 60 in central Kansas. Winds will decrease later
this afternoon and early evening as high pressure builds in and
winds decouple this evening. The lower boundary layer remains mixed
for much of the night however cold temperatures are expected with
readings in the lower 30s for lows.

.LONG TERM...(Thursday through Tuesday)
Issued at 353 AM CDT Wed Apr 18 2018

The main takeaways for the extended period reside with rain chances
for the weekend along with near normal temperatures for the
beginning of next week.

An upper level ridge will build into the central Plains by Thursday,
ahead of the next storm system for the weekend. Surface ridging will
also overspread the central US in-conjunction to the upper ridge.
Light winds and sunny skies should result in a pleasant Thursday
afternoon with highs in the mid to upper 50s. Although minimum RH
percents reach the lower 30s Thursday, fire weather concerns should
remain low given the light wind speeds expected.

The surface ridge will progress eastward allowing southerly surface
flow to overspread the region by Friday. WAA will remain weak
however as moisture trajectories from the Gulf orient towards
western OK/TX. ECMWF/GFS solutions have trended ever so slightly
north with the upper low track. That being said, the bulk of
precipitation looks to remain south and west of the CWA Saturday and
Sunday. Current indication suggest QPF amounts will remain less than
a quarter inch, with the highest amounts south of I-70. Thermal
profiles remain consistent with all precipition falling as liquid
with H85 temperatures well above 0C.  Upper level ridging builds
into the region early next week, ahead of another upper level trough
for midweek. Great disparity exists amongst GFS/ECMWF/Canadian
solutions regarding timing and track of the trough. More seasonable
temperatures are expected next week with high temperatures reaching
the upper 60s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 620 AM CDT Wed Apr 18 2018

Expect MVFR cigs to move into the terminals in the 13Z-14Z time
period then become VFR again in the 16Z-18Z time frame. Northwest
winds around 20 kts with gusts to 30+ kts will be common through
00Z then decrease to around 10 kts before falling below 10 kts
after 03Z Thursday.

&&

.FIRE WEATHER...
Issued at 353 AM CDT Wed Apr 18 2018

Gusty northwest winds of 20 to 25 mph with gusts to around 40 mph
are expected into mid afternoon before decreasing. Minimum relative
humidity is expected to range from 31 to 49 percent, with the lower
readings from Belleville to topeka and Ottawa southward. Very high
fire danger is forecast today for much of the area except the far
northeast corner of northeast Kansas.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...53
LONG TERM...Baerg
AVIATION...53
FIRE WEATHER...53



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