833 
FXUS63 KTOP 230817
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
317 AM CDT Thu May 23 2019

.SHORT TERM...(Today and tonight)
Issued at 317 AM CDT Thu May 23 2019

Very little on the radar in these early morning hours of 
Thursday, as surface high pressure over northwest has left 
northeasterly winds across much of Kansas and into northern 
Oklahoma and the panhandles. Much higher instability air and 
convergence along and over this boundary continue to bring strong 
to severe thunderstorms across Southeast Kansas and northeastern 
Oklahoma. A few of these storms may skirt the far southern 
counties before sunrise, but coverage is expected to be sparse. 
Even with clouds on the increase today, highs should still rise 
into the upper 60s north to the middle 70s in the east. 

Upper low over Arizona this morning is progged to lift northward 
into the northern Rockies through Friday morning.  Storms generate 
along the dryline in eastern NM and along the warm front this 
morning and lift into central Kansas by the late afternoon into the 
evening hours, then passing into eastern Kansas by Friday morning. 
PW values in the column still running around 2 inches, and although 
somewhat progressive, enough training along this line of storms to 
warrant the flash flood watch in place for Thursday into Friday 
morning for areas along and west of Manhattan where ground is 
already well saturated.  Although main hazard from linear storms 
would be wind, as winds are slow to back as the convection advances 
eastward, will be a non-zero tornado threat more so across the 
western half of the CWA in the evening hours, before mean flow 
becomes more uniformly southerly.

.LONG TERM...(Friday through Wednesday)
Issued at 317 AM CDT Thu May 23 2019

For Friday through Monday, models show little change in the
synoptic pattern. Southwest flow aloft is progged to continue with
little change in heights. At the surface, models show a weak
inverted trough over the forecast area for Friday and Saturday
that eventually redevelops further west and north for Sunday and
Monday. Meanwhile models show abundant moisture within the warm
sector with PWs remaining near record levels for late May. This is
expected to help generate more than enough instability for
convection. Meanwhile the southwesterly flow is expected to
maintain decent 0-6km shear of 40KT to 50KT for organized storms.
So in general there is a potential for severe storms with heavy 
rainfall each day through the weekend. The main question is how 
will storms trigger since there is only subtle perturbations in 
the model solutions. Additionally convective outflow could impact
where storm development occurs on subsequent days. So mesoscale
forcing will have a big influence on the weather over the next
several days. Because of this have stayed rather close to the
model consensus for POPs as it become difficult to pinpoint one
period with a better chance than another. As for temps, there is
not much change in the airmass so persistence looks to be a good
first guess. The main question with regard to temps will be
whether precip persists long enough to limit warming during the
day or a convective cold pool knocks lows down. In general
expected highs to be around 80 or in the lower 80s with lows in
the 60s.

By Tuesday, another upper low is progged to move from the
southwest across the central Rockies. While there remains some
differences in the model solutions, there appears to be a 
consensus for an upper trough axis to pass through the plains and 
help bring a cold front through the forecast area Tuesday night. 
This change in the pattern is forecast to bring a break from the 
POPs for Wednesday as well as slightly cooler temperatures. 

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1123 PM CDT Wed May 22 2019

VFR conditions hold until around sunrise when CIGS should thicken
up across the area. Have delayed the onset for showers and storms
for the morning until between 16-17Z. This seems to be on track
with current storm trends and position of frontal boundaries to
the south of the area as well as recent model guidance. Winds
remain fairly light overall mainly from the east and slowly
veering through the period. As chances for storms increase, then
do expect MVFR conditions to be more common. Storms that do impact
the area should become more widespread by late afternoon into the
evening hours as the cold front advances east into the area.  

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 10 AM CDT this morning for KSZ056-058-
059.

Flash Flood Watch from 10 AM CDT this morning through Friday 
morning for KSZ008>010-020>022-034>037.

&&

$$

SHORT TERM...67
LONG TERM...Wolters
AVIATION...Drake