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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

                            
000
FXUS63 KTOP 211654 AAA
AFDTOP

Area Forecast Discussion...UPDATED
National Weather Service Topeka KS
1154 AM CDT Wed Aug 21 2019

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 325 AM CDT Wed Aug 21 2019

Two areas of convection were occurring near or in the cwa this 
morning at 0730Z. Thunderstorms were occurring from Herington to 
Emporia to near Osage City in area of 925 thermal advection and 
surface to 925 mb convergence. Main arc of thunderstorms was 
occurring across central and southeast Nebraska into northwest 
Missouri. This was occurring north of the warm front near the 
Nebraska border and in a area of deep moisture convergence and 
within the theta-e axis. Latest mesoanalysis shows precipitable 
water values approaching two inches across eastern Kansas and into 
southern and central Nebraska early this morning. The best 925 mb 
moisture transport was focused into east central Kansas where the 
thunderstorms were producing rainfall rates of at least an inch an 
hour. Expect rainfall to be maximized within the moisture/theta axis 
as described above and where the moisture transport is maximized. 

For today, the main concern will be the thunderstorms moving south 
out of Nebraska and any additional development across east central 
Kansas. Storms moving out of Nebraska will have the potential to 
produce locally strong wind gusts and heavy rainfall. CAMS have not 
been handling the ongoing areas of convection very well and will 
adjust precipitation chances based on short term tends as storm 
scale and mesoscale processes dictate. Overall expect storms to fill 
in across the area today with some dissipation expected late morning 
with storms redeveloping along boundaries in the afternoon and 
evening. Expect storms to focus initially across north central and 
northeast Kansas north of the frontal boundary as the low level jet 
increases this evening. Locally heavy rainfall will again be a 
concern with theta-e axis expected to lay west to east north of I-70 
this evening and then shifting into east central Kansas and Missouri 
overnight as the low level jet veers to the west by 12Z Thursday. 
Potential will also exist for some storms with damaging wind gusts.
Boundary location will dictate where the best potential for 
convection will lie on Thursday. Clouds and precipitation will keep 
temperatures in the 80s for today bringing relief from yesterday's 
heat.

.LONG TERM...(Thursday through Tuesday)
Issued at 325 AM CDT Wed Aug 21 2019

A mid level wave is forecast to move across Kansas and align with 
the area of frontogenesis across east central Kansas Thursday 
evening. Precipitable water values will approach 1.5 to 2 inches 
along and south of I-35 Thursday night. The warm frontal boundary is 
forecast to be southwest the forecast area on Friday and remaining 
west of the area until Sunday when warm advection develops ahead of 
a mid level wave moving across the central Plains. A warm up is 
expected Sunday and Monday with cooling temperatures next Tuesday 
behind a cold front that looks to bisect the cwa. Model differences 
preclude a high confidence forecast for the early part of next week 
at this time. 

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1151 AM CDT Wed Aug 21 2019

VFR conditions will persist however thunderstorms will develop
across the area after 21Z and persist at or around the TAF sites
through much of the night. For now will carry MVFR conds however
there could be periods of IFR conditions after 06Z tonight and
will include once confidence in timing improves.

&&

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

$$

SHORT TERM...53
LONG TERM...53
AVIATION...Omitt