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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

                            
000
FXUS63 KTOP 231113
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
613 AM CDT Sun Jun 23 2019

...AVIATION UPDATE...

.SHORT TERM...(Today and tonight)
Issued at 403 AM CDT Sun Jun 23 2019

09Z water vapor imagery still shows the upper trough over the
central Rockies. An area of low pressure at the surface was noted
over northern OK with an inverted trough stretching north through
the western portions of the forecast area. 

For this morning, showers and thunderstorms should continue to
move east with good moisture still in place over the region and 
at least an MCV lifting over the area. The last several runs of 
the HRRR have shown this idea. The main question is whether storms
redevelop this afternoon as the upper trough moves out from the 
Rockies. The RAP and to a lesser extent the NAM show the low level
moisture recovering with dewpoints warming back into the lower 
70s across east central KS. However the RAP is the only solution 
with much of a signal for widespread storms redeveloping. Most of 
the other CAM guidance would only have isolated activity. Think 
that as long as the upper trough remains to the west, the inverted
trough is unlikely to move east and am inclined to accept the 
RAP/NAM solutions for the airmass to recover this afternoon. So 
have kept some likely POPs in the forecast. Trended QPF amounts up
to near a half inch, but this could easily be to low given the PW
prog of 1.5 to 2 inches. Have also extended the flash flood watch
into the evening thinking there could be one more round of heavy 
rainfall this afternoon. Cloud cover and rain should hold temps in
the mid 70s and lower 80s. By this evening, the upper trough is 
expected to begin moving into the mid MO river valley with the 
surface low lifting northeast into IA. This should push a cold 
front through the area with westerly winds bringing in some dryer 
air. So POPs are forecast to diminish through the evening with 
precip moving east of the area before midnight. 

.LONG TERM...(Monday through Saturday)
Issued at 403 AM CDT Sun Jun 23 2019

Cooler weather is expected on Monday, although good insolation 
should still warm temps into the lower 80s. Lower RH from the 
dryer air will be a nice break from the recent humidity. Models
are in agreement with height rises through next week as an upper
trough develops and amplifies over the northwest. This should
generally prove to be a dry pattern. However 700MB temps never
really warm up so much to completely rule out convection and there
are some indications of a weak wave rounding the ridge or getting
trapped within the upper ridge that could aid in thunderstorms 
popping up. The one period that there is some consensus for this
is Tuesday night, so there are some small chance POPs in the
forecast. Otherwise most of these features have been some what
transient and lowers confidence in their predictability. For this
reason have a dry forecast after Tuesday night thinking chances 
right now are less than 20 percent. Temps should trend warmer by 
Tuesday. For Wednesday through Saturday there is not a great deal 
of change in airmass progged by the models. So the forecast is 
somewhat persistent with highs around 90 and lows around 70 for 
Tuesday through Saturday. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 613 AM CDT Sun Jun 23 2019

Biggest uncertainty is what the coverage of TS will be like this
afternoon and early evening. Conceptually there are a lot of
positive factors for at least a broken line of storms to 
redevelop along the boundary. But a lot of the CAMs continue to 
show mainly isolated storms. Will lean more towards the RAP idea 
storms for now and include a tempo for the most likely window for 
storms. The other question in the forecast is the MVFR CIGS. The 
NAM especially wants to hold onto the low clouds well into the 
night. Think with reasonable dry air advection overnight that 
chances are the NAM is overdoing the low level RH. 

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through this evening for KSZ010>012-022>024-
026-035>040-054>056-058-059.

&&

$$

SHORT TERM...Wolters
LONG TERM...Wolters
AVIATION...Wolters