533 FXUS63 KTOP 122327 AFDTOPArea Forecast Discussion National Weather Service Topeka KS 627 PM CDT Fri Sep 12 2025
.KEY MESSAGES...
- Above normal temperatures are forecast to continue through the weekend and into next week.
- Chances (20-50%) for showers and storms are expected to spread west to east on Sunday.
- There could be another organized chance (30-45%) for precipitation by the middle of next week.
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.DISCUSSION... Issued at 211 PM CDT Fri Sep 12 2025
An upper level ridge axis was over the southern and central plains per the 19Z water vapor imagery and profiler data. An elongated cyclonic flow was noted upstream across the Great Basin and into the Northern Rockies while the stronger flow was moving over the Gulf of Alaska and into western Canada. Surface obs placed a broad area of low pressure over the NEB Panhandle and adjacent areas of CO and SD. Southwesterly surface winds and good mixing were helping temps warm into the lower 90s.
The upper ridge axis is progged to remain over the forecast area through Saturday with general subsidence and warm weather continuing. Forecast soundings maintain some inhibition to a surface parcel through the day Saturday. So with the expected lack of forcing, precip chances should be close to nil. Highs Saturday should be similar to today`s given good insolation. Although models show a little less mixing and some cooling at 925MB suggesting readings may be a degree cooler.
An upper trough axis is still expected to propagate east into the Great Plains by Sunday with shortwave energy lifting through north central KS and into NEB. Initially mid level lapse rates are forecast to be rather modest, but as heights fall and mid levels cool there should be some steepening of lapse rates and MUCAPE around 1000 J/kg where surface heating occurs. Bulk shear becomes marginally stronger across north central KS such that an organized updraft could develop. If everything comes together just right Sunday afternoon or evening, there could be a conditional risk for an isolated severe storm. At this point the risk appears to be to low to begin messaging. The overall trend from the models has been to limit QPF on Sunday. Because of this the NBM has backed off on POPs. Additionally with better chances remaining across north central KS, there may be enough insolation across northeast and east central KS for highs to make it into the lower 90s.
The initial wave is progged to lift north of the forecast area by Monday favoring dry weather and highs returning to the upper 80s and around 90 for most areas. For the later half of next week, models are struggling with the overall pattern and spreads from the ensembles increase. So have stuck with the blend for Tuesday through Friday. Another shortwave mid-week could bring a weak front and precip chances into the area. Temps are forecast to trend slightly cooler through the end of next week, but given the lower predictability from the models there is room for these numbers to move in the coming days.
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.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 622 PM CDT Fri Sep 12 2025
VFR conditions prevail for the 00Z TAF period. Wind and nighttime LLWS are the main hazards in the forecast. A 35 to 40 kt LLJ around 1 kft and slight directional shear within the layer will produce LLWS at sites. Sfc winds increase after sunrise Saturday, reaching 10 to 15 kts during the afternoon hours. Gusts around 20 kts will be possible.
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.TOP WATCHES/WARNINGS/ADVISORIES... None.
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DISCUSSION...Wolters AVIATION...Teefey
NWS TOP Office Area Forecast Discussion