Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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829 FXUS63 KTOP 191935 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 235 PM CDT Fri Jul 19 2024 .KEY MESSAGES... - Chances for off and on showers and thunderstorms are expected this weekend through Tuesday. - Cooler than average temperatures into early next week, then warming through late week. && .DISCUSSION... Issued at 234 PM CDT Fri Jul 19 2024 As of 19Z, shortwave energy is noted in the SD/NE vicinity in between the ridge still parked over the Four Corners and the upper low circulating over the Hudson Bay. Thunderstorms associated with that shortwave are moving through central NE, and additional clusters of storms are expected to develop in western KS later this evening. It is uncertain whether the storms currently in central and eastern NE will maintain themselves as they approach the area. Only the HRRR brings any of this activity into northern KS. If it does make it by late afternoon or early evening, can`t entirely rule out one of these storms producing gusty winds in north central KS where the inverted-V profile looks more favorable and effective shear approaches 35-40 kts. However, lapse rates and instability overall are far better in western KS. That said, even if any of the storm clusters from out there manage to make it this far east late tonight and overnight, they would be moving into a less favorable environment for severe weather. CAMs have been tracking the strongest storms west of the area with our area more favored to see general thunderstorms as MUCAPE remains under 1000 J/kg and lapse rates are only around 6 deg C/km. Hit or miss showers and thunderstorms are expected through much of the weekend as the upper shortwave develops into a cut-off low and stalls over the Missouri River valley region. Coverage looks scattered throughout Saturday and Sunday and should not be a washout, though most thunderstorms should occur late Saturday afternoon into evening when there may be pockets of MUCAPE of 1000- 1200 J/kg. Shear weakens by this point and looks to remain weak until the system eventually moves away. The probability for any particular location to receive an inch of rain is low, but the HREF 75th percentile does show isolated locations with 1-1.5" by Sunday morning. Based on that, it seems reasonable that any spot that sees thunderstorms could get a quick inch or more of rain. The upper low should start to weaken by Tuesday, keeping chances for scattered showers and storms in the area through Monday and gradually tapering off through Tuesday. The trough then moves east Wednesday, bringing an end to the rain chances. Clouds and rain keep cooler temperatures into early next week with highs in the mid 70s to low 80s. A warming trend is expected Wednesday onward as mid- level heights rise, bringing afternoon temperatures back toward 90 degrees. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1233 PM CDT Fri Jul 19 2024 VFR is forecast through the period. Scattered showers with embedded thunderstorms move into the area overnight with scattered activity remaining in the region through the day Saturday. Have gone with VCSH for now, as there is not enough confidence to narrow the time frame for any embedded thunder near TAF sites. Otherwise, winds remain under 10 kts from the south to southeast. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Picha AVIATION...Picha