Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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223 FXUS63 KTOP 112315 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 615 PM CDT Sat May 11 2024 .KEY MESSAGES... - Rain chances increase through the day Sunday into the 85 to 98 percent range Sunday night into Monday morning. Showers may be more hit or miss in the morning and early afternoon hours of Sunday. - Total rainfall is forecasted to range between 0.8 to 1.78 inches - Another system expected to bring chances for showers and storms Wednesday through Friday morning. && .DISCUSSION... Issued at 234 PM CDT Sat May 11 2024 Early this afternoon an upper level trough was located across the southwestern US. A down stream H5 ridge was shifting east across the southern Plains and KS. An upper trough across the eastern Great Lakes was digging southeast into the New England and the Mid Atlantic States. At the surface ea broad surface ridge of high pressure was centered across western AR and extned northward across western MO. Surface winds were light and variable along and just west of the surface ridge axis. Winds were become southerly across north central KS. Tonight through Tuesday: The upper trough across the southwestern US will lift east-northeast across the central Rockies, then east across KS and the southern Plains Sunday night into Monday night. Residual moisture return across the southern and central Plains will result into isentropic lift, that will provide enough ascent for a few to scattered rainshowers to develop across north central KS after sunrise on Sunday. These showers will gradually shift east through the morning hours into northeast and east central KS. Later in the afternoon the DCVA ahead of the upper trough will improve the large scale ascent and richer moisture will begin to advect northward into the Plains. The stronger ascent will cause widespread showers along with scattered thunderstorms to develop in western and central KS and push east into north central late Sunday afternoon, then east across the CWA Sunday night into Monday morning, with the greatest PoPs occurring late Sunday night into Monday morning, with a 85-98 percent chance of rain. MUCAPE is expected to be under 1000 J/KG and effective shear should remain in the 20 to 25 KTS range. Point forecast sounding show any thunderstorms to remain elevated across the CWA Sunday night into Monday morning. The chances for any strong or marginally severe thunderstorms look to be very low. A surface front will pass southward across the CWA late Monday night, as a surface low deepens over south central KS and tracks east- northeast into western MO. by Noon on Monday. The heavier rainfall and thunderstorms should shift east and exit the CWA Monday afternoon, with residual showers rotating around the 850mb low across mainly the eastern half of the CWA. The showers should end early Monday evening as the H5 trough axis shifts east- northeast into the upper Midwest. Total rainfall from Sunday through Tuesday morning will range betweeen 0.8" to 1.8" across the CWA. It should be a gradual moderate rainfall but there could be heavier rainfall with any thunderstorms Sunday night. I don`t expect any flooding, though a few rivers may rise to near flood stage. Highs on Sunday should reach the mid 70s to around 80 degrees before the rain moves in. Monday will be cooler with northeast to north winds, cloud cover, and occasional rain showers. Highs on Monday will only reach the mid 60s to around 70s degrees. Tuesday through Friday: An upper trough will move onshore across the Pacific northwest, then dig southeast across the Great Basin Tuesday afternoon. Tuesday we will see a break in the rain chances with some insolation. Highs will reach the lower to mid 70s. The upper trough across the Great Basin will shift east into the high Plains late Tuesday night. Residual Gulf moisture will advect northward across the Plains. The combination of isentropic lift and ascent from DCVA ahead of the H5 trough axis will cause showers and thunderstorms to develop Tuesday morning. The scattered to numerous showers and thunderstorms will continue into Saturday, as the lead H5 trough amplifies across the Plains and a secondary H5 trough digs southeast into the Plains from the Pacific northwest. It is too early to forecast any strong to severe thunderstorms on Friday into Friday evening. The effective shear increases but the MLCAPE remains below 1000 J/kg the LREF ensemble cluster mean. Saturday: The upper air pattern transitions to a zonal flow pattern across the northern and central Plains. A southern stream cut off low remains stationary across the eastern Pacific, off the Baja CA coast. there may be a few morning showers and thunderstorms during Saturday morning but the afternoon hours look dry and temperatures will warm into the lower to mid 80s. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 615 PM CDT Sat May 11 2024 VFR conditions will continue through at least 15Z. Precipitation chances slowly increase in the latter half of the forecast but confidence in timing is only high enough for a PROB30 inclusion at the end of this period. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Gargan AVIATION...Poage