Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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286 FXUS63 KTOP 281131 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 631 AM CDT Sun Apr 28 2024 .KEY MESSAGES... -Scattered storms could develop (30-50% chance) along a front moving across northeast KS today. A few severe storms will be possible in far eastern KS. -After a brief break in precipitation chances on Monday, a very active pattern brings more rounds of rain and possibly severe weather during the workweek. && .DISCUSSION... Issued at 355 AM CDT Sun Apr 28 2024 At 09Z this morning, mid-level low pressure was spinning over southwest Nebraska. A large complex of thunderstorms was ongoing from around Chicago back through northern Missouri, southward through central Texas, along and ahead of where a surface boundary was positioned. Surface low pressure and the associated front will slowly advance eastward across the forecast area today. Ahead of the boundary, sfc heating will contribute to an increase in instability once again today. HREF shows between 1000 and 1500 J/kg of SBCAPE developing by early afternoon. Shear is not as impressive as previous rounds of storms, with various models only showing between about 20-30 kts of bulk shear. Thinking is that there will be enough forcing along the boundary and ahead of the trough axis aloft to generate scattered storms this afternoon, mainly in far eastern sections of the forecast area. A few storms could be capable of small hail and strong winds. However, widespread severe weather is not expected today. The cold front should pass to the east of the area late this evening as high pressure begins to build in. Skies will clear and winds will become light. Given recent rain and wet grounds, could see some fog developing tonight, especially in low lying areas and in river valleys. High pressure will move southeast Monday as the next in a series of mid-level systems digs across the Pacific Northwest. Conditions should stay dry Monday as temps warm into the low 70s. Return flow strengthens on Tuesday as low pressure deepens across KS and brings another cold front toward the area. Moisture advection and ascent as a shortwave approaches will likely lead to more thunderstorms by Tuesday afternoon and evening. A few deterministic models (GFS/NAM) have upwards of 2000 J/kg of MLCAPE and around 40-45 kts deep layer shear by 21Z Tuesday. Thus, more severe weather could occur. An active and progressive pattern will bring additional opportunities for storms through the workweek. On Wednesday, another shortwave trough and a low level WAA pattern could generate another round of wet weather. Once again, some models show sufficient instability and deep layer shear for severe weather. Chances for thunderstorms will linger into Thursday as low pressure and an attendant cold front move across northeast KS. A drier air mass is then expected by the end of the week, providing another possibly brief break in precipitation. Given this active pattern, there are numerous details to sort out with each consecutive round of thunderstorms through the week, so be sure to check back with the forecast for updates/changes. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 622 AM CDT Sun Apr 28 2024 The main forecast challenges are ceilings and whether scattered storms develop and impact airports today. Have kept VCSH in TAFs early this morning with a few lingering showers on radar. Then went with VCTS toward midday when chances for storm development increase along a cold front. The expected scattered coverage of storms leads to lower confidence on whether airports will be impacted, so will amend if needed. Ceilings may fluctuate this morning, but am thinking a period of MVFR is likely for a few hours. South winds shift to the west-northwest this afternoon/evening as the aforementioned from moves through TAF sites. && .TOP WATCHES/WARNINGS/ADVISORIES... Flood Watch until 10 AM CDT this morning for KSZ040-KSZ054- KSZ055-KSZ056-KSZ058-KSZ059. && $$ DISCUSSION...Teefey AVIATION...Teefey