Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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480 FXUS63 KABR 051739 AAB AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1239 PM CDT Fri Jul 5 2024 .KEY MESSAGES... - There is a 30% chance of afternoon and evening, daytime heat driven, showers and thunderstorms today. - The pattern of mainly afternoon and early evening showers and thunderstorms will continue through the weekend, mainly focused over eastern South Dakota into west central Minnesota where there is around a 60% chance of showers and thunderstorms each afternoon. - Expect a gradual warming trend across the region through next week. By the end of the week we should be seeing temperatures above average (5-10 degrees). && .UPDATE... Issued at 1233 PM CDT Fri Jul 5 2024 See the updated aviation discussion below. UPDATE Issued at 1046 AM CDT Fri Jul 5 2024 The only forecast change this morning was to push POPs off until 21Z and after. With no significant synoptic forcing, showers and thunderstorms will be dependent on daytime heating. Hi-res models concur and don`t show any convection until later this afternoon. Other forecast fields look to be on track. && .SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/... Issued at 305 AM CDT Fri Jul 5 2024 The morning surface weather map showed our exiting area of low pressure over southern WI and a large ridge of high pressure across MT and WY. At 500mb the main low was over southern MN with a broad trough set up across the Plains States through the New England states. While brief ridge to northwesterly flow will slide overhead in the afternoon and evening, embedded waves will remain with another trough set up along the MT/ND/WY border by 06Z Saturday. The result will be diurnally driven showers and thunderstorms drifting southeast. CAPE values will jump to around 1000 J/kg this afternoon and evening, lowest over south central SD. While the main focus will be near and east of a line from Aberdeen to Redfield, along with western Corson County, any location could experience a shower or brief thunderstorm this afternoon into the early evening hours. The low chances of precipitation will continue overnight across central SD and expands to the rest of the forecast area during the day Saturday, as the 500mb trough moves overhead. Again, CAPE values will top out near or slightly above 1000 J/kg, highest over southern SD and to our south (NE) where higher shear values and lapse rates exist. There is a SPC Marginal Risk (level 1 of 5) of severe weather over our far southwestern counties mainly Saturday afternoon. && .LONG TERM /SATURDAY EVENING THROUGH THURSDAY/... Issued at 305 AM CDT Fri Jul 5 2024 The general trend in the upper level pattern through the end of next week features a semi-persistent trough across the region, with weak embedded waves. We see one of these weak upper level waves overhead for Saturday evening/overnight across the eastern CWA, a second coming across Sunday and two more Monday night and Tuesday evening, maybe even another later Thursday. With generally weak low level flow, and ample ET/low level humidity, BUFKIT profiles in both the GFS/NAM support a weakly unstable atmosphere with skinny CAPE and weak shear, for mainly diabatically driven showers and weak thunderstorms through at least Monday. We do see evidence for the warm airmass inundating the west to gradually shift east, with warmer air aloft gradually migrating east into the northern Rockies for the latter half of the work week, and potentially reaching the CWA by Friday. As such, for temperatures, anticipate a slow steady warming trend, with fairly good signal for the warming trend in the NBM 25th/75th highs/lows...though by Day 7 the NBM highs/lows are only just then getting to about 5-10F above average. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1233 PM CDT Fri Jul 5 2024 Terminals KABR,KATY,KPIR,KMBG VFR conditions will prevail. The only aviation concern will be daytime heating showers and thunderstorms this afternoon. Any storm that does develop will be isolated in nature making timing and location difficult to forecast. TAFs will be amended as necessary. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Serr SHORT TERM...KF LONG TERM...Connelly AVIATION...Serr