Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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528 FXUS65 KCYS 171145 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 545 AM MDT Sat Aug 17 2024 .KEY MESSAGES... - Hot temperatures will persist through the weekend with widespread daytime highs in the 90s for areas along and east of I-25. - Daily chances for showers and thunderstorms will exist across the region over the next several days as several shots of monsoonal moisture ride along the western periphery of the upper level ridge. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 355 AM MDT Sat Aug 17 2024 Hot temperatures are expected to persist through the duration of the short term forecast period beneath strong ridging aloft over a large portion of the central CONUS. 700-mb temperatures of +16 to +18 deg C should easily support daytime highs in the 90s over much of the high plains over the next couple of days. Mostly dry today w/ the influence of the thermal ridge and resulting strong capping and very dry boundary layer. This may change by later in the afternoon in response to a surge of monsoonal moisture along the western periphery of the aforementioned ridge. Multiple CAMs suggest the highest PoPs should be confined to the western zones with the greatest coverage after 00z, although storms should not be particularly widespread. Additional disturbances & associated shots of monsoonal moisture may contribute to possible showers & storms on Sunday afternoon and evening as well, but with the hi- res suite suggesting very little coverage in response to the dry boundary layer, have reduced PoPs below consensus guidance. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 355 AM MDT Sat Aug 17 2024 Monday/Tuesday...Atmospheric moisture content remains about the same for Monday, with a decrease on Tuesday. Despite ridging aloft, we still anticipate scattered to numerous showers and scattered thunderstorms on Monday, most numerous near the Colorado state line, with a significant decrease in coverage for Tuesday. Maximum temperatures will be warmer for Tuesday with 700 mb temperatures near 18 Celsius. Wednesday...Although ridging aloft continues, precipitable water values remain nearly the same as Tuesday, ranging from 0.7 to 1.3 inches. Thus, it looks like widely scattered to scattered late day showers and thunderstorms again, most numerous near the Colorado state line and west of a Douglas to Kimball line. 700 mb temperatures remain near 19 Celsius, yielding maximum temperatures from the mid 80s to upper 90s. Thursday...The ridge axis aloft moves further east over the Central Plains states, with an increase in atmospheric moisture for our counties, thus providing more fuel for scattered afternoon and evening showers and thunderstorms, most numerous near the Colorado state line. With more cloud and precipitation coverage, temperatures will be slightly cooler. Friday...Moist southwest flow aloft continues with another round of scattered afternoon and evening showers and thunderstorms, most common near the Colorado state line. Slightly cooler with more cloud cover compared to Thursday. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 540 AM MDT Sat Aug 17 2024 Ridging aloft will continue, while a weather disturbance over Wyoming brings a chance of showers and thunderstorms this evening mainly west of a Douglas to Cheyenne line. Clear skies will prevail into late this afternoon, with scattered to broken clouds from 12000 to 15000 feet developing thereafter. Showers will be in the vicinity of Rawlins and Laramie after 00Z. Winds will gust to 25 knots at the Wyoming terminals from 16Z to 00Z. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...CLH LONG TERM...RUBIN AVIATION...RUBIN