Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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222 FXUS65 KCYS 042054 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 254 PM MDT Thu Jul 4 2024 .KEY MESSAGES... - It will be much cooler across much of the area this afternoon and on Friday. Daytime highs are expected to remain in the 70s for most locations. - Near to slightly below normal temperatures will persist over the next several days, with daily chances for isolated to widely scattered showers and thunderstorms. The threat for strong to severe thunderstorms should remain limited through at least Friday. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 248 PM MDT Thu Jul 4 2024 A quiet weather day for most of the region behind a cold front that swept through the region last night, remains across the area. Surface observations are showing daytime highs in the 60s and 70s for the cwa as of 20Z. GOES-16 satellite imagery is showing a wide swath of fair weather cumulus, and a few isolated rain showers east of the South Laramie Range. Expect this trend to continue with wind gusts 10-20mph through the rest of this afternoon, and a possible stronger wind gust if a weak thunderstorm develops. Quiet conditions should prevail this evening for those that plan to head outdoors for a holiday event or two. One caution is that the flashy fuels are quite dry for areas east of the Laramie Range, so fire spread is possible for those that are the spark for isolated events. Mostly quiet conditions are anticipated for Friday as well. Daytime highs in the 70s for the majority of the cwa is likely, with a few locations along the North Platte River Valley in the NE Panhandle eclipsing the 80 degree mark. There will be a slight chance of rain showers and isolated thunderstorms Friday evening, but it will remain sub-severe. Saturday will be more of the same, with temperatures becoming slightly warmer by the afternoon. Expect daytime highs to be in the mid-70s to mid-80s for most of the cwa, with the exception being in higher terrain. Isolated chances for thunderstorms after 21Z through 3Z for the I-25 corridor and east. We have a Marginal Risk for severe weather on Saturday, so this may need another look in the next 12-24 hours for the potential of large hail and/or strong wind gusts. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Issued at 248 PM MDT Thu Jul 4 2024 The cool weather pattern will gradually break down over the course of next week, with a return to hot weather increasingly likely by the end of the week. Sunday will be another cool day across the area behind the latest in a series of troughs skirting down the eastern edge of the Rockies this week. Longwave ridging continuing over the west coast and troughing over the central US will continue to allow these cool fronts to slip through our area through the weekend. High temperatures look to run about 10-15F cooler than average Sunday with 700-mb temperatures sitting below the 10th percentile in the NAEFS mean and cloud cover lingering along/east of the Laramie range. Frontogenesis running up against the mountains will lead to some morning shower activity followed by another potential round in the afternoon and evening hours. Through the rest of the week, ensemble guidance shows the strong ridge parked over the west coast gradually shifting eastward through the week. Towards the end of the work week, the ensemble mean ridge position is more or less over the Great Basin, which would gradually transition our area to a much hotter pattern. Highs should return to near average values Tuesday before creeping above normal again by Wednesday or Thursday. While models have continually kicked the can down the road with the eastward shift of the ridge over the last week or so, they are pretty universally showing this occurring by mid next week now. Precipitation opportunities during this period will also be pretty limited, but not zero. Some ensemble members are completely dry for nearly a week after 12z Monday, but other members have isolated afternoon convection mainly over the higher terrain. Widespread convective activity looks fairly unlikely though. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1142 AM MDT Thu Jul 4 2024 VFR conditions expected for the forecast period. Breezy NW winds will weaken and shift more northeast around sunset, with normal diurnal winds resuming after midnight. A few showers/weak thunderstorms are possible this afternoon around KCYS and KCDR. Another round is possible between about 04z and 10z, mainly around KBFF. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...BW LONG TERM...MN AVIATION...MN