Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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654 FXUS65 KCYS 052311 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 511 PM MDT Wed Jun 5 2024 .KEY MESSAGES... - High winds will diminish this evening leading to a tranquil overnight. - Warm weather will continue through late week, with widespread highs in the 80s and lower 90s on Thursday and Friday. - Saturday through Monday will see increasing chances for afternoon and evening showers and weak thunderstorms. The warmest day will be Saturday with slightly cooler temperatures for Sunday and Monday. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 133 PM MDT Wed Jun 5 2024 Generally tranquil weather is expected through the short-term forecast period. Gusty afternoon winds are expected to quickly diminish early this evening after sunset as surface pressure gradients relax over southeast Wyoming. Expect light winds overnight under mainly clear skies - a few isolated high cirrus clouds will drift from northwest to southeast in the broad northwest flow pattern over the high plains. Unseasonably warm weather is again expected on Thursday across the Nebraska Panhandle and southeast Wyoming. Subtle mid-level height rises and lighter wind speeds will help add a few degrees to high temperatures over the higher terrain. Temperatures from I-25 eastward will generally end up similar to today as a lack of stronger downslope flow will help offset the slightly higher heights. Overall, expect temperatures to end up around 15 degrees above average. A few locations in southeast Wyoming such as Cheyenne, Rawlins, and Laramie may end up within 5 degrees of record high temperatures for early June. Expect isolated high clouds to drift from west to east over the region on Thursday night with low temperatures continuing to run around 5-10 degrees above average. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 133 PM MDT Wed Jun 5 2024 Long Range forecast remains on track through the weekend and into early next week. Models continue to show an early summer- like pattern with a brief cool down during the weekend as the upper level flow temporarily transitions to northwesterly flow aloft. For Friday, expect the warmest day of the week as a shortwave ridge axis/700mb thermal ridge quickly translates across the area during the morning. Should be a very warm or a little hot with highs in the mid to upper 80s in most locations, and generally in the low to mid 90s over the lower elevations of western Nebraska and near the Wyoming/Nebraska border. Models do show a surface cold front moving southward out of Montana during the afternoon hours as the upper level flow backs out of the northwest a bit behind the short wave ridge. Winds are forecast to shift into the north and eventually into the east later on Friday...which will result in cooler temperatures. It looks like areas further south near or along I-80 will be slightly warmer compared to areas north of the North Platte River Valley, which may see some of that slightly cooler air earlier in the day from the surface cold front. Should see an increase in convection later in the day, but coverage should be isolated or widely scattered at best, so kept POP in the 20 to 35 percent range for now. Cooler temperatures expected this weekend as the upper level flow becomes more northwesterly on Saturday and Sunday. Surface winds will shift into the east or southeast across most of the area with broad upslope flow in the low levels. Further west, winds will remain out of the west or northwest resulting in convergence near the Laramie Range. Models show a good chance at widespread showers and thunderstorms along and east of the mountains, including far western Nebraska. Kept POP between 60 to 80 percent in these areas with lower values further north towards Douglas and Chadron Nebraska. Models show 700mb temperatures hovering around 10c, so highs in the low to mid 70s are a good bet. However, if cloud cover lingers through most of the day, temperature may struggle to reach 70 degrees. Cloud cover and cooler temperatures aloft on Sunday will result in highs in the upper 60s to lower 70s across most of the area Sunday afternoon. The only exception will be Carbon County, which will be west of the frontal boundary with highs near 80. There is considerable uncertainty with timing and coverage of strong to severe thunderstorms this weekend. At this time, looks like Saturday will have a very low chance due to limited CAPE and cloudy skies as the cooler airmass settles into the Front Range. Sunday looks like more probable day for severe weather based on deterministic guidance. However, ensemble guidance shows the opposite, favoring Saturday afternoon and evening. Will continue to monitor, but both days may end up being marginal days if current trends continue. For early next week, models and ensembles favor a slow warm-up as we head into Tuesday and Wednesday with highs returning to the 80s. There are some diverging model solutions on Monday as another Pacific shortwave pushes across the area, but guidance shows temperatures increasing back above normal with another round of showers and thunderstorms Monday afternoon. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 509 PM MDT Wed Jun 5 2024 VFR conditions expected through the TAF period. Winds will shift to the north and northeasterly across the Panhandle terminals and KCYS. All winds will begin to decrease over the next two hours, becoming calm overnight. Clear skies remain, with only a few mid-level clouds moving across the region. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Warning until 6 PM MDT this evening for WYZ109-110. NE...None. && $$ SHORT TERM...MAC LONG TERM...TJT AVIATION...AM