Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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851 FXUS65 KCYS 311951 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 151 PM MDT Fri May 31 2024 .KEY MESSAGES... - Daily chances for isolated to scattered showers and thunderstorms continue through the weekend. A few storms may have the potential to become strong to severe each day. - Warm and dry weather is expected most of next week, aside from an uncertain potential for a cold front which could bring some shower/storm activity on Tuesday or Wednesday. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 150 PM MDT Fri May 31 2024 Surface high pressure located over southwest South Dakota this afternoon creating an easterly surface wind component over the eastern half of the CWA. Stratus this morning east of the Laramie Range has been persistent and slow to break up in southeast low level upslope flow. 1PM temperatures remain quite cool with upper 50s in the Panhandle and southeast Wyoming plains east of the Laramie Range. Cheyenne finally broke out maybe an hour or so ago. Latest SPC Mesoanalyst page showing quite a bit on CIN across the Panhandle into southeast Wyoming in these southeast winds and stratus. Where skies are clearing...current SBCAPE has risen to 500-1000 J/KG across western Laramie County into southern Platte County. Lack of surface heating from the low clouds shows SBCAPE not rising too much through the afternoon with low level CIN returning by 00Z. Given the persistent stratus...do not think we will see much this afternoon convection wise. Another late night show possible as a dry cold front drops into the southeast Wyoming plains as parent upper shortwave tracks across eastern Montana and western SOuth Dakota. HRRR and RAP simulated radar showing convection developing across the northern Nebraska Panhandle towards 06Z tonight that could become strong to severe for a time through 11Z. Really questionable on severe convection Saturday as GFS showing really dry air pushing into the Panhandle. Dryline on the GFS pushes through the Panhandle by 21Z Saturday. So its not matching up well with peak heating. Confidence not high on severe convection Saturday afternoon/evening and the SPC Slight Risk area. Guess it depends on timing of the dryline moving eastward. A slower timing would improve severe convection chances. Later shifts will need to watch the timing of the dryline push. As for Sunday...it all depends on the timing of the dryline push on Saturday. Could see a dry forecast for Sunday...but for now...kept chance PoPs (30-40 percent) for Sunday afternoon. && .LONG TERM /MONDAY THROUGH THURSDAY/... Issued at 150 PM MDT Fri May 31 2024 The long term looks relatively uneventful with mostly dry and mild conditions expected throughout next week. Quasi-zonal flow for the first half of the work week will lead to breezy and windy conditions across much of the CWA. A strong shortwave trough passing just to the north of the CWA on Tuesday will lead to the greatest potential for high winds across the southeast Wyoming wind prones. The GFS has 700 mb wind speeds of 50 to 60 kts, and elevated CAG to CPR 700 mb height gradients. In-house guidance is also pinging the potential for high winds around the wind prones. Cannot rule out some slight precipitation chances with the passage of this shortwave either. Cooler temperatures can also be expected on Tuesday as the shortwave ushers in slightly cooler 700 mb air. By Wednesday, ridging begins to build over western CONUS, leading to a warmer and drier airmass infiltrating the CWA. Temperatures through Friday will gradually increase, with most locations seeing highs in the 80s by Friday. Minimal precipitation chances are expected during this time frame as subsidence keeps conditions dry. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1151 AM MDT Thu May 31 2024 Westerly flow aloft will prevail. Wyoming TAFS...At Rawlins and Laramie, scattered clouds around 10000 feet will occur, otherwise clear skies will prevail. Winds will gust to 27 knots until 01Z, and to 25 knots at Rawlins after 15Z Saturday. At Cheyenne, ceilings near 1500 feet will improve to 5000 to 8000 feet through 12Z, then skies will be clear. Nebraska TAFS...At Chadron and Alliance, ceilings will range from 3500 to 7000 feet through the afternoon, then scattered clouds will be around 7000 feet until 06Z, then fog will reduce visibilities to 2 miles with ceilings near 1500 feet until 15Z, then ceilings will be around 3500 feet. At Scottsbluff and Sidney, ceilings will improve from 2500 feet to 3500 feet early this afternoon, then scattered to broken clouds from 3500 to 5000 feet will occur this evening, before fog reduces visibilities to 2 miles and ceilings to near 1500 feet from 06Z to 15Z, then scattered to broken clouds around 3500 feet will occur. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...GCC LONG TERM...SF AVIATION...RUBIN