Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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145 FXUS65 KRIW 240918 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 318 AM MDT Mon Jun 24 2024 .KEY MESSAGES... - Hot and dry weather persists. Highs may near 95-100 degrees in parts of the CWA once again today. - Afternoon showers may create strong gusty outflow winds with little to no rain reaching the surface. - Chances for precipitation and cooler temperatures look to arrive for the second half of the week. && .DISCUSSION... Issued at 317 AM MDT Mon Jun 24 2024 Yesterday saw record breaking heat arrive to the Cowboy State. Highs ranged from the mid to upper 90s east of the Divide and mid to upper 80s west of the Divide. The Bighorn Basin was the hot spot with Greybull hitting 104 degrees breaking its previous of 101 set back in 2007/2001. After doing some digging in the climate data, the high of 104 was actually one of the top 5 highest temperatures recorded in the month of June for Greybull. Unfortunately the heat will remain for one more day before we see slightly cooler temperatures for Tuesday. Today will be a near copy-paste day as yesterday with the only difference being slightly lower highs and stronger winds. The pressure gradient remains confined as our region is sandwiched between a shortwave to the north and an area of high pressure to the south. Similar to yesterday warm advection will aid in producing temperatures nearly 10-20 degrees above normal. Models are showing some of the warmest temperatures in parts of the Wind River Basin with a (30-60%) chance of seeing 95F or higher temperatures. The Bighorn Basin is expected to once again be the hot spot with eastern portions having a (20-50%) chance of nearing or exceeding the century mark. One thing that may limit the extent of the warming is the possibility of afternoon virga showers developing. Some CAM`s have recently shown showers develop in the afternoon but with it being so dry and hot throughout the atmosphere precipitation will struggle to reach the surface. Due to the large difference between dewpoints and temperatures strong gusty outflow winds are possible with any showers. Some CAM`s are showing outflow gusts of 30-40 mph in parts of the southern and central CWA. Elevated to near critical fire weather conditions will continue today and through much of the first half of the week. Winds will increase this afternoon with gusts of 25-35 mph at times. The combination of these winds, above normal temperatures, and low RH values will create concerns regarding fire development. The hot and dry conditions continue through the first half of the week. Winds will likely be the only limiting factor in regards to the degree of fire weather conditions as winds are expected to lighten by Tuesday. Warm temperatures and dry conditions continue through the first half of the week. Temperatures are expected to cool slightly, with highs Tuesday and Wednesday around 5 or so degrees cooler than today. The second half of the week will likely bring some relief to the heat and dry conditions. Recent models have started to show the possibility for some showers starting as early as Wednesday. These showers are a result of a potent trough starting to move into the PACNW. This trough looks to push out the area of high pressure that has brought the hot and dry conditions to the CWA. One thing to monitor over the next few days will be the potential for showers and thunderstorms as the trough moves into the region by the second half of the week. The setup looks very similar to last Friday where much of the CWA saw showers and thunderstorms move through. PWAT values are looking above normal with this system so some areas may get some much needed rain to end the week. Temperatures look to cool slightly with this trough as 700 MB temperatures range from 1-7 degrees Friday into Saturday. Overnight temperatures may be chilly in spots those nights, especially west of the Divide where temperatures may flirt with the mid 30s. Overall, the heat and dry conditions are expected to persist for the next few days. Fortunately, there are multiple chances for precipitation by the second half of the week with a brief cooldown as well. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1045 PM MDT Sun Jun 23 2024 VFR conditions are expected through the period as high pressure persists across the area. Clear skies and light winds will be in place for most locations through 16-18Z. Winds will then increase by this time, with several locations gusting close to 30 kt through the afternoon. Virga showers will again be possible along and east of a KRKS-KLND-KCPR line. Locally higher outflow winds approaching 50 kt could occur with these showers, due to the large temperature/dewpoint spreads. These showers will end by 00Z. Winds will decrease after 01Z, becoming light (11 kt or less) by the end of the TAF period. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Dziewaltowski AVIATION...LaVoie