Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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689 FXUS65 KRIW 242320 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 520 PM MDT Mon Jun 24 2024 .KEY MESSAGES... - The persistent ridge will keep hot and mostly dry weather around through Thursday. - Slight chances of mostly virga showers across southern portions today (40% chance) and tomorrow (20% chance). Gusty outflow winds continue to be the main concern. - Better chances for showers and thunderstorms looks to come Wednesday and especially Thursday thanks to a shortwave drawing up Gulf moisture into the region. This should also provide a brief reprieve from the heat. - Ridging and above normal temperatures look to return for the weekend. && .DISCUSSION... Issued at 313 PM MDT Mon Jun 24 2024 Similarly to yesterday, some convection exists across Sweetwater County, and as expected, has also developed across southern Natrona County. This convection will continue to move east and should exit the region by 6/7PM. Elsewhere, mostly clear skies are dotted with fair weather, high-based CU. Dewpoint depressions are around 60 degrees, so any convection has the potential to produce strong winds. The ridge continues to keep the oven doors open for us though. Temperatures remain in the middle to upper 90s this afternoon across most areas east of the Divide. Tomorrow will again look very similar to today in terms of temps and RHs. Winds will be lighter and convection will be much more isolated tomorrow, however. When we get into Wednesday, the story begins to shift a bit more to focus on convection and less on the heat. It will still be hot, with 90s widespread east of the Divide, however, we will get through the hottest days yesterday and today and gradually get a degree or two cooler each day through Thursday. Convection will become more intense and widespread Wednesday, and especially Thursday, however. A shortwave begins to push into the PACNW Wednesday, and across northern MT Thursday and Friday. Wednesday and Thursday afternoons, this trough will help to draw Gulf moisture into southern WY. PWATs will be 2 to even 3 STD above normal both days. Wednesday, convection will be generally weak, as the forcing won`t be there, but as the shortwave gets closer Thursday, convective forcing will improve and widespread convection is expected. Locally heavy rain will be the main concern, due to the high PWATs. The shortwave will exit to the northeast on Friday, but will leave us in a cooler, quieter weather pattern in its wake. I say cooler, but this is comparative to the blast furnace temps of the first half of this week. Temps Friday will be in the 70s and low 80s for most (rather than 90s). Saturday will start a warming trend again, but will still be a few degrees below normal. Ridging looks to build back up through the weekend and the above normal temps will quickly return by Sunday. Models do indicate that another shortwave may bring another round of cooler temps to start the next work week, but confidence remains low at this time. Long range outlooks for July favor warmer and drier than normal conditions continuing for the long-term. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 515 PM MDT Mon Jun 24 2024 Most of the convection over portions of Natrona and Sweetwater counties has ended/is ending, so the threat of a severe wind gust is quickly diminishing. However, wind gusts around 30 kt will continue through 03Z across much of the forecast area. Winds will continue to slowly decrease through 06Z, with light winds expected afterward. Gusts around 25 kt will return to most areas Tuesday afternoon, portions of the Bighorn Basin and Johnson County having northerly winds late in the morning through the first half of the afternoon. Thunderstorms will be more isolated across the area Tuesday afternoon, with the best chances occurring again over southern Fremont/Natrona counties and along the WY/MT border. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Hensley AVIATION...LaVoie