Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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330 FXUS65 KRIW 040639 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1239 AM MDT Thu Jul 4 2024 .KEY MESSAGES... - More isolated in nature for rain showers and thunderstorms Thursday afternoon Bighorn Basin and eastern Counties, but severe weather is not expected. - Mainly dry and a warming trend through the long term forecast with increasing fire weather risk the main hazard going forward. && .DISCUSSION... Issued at 1225 AM MDT Thu Jul 4 2024 IR currently depicts the shortwave trough pushing east into the upper Great Plains with northwest flow aloft continuing over the CWA. A couple light rain showers are pushing through Natrona County that will dissipate through the early morning hours with no impacts expected. One last but weaker wave will pass through mid to late afternoon once again with less PVA associated with it. As such, more isolated in nature will be thunderstorm coverage developing off the Absarokas once again (20-30% coverage) push east through the Bighorn Basin and into Natrona County in the evening hours through sunset before dissipating as it loses any instability. Otherwise, unseasonable cooler than average temperatures during the afternoon with some breezy westerly winds developing my early afternoon through sunset. Strongest gusty over 30-35 mph for points across Sweetwater County and into the Green River Basin. Less than 20-30 mph for other areas with most remaining dry throughout. Severe weather is not expected as there is much weaker ingredients than previous day, in which it did not occur as well. Some stronger than synoptic gusts could occur near any storm activity but nothing significant expected. The main story moving forward into the long term forecast will be mainly dry conditions with a warming trend over the weekend and into next week. Higher heights centered near the Sierra Nevadas will continue to build with increasing convergence aloft with ridging extending through the upper Rockies from Friday onward. Some breezy afternoons with Saturday the strongest day with gusts up to 30-40 mph likely due to the strongest gradient occurring. This will bring elevated fire weather risk to the forefront moving forward, and again, Saturday being the day that stands out. With the weaker upper level flow, there is still a small chance for higher terrain storm development associated with air mass type occurrence, but otherwise, dry for most with less than 10 percent chance for this Monday onward. This blocking high will keep a deep low coming out of the GOA to remain well off the West Coast pushing the PFJ well into Canada as well. No significant weather impacts outside of elevated fire weather concerns moving forward. Enjoy the cooler temperatures for the 4th (albeit not as cool as last year), before the heat returns pushing well into the 90s east of the Divide and mid to upper 80s to the west starting Monday onward. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 930 PM MDT Wed Jul 3 2024 Any remaining showers across the area will end by 08Z. Winds will also continue to subside through the rest of the night. West- northwest winds, with gusts around 25 kt, will return to KBPI/KPNA and KRKS by 18Z, while winds will keep a northerly component across areas east of the Divide. Showers and thunderstorms will be possible again across northern portions Thursday afternoon, but coverage may not be as widespread as today. Confidence remains too low to include in any terminal forecast at this time. Winds west of the Divide will begin to subside after 01Z, with light winds across the forecast area 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...Lowe AVIATION...LaVoie