Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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935 FXUS65 KRIW 210657 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1257 AM MDT Sat Sep 21 2024 .KEY MESSAGES... - A cold front is passing through early this morning, with increased northerly wind behind the front through Friday evening east of the Continental Divide down into Sweetwater County. - It will be cooler today behind the cold front and remain cool through Tuesday as another weather system brings a cold front through on Monday. - A dirty ridge will bring back above normal temperatures by the middle part of next week. - Very little precipitation is on the horizon for WY, which will exacerbate drought conditions across the state. && .DISCUSSION... Issued at 1256 AM MDT Sat Sep 21 2024 A loosely coupled upper-low currently located over central CA and a trough in western MT will continue to slide eastward today. The shortwave trough has already passed north of WY this morning and the upper-low will pass to the south tonight, which means most of the area will miss out on any precip chances as the weather systems split the state. Some rain drops may fall across far southeastern Sweetwater/Natrona County tonight as the upper-low passes to the south. A strong cold front is sweeping through the area this morning and will bring much cooler temperatures today into tonight. This cold front is also bringing strong wind to northern portions of the area east of the Continental Divide. A peak wind gust of 62 mph was measured at Buffalo - Johnson County Airport around 11 PM. Windy conditions will push south through this morning with the cold front, but gusts that high are not expected. Gusts of 30 to 50 mph will occur early this morning as this cold front shifts south. Overnight lows tonight will be chilly in the mid to upper 30s for lower elevations east of the Continental Divide. Wouldn`t be surprised if there was frost in low spots Sunday morning. For those who still have a garden it doesn`t look like this will be a freeze event, so impacts should be minimal to vegetation. A brief ridge moves overhead on Sunday in between weather systems, which will allow for temperatures to rebound a bit, back to about seasonal averages for this time of year. Another trough surges down from the northwest very quickly on Monday. Very light precip accumulations are possible (30%) with this weather system as it really won`t have enough time to drop more than a few hundredths of liquid for any location. Model guidance has come into better agreement on the weather pattern for the middle part of the week. Model guidance now shows a substantial ridge developing by Wednesday and remaining in place until, at least, next weekend. This will result in temperatures that are well above normal and no precipitation. With no meaningful precipitation in sight drought conditions will worsen. Also, fire weather season looks like it is trying to hold on a bit longer. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1006 PM MDT Fri Sep 20 2024 Mostly clear skies prevail overnight. Winds will be breezy overnight, with several hours of northerly gusts in the 20 to 30 kt range for many sites, especially those east of the Continental Divide. This wind shift is associated with a cold front pushing south from Canada can already be seen in the northern Bighorn Basin, and will continue to progress southward overnight. Winds remain northerly and northeasterly on Saturday, with KRKS having some notably strong 30 to 35 kt northeasterly gust during the afternoon and evening hours. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Rowe AVIATION...VandenBoogart