Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
827 FXUS65 KPIH 141945 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 145 PM MDT Fri Jun 14 2024 .SHORT TERM...Tonight and Saturday Noticeable changes are ahead for us in eastern Idaho as a major pattern change is expected to bring wind and cooler temperatures to the area. Afternoon satellite imagery shows not much of the way in cloud cover this afternoon but we are starting to see some scattered CU development across the central mountains. Temperatures this afternoon are warm, in the 80s across many of the lower valleys. Not expecting much in the way of precipitation this evening although a few very isolated thunderstorms up around the Montana Divide and towards Island Park will be possible. As we get into Saturday, we really start to see noticeable change to sensible weather across eastern Idaho. A potent U/L trough will move into the Pacific NW tomorrow causing the pressure gradient to tighten significantly over our area, especially across the Arco Desert where a High Wind Warning has been issued. Expecting a greater than 50% probability here of seeing gusts in excess of 60 mph with winds likely sustained in the 35-40 mph range for a good portion of the day. This looks to be the windiest area but the Lemhi Highlands, Snake River Plain, Lost River Range and Big Lost Highlands look quite breezy as well. A wind advisory was issued for the non-mountainous portions of the areas mentioned above. Precipitation looks to remain north of our area but we`ll see a significant increase in cloud cover compared to previous days as well as much cooler temperatures. Expect highs around 10-15 degrees cooler than Friday which equates to 70s in the lower terrain with 50s and 60s in the mountains. McKaughan .LONG TERM...Sunday through Friday Sunday will be breezy, but no where near what is expected Saturday. Monday and Tuesday still look chilly with rain and mountain snow in the forecast. If anything, the trend is toward bringing less precipitation into southern Idaho. There is still a high likelihood of measurable snow for the central mountains and along the Montana border, but the chances have dropped slightly elsewhere...down to 10-40%. The potential for more than 2" sits at 35-70% for the central mountains and 20-40% for places like Monida Pass and around Island Park. With things trending a bit farther north, temperatures...at least with this run of the Blend of Models is a few degrees warmer. On Tuesday, it has mid 50s to mid 60s for the valleys, and still 30s/40s for the mountains. The weather remains unsettled as weak low pressure sets up across the northwestern U.S., although temperatures quickly rebound by the end of next week. Keyes && .AVIATION... We should remain VFR over the next 24 hours. We MIGHT see a shower or storm in the next 24 hours at DIJ, but chances are too low to even include in the TAF. It looks like a similar situation at SUN tonight and Saturday, although trends continue to shift any potential farther north and west. The main concern will be gusty winds, with even stronger winds tomorrow. Through this evening, look for 10-20kt sustained winds at all TAF sites with higher gusts. Starting not too long after sunrise, looks for 20-30kt sustained winds at PIH, IDA and DIJ...with gusts of 30-45kts possible. Winds at BYI peaks at 15-20kts sustained with gusts of 25- 35kts, and at SUN...10-20kts with locally higher gusts. Keyes && .FIRE WEATHER... A cold front will be pushing through during the late night and morning hours on Fri night/Sat, increasing the wind strongly, but bringing afternoon temperatures down for Sat, and driving up humidity. This front, except for the initial thunderstorms late tonight, does not seem to be packing much moisture and there is no threat seen on Sat or Sat night for thunderstorm activity. There is more cold air to come Sun, Mon, and Tue, when conditions will be wetter and there is a chance of snow at elevations above 6500ft in the northern half of eastern Idaho. Messick && .HYDROLOGY... A flood warning remains in effect for the Teton River at Driggs through Saturday and the Snake River at Heise until further notice. The latter has seen a slight drop in river levels due to reduced releases upstream so it`s possible that river levels drop a bit more over the days ahead. Given the uncertainty though, will continue the flood warning for now and will consult with local emergency managers over the days ahead. McKaughan && .PIH WATCHES/WARNINGS/ADVISORIES... High Wind Warning from 11 AM to 9 PM MDT Saturday for IDZ052. Wind Advisory from 11 AM to 9 PM MDT Saturday for IDZ053-054-067- 068. && $$