Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
653 FXUS65 KBOI 131606 AFDBOI Area Forecast Discussion National Weather Service Boise ID 1006 AM MDT Thu Jun 13 2024 .DISCUSSION...Models continue to indicate marginal threat (less than 20 percent chance) of thunderstorms south of Twin Falls late this afternoon and evening. Otherwise, southwest flow aloft will provide the region with dry conditions and above-normal temperatures today. No updates. && .AVIATION...VFR and mostly clear, except for smoke layers aloft south of KBOI and KMUO. Surface winds: variable less than 10 kt. Winds aloft at 10kft MSL: SW 10-20 kt. KBOI...VFR under mostly clear skies. Surface winds: variable mainly NW less than 10 kt. Weekend Outlook...VFR. Increasing clouds and cooler with breezy NW winds (gusts 15-30 kt), especially Saturday afternoon. Low confidence (less than 30 chance) of showers in SE Oregon and the West Central ID Mountains Sunday night. && .PREV DISCUSSION... SHORT TERM...Today through Saturday night...Southwest flow aloft will advect warm air into the region today, leading to highs 5 to 10 degrees warmer than Wednesday. Models continue to indicate a slight chance of showers and thunderstorms in and near Twin Falls County from late this afternoon into the overnight hours, and SPC has now added this area to the "general thunder" depicted on their Day 1 outlook. Otherwise, we expect the remainder of the area to be dry through the short term. A large upper level low in the Gulf of Alaska will move southeast, and in response 500 mb heights will fall, resulting in cooler temperatures. Friday should be 5-10 degrees cooler than today, and then Saturday will be another 10-15 degrees cooler. Confidence is high in a cool Saturday, with a less than 30% chance of reaching 80 degrees anywhere in the CWA. Two relatively weak cold fronts will cross the area during this time, one Thu night and another Fri night. Each will briefly increase NW winds. Finally, a fire created a smoke plume south of the Owyhees Wed afternoon. This fire is expected to do so again today, but most likely to a lesser degree owing to weaker winds in that area. LONG TERM...Sunday through Thursday...The large low centered in the Gulf of Alaska in the short term will move southeast into the PacNW Sunday night, potentially spreading showers into the area. As the low continues to move SE, models diverge on timing and exact location. Some bring it overhead Monday while others keep it slightly north and have it passing by Monday night. This difference is critical in determining how far south precipitation may be seen. At this time, ensembles are split rather evenly, but the EC members favor a more southern track, and this latest forecast has increased the chance of precipitation over most of the area Monday and Tuesday. This southern track would also lower temperatures 10-20 degrees below normal. Very few locations in the lower elevations are forecast to reach 70 Monday, with highs in the mid 60s expected in the western Magic Valley and all but the lowest parts of the Treasure Valley. Temperatures will gradually warm back up to near normal Tuesday through Thursday, and there is a slight chance of showers in the northern mountains Wed/Thu. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...BW AVIATION.....BW SHORT TERM...SP LONG TERM....SP