textproduct: Boise

LONG TERM...Saturday through Wednesday

The jet stream will flow up and over an upper level ridge positioned off of the west coast and then down and around a broad upper level trough over the continental U.S. This pattern will have enough of a northerly component in our area to cool temperatures down to seasonal normals for this time of year. A shortwave trough embedded in the jet stream will ride over the top of the ridge and into the Pacific Northwest on Saturday night and Sunday bringing a 20 to 30 percent chance of precipitation to much of southwestern Idaho and southeastern Oregon. It looks dry behind that shortwave on Monday, but another shortwave will approach the area on Tuesday and Wednesday increasing the chance of precipitation again. Snow levels are expected to generally remain at or above 4000 feet, so any snow accumulations should be limited to the mountains.

AVIATION

VFR in valleys. Areas of MVFR/IFR in mountains due to low ceilings and light precipitation obscuring mountains will continue until around 06Z generally north of a KBKE-KBOI-KSUN line. Ceilings will slowly improve after midnight, but reductions in visibility due to fog in vicinity of KMYL and KBKE are possible from 09Z to around 14Z tomorrow morning. Expect mostly VFR conditions on Thursday across southwestern Idaho and southeastern Oregon. Surface winds: variable 10 kt or less, becoming east to southeast at 10 to 15 kts across the Snake River plain on Thursday. Winds aloft at 10kft MSL: W 20-30 kt.

KBOI...VFR. There is about 10 percent chance of light rain at the airport between 00Z and 06Z with an area of rain passing over the foothills and mountains north of Boise this evening. Dry weather expected on Thursday with surface winds becoming southeasterly at 5 to 10 kts.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None. OR...None.