textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Above normal temperatures into next weekend. Slightly cooler Tuesday and Wednesday but warmer again Thursday through Sunday.

- Isolated afternoon/evening showers and thunderstorms today and Tuesday near the ID/NV border and in south-central Idaho.

- Windy this afternoon and again Tuesday afternoon, especially in the Snake Basin in Idaho, with Tuesday the windier day.

SHORT TERM /Through Wednesday Night/

Issued 211 PM MDT MON MAY 4 2026 At 2 PM MDT convective clouds were forming along and south of the ID/NV border but dry north-northeasterly flow aloft should limit or prevent them from getting any more than a few miles across the border into southern Idaho (Owyhee and Twin Falls Counties). An upper low in California will make closest approach to our CWA this evening then go into the southern Great Basin Tuesday. Tuesday afternoon will have a slightly better (15-25 percent) chance of showers and thunderstorms than this evening in Twin Falls, Jerome, and Camas Counties as a deformation zone passes directly over that area. Wednesday should be drier again. Gusty north or northwest winds 15-25 mph with gusts to 30 mph this afternoon, and 20-30 mph with gusts to 40 mph Tuesday afternoon, will create patchy blowing dust and locally reduced visibility in the Snake Basin and southern Malheur and Harney Counties. Tuesday and Wednesday will also be several degrees cooler than today under northerly flow aloft. Lingering surface wind tonight will raise min temps a few degrees, but Wednesday morning looks 5-10 degrees cooler after winds die down Tuesday evening.

LONG TERM /Thursday through Monday/

Issued 211 PM MDT MON MAY 4 2026 An upper level ridge will continue to build over the Western United States through next week. Warm and dry conditions will continue, with temperatures about 5-15 degrees above normal through next week. A weak shortwave trough will move through the region on Saturday, cooling temperatures off a few degrees and bringing a 20-30% chance of precipitation to high terrain over the region. By Sunday, the ridge will build back in over the region, bringing a return to warm temperatures over 80F in the lower elevation valleys. Currently, the Treasure Valley will see a 30-40% chance of reaching 90F by next Monday afternoon.

AVIATION /00Z Tuesday through Wednesday/

Issued 604 PM MDT MON MAY 4 2026 VFR with with mostly clear skies through Tuesday. Patchy valley smoke in the Boise Mountains. Isolated showers/thunderstorms near the NV border and high terrain of SW ID through this evening. Surface winds: W-NW 10-20 kt with gusts to 25 kt in the afternoon, continuing overnight. Winds aloft at 10k ft MSL: NW- NE 15-30 kt.

KBOI...VFR with some high clouds. Surface winds: NW 8-13 kt with gusts up to 20 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.