Marine Weather and Tide Forecast for Boise City, ID

SHORT TERM /Through Wednesday Night/
Warm today with high temps 10-15 degrees above normal. A strong cold front will pass through eastern Oregon tonight and western Idaho tomorrow morning. Ahead of the cold front, high based showers and thunderstorms are developing in SW Idaho highlands and in Central Idaho Mountains. These storms are capable of producing outflows 40-60 mph in an environment with 1000 J/kg of DCAPE. Also ahead of the front, winds across the area are increasing. In SE Oregon, sustained winds of 20-30 mph and gusts up to 40 mph with dry conditions have prompted the issuance of a Red Flag Warning. Winds in SW Idaho will be slightly lower, 10-20 mph sustained and gusts up to 30 mph outside of thunderstorms. Winds will also kick up blowing dust, locally reducing visibility and air quality. While storms today are high based and dry, tonight and tomorrow behind the front precipitation chances increase and temperatures drop down to near normal. Scattered showers continue over the region through Wednesday, with storm total rainfall amounts around 0.25 inches for much of the area, lower in the Snake Plain and higher over mountains. Thunderstorms are possible each afternoon/evening with gusty winds and heavier rainfall rates.

LONG TERM /Thursday through Monday/
An active weather pattern will continue through most of the long-term period, as the upper low lingering over the Great Basin will continue widespread showers and thunderstorms Thursday through Saturday. Temperatures will mostly hover near or slightly below normal through the end of the week. An upper trough will slowly steer into the northwest region from off the coast of British Columbia over the weekend. There is strong guidance agreement that this larger system will swallow the low over the Great Basin and steer it as a shortwave trough over our area. This pattern will likely continue widespread showers and thunderstorms on Saturday. Sunday will likely see showers/thunderstorms over higher terrain as this merged system moves out, before a broad ridge builds in and returns warmer and drier conditions early next week.

AVIATION /18Z Monday through Tuesday/
Issued 1127 AM MDT MON MAY 25 2026 Generally VFR. Scattered thunderstorms over SW ID and E-central OR this afternoon/evening. Thunderstorms capable of 30-50 kt outflows and blowing dust. Showers increasing across eastern OR early Tue/AM, with ceilings lowering to MVFR near KBKE/KBNO.
Surface winds outside of storms: SE-SW 10-20 kt with afternoon gusts to 15-35 kt, with strongest winds over eastern OR. A cold front tonight will switch winds to W-NW 10-20 kt with gusts 30-40 kt, strongest near KBKE/KONO. Winds aloft at 10kft MSL: S-SW 10-25 kt.

KBOI...VFR. A 30% chance of thunderstorms affecting the terminal this afternoon from 20Z to Tue/00Z. Thunderstorms will be capable of outflows to 30-50 kt, lightning, and blowing dust.
Surface winds outside of storms: SE-S 8-12 kt with gusts up to 20 kt this afternoon, becoming NW 10-15 kt tonight following a cold front.

FIRE WEATHER
Above normal temperatures, minimum RH 10-15%, and gusty winds 30-45 mph have prompted the issuance of a Red Flag Warning in Southeast Oregon this afternoon and evening. A cold front, expected late tonight, will bring gusty pre-frontal southwest winds within the already warm and dry environment. Scattered thunderstorms in southwest Idaho this afternoon and evening will bring lightning and outflow wind gusts as strong as 60 mph.
Morning RH will be substantially higher Wednesday through next Sunday, and there will be a 30-40% chance of wetting rain each day as the main low pressure system aloft remains right over the district.

BOI WATCHES/WARNINGS/ADVISORIES
ID...None.

OR...Red Flag Warning until 8 PM PDT this evening for ORZ670-672.