textproduct: Boise

KEY MESSAGES

- Weak system will bring showers to area today, but exit region on Tuesday with warm and dry conditions ahead of next cold front.

- Strong cold front on Wednesday afternoon. Snow levels fall to 3500-4500ft with 3 to 6 inches of snow above 6000ft. Windy conditions on Thursday afternoon with a 80% chance of wind gusts greater than 30 mph from Mountain Home to Twin Falls.

- Pattern change to cooler and unsettled northwest flow possible early next week.

SHORT TERM /Through Wednesday Night/

Scattered showers continue into Monday afternoon as a weak system slowly tracks across NV/UT and into WY. Conditions dry out by Monday night. Upper level ridging returns on Tuesday ahead of the next system. Temperatures Tuesday will be the warmest of the period, with low 60s possible across the Snake Basin, or around 5-10 degrees above normal. Surface winds shift to the southeast and become breezy ahead of an approaching trough. A potent cold front moves through the area on Wednesday afternoon, with snow levels falling to 3500-4500 feet by Thursday morning. Snow amounts of 3 to 6 inches possible over the mountains above 6000 feet with this system.

LONG TERM /Thursday through Monday/

Gusty winds will persist come Thursday, with the highest gusts in the Snake River Plain. Thursday afternoon, the chance of 30+ mph gusts are 80% or greater from Mountain Home east towards Twin Falls. Have upped the forecast winds to include gusts of 45-50 mph in the same area described above. While this is where the strongest winds will be seen, it will be breezy area-wide Thursday following the cold frontal passage. Temperatures on Thursday will cool to be at or below normal, before a warming trend establishes itself Friday and beyond.

Northwest flow aloft will dominate throughout the majority of the long-term period, as high pressure builds in over the North Pacific and a low closes off near the Baja Peninsula. While by Saturday the ridging in the North Pacific will extend east over our area, there will be enough moisture transport in the northwesterly flow to support slight chances of precipitation over higher terrain throughout the period; where orographic lift will be the primary driver of any precipitation. Sunday will be the warmest day as a result of the ridging, with temperatures 5-10 degrees above normal. Monday, the ridging over our area will flatten out as the polar jet stream dips down with an embedded shortwave. While details are still fuzzy at 7 days out, this feature will result in a 30-50% chance of precipitation across our northern zones.

AVIATION /12Z Monday through Tuesday/

Scattered showers across the area and areas of fog will result in MVFR-LIFR ceilings and visibilities this morning. Mtns obscured. Precipitation will end after Tue/00z with condition's generally VFR Tue/PM. Areas of fog will redevelop overnight Tue. Snow Levels: 6-7.5 kft MSL. Surface winds: variable up to 8kt, then W-NW 5- 15 kt with gusts to 20 kt Mon afternoon. Winds aloft at 10kft MSL: W-SW 10-20 kt, veering to N Monday afternoon.

KBOI...Periods of rain through Monday afternoon with MVFR conditions. IFR conditions possible (20% chance) Monday morning. Conditions improving to VFR Monday afternoon, although fog may develop overnight Monday. Surface winds: Light and variable, becoming NW 5-15 Monday afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

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