Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
958 FXUS65 KBOI 212054 AFDBOI Area Forecast Discussion National Weather Service Boise ID 254 PM MDT Tue May 21 2024 .SHORT TERM...Tonight through Thursday night...A strong upper level system will move towards and then through the area tonight and Wednesday. This will bring plenty of precipitation along with a cold front. There is also a chance of thunderstorms behind the front beginning Wed morning and lasting through the afternoon. The front will enter our Oregon zones early Wed morning, move through the Boise area around noon, and make it through the western Magic Valley around 6 PM MDT. Showers will occur both ahead of and behind the front, from this evening through tomorrow. Precipitation totals are expected to range from 0.01 to 0.30 in lower elevations, up to 1 to 1.5 inches in higher elevations. Snow levels will start out around 7000 ft MSL, and fall to 4500-6000 by late Wed afternoon. With snow showers lingering in the mountains into Thu night, total snowfall above around 7000 ft MSL will range from 6-12 inches, with the highest totals above 8000 ft. Temperatures Wednesday will be 15-20 degrees below normal, and it will be breezy (gusts 30-40 mph), especially over southeast Oregon and in/near the Treasure and Magic Valleys. However, at this time, it does not appear as if a wind advisory is warranted. Thursday will be breezy in the western Magic Valley, with gusts to 25-35 mph, and temperatures will be 10-15 degrees below normal. We will dry out Thursday night as NW flow behind the departing system backs to zonal. .LONG TERM...Friday through Tuesday...A weak short wave trough will move through Friday, spreading clouds across the area, but very little if any precipitation. A stronger system will move in Saturday. Details on the exact path of this system are not clear yet, but our best bet is the center will pass by to our north. This would give us a good cold front along with showers mainly in the higher elevations of the northern part of the CWA. Snow levels are forecast to range from 6-7000 ft MSL. Upper level ridging is expected to build into the area late Sunday night and Monday, bringing dry and warmer conditions. Tuesday, we may get a passing glance from another upper level trough, but uncertainty is high. After climbing a few degrees above normal Monday, temps might be 10 degrees above normal by Tuesday. && .AVIATION...VFR through evening under increasing and lowering clouds. A cold front will bring numerous showers to SE Oregon after Wed/03Z in E Oregon, and after Wed/06Z in SW Idaho creating low-VFR and local MVFR in valleys. Areas of IFR/LIFR in mountains obscuring higher terrain. Snow levels 6500-7500 ft MSL through Wednesday morning, lowering to 4500-5000 after Thur/00Z. Thunderstorms are possible on Wednesday. Surface winds: SW to NW 5-15 kt local gusts to 25 kt east KMUO through Wed/00Z. Widespread gusty winds to 30 kt with cold frontal passage and continuing through Wednesday. Winds aloft at 10k ft MSL: W-SW 10-20 kt. KBOI...VFR. Rain beginning Wed/09-11Z with MVFR ceilings. Winds: NW shifting to SE around sunset. Frontal passage tonight will switch winds to NW with gusts up to 20 to 30 kt. && .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 SHORT TERM...SP LONG TERM....SP AVIATION.....DG