067
NZUS99 KBOI 131609
TXTSFD
IDAHO STATE FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
909 AM MST TUE JAN 13 2026
HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE ACROSS IDAHO THROUGH THE
REMAINDER OF THE WEEK AND INTO THE WEEKEND. THIS STABLE PATTERN WILL CONTINUE
TO SUPPORT STRONG TEMPERATURE INVERSIONS, TRAPPING COLD AIR AND POLLUTANTS IN
THE VALLEYS WHILE MOUNTAIN LOCATIONS EXPERIENCE MOSTLY SUNNY SKIES AND MILD
TEMPERATURES. AIR STAGNATION ADVISORIES REMAIN IN EFFECT FOR MANY VALLEY
LOCATIONS ACROSS SOUTHERN AND CENTRAL IDAHO DUE TO THE LACK OF ATMOSPHERIC
MIXING. AREAS OF DENSE FOG AND FREEZING FOG ARE EXPECTED TO REDEVELOP TONIGHT
AND PERSIST INTO THE MORNING HOURS, PARTICULARLY IN THE TREASURE VALLEY AND THE
SNAKE RIVER PLAIN. A WEAK WEATHER DISTURBANCE IS FORECAST TO SLIDE DOWN THE
FRONT SIDE OF THE RIDGE ON THURSDAY, CLIPPING THE EASTERN EDGE OF THE STATE.
THIS SYSTEM MAY BRING INCREASED CLOUD COVER AND A FEW FLURRIES TO THE MOUNTAINS
NEAR THE WYOMING AND MONTANA BORDERS, BUT IT WILL LIKELY BE TOO MOISTURE
STARVED TO PRODUCE SIGNIFICANT PRECIPITATION. THE RIDGE IS EXPECTED TO
STRENGTHEN AGAIN FRIDAY THROUGH SUNDAY, MAINTAINING DRY CONDITIONS AND LIGHT
WINDS STATEWIDE. LONG RANGE MODEL ENSEMBLES HINT AT A POTENTIAL SHIFT IN THE
PATTERN BY THE MIDDLE OF NEXT WEEK, WHICH COULD FINALLY BRING A RETURN OF
UNSETTLED WEATHER TO THE REGION.
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