Radar — KTFX
Surface Analysis — Western U.S. (North)
Satellite
- wildfire smoke continues to bring hazy skies and air quality degradation through the week.
- hot temperatures persist through the week, with saturday being the hottest day.
- daily chances for showers and thunderstorms continue across southwest and central mt through thursday.
- gusty winds saturday and sunday with the strongest winds along the rocky mountain front will create increased fire weather concerns.
- meteorological overview:
Being on the periphery of the upper-level ridge, southwesterly flow dominates the weather pattern through friday. This pattern entails hot temperatures region wide and daily chances for isolated to scattered showers and thunderstorms for southwest/central through at least thursday. Severe thunderstorm chances remain low wednesday and thursday. However, with a hot and dry surface layer, we can't rule out some gusty winds with showers and thunderstorms. This pattern also continues to advect in wildfire smoke from the pacific northwest, which will keep hazy skies and air quality degradation.
Heading into the weekend, the upper-level ridge begins to breakdown. Increasing southwest flow will help bring in the hottest temperatures of the week the state. The ridge breakdown with a dry cold front passage will bring a relief to the heat for the first part of next week. However, with the ridge breakdown comes gusty to strong winds late saturday into sunday, especially along the rocky mountain front. Combined with low relative humidity, this causes concerns for critical fire weather. This troughing pattern won'tlast too long, as ensembles hint at another ridge building in mid week.
- forecast confidence & scenarios:
Heat this weekend:
There is good confidence in impactful heat settling in saturday. The european model extreme forecast index shows a 0.7 to 0.95 east of the continental divide saturday, meaning it will be unusually hot for this time of year. There remains some model and run to run inconsistency with how hot it will get. Another big question mark is the wildfire smoke and if an increase fire weather behavior across the pacific northwest will produce more smoke and dampen the high temperatures. Regardless, there remains good confidence in impactful heat saturday, especially across north- central mt.
Winds this weekend:
Models still hint at the increasing potential for gusty to strong winds develop along the rocky mountain front and north-central mt late saturday into sunday. Models have been consistently showing a 50-70KT 700mb jet developing along the rocky mountain front and north-central mt plains late saturday night into mid sunday morning. The timing of this jet is not the most ideal for high winds, but good ridgetop stability suggests mountain wave activity will be possible. Another concern is impact on recreation along the rocky mountain front/back country due to falling trees. Right now, there's a 20-60% chance for 55 MPH winds along the immediate northern rocky mountain front foothills. Another concern with winds is increased fire weather behavior saturday and sunday with the combination of critically low relative humidity. -wilson
29/06Z taf period
Regional wildfire smoke will continue to be present across the northern rockies through the 2906/3006 taf period, with predominately low-VFR/VFR conditions expected. The one exception will be the kctb terminal where MVFR conditions are possible between 29/21Z and 30/03Z due smoke spreading northeast from the silvertip fire. Slantwise visibility will be reduced upon ascent and descent across all terminals over the next 24 hours. Otherwise the only other concern will be scattered showers and thunderstorms developing across southwest montana beyond 18Z wednesday and persisting through 03Z thursday. Main impact from these showers and storms will be gusty and erratic winds at the kbzn, keks, and kwys terminals through this timeframe.
For kgtf: light and variable winds will back to the east during the late afternoon hours; increasing thereafter and becoming gusty due to deep, diurnal mixing. The probability of this east wind exceeding a 15KT crosswind is 30% between 30/00Z and 30/04Z. - moldan
Gtf 93 59 95 59 / 0 0 10 30 ctb 89 54 90 55 / 0 0 0 10 hln 93 59 93 59 / 10 10 10 20 bzn 92 56 93 56 / 20 20 10 20 wys 84 46 86 47 / 40 30 10 0 dln 87 53 89 54 / 20 10 20 10 hvr 95 59 98 59 / 0 0 10 20 lwt 90 56 91 57 / 0 20 20 30