Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
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111 FXUS66 KPDT 022343 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 450 PM PDT Tue Jul 2 2024 Updated Aviation Discussion .SHORT TERM...Tonight through Thursday...Forecast area continues to be under a dry northwest flow with a ridge of high pressure off the coast and an upper level trough over the central USA. Some locally breezy conditions (15-25 mph) will occur along portions of the east slopes of the Cascades through the evening before decreasing overnight. Overall pattern and conditions remain fairly constant through Wednesday indicating persistent conditions for temperatures and winds. Main changes begin to take place on Thursday as the ridge of high pressure over the eastern Pacific begins pushing into the Pacific Northwest. This will be the beginning of a long hot dry period that will persist into next week. High temperatures will climb into the lower to mid 90s across the lower elevations with pleasant 80s in the mountains. Skies will be generally clear through the day providing easy viewing of evening firework displays. Winds will also be light and generally under 10 mph. Conditions will be dry with afternoon and evening relative humidities down to 10-20 percent with fine grass fuels being extremely dry. All said, be wise in the use of fireworks to avoid sparking fires in the "Land of the Free and the Home of the Brave"! .LONG TERM...Friday through Tuesday...No changes in messaging. Forecast confidence is high (>90%) that we will see the hottest temperatures of the summer so far as strong, persistent ridging moves over the PacNW during the day Friday and sticks around for the foreseeable future. The only thing ensembles really waver on is the exact positioning of the ridge axis, and the extent to which a shortwave on Friday riding the ridge to our northeast modulates the high pressure position at all. This would only serve to delay the inevitable, however, as guidance exhibits a strong signal on the region being enveloped by high pressure by Saturday at the latest, and likely (70-80%) lasting through most of next week. We have issued an Excessive Heat Watch for most of our non-mountain zones starting this Friday and lasting through the middle of next week. NBM probabilistic shows high probabilities (generally 60-80%) in highs eclipsing the century mark starting on Saturday for the majority of our population centers. We`ll have to keep an eye on where this ridge of high pressure ultimately centers itself early next week, as the NBM may be a bit gun-shy on temps should the high fall directly overhead as the deterministic GFS and ECMWF currently suggest. Otherwise, fire weather concerns will be low, as hot temperatures will cause RHs to sink well into the teens, but winds are expected to be weak, outside of the usual cross-Cascade gradient that will only be exacerbated under this heat wave. Still, the forecast looks to be very stagnant: hot, dry, and clear. Stay hydrated! Evans/74 .AVIATION...00z TAFs...Clear skies will continue through Wednesday afternoon. WNW winds 10-20kt gusting to 25-30kt this evening will diminish overnight, and winds on Wednesday will be primarily light and terrain driven with the exception of breezy winds at DLS. Wister/85 && .PRELIMINARY POINT TEMPS/POPS... PDT 55 83 55 90 / 0 0 0 0 ALW 57 86 58 93 / 0 0 0 0 PSC 59 89 59 94 / 0 0 0 0 YKM 55 88 56 92 / 0 0 0 0 HRI 58 88 57 95 / 0 0 0 0 ELN 55 83 55 90 / 0 0 0 0 RDM 46 84 49 92 / 0 0 0 0 LGD 50 79 51 87 / 0 0 0 0 GCD 48 83 50 90 / 0 0 0 0 DLS 56 88 59 97 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Excessive Heat Watch from Friday afternoon through Tuesday evening for ORZ041-044-505-507-508-510-511. WA...Excessive Heat Watch from Friday afternoon through Tuesday evening for WAZ024-026>029-521. && $$ SHORT TERM...91 LONG TERM....74 AVIATION...85