825 FXUS66 KPDT 062018 AFDPDTArea Forecast Discussion National Weather Service Pendleton OR 118 PM PDT Sat Sep 6 2025
.DISCUSSION...Our wet, active pattern continues as a parent low spinning off the PacNW coast continues to circulate a series of upper-level waves through the region. For today, this wave shows up very clearly on visible satellite imagery as a cloud shield envelops the northern half of the forecast area while some clearing takes place over central Oregon. Given the moisture and lift supplied by this wave, this will allow another round of storms to fire off this afternoon and evening, sweeping northward into the Basin, as well as riding along the spine of the Cascades. Latest CAMs suggest these storms will flare up at around 3-5 PM this afternoon, replacing the ongoing light showers riding up through the Blues, into the Basin and up into the WA Cascades.
Convective parameters suggest that the main limiting factor to these storms is shear, which has been the case over the last several days, however should note that latest CAMs are hinting at a developed line of storms once everything kicks off this evening, capable of strong outflow winds as high as 50 mph, as well as small hail. Confidence in anything severe forming is low (20-30%) given the cloud cover over much of the forecast area stemming from the activity this morning as well as the lack of bulk shear, but would not be surprised if some storms flirt with severe criteria.
Storms are once again expected to be wetting in nature as they have over the last few days. Did issue a Red Flag Warning last night for the central WA Cascades for storms this evening and overnight, as wetting rains may be spottier up there where the fuels are drier. Once we start heading into next work week and this parent low begins pushing onshore, however, wet and cool conditions will dominate, hindering storm development and thus dampening any fire weather concerns. Monday and Tuesday look to be particularly cool and wet, with high temps struggling to climb over the mid 70s across even the lower Basin. Cannot rule out an isolated thunderstorm, especially over the mountains, but the convective threat overall looks to be maximized today, steadily decreasing over successive days. Evans/74
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.AVIATION...18z TAFs (Previous Discussion)...A complex weather setup for today will make for variable conditions, varying from lingering area smoke/haze, to another round of showers and thunderstorms on top of what has already occurred this morning. This morning`s round of showers is starting to peter out but may still inflict brief MVFR conditions for mainly PSC, PDT, RDM, and BDN. Then, once some clearing takes place this afternoon, weather models suggest another round of showers and thunderstorms developing across central Oregon and spreading northward.
Due to the scattered nature of these showers and storms, confidence is only moderate (40-50%) on any one site receiving anything, but best odds look to be in DLS and YKM for at least this evening for thunderstorms in particular, with showers elsewhere. Winds will remain light and mostly terrian-driven, however outflow winds from storms may make for brief gusty conditions. Evans/74
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.PRELIMINARY POINT TEMPS/POPS... PDT 61 86 58 81 / 30 40 20 30 ALW 66 87 62 83 / 20 40 30 20 PSC 61 89 58 84 / 10 20 10 10 YKM 63 87 56 82 / 30 40 10 20 HRI 63 88 60 83 / 20 30 10 30 ELN 59 82 54 81 / 30 50 20 20 RDM 50 79 50 74 / 40 40 10 60 LGD 56 84 52 83 / 40 50 30 30 GCD 55 83 52 81 / 40 30 10 20 DLS 64 82 61 80 / 40 30 10 50
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.PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...Red Flag Warning until 3 AM PDT Sunday for WAZ690-695.
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SHORT TERM...74 LONG TERM....74 AVIATION...74
NWS PDT Office Area Forecast Discussion