375 FXUS66 KPDT 071514 AFDPDTArea Forecast Discussion National Weather Service Pendleton OR 814 AM PDT Sun Sep 7 2025
.MORNING UPDATE...Scaled back PoPs quite a bit for today, as 12z CAMs are not very bullish at all on showers and storms today. Could still see some isolated activity develop, especially along the mountains of central and eastern Oregon and the central Washington Cascades, but today looks to be much more muted in terms of rain today, especially compared to yesterday. Evans/74
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.PREV DISCUSSION... /issued 1040 PM PDT Sat Sep 6 2025/
UPDATED AVIATION...06Z TAFs...T-storms have fizzled out over central OR and the Gorge. VFR conditions will persist across most of the TAF sites with PSC seeing sub-VFR at 6SM due to HZ with around 30% confidence they could see MVFR at 4-5SM as the HZ thickens through the period. Winds will be light and variable under 10kts except for DLS which will see 10-16kts with gusts to 25 beginning around 18Z. CIGs will be 15-25kft. Bennese/90
PREV DISCUSSION... /issued 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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.PRELIMINARY POINT TEMPS/POPS... PDT 85 58 81 56 / 20 20 40 70 ALW 85 63 83 60 / 20 40 20 70 PSC 88 59 83 58 / 10 10 10 60 YKM 87 57 82 58 / 30 10 20 60 HRI 87 59 82 58 / 10 10 30 60 ELN 82 54 80 53 / 20 20 20 60 RDM 80 51 72 47 / 30 20 80 70 LGD 85 52 82 51 / 40 40 30 60 GCD 84 53 81 51 / 20 20 30 50 DLS 83 61 80 61 / 30 10 50 70
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.PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. &&
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SHORT TERM...74 LONG TERM....74 AVIATION...90
NWS PDT Office Area Forecast Discussion