Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
147 FXUS66 KPDT 081715 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1015 AM PDT Tue Jul 8 2025 Updated Aviation Discussion .AVIATION...18Z TAFs...VFR conditions to prevail through the period. A system approaching the area today will result in isolated to scattered thunderstorms developing over the higher terrain of central and eastern OR. Sites RDM/BDN may be impacted by these storms, so have kept PROB30 groups in their TAFs with gusty and erratic winds. Otherwise, all other sites will remain dry. Winds of 12-20kts with gusts 20-30kts will develop this afternoon at nearly all sites except ALW. Winds will decrease at most sites late in the evening, except site DLS where winds will continue to be 12-17kts with gusts around 25kts. Lawhorn/82 && .PREV DISCUSSION... /issued 1145 PM PDT Mon Jul 7 2025/ .SHORT TERM...Today through Wednesday...Heat and mountain thunderstorms will be the main story of the forecast through the midweek as the PacNW finds itself wedged between a ridge axis to the north and a cutoff low to the south, currently centered off the central California coast. This low will gradually lift up through our forecast area, making for an uptick in winds Tuesday night into Wednesday, as well as a chance for thunderstorms across the mountains of central and eastern Oregon, thus making for elevated fire weather risks. Today will be quiet, with dry and hot conditions prevailing, before temps begin their real surge on Tuesday. A Heat Advisory is in effect on Tuesday for the lower Basin and adjacent valleys, as temperatures are expected to climb to as high as 105 degrees in some areas, namely the WA lower Basin. Temps will fall off as soon as the dry front associated with the upper low moves through Tuesday evening, but this front will also kick off convective activity across central Oregon around the same time, gradually spreading northeastward heading into Wednesday. Have upgraded the Fire Weather Watch for our central Oregon zones into a Red Flag Warning as a result, as CAMs continue to consistently pick up on the thunderstorm threat for the area. Also included OR696 in the RFW as well, since CAMs seem to be trending storm activity more and more northeastward. Lack of QPF coverage across guidance further increases confidence in dry thunderstorms. Storm activity is not quite as widespread across the eastern mountains Tuesday night into Wednesday, so held off on any fire weather products for those zones, especially given the lack of new fire starts for the area despite the persistent storm activity there over the last week. Concern instead shifts toward the Basin, as winds will pick up as mentioned before with the frontal passage. While RHs will be bone dry on Tuesday, winds don`t really start to pick up until the evening, leaving Wednesday as the main potential critical day. RHs increase with this frontal passage, but models are pretty confident in Wednesday being a blustery day, with widespread gusts up to and over 30 mph. Have issued a Fire Weather Watch for both the OR and WA Basin zones as a result. WA690 in the Kittitas Valley is borderline, but with RHs forecasted to be in the 30s up there, am less confident about fire weather headlines for the zone at this time. Evans/74 .LONG TERM...Thursday through Monday...Ensemble guidance generally points toward a benign pattern after Wednesday. Once the upper-level low lifts out of the region, ensemble clusters generally waver between a light NW flow or zonal pattern, which would yield dry and gradually warming conditions through next weekend. Winds look to be relatively light outside of the Cascade Gaps, which are expected to see their usual breeziness, except for the Kittitas Valley, where a NW flow pattern could perhaps generate stronger gusts. Sensible weather threats are otherwise limited under the synoptic pattern ensemble guidance currently depicts. Evans/74 && .PRELIMINARY POINT TEMPS/POPS... PDT 100 64 90 60 / 0 10 0 0 ALW 100 69 91 63 / 0 10 0 0 PSC 103 65 93 60 / 0 10 0 0 YKM 101 63 90 58 / 0 0 0 0 HRI 102 67 92 62 / 0 10 0 0 ELN 97 65 82 57 / 0 0 10 10 RDM 96 52 87 50 / 20 20 0 0 LGD 97 61 87 57 / 20 20 10 10 GCD 100 56 89 54 / 20 20 20 20 DLS 96 65 83 62 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Fire Weather Watch from Wednesday morning through Wednesday evening for ORZ691. Heat Advisory until 9 PM PDT this evening for ORZ044-507. Red Flag Warning from 2 PM this afternoon to 11 PM PDT this evening for ORZ696-700-705. WA...Fire Weather Watch from Wednesday morning through Wednesday evening for WAZ691. Heat Advisory until 9 PM PDT this evening for WAZ027>029. && $$ SHORT TERM...74 LONG TERM....74 AVIATION...82