Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
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446 FXUS66 KPDT 061542 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 842 AM PDT Mon May 6 2024 .UPDATE... Current forecast looks reasonable and few changes were made. Just adjusted temperatures where needed. Another round of precipitation is expected, but lower QPF than Sunday`s system. && .PREV DISCUSSION... /issued 445 AM PDT Mon May 6 2024/ AVIATION...12Z TAFs...VFR conditions expected over the next 24 hours. Periods of MVFR or lower may be possible under showers moving across, but these should be brief an not predominant. Cloud decks will range between 5-10k feet. Breezy westerly to southwesterly winds continue through the next 24 hours, with gusts 20-35 knots possible. Goatley/87 PREV DISCUSSION... /issued 302 AM PDT Mon May 6 2024/ SHORT TERM...Today through Wednesday...The upper level low that brought the abundant precipitation to the forecast area has moved into the northern Rockies. The last of the precipitation associated with it is over Wallowa County and will exit into Idaho by sunrise. This leaves the region under a west to northwest flow with another shortwave trough coming onto the coast at this time. This will spread moisture and increase instability across the forecast area this morning leading to increasing shower activity by mid to late morning. Showers will peak in the afternoon and persist into the evening before a decrease overnight. There will also be a 15-25% chance of thunderstorms mainly over the eastern portion of the forecast area into the evening. Existing Winter Weather Advisories will continue for the crest of the Oregon Cascades and higher elevations of the northern Blue Mountains. As mentioned, shower activity will decrease overnight but not end as showers are expected to linger over the mountains which persist through Tuesday. Showers will come to an end Tuesday night as a ridge of high pressure over the eastern Pacific begins building into the region. Breezy to windy conditions are expected again today and persist through Tuesday with some minor decrease in winds overnight. LONG TERM...Thursday through Monday...The long term remains mostly quiet in regards to sensible weather concerns as high pressure ridging brings in notably above normal temperatures, but keeps our region quiet otherwise with clear skies. The overall synoptic pattern remains fairly benign. Thursday starts with high pressure ridging stretching out from the Pacific and over the PacNW and into the Northern Rockies/Southern Canada while a lobe of low pressure cuts off from the main system over the Great Lakes and retrogrades into California and Nevada. Through the weekend this is expected to allow high pressure to eventually encompass the entirety of the West Coast as that low pressure weakens, with a breakdown of this deep ridge sometime late in the weekend or early next week. Analysis of the ensemble clusters shows good agreement in the above synoptic pattern, noting a rise in variance between the major clusters on Sunday as the potential for a breakdown in the ridge begins, with further variance building by Monday. Overall there is high confidence (70-80%) in the synoptic pattern and therefore overall forecast. With the ridge promoting warmer than normal temperatures, Thursday starts off around 4-8 degrees above normal. By Saturday and Sunday, much of the region will be seeing highs around 12-16 degrees above normal. These temperatures will see our lower elevation areas in the widespread 80`s, with some locations even flirting with 90 degrees. The NBM shows a 30-60% chance of highs greater than or equal to 90 for the Columbia Basin and portions of the Yakima Valley on Saturday, with this chance increasing to 40-70% on Sunday, with even a 5-25% creeping into the Foothills of the Blues. Highs drop around 3-5 degrees then by Monday as we see the eventual breakdown of the ridge, but this would still be around 8-12 degrees above normal and still remaining in the high 70`s to mid 80`s. Our first shot of summer looks inevitable, a sign of warmth to come. Goatley/87 && .PRELIMINARY POINT TEMPS/POPS... PDT 55 38 57 36 / 70 60 20 0 ALW 59 41 61 41 / 60 60 20 0 PSC 64 44 66 42 / 20 30 10 0 YKM 61 38 63 37 / 10 20 0 0 HRI 62 42 64 39 / 40 30 10 0 ELN 56 39 57 39 / 10 20 0 0 RDM 51 30 51 28 / 50 40 0 0 LGD 53 36 51 34 / 70 80 40 20 GCD 51 33 48 32 / 80 90 50 20 DLS 58 44 60 42 / 50 40 10 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Winter Weather Advisory until 5 AM PDT Tuesday for ORZ502. Winter Weather Advisory until 11 PM PDT this evening for ORZ509. WA...Winter Weather Advisory until 5 AM PDT Tuesday for WAZ030. && $$ SHORT TERM...77 LONG TERM....87 AVIATION...87