Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
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251 FXUS66 KPDT 042203 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 303 PM PDT Thu Jul 4 2024 .SHORT TERM...An anomalously strong offshore upper-level ridge continues to build and slowly migrate eastward. Heights are rising across the forecast area, and temperatures have warmed in response. In general, temperatures are 5-10 degrees warmer this afternoon relative to yesterday. Expect continued warming of similar magnitude tomorrow afternoon and Saturday afternoon. Heat highlights go into effect tomorrow afternoon as the region will see the onset of a long-duration heat wave. Temperatures in the 90s and lower 100s will be widespread for the lower elevations, and nighttime cooling will be modest. While winds are generally expected to be light and diurnally driven across the region as the ridge builds overhead, two exceptions will be Friday afternoon and evening through the Kittitas Valley, and again Saturday afternoon and evening in portions of central Oregon. Confidence is medium-high (50-70% chance) in Red Flag conditions being met, thus Fire Weather Watches are in effect for fire weather zones WA690 (Friday) and OR610/OR611/OR640 (Saturday). Uncertainty in Red Flag conditions Saturday is due to model differences in the magnitude of winds aloft, and resultant winds that mix to the surface, as a shortwave tracks across the northern Rockies. Plunkett/86 Sunday through Thursday...High pressure ridging will be in firm control of the region through the duration of the long-term forecast period, shifting ever so slowly across with minimal changes to daily conditions outside of overall quantity of heat and thereby HeatRisk. Sunday the high begins just off to our southwest with an upper level northwesterly flow anticipated. The center of the ridge should place itself directly over the inland PacNW by Tuesday, and then by Thursday we should see upper level flow shift to a southwesterly direction. Highs will slowly and steadily increase through the middle of next week, with widespread triple digits for our lower elevations (90-100% confidence) and temperatures nearing 110 for portions of the Columbia Basin (70-90% confidence). The NBM presents the best chances for these 110 temperatures on Tuesday and Wednesday with similar probabilities each day. Our one chance at a cool down may occur on Wednesday into Thursday when a shortwave trough should round the high pressure ridge. This feature isn`t expected to help produce much in the way of significant weather, but should help "temper" our conditions back down into the upper 90`s to low triple digits - a meager cooling trend, but one nonetheless. HeatRisk remains moderate to high through Wednesday, with patches of major HeatRisk on Tuesday. This threat begins to temper by Thursday with the high category retreating as our afternoon highs drop around 5 to 10 degrees and overnight lows start dropping back into the 50s to low 60s. In any case, hope everyone is prepared for the heat, as it doesn`t look like it`s going anywhere anytime soon. Goatley/87 && .AVIATION...18Z TAFs...VFR conditions expected over the next 24 hours with winds generally 10 knots or less and clear skies. Goatley/87 && .PRELIMINARY POINT TEMPS/POPS... PDT 56 95 60 96 / 0 0 0 0 ALW 60 98 63 98 / 0 0 0 0 PSC 61 100 64 101 / 0 0 0 0 YKM 58 100 61 100 / 0 0 0 0 HRI 59 100 62 101 / 0 0 0 0 ELN 59 99 64 99 / 0 0 0 0 RDM 51 97 56 100 / 0 0 0 0 LGD 53 92 57 93 / 0 0 0 0 GCD 52 95 55 97 / 0 0 0 0 DLS 64 104 66 104 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Excessive Heat Warning from noon Friday to 10 PM PDT Thursday for ORZ041-044-507-508-510. Heat Advisory from noon Monday to 10 PM PDT Thursday for ORZ050. Heat Advisory from noon Friday to 10 PM PDT Thursday for ORZ505- 511. Fire Weather Watch from Saturday afternoon through Saturday evening for ORZ610-611-640. WA...Excessive Heat Warning from noon Friday to 10 PM PDT Thursday for WAZ024-026>029-521. Heat Advisory from noon Friday to 10 PM PDT Thursday for WAZ523. Fire Weather Watch from Friday afternoon through Friday evening for WAZ690. && $$ SHORT TERM...86 LONG TERM....87 AVIATION...87