Area Forecast Discussion
Issued by NWS Portland, OR
Issued by NWS Portland, OR
331 FXUS66 KPQR 171704 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 1002 AM PDT Mon Jun 17 2024 Updated public discussion... .SYNOPSIS...One more seasonably cool day across the region as showers continue to taper off behind departing low pressure. Temperatures rebound back to normal on Tuesday, with high pressure then bringing a stretch of hotter weather from Wednesday through Saturday. && .SHORT TERM...Now through Tuesday Night...Showers will continue to taper off across most of the area today as the region settles into drier northwest flow in the wake of the trough. A few showers may linger as long as this evening along the Cascades, with additional model QPF amounts ranging from a tenth to a quarter inch. Temperatures will remain below normal for one more day as 850 mb temps of 2-3 C correspond to highs in the mid to upper 60s in the interior lowlands. Showers will come to an end across the area and temperatures will rebound back to seasonal normals in the low to mid 70s on Tuesday as the influence of the upper trough continues to diminish and 850 mb temps climb to around 8 C by Tuesday afternoon. /CB .LONG TERM...Wednesday through Sunday...A stretch of hotter weather begins on Wednesday as ensemble clusters and deterministic solutions continue to depict a Rex Block type pattern developing over the West Coast with an upper level ridge over western Canada and a trough over California. Ensemble solutions show good agreement on highs in the mid 80s across much of the area on Wednesday afternoon, though low level onshore flow will continue to moderate temperatures along the coast. Temperatures look to peak Thursday into Friday as probabilistic guidance continues to trend slightly higher, now showing a 60-70 percent chance to reach 90 degrees from Portland to Salem on both days and around a 35 percent chance to hit 90 at Eugene on Friday. The upper end of the guidance envelope has also trended upward, as the chance to reach 95 degrees from Portland to Salem has increased to 10-15 percent on Thursday and around 30 percent on Friday. Despite these higher probabilities, a look at individual ensemble members from the GFS, Euro, and Canadian model suites still point to highs ultimately maxing out in the low 90s both Thursday and Friday. That said, the possibility for temperatures to reach as high as the mid 90s later in the week can`t be discounted, particularly for Friday. Guidance then indicates the start of a downward trend on Saturday as temperatures drop back into the 80s, with highs falling off into the 70s by Sunday as ensemble clusters show good agreement on the next trough arriving over the region. There is still uncertainty as to if this feature will be accompanied by any meaningful precipitation, with the latest NBM guidance holding onto a 20-30 percent chance of rain for the northern coastal areas by Sunday. /CB && .AVIATION...An upper level trough over the Pacific NW will slide east of the Cascades this morning bringing northwesterly flow aloft today. Isolated showers expected to continue to decrease as well, with predominately VFR conditions likely by this afternoon. Highest chances for MVFR cigs this morning at the coast (60-80%), while inland terminals have closer to a 20-40% chance of MVFR cigs between 12-18Z today. PDX AND APPROACHES...There is around a 30-40% chance of MVFR cigs developing between 12-18Z this morning. Otherwise, expect predominately VFR conditions through the period. Northwest winds increase to around 6-8 kt this afternoon. /DH && .MARINE...High pressure offshore is expected to persist through the week. Northwest winds 10-15 kt across coastal waters today becoming northerly on Tuesday. North winds begin to increase later Tuesday afternoon as a thermal trough strengthens from northern CA into southern OR. Expect will see periods of winds gusting up to 25 kt through Friday during the late afternoon and evenings. Seas around 4 to 6 feet will generally be wind driven through the week. /DH && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland www.twitter.com/NWSPortland