National Weather Service Area Forecast Discussion for Long Beach, WA USA
000 fxus66 kpqr 221055 afdpqr Area Forecast Discussion National Weather Service Portland, OR oregon 253 am pst sun jan 22 2017 .synopsis...low pressure offshore will slowly drift southward later today through monday. one more band of rain early this morning, then showers. but showers will be decreasing from north to south as the low moves southward. minor threat of showers on monday, but otherwise building high pressure will bring generally dry weather for tue through next weekend. at least we thought. now, a weak front will push into the region later wed and wed night, with a minor threat of rain. but still, temperatures generally near seasonal levels for the coming week. && .short term...today through tuesday...impressive low pressure off the oregon coast this am, with an estimated central pressure around 965 mb. an occluded front connected with this low now over southwestern oregon, and will lift north across the region this am. will see a 2 to 4 hour long duration of rain with the front as it moves across the region this am, then quick transition to showers behind the front. showers will decrease later this afternoon, with mix of sun and clouds, though more clouds than sunshine. will keep some threat of thunderstorms for the coast, and inland areas to south of portland, with the best threat along the coast from lincoln city southward. seems reasonably, as have plenty of lightning strikes off the south oregon coast as of 2 am. normally, would be concerned about strong winds with such a low, but not this time. winds will turn southerly and be gusty for a time behind the front, but strong winds will remain well offshore. pressure gradients stay too southeasterly, which will keep peak wind gusts in the 25 to 30 mph for most areas later this am into early this afternoon, and maybe 40 to 45 mph along the oregon coast. but winds will ease and turn back southeasterly later in the afternoon. also, the low is now starting to drift back to the west-northwest. models have been indicating this would happen, as the low prepares to move southward towards california. offshore pres gradient has strengthened a bit this am, but overall air mass not a cold as would expect. likely due to some mixing that occurred on sat. but with temperatures around freezing, and models soundings still supportive of snow, will maintain winter weather advisory for the columbia river gorge and hood river valley. but best threat of snow will be east of multnomah falls, and likely above 500 feet. in general, would expect up to 2 inches of snow in the columbia gorge, and 2 to 4 inches for the hood river valley. higher up, likely to see 3 to 6 inches of snow on the cascades and higher peaks of the coast range, but no advisory expected. with showers decreasing this afternoon, likely that accumulating snowfall will end by early to mid afternoon. but for now, will keep winter weather advisory up until 6 pm today. on mon, the low will be much farther to the south, and off the calif coast. will keep some minor threat of showers over the region, but trend will be a decreasing shower threat on mon. dry mon night into tue, with some patchy fog. models continue to hint at some light moisture around region later tue. will increasing clouds, and put occasional sprinkles in for tue afternoon and tue night. rockey. .long term...tuesday night through saturday...overall, dry as high pressure builds over the region. will see seasonal temperatures for the region for rest of the week. one fly as appeared in the ointment...wed night. past and previous model runs have hinted at a front of varying strength moving into the region late wed and wed night. am convinced now that will see some precipitation, albeit not much. will put increased clouds for wed and thu, along with an increasing chance of rain late wed afternoon and wed night, then minor threat of showers on thu. rockey. && .aviation...mostly vfr conditions at all terminals this morning. only exception is some patchy fog along the columbia river impacting kvuo. rain is starting to move in from the south with light rain being reported at both keug and ksle. ceilings and visibility both appear to remain vfr even after the rain arrives. the only exception was konp where ceilings briefly dropped to low end mvfr, however this was short lived, and ceilings quickly improved to vfr. pdx and approaches...still cannot rule out mvfr cigs at kpdx during the heavier precipitation moving into the area in the next hour or two, but considering there has been little visibility or cig restriction with the precip moving through ksle and keug, expect vfr conditions. /bentley && .marine...east winds will continue to strengthen and veer through the morning hours as a strong surface low continues to strengthen and move nw off the oregon coast. expect the strongest winds after the winds switch to southerly once the warm front passes in the next few hours. winds are coming up about as expected, so did not make many changes to the ongoing forecast or headlines. the forecast for seas is quite complicated. the long period westerly swell held on much longer than expected, but finally began to subside around midnight. seas have now come down to the 14 to 16 ft range but will slowly begin to increase again as the approaching surface low continues to move northward. given the strength of the surface low, one would expect seas to be quite high today, although, the strongest winds are rarely being generated towards our waters. in addition, there was little opportunity for a dynamic fetch to develop with this system, especially in our area. beyond monday, marine concerns will be quieter as high pressure builds into the ne pacific waters which will limit winds. the next chance for higher seas won`t arrive until wednesday night/thursday as a swell train arrives from a strong surface low pressure near the aleutians. /bentley && .pqr watches/warnings/advisories... or...winter weather advisory until 6 pm today for... western columbia river gorge central columbia river gorge upper hood river valley. wa....winter weather advisory until 6 pm today for... western columbia river gorge central columbia river gorge. pz...gale warning until 10 pm today on all coastal waters. small craft advisory for rough columbia river bar conditions today and tonight. && $$ interact with us via social media: www.facebook.com/nwsportland www.twitter.com/nwsportland this discussion is for northwest oregon and southwest washington from the cascade crest to 60 nautical miles offshore. the area is commonly referred to as the forecast area.
Information courtesy of the National Weather Service - NWS Portland...
Issuing Weather Forecast Discussion Homepage