National Weather Service Area Forecast Discussion for Long Beach, WA USA
000 fxus66 kpqr 241724 rra afdpqr Area Forecast Discussion National Weather Service Portland, OR oregon 1024 am pdt sat sep 24 2016 .synopsis...higher pressure builds in today over the pacific nw, shunting a warm front north towards british columbia sunday. the center of the high will shift east of the cascades sunday, bringing offshore flow to the region for dry and warmer weather through monday. a weak cold front will sag into nw oregon on tuesday. && .short term...(today through monday) weak high pressure will continue to build in over the pacific northwest today as an upper level ridge builds offshore. there is still a solid deck of low clouds and patchy fog in the interior valleys along interstate 5, and this will take until sometime in the afternoon before it will clear, and have slowed down that clearing in the grids and the forecast. the coast was already clearing. overall, this will bring a dry day today with moderating temps. models indicate the upper ridge shifting east over the pacific nw sunday, pushing the surface high east of the cascades. 500 mb heights are quite high with this ridge topping 590 dm, while projected 850 mb temps over the interior top out between 18 and 20 deg c sunday. the moist ground is likely to allow for development of fog and perhaps some low clouds again sunday morning, but models do not appear to suggest the fog/clouds would be as long lived as today, which would allow for substantial warming in the afternoon. model soundings indicate it is not likely to see mixing all the way up to 850 mb, but still enough warming that most of the interior low elevations ought to top out with a high temp somewhere over 80. the ridge is expected to continue to progress east monday with a little more east flow through the gorge monday morning than on sunday, so expect whatever fog and low clouds that do develop will be rather short lived. monday should be pleasant much like sunday. onshore flow returns late in the day monday ahead of the next system expected to increase clouds monday night and tuesday. tolleson .long term...(monday night through friday)...no changes. previous discussion follows. a weak upper-level shortwave moves north of us on tuesday bringing a weak surface front across the area. this front will bring clouds and turn winds back onshore and cool down temperatures midweek. the south washington and far north oregon coast may see a trace of drizzle or light rain, but everywhere else should remain dry. zonal flow with continued low-level onshore winds will keep temperatures cool and weather fairly nice wednesday and thursday. will see increasing clouds thursday night ahead of our next system. there is some uncertainty on the timing with this system, as the gem wants to bring it in thursday night, but leaned toward the gfs and ecmwf which are in fairly good agreement that rain will move in friday morning. this looks to be another stingy system in the way of precipitation. will have a widespread chance for rain, but amounts do not look very impressive. weather going into next weekend right now looks to continue to be cool and showery as an upper-level trough remains over the area. -mccoy && .aviation...fog and low stratus will continue to bring reduced flight conditions to interior taf sites this morning. most inland sites have improved above airport minimums this morning, but expect lifr cigs to persist through around 18z. low stratus in the interior will be slow to scatter today, with ifr/mvfr cigs likely through around 21z. vfr conditions expected this afternoon and tonight. patchy fog or low stratus possible sun morning at khio, ksle and keug. meanwhile, a slight offshore drift along the coast has allowed conditions to improve to vfr. however, there could be brief periods of ifr cigs through around 18z as stratus deep in the coastal gaps move across the terminal. offshore flow strengthens later today and should keep conditions vfr through sun. kpdx and approaches...low stratus will continue to bring ifr/lifr cigs trough around 19z. status looks to scatter out shortly after that, with vfr conditions expected by 20z. vfr conditions continue into sun. east winds near the columbia river gorge should prevent low stratus sun morning. /64 && .marine...seas finally fell below 10 ft earlier this morning and are currently around 8 ft. expect seas near 5 to 7 ft to continue through monday. winds will not be much of an issue today due to high pressure and weak pressure gradients. however, n winds will ramp up sunday to near sca criteria with gusts to 25 kt possible. similar conditions expected monday, then brief easing mon night/early tue as a dry cold front moves through. behind that front, expect another surge of n winds later tue into wed as strong high pressure builds offshore. /64/weagle && .pqr watches/warnings/advisories... or...none. wa...none. pz...small craft advisory for rough columbia river bar until 2 pm pdt this afternoon. && $$ 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