National Weather Service Area Forecast Discussion for Long Beach, WA USA
000 fxus66 kpqr 242203 afdpqr Area Forecast Discussion...corrected National Weather Service Portland, OR or 256 pm pdt mon apr 24 2017 .synopsis...expect periods of rain through midweek with decreasing showers thursday and friday. drier weather looks to return saturday, but is looking short lived with additional wet weather possible sunday or monday. && .short term...today through thursday...a surface low pressure is currently moving across the pdx metro and into the columbia river gorge and helping to spread the widespread rain across the area this morning to the east of the cascades. the airmass is beginning to destabilize as -28c air at 500mb moves into northwest oregon and southwest washington. precipitation has turned increasingly convective with a couple small cells producing locally heavy rain across portions of the willamette valley. expect additional showers to develop in the wake of the current activity. snowfall amounts have been notable above 5000` today with 7-11" so far. several more inches of snow will be possible so will keep the winter wx advisory going until it expires at 8pm. shortwave ridging building into the pacific northwest should bring decreasing showers overnight. however, the next occluding frontal storm system will push more rain into the area tuesday afternoon, which will likely continue into early wednesday. our cwa will continue to remain on the polar side of a strong jet so showers should continue into wednesday and thursday, but will become more tied to the terrain especially at night. /neuman .long term...thursday night through monday...the strong jet aimed over the pacific northwest during the middle of the week will slowly become more north-south oriented and shift east of the region thursday night and friday. this should result in decreasing showers during this period. models are in decent agreement that shortwave ridging will push over the pacific northwest friday night and saturday and will bring some sunshine and mild temperatures. this pleasant weather could last into sunday, but it could certainly be short lived based on the latest operational and ensemble model guidance. as a result, trended pops into at least mentionable thresholds and closer to climo for sunday and monday. /neuman && .aviation...surface low is currently over kpdx and will continue slowly moving ene. have seen most winds start to favor a westerly onshore direction. this will bring continued mvfr cigs across most terminals through at least 20/03z. exceptions are keug where it is showing vfr and expect ksle to improve over the next couple hours. most guidance shows the remainder of the taf terminals to remain under mvfr cigs for the next 24 hours. not too sure how likely that will be as a front will approach starting late tonight and start to mix the lower levels a bit. inland terminals will likely start picking up an mvfr cig 020-030 after 25/12z and lasting until at least 25/18z. kpdx and approaches...expect mvfr cigs to continue improving behind the surface low moving off to the east. feel cigs will remain sub 040 through 03-04z before lifting up to around 040 for several hours. another mvfr deck arrives around 12z with cigs most likely around 025 but possibly as low as 010-015. that lower deck will likely remain through the morning arrivals before lifting 16-18z tuesday. /jbonk && .marine...lower end sca wind gusts 20-25 kt will continue this afternoon then diminish by early this evening. seas around 10 ft should subside shortly after the winds diminish this afternoon. active weather pattern continues as there is another system on tuesday that will likely bring high-end small craft advisory wind and possibly brief low-end gales. seas look to remain around 7 to 9 ft but may spike to 10-11 feet for a couple hours if winds overachieve much. surface high pressure then begins to build offshore shunting the surface lows mainly north of the waters and keeping a relative lull in winds through friday. seas next reach 10-11 ft thursday through early friday as the southern end of a swell train clips the northern waters from a surface low crossing the alaskan panhandle. /jbonk && .pqr watches/warnings/advisories... or...winter weather advisory until 8 pm pdt this evening for cascades in lane county-northern oregon cascades. wa...winter weather advisory until 8 pm pdt this evening for south washington cascades. pz...small craft advisory for winds until 4 pm pdt this afternoon for coastal waters from cascade head or to florence or out 60 nm. small craft advisory for hazardous seas until 5 pm pdt this afternoon for coastal waters from cascade head or to florence or out 60 nm. small craft advisory for rough columbia river bar until 6 pm pdt this evening. small craft advisory for rough columbia river bar from 3 am to 7 am pdt tuesday. && $$ 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