Florence OR to Point St. George between 150 and 250 NM Offshore Forecast
|Today...Nw Winds 5 To 10 Kt, Becoming W. Seas 4 To 5 Ft.|
|Tonight...W To Nw Winds Less Than 10 Kt, Becoming Variable. Seas 3 To 4 Ft.|
|Sun...Variable Winds 5 To 15 Kt, Diminishing To Less Than 10 Kt. Seas 3 To 5 Ft.|
|Sun Night...Variable Winds 5 To 15 Kt, Diminishing To Less Than 10 Kt. Seas 4 To 5 Ft.|
|Mon...N To Nw Winds 10 To 20 Kt. Seas 4 To 6 Ft.|
|Mon Night...W To Nw Winds 10 To 20 Kt, Becoming W To Sw 5 To 15 Kt. Seas 4 To 6 Ft.|
|Tue...S To Sw Winds 5 To 15 Kt, Becoming S 20 To 30 Kt. Seas 5 To 8 Ft.|
|Tue Night...S To Sw Winds 20 To 30 Kt, Increasing To 30 To 40 Kt. Seas 9 To 15 Ft.|
|Wed...Sw Winds 20 To 30 Kt. Seas 10 To 15 Ft.|
|Wed Night...Sw Winds 10 To 20 Kt, Becoming W. Seas 10 To 18 Ft.|
| Area Forecast Discussion|
National Weather Service Medford OR
904am PDT Sat September 19 2020
The upper trough that brought showers and isolated thunderstorms yesterday has moved east of the forecast area. Plenty of low level moisture in a weak cyclonic flow behind the upper trough has resulted in a few lingering showers mainly north of the Umpqua Divide in eastern Douglas County. The past 24 hour lightning data shows a total of 15 lighting strikes, 10 in Douglas County, 14 in northern Klamath County and one in easter Jackson county. Areas that picked up beneficial rainfall were mainly over Coos and Douglas with the highest rainfall totals in eastern Douglas County including portions of the Archie and Thielsen Fires. Lesser rainfall amounts were observed in portions of Josephine and Curry county.
Any showers north of the Umpqua Divide should end late this morning with dry weather for all areas this afternoon. Cloud cover west of the Cascades should also gradually dissipate over time with partly to mostly sunny skies in the afternoon. Dry weather is expected Sunday through at least the middle of next week before the next front inches towards the area Wednesday night or Thursday. -Petrucelli
Updated 200am PDT Saturday 19 September 2020...Relatively calm conditions with light south winds and seas generally at or below 5 feet will continue through Saturday morning. A thermal trough will build near the coast late Saturday into Sunday, producing increased north winds and choppy wind driven seas south of Cape Blanco, however, conditions are expected to remain below advisory criteria. The thermal trough will weaken Monday and winds and seas will subside at that time. Sub-advisory conditions are then expected through Tuesday, then northwest swell will increase Wednesday as a new series of fronts approaches the area. -Spilde/BPN
There is high confidence in the forecast through Tuesday. The recent reduction in smoke in the air mass will persist today. The axis of an upper level trough has moved east of our area. But, a shortwave in the northwest flow aloft will continue a chance of light showers in Coos and Douglas counties through around 10 to 11am this morning. Otherwise, no rain is expected through Tuesday night.
A thermal trough will build near the coast late today into Sunday, then move inland and weaken later Sunday into Monday. This will bring warmer and drier conditions for Sunday and Monday. But also, winds aloft backing to southwest will begin a trend on Sunday of increasing smoke from existing wildfires. The HRRR indicates that this increase will be mainly east of the Cascades and more noticeable beginning Sunday night. A much less broad plume from the Slater and Red Salmon complexes is forecast to be elevated over Jackson County on Sunday night. A southwest flow aloft is then expected to continue maintenance of the smoke layer or a trend of gradually increasing smoke through Tuesday night. While this trend is not welcome, at least the thickness of smoke is unlikely to attain the levels from before our recent frontal passage.
While dry and warm conditions will be persistent early in the week, the upper level weather pattern itself will be seasonably progressive. A series of weak disturbances in the westerly flow will be focusing their meager energy well north of our area. This will bring occasional increases in mid and high level cloud cover. But, the main impact will be to bring gusty, breezy late day westerly winds of around 10 to 20 mph on Monday and Tuesday, strongest east of the Cascades. By Tuesday, a closed upper level low will move into the Gulf of Alaska while a ridge begins to build into central and southern California.
Our weather from Wednesday through the remainder of the week will likely be determined by the movement and strength of the northern stream trough and southern stream ridge. There is a wide range of model solutions, with appropriate variation in ensemble member solutions. In this situation, it is safe to say that Washington will have periods of rain while the large majority of California is warm and dry. In between, which of course encompasses our area, the timing and strength of disturbances is uncertain. We can say that the probability of late week rain will be higher for the coast and Douglas County...diminishing to the south and east. We can also say that the instances of breezy afternoon and evening winds are likely to continue. With this uncertainty, the blended model solution was utilized in the long term portion.
.MFR WATCHES/WARNINGS/ADVISORIES... OR...None.
Pacific Coastal Waters...None.