Florence to Cape Blanco OR out 10 NM Marine Forecast
|Tonight...N Wind 10 To 20 Kt Except N 10 To 15 Kt Cape Arago Southward. Wind Waves 3 To 4 Ft. Mixed Swell Sw 1 Ft At 14 Seconds And Nw 2 Ft At 8 Seconds.|
|Wed...N Wind 10 To 20 Kt. Wind Waves 3 To 4 Ft. Mixed Swell Sw 1 Ft At 14 Seconds And Nw 2 Ft At 7 Seconds.|
|Wed Night...N Wind 10 To 20 Kt. Wind Waves 4 To 5 Ft. Mixed Swell Sw 1 Ft At 13 Seconds And W 1 To 2 Ft At 7 Seconds.|
|Thu...N Wind 10 To 15 Kt. Wind Waves 3 To 5 Ft. Mixed Swell Sw 1 Ft And W 1 Ft.|
|Thu Night...N Wind 10 To 20 Kt. Wind Waves 4 Ft. Mixed Swell Sw 1 Ft And W 1 Ft.|
|Fri...N Wind 10 To 15 Kt. Wind Waves 3 To 4 Ft. Mixed Swell Sw 1 Ft And W 1 Ft.|
|Fri Night...N Wind 10 To 15 Kt. Wind Waves 3 To 4 Ft. Mixed Swell Sw 1 Ft And W 1 Ft.|
|Sat...N Wind 10 To 15 Kt. Wind Waves 3 To 4 Ft. Mixed Swell Sw 1 Ft And W 2 Ft.|
|Sun...N Wind 15 Kt. Wind Waves 4 To 5 Ft. Sw Swell 1 Ft... Shifting To The W.|
| Area Forecast Discussion|
National Weather Service Medford OR
315pm PDT Tuesday July 27 2021
CalTrans is reporting a debris flow off of Whitney Creek in the Lava Fire burn scar due to heavy rain ongoing in the Mt. Shasta area over the glacier sending surges of water, mud and rock. A flash flood warning is in effect for the next three hours. Please avoid this area if at all possible. Otherwise, wetting rains have fallen across portions of the East Side with some showers west of the Cascades ongoing. Some sunlight has peaked through the heavy clouds (especially in Lake County) which could produce some additional thunderstorms this evening.
Overall, this pattern of the monsoon moisture will continue for the next several days with periods of showers and thunderstorms in the forecast. In general, this thunderstorm risk will largely be tied to the terrain, particularly on Wednesday with a lack of trigger. On Thursday, chances increase everywhere east of the Coast Range with the best chances from the Cascades and east. The better chances occur once again on Friday before the thunderstorm threat shifts eastward over Klamath and Lake County Saturday into Monday.
In addition, temperatures will become hot for much of the area beginning tomorrow. We're looking at temperatures in the upper 90s to mid 100s across the West Side Valleys. Heat stress will really begin in earnest on Thursday as clouds from thunderstorms will keep overnight temperatures well above normal with mid to upper 60s to a few places seeing lows of 70 degrees. This pattern will really continue through Friday evening, with temperatures starting to decrease overnight over the weekend. Have issued an excessive heat watch for the West Side Valleys for this heat illness risk. Please see the NPWMFR for more details.
This whole pattern will continue into early next week before the thunderstorm risks diminish fully, and temperatures return closer to normal by next week. -Schaaf
Updated 200pm PDT Tuesday, 27 July 2021... A weak thermal trough will persist along the coast through mid week creating some gusty 20-25 north winds, especially for portions of the waters south of Cape Blanco. Winds will increase slightly on Thursday afternoon and evening. Steep seas are expected to continue through Thursday for areas south of Cape Blanco due to a mix of short period wind seas and fresh swell result steep seas. Friday into the weekend, a weak thermal trough may persist along the coast and may result in continued small craft conditions, especially for areas south of Cape Blanco. -CC
Updated 200pm Tuesday 27 July 2021...A very moist air mass for late July is bringing a corridor of rainfall, in some cases, wetting rainfall, from northern California into southern Oregon. The best rainfall is occurring currently along the entire length of Highway 97. Expect this area to shift north-northeastward this afternoon/evening, which will probably bring wetting rain on the Bootleg Fire. Isolated thunderstorms are still possible, but since this morning, there have only been a handful of cloud to ground flashes. Best bet for some convection this afternoon/evening will be over eastern Lake County where there has been some sun through early this afternoon, resulting in destabilization.
Expect most places to have good to excellent humidity recovery tonight into Wednesday morning with showers gradually ending. But, the cooler, moist pattern won't last long. It will heat up tomorrow afternoon and models are showing humidity dropping substantially again in the afternoon. With more sunshine than today, expect more instability, and a slight chance of thunderstorms, mainly across northern and eastern parts of the area and from the Cascades east.
Thursday through this weekend, with high pressure aloft to the east and an upper trough remaining off the California coast, deep southerly flow aloft will persist. We'll heat up to 5-15 degrees above normal again Thu-Sat (high temps inland well in the 90s and even lower 100s again).
Model guidance is showing some good instability on Thursday afternoon/evening, focused near the Cascades north of Howard Prairie and in the sweet spot for convection in our area, near and just north of Crater Lake/Chemult/Crescent areas. Some (but not all) models show a decent short wave moving north-northwestward from Reno/Tahoe region Wednesday night and reaching that area at peak heating Thu pm/eve. Enough mid-level moisture is present to justify an area of scattered thunderstorms there, so have issued a Fire Weather Watch for abundant lightning on dry fuels for FWZs 617 (Toketee Falls eastward), 623 (north of Howard Prairie) and 624 (north and west of a line from Chiloquin to Silver Lake). This does NOT currently include the Bootleg or Jack fires, but we'll evaluate and adjust as needed.
We'll continue the diurnal risk of convection through this weekend and perhaps even into next week, primarily focused from the Cascades eastward. We'll have to monitor any shortwaves that might have the ability to back the flow more to the southeast to get covection onto the west side. The good news is that outside of the fairly typical upvalley breezes and any gusty outflows from thunderstorms, winds should be on the light side. -Spilde
.MFR WATCHES/WARNINGS/ADVISORIES... OR... Fire Weather Watch from Thursday afternoon through Thursday evening for ORZ617-623>625. Excessive Heat Watch from Thursday morning through Friday evening for ORZ023-024-026.
CA...Excessive Heat Watch from Thursday morning through Friday evening for CAZ080>082.
Pacific Coastal Waters...Small Craft Advisory until 11pm PDT Thursday for PZZ356-376.