Cape Blanco OR to Point St. George CA from 10 to 60 NM Marine Forecast
|Tonight...N Wind 15 To 20 Kt. Wind Waves 4 To 5 Ft. Mixed Swell S 1 To 2 Ft At 14 Seconds And Nw 2 Ft At 8 Seconds.|
|Wed...N Wind 15 To 20 Kt. Wind Waves 5 Ft. Mixed Swell S 1 To 2 Ft At 14 Seconds And Nw 2 Ft At 7 Seconds.|
|Wed Night...N Wind 15 To 20 Kt. Wind Waves 5 To 6 Ft. Mixed Swell S 1 To 2 Ft At 13 Seconds And W 1 To 2 Ft At 7 Seconds.|
|Thu...N Wind 20 To 25 Kt. Wind Waves 5 To 7 Ft. Mixed Swell S 1 To 2 Ft And W 1 Ft.|
|Thu Night...N Wind 20 To 25 Kt. Wind Waves 5 To 7 Ft. Mixed Swell S 1 To 2 Ft And W 1 Ft.|
|Fri...N Wind 20 Kt. Wind Waves 5 To 7 Ft. Mixed Swell S 1 Ft And W 1 Ft.|
|Fri Night...N Wind 15 To 20 Kt. Wind Waves 5 To 7 Ft. Mixed Swell S 1 Ft And W 1 Ft.|
|Sat...N Wind 20 Kt. Wind Waves 6 To 7 Ft. Mixed Swell S 1 Ft And W 2 Ft.|
|Sun...N Wind 20 Kt. Wind Waves 6 Ft. S Swell 1 Ft...Shifting To The W.|
| Area Forecast Discussion|
National Weather Service Medford OR
752am PDT Tuesday July 27 2021
Radar is showing a few bands of showers moving across portions of southern Oregon and northern California. These showers are producing measurable rain, albeit the rain measured has been extremely light. Since 11 pm PDT last night, the area has seen 52 lightning strikes with the most active cell occurring in Douglas County around the Jack Fire. These showers will continue today, and a few of those showers could produce lightning-- although storms will be isolated today. The overall forecast looks to be well enough on track, so no changes are needed for the forecast for this morning/afternoon; but will be taking a more extensive look at thunderstorm chances over the next couple of days as the situation seems to be evolving. Please read the previous discussion below for more information. -Schaaf
27/00Z NAM/GFS/EC in.
Lots of clouds streaming from south to north over the Medford forecast area this morning. Radar shows returns, but very little in the way of precipitation is reaching the ground due to very dry conditions in the lower atmosphere. The 27/00Z KMFR sounding showed precipitable water of 1.31 inches, which is close to the daily maximum recorded value for this location and date. However, most of it is between 700 mb and 500 mb.
The most likely scenario for the remainder of Monday night is light showers with mostly virga falling from them. However, some sites, especially the higher elevation ones, may record measurable precipitation. Isolated thunderstorms remain a possibility, and some strikes were recorded over north central Douglas county earlier this morning.
A long wave trough is west of southeast Alaska and a strong long wave ridge is over the central U.S. The pattern will change little over the coming week, so the southerly flow aloft will continue to bring monsoonal moisture into the area.
As for Tuesday, short waves will move through the area today, and this, combined with surface heating and increasing moisture, will support showers and embedded thunderstorms over the forecast area. Wetting rains are possible primarily east of the Cascades, but some west side locations, mostly east of I-5, may get some as well. Quarter inch rainfall totals aren't out of the question, and much of the data places the heaviest rainfall right over the Bootleg Fire. Rainfall rates will be insufficient for flooding over the burn scars though.
The ridge will build to the west over the latter half of the week. This will bring the heat back to the area. It will be very hot inland Wednesday through Saturday. The hottest day looks to be Friday with inland west side highs around 15 degrees above normal. Cloud cover will keep the east side cooler with forecast highs around 5 degrees above normal. There will be enough moisture for isolated to scattered afternoon and evening thunderstorms every day during this interval, mostly from the Cascades east and Siskiyous south.
There are some indications of a pattern change late Sunday or early next week to slightly cooler, but still above normal, temperatures and more stable conditions, but confidence is low on this. Afternoon and evening thunderstorms remain in the forecast through Monday.
AVIATION...For the 27/12Z TAF Cycle... LIFR/IFR conditions are expected along the immediate coast and into coastal valleys through this morning. Also, weak storms are also ongoing this morning west of the Cascades. Some of those storms might come close to MFR later this morning. We'll monitor radar and see if we need to add VCTS or TS to the TAF. Otherwise, the environment appears to destabilize further this afternoon. Look for more thunderstorms across the region later this afternoon and evening. Some storms may be strong over the Cascades. Prepare for lower ceilings and poor visibilities near thunderstorms throughout the day. If storms are strong enough, localized IFR visibilities are likely.
Other than the storms today, we'll see the LIFR ceilings move over the coast later tonight and Wednesday morning. -Smith
MARINE...Updated 200am PDT Tuesday, 27 July 2021...Seas will remain steep south of Cape Blanco through this afternoon as fresh swell moves through the waters. A weak thermal trough will persist through the next few days creating some gusty 20-25 north winds in the outer waters Tuesday and again on Wednesday. It seems the strongest winds will occur farther offshore and near Port Orford with weaker winds closer to shore to the south near Brookings. These gusty north winds will persist later this week into the weekend.
Updated 200am Tuesday 27 July 2021...There is an isolated thunderstorm threat over a fairly large portion of the forecast area through Tuesday.
A short wave will arrive from the south Tuesday. PW values (Precipitable Water values) will be 1.00-1.50 inches, which is a lot for this time of year. However, cloud cover will limit surface heating, so instability will be reduced. This looks to be a widespread shower event with embedded and isolated thunderstorms, though any thunderstorms will be effective rain-producers. Chances of wetting rain (>0.10") are highest from about eastern Siskiyou County north-northeastward into Klamath County and western Lake County, up to and including the Bootleg fire.
Wednesday through Saturday, it will heat up again with moist southerly flow persisting over the area. Instability will develop each afternoon/evening during this time period, and convective activity will be dictated by short waves embedded in the southerly flow. Short waves will be more active Thursday, so that will likely be the busiest day for thunderstorms.
.MFR WATCHES/WARNINGS/ADVISORIES... OR...None.
Pacific Coastal Waters...Small Craft Advisory until 11pm PDT this evening for PZZ356. Small Craft Advisory until 5pm PDT Wednesday for PZZ376.