611 FXUS66 KMFR 192158 AFDMFR Area Forecast Discussion National Weather Service Medford OR 258 PM PDT Tue Oct 19 2021 .SHORT TERM...Wet and windy weather is in store for the remainder of the week as a series of increasingly strong and moist frontal systems moves across the area. The first of these fronts will come through tonight, followed by another strong and moist front Thursday night into Friday. Then additional strong and very moist fronts are expected on the weekend and into early next week. Current satellite and radar imagery shows a frontal band of precipitation located just off the coast of Southern Oregon and Northern California this afternoon. Ahead of this front, winds are picking up and becoming strong and gusty across the marine waters and for some areas inland, such as the Rogue Valley, Shasta Valley and higher mountains east of the Cascades. Models continue to show a strong 925 mb jet of 70 kt moving into the southern coast late today and tonight and a 50 to 65 kt 700 mb jet moving inland across the area late today through Wednesday morning. South winds will increase late this afternoon into tonight with strong, gusty south winds developing along the southern Oregon coast, into portions of the Rogue Valley as well as increasing across the Shasta Valley and higher terrain east of the Cascades. Ensembles support winds gusting up to 60 mph along portions of the southern Oregon Coast, mainly from Pistol River to Cape Blanco. Advisory level winds are expected, for the Rogue, Shasta Valleys and the Summer Lake area and mountains east of the Cascades, with winds gusting up to 45 to 55 mph. High wind warnings and wind advisories remain in place for these areas (please see the NPWMFR for details). Winds will gradually east on Wednesday morning for western areas and Wednesday afternoon for areas east of the Cascades. With the front, precipitation will spread into the coast and across areas from the Cascades west this evening then spread eastward across the area tonight into early Wednesday morning. Snow levels will vary from 5000 to 6500 feet across the area as precipitation moves inland. So, expect moderate snow accumulations over higher mountains in Western Siskiyou County, especially in the high terrain areas of McCash and River Complex burn areas, as well as moderate snowfall in the Mount Shasta area, above 5000 feet. A winter weather advisory remains in effect for these areas through Wednesday morning (WSWMFR). Additionally, light snow accumulations are expected over higher portions of the Southern Oregon Cascades and Siskiyous, especially above 5500 feet. In addition to rain and higher elevation snow, expect a slight chance for thunderstorms this evening and tonight along the coast and across the marine waters. Light showers are expected behind the front on Wednesday, mainly focused along the coast, into the Umpqua Basin, mountains and Mount Shasta areas. Showers will decrease in coverage Wednesday night. Then, another front will approach the area Thursday morning then move inland late Thursday afternoon through Friday morning. This front is forecast to bring moderate to heavy precipitation to the area. Snow levels are expected to be higher with this front, around 8000 to 9500 feet elevation with and ahead of the frontal passage, lowering to 6000 feet behind the front. Strong, gusty winds are also possible over inland areas ahead of this front on Thursday with models showing another 50-65 kt 700 mb jet moving over the area. Also models and ensembles support a chance for thunderstorms with the frontal band Thursday night and Friday morning along the coast and over the marine waters. .LONG TERM...All signs are pointing towards an active weather pattern for at least the next 7-10 days. A parade of systems will move through the area bringing bouts of moderate to to heavy precipitation, gusty winds and mountain snow, by the start of next week. Thursday, a deepening low will move northeast inside of 140W and move towards Vancouver Island. However a strong front will approach the coast bringing the potential for strong winds along the coast, south of Cape Blanco, and possibly the Shasta and Rogue Valleys. The heaviest precipitation should remain offshore until Thursday evening. However a series of disturbances ahead of the front could bring some light to occasional moderate precipitation to portions of northern Cal, specifically around the Mount Shasta area. Snow levels will be high (around 10,000 feet) during the day Thursday, so were not expecting any concerns. Thursday evening into Thursday night, moderate to heavy precipitation will move into the area with the heaviest rain along the coast, coastal mountains and northern Cal. This storm has have an AR (atmospheric river) signature to it, but only for about a 12 hour period with a southwest orientation which will serve to wring out even more moisture as it encounters the coastal mountains. The front will move through the area Friday afternoon with precipitation rates diminishing and snow levels will come down some, but still mainly affecting the higher passes like Diamond and Crater Lake and possibly the Everitt Memorial highway at Mount Shasta. As previously mentioned, the pattern remains active with the next storm arriving Saturday morning, followed by another one Sunday morning or early Sunday afternoon. Confidence is high in the active pattern and storms being moderate to strong in intensity, but as always, it will all come down to the individual timing of each one. -Petrucelli && .AVIATION...19/18Z TAFs...The main concern today into tonight will be winds. Low level wind shear is expected at the coast, south of Cape Blanco and North Bend later this afternoon and this evening. Those winds will eventually spread inland throughout the late evening and overnight hours. Inland, winds aloft continue to increase later this afternoon into early tonight creating a low level wind shear environment over many terminals in the valleys. These wind shear forecasts have been included in the RBG and MFR TAFs. In addition to the wind, rain will begin to fall across the region late this evening along the coast and spread inland into tonight. With the strong south winds MFR will likely end up on the drier side of things with a 70% chance of rain after midnight. -Smith && .MARINE...Updated 230 PM PDT Tuesday, 19 October 2021... Southerly gales are expected this afternoon and tonight with wind driven seas becoming very high and hazardous. Could not rule out brief periods of storm force wind gusts beyond 5 nm from shore at peak intensity tonight. If storm force winds do occur, then they will be brief and isolated. Seas are forecast to peak at 18 to 23 ft tonight over the outer waters and 12 to 17 feet over the inner waters. After this system moves through, seas remain chaotic Wednesday with southerly fresh swell moving through the waters mixed with a relatively high 10 foot westerly swell. Another very strong cold front is expected early Thursday into Thursday afternoon with another episode of gales likely. We did not issue a gale watch for this event since we already have a gale warning out already. The stormy pattern looks to continue this weekend into next week. -Petrucelli/Smith && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Wind Advisory from 9 PM this evening to 2 PM PDT Wednesday for ORZ030-031. High Wind Warning from 9 PM this evening to 5 AM PDT Wednesday for ORZ021-022. Wind Advisory from 5 PM this afternoon to 5 AM PDT Wednesday for ORZ026. CA...Wind Advisory from 9 PM this evening to 2 PM PDT Wednesday for CAZ085. Winter Weather Advisory from 10 PM this evening to 6 AM PDT Wednesday for CAZ080-082. Wind Advisory until 8 AM PDT Wednesday for CAZ081. Pacific Coastal Waters... Small Craft Advisory until 5 PM PDT this afternoon for PZZ350-356. Small Craft Advisory from 5 AM Wednesday to 5 AM PDT Thursday for PZZ350-356-370-376. Gale Warning from 5 PM this afternoon to 5 AM PDT Wednesday for PZZ350-356. Gale Warning until 5 AM PDT Wednesday for PZZ370-376. $$ CC