Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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030 FXUS66 KMFR 170550 AFDMFR Area Forecast Discussion National Weather Service Medford OR 1050 PM PDT Mon Sep 16 2024 ...Updated AVIATION discussion... .DISCUSSION...The forecast is on track for tonight. A few scattered showers are moving over Siskiyou and Modoc counties, spinning around a low pressure system moving across California. Moderate chances for showers (30-60%) and thunderstorms (20-30%) will remain over eastern Lake and Modoc counties through Tuesday morning. Another low pressure system looks to pass to the west tomorrow, with precipitation focused on areas west of the Cascades (60-100% through the day), with lesser chances (50-80%) east of the Cascades. Higher elevation areas are expected to see 0.5 and 1.0 inches of rainfall, while lover elevations will see 0.25 inches or less through early Wednesday morning. Please see the previous discussion for more details on the short- and long-term forecasts. -TAD && .AVIATION...17/06Z TAFS...Cloud cover remains over much of northern California and southern Oregon due to a lingering low pressure system to the south. Little shower activity remains on radar, with MVFR and IFR ceilings remaining over areas east of the Cascades and VFR ceilings over other inland areas. Marine stratus is at MVFR levels as well for areas north of Cape Blanco, with IFR levels possible but not strongly expected. Another low pressure system will move south over the Pacific through the day Tuesday, with precipitation mostly falling west of the Cascades. Thunderstorms are possible over the ocean but have single digit chances over land. Showers may locally lower visibility and ceilings as well as obscure elevated terrain through Tuesday and possibly into early Wednesday morning. -TAD && .MARINE...Updated 800 PM Monday, September 16, 2024...Overall conditions will improve through tonight as the thermal trough weakens and the upper level low moves inland. Winds will shift to the south ahead of an incoming front Tuesday, but winds and seas will remain relatively light with widespread rain and a slight chance (15-20 percent) for thunderstorms. Any thunderstorms that develop will have the potential for strong, erratic and gusty winds. Moderate to occasionally strong north winds and steep seas will develop Wednesday as the thermal trough redevelops, with small craft advisory conditions expected through the rest of the week. -BPN && .PREV DISCUSSION... /Issued 506 PM PDT Mon Sep 16 2024/ SHORT TERM...Tonight (9/16) through Wednesday night (9/19)... Satellite imagery is showing extensive cloud cover across portions of southern Oregon and northern California. Above the lower cloud layer is a second layer of higher clouds that are circulating anti- clockwise indicative of a low pressure system traversing across northern California and northwest Nevada. Meanwhile, RADAR imagery is showing some showers pushing from northeast to southwest across portions of Klamath, Siskiyou, and Modoc Counties. There may be additional showers and thunderstorms later this afternoon and evening, specifically for portions of Lake and Modoc Counties. This low will traverse out of our area this evening and tonight and the next low will approach the Pacific Northwest on Tuesday. This will bring the next set of precipitation across the area, mainly favoring West Side. In general, rainfall will be wetting along and west of the Cascades. Temperatures will remain cooler than normal as well. Showers may linger on Wednesday, but gradually dissipate. Temperatures will start to warm up on Wednesday as well. -Schaaf LONG TERM...Thursday (9/20)through Monday (9/23)...A ridge of high pressure returns to the area, allowing conditions to dry out and temperatures to warm up. Another front will push through the Pacific Northwest over the weekend, and ensembles differ on the strength and location of the front. That being said, the National Blend of Models favors a 20 percent chance or less for precipitation for the coast, Umpqua Basin and the Cascades from Highway 140 northward. Stay tuned to the forecast as we are entering the shoulder of fire season where wetter weather begins to return. This is the case as ensembles suggest that another system could return by midweek next week. Fire season is not quite over, but it has slowed significantly by this point, and we will continue to see how things play out. -Schaaf && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Tuesday for PZZ350-356-370-376. Hazardous Seas Warning until 5 AM PDT Tuesday for PZZ356-376. && $$