552 FXUS66 KMFR 022335 AFDMFRArea Forecast Discussion National Weather Service Medford OR 435 PM PDT Thu Oct 2 2025
...Updated AVIATION discussion for 00Z TAFs...
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.DISCUSSION...Updated to add a freeze watch for the east side Friday night and Saturday morning. Freezing and subfreezing temperatures are possible for many areas east of the Cascades, with cooler temperatures following on Saturday night and Sunday morning.
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.AVIATION...03/00Z TAFs...Showers continue across northern California and southern Oregon this afternoon and likely into the evening. Lightning strikes have not been observed in the official coverage area, but are showing up in nearby counties. Inland activity looks to move eastward through the TAF period as an upper trough moves out of the area, while slight chances of showers develop along the coast north of Cape Blanco towards the end of the TAF period.
Marine stratus looks to bring IFR to LIFR ceilings and visibilities to coastal areas this evening into late Friday morning. Inland areas may see periods of MVFR ceilings as well. For Medford, this possibility depends on the quantity of clouds banking up against the southern end of the Rogue Valley. There`s moderate confidence in the chances of inland MVFR, but timing remains in the TAF forecasts for these terminals to reflect the possibility. Any inland development also looks to clear out late Friday morning. And ongoing showers may cause locally low ceilings and visibilities as well as obscure terrain through the TAF period. -TAD
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.PREV DISCUSSION... /Issued 305 PM PDT Thu Oct 2 2025/
DISCUSSION...Three upper level features will be the drivers of our weather through Tuesday, and forecast confidence is high through that time. The first is an upper trough now over the Pacific Northwest and northern California coast area. The second is a much weaker trough late Friday night into Saturday night, and the third will be a strong ridge building in from the west early next week.
The broadest coverage of showers during the short and medium term period will be early this evening, with accumulations mainly from the Coast Range eastward. This includes a low end slight chance of thunderstorms early this evening from Siskiyou County north and northeast to the Cascades and Cascade foothills (including Jackson, Klamath, and southern and eastern Douglas counties), with the highest probability for northeast Douglas County. Precipitation amounts overnight of up to a tenth of an inch should be common, with local amounts to a quarter of an inch possible. Meantime, low clouds and patchy fog are expected overnight at the coast.
With the end of day-time heating, the risk of thunderstorms will end later this evening. But, the trough will continue track across our area. The lower levels of the air mass will moisten overnight in a north to northwest flow aloft. This will favor light showers late tonight into Friday morning southward and eastward from southern Douglas County near the Umpqua Divide, and particularly southward and eastward from southern Jackson County near Ashland. The coast and most of Douglas County will just have low clouds to contend with for Friday`s morning commute, though a 10% probability mention for 0.01 inches of drizzly sprinkles for Roseburg through around 9 AM on Friday does look appropriate. All in all, a dreary start to the day for most of our area.
During Friday, the trough will track southeast into Nevada and the shower activity will also shift in that direction. After the morning commute, expect showers to be most numerous for Modoc and southern Lake counties while sunny breaks in the clouds gradually developing on the west side and northern portions of south central Oregon.
For Friday night into Saturday, there is better model agreement with a stronger depiction of a weak shortwave and associated weakening cold front in the northwest flow behind the trough. This has resulted in the need to introduce a slight chance to a chance of light showers to Coos, Douglas, and northern Curry counties. This disturbance looks to have a shallow pool of moisture to work with the highest probability of meager, barely measureable showers late Friday night until shortly after sunrise on Saturday. Meantime, morning low clouds are expected in Josephine and Jackson counties. Cloud cover will be more sparse on the east side and lead to a chilly start to Saturday with lows in the upper 20s and lower 30s expected. Douglas County is likely to have lifting but persistent low cloud cover later Saturday, while other areas are expected to see increasing sun in the afternoon.
Lower clouds return to southwest Oregon late Saturday night into Sunday morning with a northerly flow between ridging far offshore and the trough, which will be centered over the Rockies.
High pressure aloft will be the dominant feature with a warming and drying trend Sunday at least into Tuesday, possibly into mid- week. After a week of cooler temperatures, inland highs by Monday will be slightly above normal. This also includes light easterly winds with Brookings joining in the slightly above normal temperatures for Monday and Tuesday.
Model uncertainty quickly increases for Wednesday with a majority of GFS and ECMWF ensemble members holding on to a weakening ridge. About 20% of ensemble members bring showers to the coast by Wednesday night. As time progresses into next Thursday, the probability of the next trough pushing out the ridge increases. But, the track and strength of the trough are in question. The probability of showers Thursday into Friday looks to be highest for northern portions of our area. -DW
MARINE...Updated 200 PM PDT Thursday, October 2, 2025...Steep northwest swell will gradually subside tonight with light winds. Winds become northerly on Friday and increase, but should remain below advisory levels. A thermal trough will strengthen along the coast Saturday with moderate to strong north winds expected Saturday night through Sunday night, strongest south of Cape Blanco. Steep, hazardous seas will develop as well. -Spilde
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.MFR WATCHES/WARNINGS/ADVISORIES... OR...Freeze Watch from late Friday night through Saturday morning for ORZ029-031.
CA...Freeze Watch from late Friday night through Saturday morning for CAZ084-085.
PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this evening for PZZ350-356-370-376.
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NWS mfr Office Area Forecast Discussion