textproduct: Medford

KEY MESSAGES

* Cooler than normal today with isolated showers and t-storms this afternoon/evening over NorCal and southern Oregon, especially mountains.

* Dry with similar temperatures Monday.

* Front dissipates to the north Tuesday with upper ridging resulting in a warming trend Wednesday and Thursday. * Slight cooling is possible Friday, then warm again next weekend.

DISCUSSION

An upper trough will move across the area today forming a closed low in NorCal by this evening. Temperatures remain about 5 F or so below normal. Satellite imagery is showing mid and high level cloudiness streaming in ahead of this system currently with some radar returns already showing up in Modoc/southern Lake counties early this morning. However, there hasn't been any indication yet that this is reaching the ground (probably mostly virga).

Models continue to trend upward with their depictions of moisture/ instability this afternoon/evening. CAMs are showing 2 separate areas, one from the mountains of western Siskiyou County up along the Cascades (near Crater Lake) and another from Modoc County up into portions of Lake County. CAPE values are mostly in the 100-200 J/KG range, but the highest CAPE exists in western Siskiyou County (200-500 J/KG). These values support development of isolated showers, and where CAPE is highest, a few lightning strikes/flashes. Not a big event, but isolated showers/thunder nonetheless. All in all, lightning probabilities are in the 5-15% range. There is also a very low chance (5%) something pops up west of the Cascades and east of the coast ranges, but most west side locations stay dry.

Showers could linger into the late evening hours tonight, but should diminish and end overnight as the closed low moves southeastward through California and eventually into southern Nevada/Arizona Monday/Tuesday. Short wave ridging over the area Monday will result in dry weather here, though temperatures won't change all that much from where they are today.

Models continue to show a weakening front moving onshore into the PacNW to our north on Tuesday. This front will get strung out in zonal flow aloft and we're not expecting precipitation to reach this far south. In fact, upper ridging should take hold again Wednesday/Thursday resulting in a warming trend with dry weather.

Another trough moves over the top of the ridge on Friday which could bring slight cooling, but the ridge rebuilds next weekend, so another warm period is likely. -Spilde

AVIATION...27/12Z TAFs

VFR conditions prevail through the TAF period for most areas, with a few patches of coastal or Umpqua Valley stratus possible early this morning as northeast low level winds back to north. High clouds will continue to stream over the area ahead of an incoming low pressure that will move inland today. Conditions will remain VFR, but it could generate a few showers, virga, or an isolated thunderstorm in the afternoon and early evening, with the highest chances (10-20%) for western Siskiyou County and the Cascades. Expect another round of gusty north winds along the coast this afternoon into the early evening. IFR stratus/fog stands the best chance of returning to the Coos coast late tonight or Monday morning. -Spilde

MARINE...Updated 200 AM PDT Sunday, September 27, 2026

A thermal trough pattern will keep gusty north winds and steep short periods seas over all coastal waters through tonight, and then south of Cape Blanco through Monday evening. West-northwest swell arrives Monday with conditions improving a bit Tuesday, especially north of Cape Blanco. The thermal trough could re-strengthen Wednesday. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Monday for PZZ356-376.

Small Craft Advisory until 8 AM PDT Monday for PZZ350-370.