Marine Weather and Tide Forecast for Yoncalla, OR

FXUS66 KMFR 292121 AFDMFR

Area Forecast Discussion National Weather Service Medford OR 221 PM PDT Tue Apr 29 2025

DISCUSSION
A weak front passing through the region today, then high pressure will resume control for Wednesday and Thursday.
Aside from some very light precipitation with this weak front, dry conditions will persist through the week with a warming trend that peaks on Thursday. A pattern similar to the one from this past weekend returns Friday through the weekend.

There is plenty of cloud cover across the region associated with this weak front. Returns on radar are focused over the East Side, but surface observations indicate that measureable precipitation (<=0.01") has been difficult to materialize. Only a few sites have recorded a trace or 0.01", so it's likely this precipitation is evaporating before reaching the ground.

This front will exit the region later this afternoon, and high pressure resumes control Wednesday. High temperatures will take another climb to above normal values, reaching 10 degrees above normal on Wednesday and 15 to 20 degrees above normal on Thursday.
Expect cool (west side) to chilly (east side) mornings both days, but with nice, warm afternoons. With the peak of the warmth expected on Thursday, highs in the valleys west of the Cascades will fall in the 80-85F range (upper 80s lower Klamath). East Side locations will have highs largely in the mid and upper 70s. These values on Thursday could easily become the warmest temperatures of the year so far and will feel more like late June/early July than early May. We don't expect records to fall as current records for May 1st are in the low 90s/upper 80s, but these temperatures could fall in the top 5 warmest temperatures for the date.

The pattern remains progressive, however, so the ridge axis quickly shifts eastward Thursday night and a large scale trough approaches the region early Friday. This pattern change will look quite similar to the one experienced just this past weekend (and more similar to early March) with widespread rain, isolated thunderstorms and significantly cooler temperatures. In fact, afternoon temperatures will swing from 15-20 degrees above normal on Thursday to 10-15 below normal on Saturday! As the trough approaches the region on Friday, increasing moisture and instability ahead of the front will bring a slight chance (15-25%) for thunderstorms along and east of the Cascades Friday afternoon/evening. In addition to the thunderstorm chances, some gusty southwest winds are expected ahead of this front. Winds should stay below advisory criteria, but gusts of 25 to 35 mph will be common across the area.

This trough will elongate just offshore on Saturday, digging southward and cutting off a low that will move into central/southern California late Saturday into Sunday. This will maintain shower activity on Saturday as we remain in an area of upper level diffluence. This trough will gradually shift eastward into the Great Basin on Sunday. Most areas will see dry conditions for Sunday, though showers will linger across southeastern areas (SE Lake/Modoc Counties). By the time this system moves off late Sunday, rainfall amounts of 0.25"-0.50" will be common across the forecast area with up to 0.75" across the higher terrain. Snow levels will lower to around 4500-5000 ft Friday night into Saturday, reaching as low as 3500 ft Sunday morning. There could be few inches (1-3") of snow in the Cascades Friday night into Saturday, but the bulk of the precipitation should have pushed east into Lake/Modoc Counties by the time snow levels lower to around 3500 ft. Over that way, there could around 2-4" of accumulation in the Warners by the time this late-season system is done. /BR-y
Show more