textproduct: Medford

AVIATION (18Z TAFs)

VFR conditions are expected at all terminals throughout the valid TAF period. There will be some high clouds around today but expecting mostly sunny skies this afternoon/early evening. Breezy diurnal wind speeds are expected as well with speeds diminishing around sunset.

-Guerrero

PREV DISCUSSION

/Issued 331 AM PDT Mon Jun 15 2026/

KEY POINTS...

* Hot temperatures continue today and Tuesday, with Heat Advisory in effect until Tuesday night, including portions of the East Side starting today.

* Temperatures trend cooler for the West Side on Tuesday, then for all areas on Wednesday. More noticeable cool down Friday into the weekend.

* Elevated fire weather concerns, especially for West Side Valleys, with low daytime humidities and breezy afternoons.

* Increasing signal for thunderstorms for latter half of week, possibly as early as Thursday, but most likely on Friday. Focus for activity expected over northern California and east of the Cascades.

DISCUSSION...The thermal trough has pushed inland, evident by a surge of stratus moving northward along the coast and over the marine waters this morning. This will bring a cloudy start to the day for places along the immediate coast south of Cape Blanco. Skies will gradually clear later this morning and afternoon as north winds increase again and erode this stratus. Skies are clear across the remainder of the region with some high level clouds starting to stream overhead. With the thermal trough inland, another hot day is expected. Expect another round of upper 90s/triple digits for areas west of the Cascades. Areas east of the Cascades will trend warmer by around 5-7 degrees today, and the current Heat Advisory expands eastward for this heat today to cover the Klamath Basin into the Modoc and eastern Siskiyou County.

The upper level pattern responsible for this heat features a strong high pressure just offshore over the eastern Pacific, that will weaken and expand eastward, eventually settling into the Great Basin region. Meanwhile, weak energy will linger off the coast of California and meander westward around this high pressure while it expands/shifts eastward. This energy comes into play for the latter half of the week. In the meantime, hot temperatures will continue into Tuesday, cooling a few degrees for the West Side on Tuesday, then for all areas on Wednesday. The current Heat Advisory continues through Tuesday evening due to a moderate (isolated areas of major) risk of heat related illnesses. Be sure to take precautions to protect yourself from the heat. If you plan to seek relief in area waterways, please remember that the water is still quite cold, and cold water shock is a real thing. Temperatures do trend cooler for the latter half of the week, but will remain above normal (mid-upper 90s West/upper 80s-low 90s East) until the weekend. So instead of being 15-25 degrees above normal like yesterday and today, it'll "cool" to only 10-15 degrees above normal.

The upper level pattern shifts on Thursday. That meandering weak energy combines with a few other weak shortwaves passing through in the westerlies and carves out a weak open trough over the eastern Pacific by Thursday afternoon. Temperatures tick upward a few degrees on Thursday under southerly flow, and it's possible we see another triple degree day here in Medford on Thursday. The larger concern however, is the thunderstorm potential that comes with this pattern. It's almost a guarantee that heat waves conclude with a thunder threat, and it seems this event is no different. Moisture and instability increase on Thursday, and there are some weak shortwaves passing through, but moisture is pretty marginal on Thursday. It's more likely that there will be some cumulus buildups with a stray shower across northern California. By Friday, however, the trough nudges closer and moisture looks more favorable for thunderstorms. Currently, it looks like the focus would be across northern California and east of the Cascades, but model guidance shows some potential convection over the Siskiyous, which could bring some storms into southeastern Jackson County. We'll keep an eye on model trends to see if thunderstorm chances expand westward with time.

The trough axis moves through the region Friday night, taking the moisture and instability east of our region for Saturday. It's possible some isolated activity lingers across far eastern Lake county early Saturday afternoon. The coolest temperatures of the forecast period are expected over the weekend as this trough passes through. Afternoon highs will still be above normal, but only on the level of 5-10 degrees.

AVIATION...15/12Z TAFs...VFR conditions will prevail for all inland areas through the TAF period, with the typical increase in afternoon winds today. Along the coast and over the marine waters, a southerly surge of stratus is bringing LIFR conditions in fog and low ceilings mainly to areas from Cape Blanco southward, with VFR conditions for the remainder of the area. This stratus could reach as far north as Bandon this morning. Expect improving conditions to VFR late this morning as this layer retreats southward to around Brookings by this afternoon.

MARINE...Updated 100 AM PDT Monday, June 15, 2026...The thermal trough has pushed inland, resulting in weaker winds across the marine waters this morning. Steep seas linger, however, due to fresh swell mainly north of Cape Blanco and beyond 40 nm from shore south of Cape Blanco. A wind reversal/southerly surge is bringing an area of marine stratus to much of the waters south of Cape Blanco. Expect areas of reduced visibilities with this stratus, which could make it as far north as Bandon by early this morning. Northerly winds strengthen again by this afternoon, which will result in the stratus shrinking/retreating south to around Brookings.

The thermal trough quickly rebounds later today into Tuesday, persisting through at least Thursday. Advisory level winds and steep seas will return to all areas by this afternoon. Conditions worsen on Tuesday as north winds strengthen, possibly reaching gales south of Cape Blanco and seas become very steep. Very steep seas could spread north of Cape Blanco around mid-week, but the worst conditions are expected south of Cape Blanco. Conditions could improve late Thursday into Friday as the thermal trough pattern weakens.

FIRE WEATHER...Updated 200 AM PDT Monday, June 15, 2026...Hot temperatures and low humidities continue today as this early season heat wave lasts through midweek. Temperatures will peak today and Tuesday with daytime highs about 20-25 degrees above normal. This will likely result in another triple digit day for for the valleys west of the Cascades today, especially in western Siskiyou County, where it could get to around 110F. Minimum relative humidities will also remain low (bottoming out in the 10-20% range for most areas)-- though RHs could even drop into single digits at times, especially over the East Side deserts and some of the West Side valleys. Meanwhile, broad north through east flow will produce moderate to poor RH recoveries over upper slopes/ridges each night, especially over the Klamath mountains, Siskiyous, and Cascades.

Elsewhere, expect fairly typical diurnal afternoon N-E winds that could become breezy at times during the afternoons/evenings through Tuesday. This will make for elevated fire weather concerns and localized conditions could get extremely close to Red Flag criteria, especially considering the low teens and potential single digit minimum humidities combined with the afternoon breezes. Undoubtedly, this period of hot, dry, breezy weather will continue to move the needle toward higher fire danger as we head into next week.

We continue to see a signal in the extended forecast for increasing moisture/instability as the heat begins to ease around mid-week. As such, lightning potential will increase. Right now, models are showing focus areas mainly to our south through Thursday. However, there is a low possibility (10-15% chance) that something pops up in some of our southern and eastern mountains (Mt Shasta region/Warners) Thursday afternoon/evening. But, by Friday afternoon/evening, the signal is stronger for a slight chance (15- 25%) of thunderstorms across northern California and across portions of the East Side. We'll continue to monitor and adjust the forecast as necessary.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Heat Advisory until 11 PM PDT Tuesday for ORZ021-023>026-029.

CA...Heat Advisory until 11 PM PDT Tuesday for CAZ080>085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 AM PDT Tuesday for PZZ350-356-370-376.

Gale Watch from Tuesday morning through late Wednesday night for PZZ356-376.