textproduct: Medford

Updated AVIATION Discussion

AVIATION...03/06Z TAFs

VFR conditions will prevail through the TAF period. East flow begins tonight, which should keep the marine layer confined offshore or just along the immediate coast. Gusty east to northeast winds will continue tonight across the higher terrain. Another round of gusty north to northwest winds is expected Monday afternoon, strongest along the coast with gusts to 30 kt.

Periods of smoke could return tonight to areas east of the Cascades, potentially impacting visibilities for Klamath Falls by early Monday morning. Confidence is low on how much visibilities will be reduced since smoke is coming from far away, so for now will go with MVFR visibilities Monday morning. It's also possible for smoke to impact the remainder of southwest Oregon and northern California late Monday into Tuesday morning.

PREV DISCUSSION

/Issued 447 PM PDT Sun Aug 2 2026/

KEY MESSAGES... *Significant warming and drying trend commences Monday with NE offshore winds developing beneath a thermal trough.

*Heat wave Tue-Thu (maybe also Fri) with upper 90s and 100-110F heat expected inland west side valleys and widespread 90s east of the Cascades and in NE California - moderate to major heat risk.

*Some cooling next weekend, but probably remaining above normal. *Still no significant signal for thunderstorms next 7 days.

DISCUSSION...

Enjoy it while it lasts! The relatively cooler temperatures from yesterday's cold front remain in place this afternoon. A short wave will traverse the north eastern part of the state tonight helping the thermal trough start to build tonight into Monday morning. Temperatures will trend warmer by about 7 to 10 degrees Monday as high pressure also begins to build with rising 500 mb heights.

The warm up will be more significant on Tuesday and Wednesday as the thermal trough still remains in place mostly west of the Cascades and 500 mb heights peaking around that time. High temperatures will push into the triple digits with Somes Bar being the warmest spot in our area with 113 for a high on Tuesday. Only one record is at risk during this heat wave with 106 in Medford on Wednesday the 6th expected to be tied. We're currently forecasting a high of 106, although there are some models solutions that go ever warmer than that. There is about a 10% chance to exceed 110 on Wednesday.

Brookings will also be rather warm to start off under the offshore flow. Odds are they'll be in the mid 80's on Monday and Tuesday before the flow near the coast becomes more onshore. Guidance is still pretty spread out on Tuesday, although if the thermal trough is still in place, then flow should be offshore and highs will remain warm along the coast.

Smoke will also be something to watch as the northerly and north easterly winds should push some thicker smoke into our forecast area. Lake and Klamath counties will see the thickest smoke, although locations west of the Cascades should also see some elevated smoke concentrations. The smoke could impact temperatures, although past experiences suggest only 1 to 2 degrees difference in high temperatures further away from the fires.

Heat risk during this heat wave will be moderate at the very least. There are some areas in the major/high risk category. However, those points are covering more rural areas. If high temperatures do warm a few more degrees during the day and overnight, then we'll likely have some more major/high risk areas. Moderate heat risk implies those sensitive to heat will be impacted by this heat and susceptible to heat related illness. Those tend to be people without access to air conditioning.

-Smith

-From night shift discussion... Heat waves often end here with thunderstorms. But, once again, there is very little or no signal for thunderstorms at the end of this one. Models keep the area dry, primarily due to a lack of atmospheric moisture. The air mass is so dry and models keep the monsoonal moisture bottled up around the Four Corners region. By the time Sunday/Monday roll around, guidance is showing westerly flow aloft again, which isn't conducive to convection. This is good news given how dry it will be. -Spilde

MARINE...Updated 300 PM PDT Sunday, August 2, 2026... A thermal trough will strengthen along the coast, bringing stronger, gale force winds and very steep seas this afternoon through Monday evening south of Cape Blanco with gusty winds and steep seas spreading north of Cape Blanco. Conditions eventually improve as winds lower by Monday night into Tuesday. However, seas will likely remain hazardous to small crafts for most of Tuesday. The seas will indeed be steep as this fresh wind wave transitions to swell Tuesday.

-Smith

FIRE WEATHER...Updated 100 PM PDT Sunday, August 2, 2026... A deep marine push behind the departing dry cold front brought cooler temperatures today, but upper level ridging will build in quickly along with a thermal trough at the surface, resulting in a very warm and very dry week ahead.

Another upper disturbance will swing into Washington this afternoon and into Idaho/western Montana tonight. This will bring some gusty W- NW breezes for a few hours again this afternoon/evening in the valleys west of the Cascades and also over the east side. Overall, expect winds of 10-15 mph with gusts of 25 mph (maybe 30 mph in the windiest locations east of the Cascades). With cooler temperatures and higher humidities, conditions should stay below levels of concern.

The strengthening thermal trough in northern California and SW Oregon will result in a period of offshore N-NE winds for the coast ranges and mountains of western Siskiyou County tonight. As with most thermal troughs, the first night usually coincides with the strongest winds, with model 925-850 winds in the 25-30kt range. This should result in some gusty winds (25-30 mph) at night at the usual locations in vicinity of the thermal belts (perhaps gusts to 40 mph in the windiest spots). Aligning with the Chetco River, these winds will descend resulting in compressional warming/drying all the way to the coast near Brookings (FWZ 618) on Monday. Look for elevated fire risk there and into FWZ 619 with highs in the 80s, low humidity and gusty NE breezes. The N-NE breezes could also align with the Illinois Valley (FWZ 620) and funnel through the Rogue Valley (FWZ622) Monday afternoon/early evening, with critical conditions likely.

On the second night (Monday night), poor RH recoveries are expected across all of SW Oregon and northern California upper slopes/ridges. Some guidance is showing RH only recovering into the low 20s (upper teens?!) Tuesday through Thursday, while daytime minimum humidities could easily drop into the single digit percentages. Fortunately, winds will diminish some form the previous day. With these hot, dry, and windy conditions continuing Monday into Tuesday with little improvement overnight, a Red Flag has been issued for the Illinois and Rogue valleys, as well as the Siskiyous and southern Oregon Cascades, beginning Monday afternoon and continuing into Tuesday evening. Current model guidance shows only minimal improvement in wind and humidity Tuesday night into Wednesday, so the Red Flag may need to be extended further into the week. Outside of the Red Flag Warning area, conditions will still be hot, dry, and windy, with conditions approaching critical values at times.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Red Flag Warning from 2 PM Monday to 9 PM PDT Tuesday for ORZ620>623.

Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday for ORZ023-024-026.

CA...Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday for CAZ080.

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

Hazardous Seas Warning from 11 PM Monday to 9 PM PDT Tuesday for PZZ356-376.

Small Craft Advisory until 9 PM PDT Tuesday for PZZ350-370.

Gale Warning until 11 PM PDT Monday for PZZ356-376.