Grants Pass, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

294
FXUS66 KMFR 130358
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
858 PM PDT Thu Jun 12 2025

.DISCUSSION...A update to the forecast was needed to include the
mention of isolated showers near the Medicine Lake region and
across northern Klamath County this evening. Moisture and
instability were sufficient enough to kick off a few showers in
these areas and even a few lightning strikes up near Chemult. An
approaching weak trough will bring a decent marine push into the
region tonight, so expect some stratus to return to coastal areas
and filter into portions of the Umpqua Basin by early Friday
morning. This stratus could be deep enough to spill over the
Rogue-Umpqua Divide and we could see some clouds banking up
against the Siskiyous here in the Rogue Valley by Friday morning.
Overall, low-impact weather is expected for the next few days, and
more details can be found in the previous discussion below. /BR-y

&&

.AVIATION...13/00Z TAFs...VFR levels continue across northern
California and southern Oregon this afternoon. Gusty winds are
present at area terminals as a weak dry front approaches the area.
These winds look to decrease this evening and tonight. A marine push
is expected to bring MVFR ceilings to the Oregon coast later this
evening, with chances of MVFR ceilings filling the Umpqua Valley as
well. Any ceilings that develop overnight are expected to clear out
before Friday afternoon. Other inland areas will remain at VFR
through the TAF period. -TAD

&&

.MARINE...Updated 830 PM Thursday, June 12, 2025...High pressure
offshore and low pressure inland are expected to persist into the
weekend. Seas will remain dominated by a mix of northerly wind wave
and fresh swell through the weekend, hovering at or just below
advisory criteria with one exception. The strongest winds and
steepest seas are expected south of Gold Beach and out 30 nm from
shore, especially during Friday afternoon and evening when very
steep seas are forecast. A weak front early on Monday is likely to
disrupt the pattern and bring improved conditions. -DW/Hermansen

&&

.PREV DISCUSSION... /Issued 506 PM PDT Thu Jun 12 2025/

DISCUSSION (Today through Wednesday)...

Overview:

The most noteworthy item of interest is the addition to some low-end
rainfall chances (10%-20%) Friday afternoon. These may need to be
refined and possibly removed due to outliers have more weight
towards these chances. However, its a low chance scenario and felt
these could be left in for now. Otherwise, the vast majority of the
forecast will remain dry through early next week outside of some
coastal rainfall/drizzle chances (10%-30%). The real story going
through early next week is the prolonged dry stretch of weather
where we will likely see further curing of fuels across the area.

Further Details:

For Friday afternoon, we do have a weak upper level disturbance
passing over the area which will likely be coupled with hitting
convective temperatures in the afternoon. The moisture is the
biggest lacking variable, and the biggest player weighted towards
these rainfall chances appears to be the NAM Nest, which typical has
a wet bias and will overdo PoPs. The HRRR is essentially dry, and
this does create some concern because the HRRR typically outperforms
the NAM Nest with convection/PoPs. That being said, its only a 10-20
percent chance and mathematically would be correct given the
scenario. Just wanted to bring attention to these PoPs being added
and the chance of them being overdone. At least the NBM did not
introduce thunder at this time which might be the correct outcome.
In fact, tomorrow afternoon may just be a day with towering cumulus
and no rainfall actually hitting the ground. We have another day to
examine, but the idea here is these PoPs were left in for now even
though this may be an outlier weighted function of the NBM.

Otherwise, we are going to likely see further curing of fuels across
the landscape through the next several days as rainfall will be
essentially non-existent for much of our area. Some early
indications are pointing to a deepening trough next weekend (~June
20-21) which would likely bring thunderstorms to the PacNW. Whether
or not this impacts our forecast area is not clear at this point,
but given this stretch of dry weather followed by thunderstorm
chances, we may be looking at the first real chances at wildfire
threats across the area and perhaps the first Red Flags of the
season. However, this is next weekend and a lot can change, but
given the mostly quiet forecast, it was worth diving into further to
find potential impacts.

-Guerrero

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT Sunday
     for PZZ350-356-370-376.

Hazardous Seas Warning from 2 PM Friday to 2 AM PDT Saturday for
     PZZ356-376.

&&

$$