687
FXUS66 KMFR 032322
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
422 PM PDT Thu Apr 3 2025

...Updated AVIATION discussion for 00Z TAFs...

.DISCUSSION...

KMAX is picking up on some echos in Modoc County this afternoon
as this upper level wave begins to exit the region. There are also
plenty of fair weather cumulus clouds covering locations west of
the Cascades this afternoon. Skies are anticipated to clear out
even further tonight with temperatures dropping down towards
freezing. We should see plenty of frost across the forecast area
and we did insert that into the gridded forecast.

Given that these low temperatures are pretty typical for this
time of year, and it is still early in the growing season, we
opted to not issue a frost advisory for any of our forecast zones
for tonight. Temperatures will likely hit the freezing mark in
the Illinois and Rogue valleys, although remains a few degrees
above freezing on the Umpqua Basin.

There was some question of fog building into the valleys, but dew
points appear to be a little too low as we mix out this
afternoon.

As high pressure remains in control, Friday and Saturday will be
quiet and rather typical for Spring weather in southern Oregon and
northern California. Highs will push into the upper 60`s and lower
70`s with clear skies.

Things begin to change up on Sunday with warm moist air pushing in
ahead of a cold front or one could analyze it as an occluded
front. In any case, models are very confident this front will hit
the Oregon coast, the only question is the exact timing. Some data
shows the front arriving as early as 5 am Sunday morning whereas
most data shows the front arriving later Sunday evening perhaps
into Sunday night. In any case, this band of rain will arrive with
snow levels starting around 8000 feet before falling to 4000 feet
behind the front, a pretty drastic change in snow levels. Snow
accumulation will be minimal with most of the precipitation
falling while snow levels are 6000+ feet. The only impact here is
the rain continuing to cause issues with landslides around the old
Archie Creek burnscar on highway 138. Total QPF is under 1 inch
with the exception of the coastal range in Curry County with up to
2 inches falling there. This rain should fall over a 36 hour
timespan and shouldn`t produce widespread impacts.

Conditions will trend cooler around Tuesday with the probability
of precipitation around 10 to 50 percent. Those higher
probabilities will be in the northern sections of our forecast
zone and the lower probabilities in the northern portions of
California. Precipitation will again be light and not impactful
through this time.

From Wednesday into Friday, conditions look wet and it appears
we`ll be under warmer southwest flow. Impacts are anticipated to
be minor, although we`ll have to keep an eye on rivers or streams
starting to run higher.

-Smith

&&

.AVIATION...04/00Z TAFs...Northerly flow aloft is continuing to
bring scattered clouds, especially over Douglas and Lake counties.
Showers are minimal on radar, so VFR levels are expected to prevail
for most areas through the TAF period. A period of marine stratus is
possible over North Bend early Friday morning, and has been included
in the forecast. Guidance also shows weak fog signals for Roseburg
and Medford early Friday morning, but there is not enough confidence
in those outcomes to add them to the forecast. -TAD

&&

.MARINE...Updated 215 PM Thursday, April 2, 2025...Seas are
expected to be around 6 to 9 feet at 9 seconds today with north to
northwest winds generally in the 10-25 kt range, strongest to the
south. As a result, a Small Craft Advisory is in effect today out to
20 NM from shore off Cape Blanco, and extending to 60 NM from shore
off Pt. St. George. A period of improving conditions is expected
tomorrow morning through Saturday. Thereafter, a building long
period (17-20 seconds) west swell is anticipated on Sunday, and this
will likely lead to steep seas and hazardous conditions over the
waters. This is looking to continue into the start of next week as
well.

-Guerrero/Hermansen

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 3 AM PDT Friday
     for PZZ356-376.

&&

$$