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000
FXUS66 KMFR 170354
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
854 PM PDT Tue Apr 16 2024

.DISCUSSION...An update is not necessary. Decreasing mid and high
level clouds and diminishing winds will aid substantial cooling
overnight. Please see the previous discussion below for further
details. High pressure will dominate the pattern through Friday
night with a warming trend from day-to-day and a wide range from
cool to cold morning lows and above normal afternoon highs.

The model trend has been to slightly slow the arrival of the next
cold front, with a higher chance of light coastal rain late
Saturday morning through Saturday afternoon, and a slight chance
extending into Douglas County Saturday afternoon and evening.

Monday afternoon and evening looks to hold the next chance of
showers, highest between the Coast Range and the Cascades, with
weak instability in advance of a coastal trough.

&&

.AVIATION...17/00Z TAFs...A lot of cumulus continues to cover higher
terrain this evening and those should dissipate later this evening
once we lose daytime heating.  VFR ceilings are anticipated through
the TAF period with some gusty winds along the coast.

-Smith

&&

.MARINE...Updated 235 PM Tuesday, April 16, 2024...A strengthening
thermal trough will bring strong gusty north winds to the waters
through much of the rest of this week. Steep to very steep wind
driven seas south of Cape Blanco will continue into Thursday. The
thermal trough will be strongest during the afternoons/evenings
through resulting in gale force north winds and very steep seas from
about Port Orford southward through Wednesday night. Conditions
hazardous to small craft are expected north of Cape Blanco during
this time frame resulting with gusty north winds and steep seas
there.

The thermal trough weakens Thursday into Friday, and this is when
conditions are expected to improve, though steep seas are likely to
linger through the end of the week. -Sven

&&

.PREV DISCUSSION... /Issued 244 PM PDT Tue Apr 16 2024/

Short Term...Tonight through Thursday Night...High pressure will
control the weather over southern Oregon and far northern
California. We will see a gradual warming trend through Thursday,
with absolutely no precipitation in sight. Daily highs of around
seasonal normals today will reach about 10 degrees above normal by
Thursday, while overnight lows remain cool. A thermal trough is
expected to form along the coast over the next few days, and this
will result in a general east flow aloft, keeping the south coast
warmer due to downsloping winds, and producing strong valley
inversions. In some cases, the valleys will see overnight lows
cooler than many of the area mountains.

In fact, lows will be cool enough to worry about frost and freeze
conditions tonight, and perhaps again tomorrow night. With dry
air in place and mostly clear skies expected, lows will drop to
near or below freezing for the West Side valleys, as well as
locations along the coast north of Cape Blanco. For inland areas,
the typical growing season hasn`t quite started yet, but
agricultural interests are at risk. More information on the frost
and freeze headlines can be found at PDXNPWMFR. -BPN

Long Term...Friday through Tuesday...

Overview:

Friday through Monday looks rather benign as far as the weather
goes. During this stretch, we are not seeing much in the realm of
precipitation, but coastal areas and northern Douglas County have a
chance (15%-30%) to see some light rainfall Saturday/Saturday night.
Otherwise, this forecast will see several days with above normal
temperatures and lots of sunshine (minus coastal areas) over the
course of this forecast. We really aren`t seeing much for impacts
through the long term at this time.

Further Details:

By Friday, we will have transitioned to a zonal flow pattern at
500mb. While this will bring clouds to the area, especially the
coast, we will generally have sun around. By Saturday, this pattern
wants to transition more to a ridging pattern but generally still a
zonal flow. Deterministic models are essentially diverging at this
point, but this isn`t a surprise at Day6 with modeling. On Saturday,
the precipitation forecast for coastal areas is very minor. The
probability for any of these mentioned areas to receive 0.10" or
more of rainfall is less than 10%.

Lets talk impacts. While we officially are not advertising any
impacts in the long term, it should be noted that any "backyard
farmers" should pay attention to overnight lows as we progress into
spring. This is the time of year when sensitive outdoor vegetation
can be damaged from frost/freeze. We base these type of headlines
for frost/freeze hazards based on climatology and agricultural
factors. So, if you don`t see frost/freeze watches, warnings, or
advisories, it simply means we are not forecasting those
temperatures and/or it is not climatologically or agriculturally
relevant. Please watch the forecast at www.weather.gov/medford for
your location if frost/freeze may be a concern for you.

-Guerrero

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Frost Advisory from 2 AM to 9 AM PDT Wednesday for ORZ021.

     Freeze Warning from 3 AM to 9 AM PDT Wednesday for ORZ024-026.

CA...None.

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

     Gale Warning until 5 AM PDT Thursday for PZZ356-376.

&&

$$