Area Forecast Discussion
Issued by NWS Medford, OR

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FXUS66 KMFR 250507
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1007 PM PDT Sun Mar 24 2024

...New Aviation Section...


.AVIATION (06Z TAFs)...

North Bend (KOTH) will be under MVFR conditions for ceilings
through much of this TAF cycle. However, inland TAF sites are
expected to be in VFR through this cycle. The one concern is
showers coming in Monday morning/afternoon which could briefly
bring ceilings and/or perhaps visibilities down into MVFR, but
that should be short lived and confidence in MVFR actually
occurring is low. Wind speeds will generally be light, but with
the front coming through a wind shift is expected, and a westerly
wind speed could become breezy at times behind the front.

-Guerrero

&&

.PREV DISCUSSION... /Issued 446 PM PDT Sun Mar 24 2024/

..Aviation discussion updated...

AVIATION (00Z TAFs)... Showers are occurring across southern Oregon
and northern California. These showers will taper off early this
evening. Then additional rain showers arrive at the coast Monday
morning. Conditions are mainly VFR except for local MVFR in showers
and along the coast and areas of mountain obscurations.  MVFR in low
clouds will increase this evening, especially from the Cascades
west. Then tonight into Monday morning, widespread MVFR returns to
areas from the Cascades west with areas of MVFR east of the
Cascades, including at Klamath Falls (KLMT).

As a front moves inland late Monday morning and afternoon,
light rain will spread into areas from the Cascades west. MVFR and
local IFR will persist for areas west of the Southern Oregon
Cascades, mainly along the coast and into the Umpqua Basin
(including Roseburg, KRBG), during the day Monday.

-CC

PREV DISCUSSION... /Issued 244 PM PDT Sun Mar 24 2024/

DISCUSSION...

SHORT TERM...Through Wednesday morning. The next several days sees
a continuation of a less active, but still spring like pattern
before the next front moves in Wednesday.

With an upper ridge building in from the west a cold air mass
still remains over the region with below freezing H850 temps. As
surface temperatures are increasing this afternoon low level lapse
rates are also increasing in this cold air mass with showers
developing, mostly from the Cascades westward. Inland the showers
diminish overnight with this same pattern continuing with showers
developing again into Monday afternoon before once again
diminishing overnight Monday.

As the upper ridge axis moves over the region Tuesday temperatures
warm aloft, bringing decreased lapse rates with showers mostly
limited to the Crater Lake area and northward along the Cascades.
The warming with the upper ridge at the surface will bring high
temperatures close to normal before the next front rolls in
Wednesday.

-Sven

LONG TERM...Wednesday (3/26) to Monday (04/01)...The long term
begins Wednesday morning with a cold front moving in. This front
will bring precipitation and breezy conditions.

Snow levels Wednesday morning will start at 4,500-5,000 feet and
fall to 3,000 to 3,500 feet west of the Cascades and 3,500 feet to
4,000 feet east. The southerly/southwesterly flow during the first
frontal passage will bring a focus on precipitation to Northern
California and the Oregon coast. The heaviest rain with this front
will likely occur Wednesday morning at the Curry County Coast, and
this area will have 0.25"-0.50" every 6 hours after through at least
Thursday. For snow, there is currently a 40-50% probability of
seeing 6 inches of snow in the Cascades from 5 AM Wednesday to 5 AM
Friday, a decrease from the forecast yesterday.

Although 700 mb forecast winds are favoring 40+ knot winds in parts
of Klamath and Siskiyou counties as the front passes through
Wednesday, the NBM is only showing a 50% probability for reaching
this through the day. However, guidance at higher elevations (~5,000
feet+) are favoring stronger winds that are closer to wind product
criteria, so may need to focus on the mountains east of the Cascades
for products in the middle of the week.

An area of low pressure is now forecasted to move southward along
the coast Friday, and QPF and snow totals have decreased as this
track is looking to be too far to bring major impacts. Although
ensembles agree that there will be a trough coming down the coast
later next week, the timing and strength of this will need to be
monitored as we get closer. Overall the cool and wet pattern will
continue through the rest of the next work weekend and into at least
the start of next weekend.

-Hermansen

MARINE...Updated 200 PM Sunday, March 24, 2024...Steep seas and
northwest winds will persist through this evening. Then seas will
diminish below small craft advisory levels and winds will become
southerly as a weak front moves across the waters tonight and Monday
morning. A strong front approaches Tuesday night and across through
the waters Wednesday with increasing south winds, possibly gales,
and very steep seas. Currently, the probability for wind gusts of 41
knots or higher (Gales) is 50 to 70 percent. High to very high seas
will continue behind this front middle/late next week with hazards
likely over the waters and/or the beaches.

-CC

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this
     evening for PZZ350-356-370-376.

&&

$$


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