Freeze Warning 6, NWS Pendleton, OR

879 
WWUS76 KPDT 110822
NPWPDT

URGENT - WEATHER MESSAGE
National Weather Service Pendleton OR
122 AM PDT Mon Oct 11 2021

WAZ027-521-112200-
/O.CAN.KPDT.FZ.W.0006.211011T1000Z-211011T1600Z/
/O.NEW.KPDT.FZ.W.0007.211012T1000Z-211012T1600Z/
Yakima Valley-Simcoe Highlands-
Including the cities of Naches, Sunnyside, Toppenish, Yakima, 
Goldendale, and Bickleton
122 AM PDT Mon Oct 11 2021

...FREEZE WARNING IS NOW IN EFFECT FROM 3 AM TO 9 AM PDT 
TUESDAY...

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...Yakima Valley and Simcoe Highlands.

* WHEN...From 3 AM to 9 AM PDT Tuesday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

ORZ044-507-508-510-WAZ028-029-112200-
/O.UPG.KPDT.FZ.A.0002.211012T1000Z-211012T1600Z/
/O.NEW.KPDT.FZ.W.0007.211012T1000Z-211012T1600Z/
Lower Columbia Basin of Oregon-
Foothills of the Northern Blue Mountains of Oregon-
Foothills of the Southern Blue Mountains of Oregon-
North Central Oregon-Lower Columbia Basin of Washington-
Foothills of the Blue Mountains of Washington-
Including the cities of Boardman, Hermiston, Ione, Pendleton, 
Pilot Rock, Heppner, Condon, Fossil, Dufur, Maupin, Moro, 
Connell, Prosser, Tri-Cities, Dayton, Waitsburg, and Walla Walla
122 AM PDT Mon Oct 11 2021

...FREEZE WARNING IN EFFECT FROM 3 AM TO 9 AM PDT TUESDAY...

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...In Washington, Lower Columbia Basin of Washington and 
  Foothills of the Blue Mountains of Washington. In Oregon, 
  Lower Columbia Basin of Oregon, Foothills of the Northern Blue 
  Mountains of Oregon, Foothills of the Southern Blue Mountains 
  of Oregon and North Central Oregon.

* WHEN...From 3 AM to 9 AM PDT Tuesday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/Pendleton

Area Forecast Discussion
National Weather Service Pendleton OR
300 PM PDT Sun Oct 10 2021

.SHORT TERM...TONIGHT THROUGH TUESDAY...Current radar and visible
satellite imagery showing partly cloudy skies as some pockets of
light showers are present at elevation across the Cascades and
Blues. A chance of rain showers will mainly occur at elevation
through the day today, but will incorporate the foothills, areas
of the east slopes of the Oregon Cascades, and the John Day-Ochoco
Highlands late tonight into Monday morning. This is all
associated with a passing cold front and associated upper level
trough. The front will exit our area through the afternoon and
early evening hours today, but the trough will instead dig south
into Northern Nevada overnight tonight before continuing through
Nevada and into the four corners region by Tuesday morning. Rain
chances diminish quickly Monday morning as a dry and cold airmass
infiltrates into the Pacific Northwest behind the dropping trough.
This will bring widespread frigid temperatures through our area,
which will begin tonight for some spots along the east slopes of
the Washington Cascades. Thus, a freeze warning has been issued
tonight into Monday morning for the Simcoe Highlands and the
Yakima Valley, and a freeze watch has also been issued for the
Lower Columbia Basin and through the foothills of the Blues
Monday night into Tuesday morning. This will be the first hard
freeze for most spots as overnight lows will plummet into the
upper 20s to low 30s. Highs will also stay about 10 degrees below
normal both Monday and Tuesday, with temperatures peaking in the
mid to upper 50s across the Basin.

The wind advisory that was active this morning for the Eastern
Gorge and the Simcoe Highlands has been cancelled due to winds
subsiding to below advisory criteria. However, breezy northwest
winds will continue through the evening between 20-30 mph, but
will subside to 15-20 mph by Monday. Localized blowing dust will
also be possible for the Lower Columbia Basin through this
evening, but confidence is lacking as very little was observed
this morning via visible satellite, observations, and webcams.

A transient ridge moves onshore and through our area from the
southwest on Tuesday, which keeps skies mostly clear Monday
evening through Tuesday afternoon. This ridge is short-lived as
another upper level trough will move along the Washington coast
late Tuesday into the early morning hours on Wednesday. Showers
look to stay confined at elevation along the Cascades late Tuesday
before spilling over into the Basin on Wednesday. 75

.LONG TERM...WEDNESDAY THROUGH SUNDAY...Sensible weather concerns
in the extended forecast will mostly revolve around a quick
moving cold front and shortwave trough Wednesday. Otherwise,
guidance is in good agreement of a benign weather pattern from
Thursday into the weekend.

Wednesday, a shortwave trough coupled with a surface cold front
will move across the forecast area through the morning and early
afternoon. This will provide a chance of light rain for the lower
elevations, while the mountains will see a chance of snow in the
morning then turning to rain showers by the afternoon. Breezy
westerly winds will also develop ahead and behind the frontal
boundary passage in the morning, then gradually decreasing
overnight. Thursday, a shortwave ridge moving over the region will
provide dry and calm conditions while turning flow aloft to the
west. Through early Sunday, flow aloft will continue to be
westerly as a broad ridge moves across the western CONUS.
Moisture caught in the westerly flow aloft will provide a chance
of upslope snow/rain showers in the WA Cascades Thursday into the
weekend. Otherwise, the rest of the forecast area will remain
mostly dry with a gradual warming trend each day and terrain
driven locally breezy conditions in the afternoons.

Overall, ensemble and deterministic guidance is in great
agreement with each other through the extended period. Amongst the
WPC 500mb cluster analysis and the 500mb EOF patterns, the main
source of  lies in the amplitude of the ridge moving into the
western CONUS late Thursday through Saturday. Though current
forecast is reflective of a more zonal pattern with gradual
warming at the surface, a higher amplitude ridge with southwest
flow aloft over the forecast area could result in better warming
at the surface between Friday and Saturday. In the end, the better
warming would result in a chance for portions of central OR and
the Columbia Basin/Gorge seeing a chance at afternoon highs in the
low 70s, as opposed to mid 60s. Lawhorn/82

&&

.AVIATION...18Z TAFs...VFR conditions to prevail through the
period, though MVFR conditions may be possible with weather
impacts. Behind the cold front passage today, breezy westerly
winds will continue, with sites YKM/PSC/ALW/RDM expected to see
15-20kts with gusts up to 25kts possible. Sites DLS/PDT will see
20-25kts winds with gusts 30-35kts possible at times. Winds will
gradually decrease this afternoon into the evening, becoming less
than 12kts at all sites by 06Z tonight. CIGS will be 5k-12kft and
sct-ovc at sites DLS/PDT/RDM/BDN/ALW through the period with
higher clouds possible at all sites through this afternoon. Sites
RDM/BDN may see CIGS drop to 3kt-5kft as another round of
precipitation moves into the area. Precip will start off as rain
later this evening, but rain and snow may be possible at site BDN
after midnight. Lawhorn/82

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  35  56  26  54 /  20  10   0   0
ALW  37  55  30  55 /  20   0   0   0
PSC  38  62  32  59 /  10   0   0   0
YKM  31  59  26  58 /   0   0   0   0
HRI  39  60  30  59 /  10   0   0   0
ELN  34  56  27  56 /  10   0   0   0
RDM  29  51  21  54 /  20  10   0   0
LGD  32  50  26  51 /  20  10   0   0
GCD  31  47  25  52 /  30  20   0   0
DLS  43  61  36  61 /  10   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Watch from late Monday night through Tuesday morning for
     ORZ044-507-508-510.

WA...Freeze Watch from late Monday night through Tuesday morning for
     WAZ028-029.

     Freeze Warning from 3 AM to 9 AM PDT Monday for WAZ027-521.

&&

SHORT TERM...75
LONG TERM....82
AVIATION...82