Freeze Warning 3, NWS Pendleton, OR

720 
WWUS76 KPDT 282110
NPWPDT

URGENT - WEATHER MESSAGE
National Weather Service Pendleton OR
210 PM PDT Tue Sep 28 2021

ORZ511-290700-
/O.CON.KPDT.FZ.W.0003.210929T0900Z-210929T1800Z/
Central Oregon-
Including the cities of Bend, Madras, Prineville, and Redmond
210 PM PDT Tue Sep 28 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 11 AM PDT
WEDNESDAY...

* WHAT...Sub-freezing temperatures between 28 and 32 expected.

* WHERE...Central Oregon.

* WHEN...From 2 AM to 11 AM PDT Wednesday.

* 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

117 
WWUS76 KPDT 290326
NPWPDT

URGENT - WEATHER MESSAGE
National Weather Service Pendleton OR
826 PM PDT Tue Sep 28 2021

ORZ511-291800-
/O.CON.KPDT.FZ.W.0003.210929T0900Z-210929T1800Z/
Central Oregon-
Including the cities of Bend, Madras, Prineville, and Redmond
826 PM PDT Tue Sep 28 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 11 AM PDT
WEDNESDAY...

* WHAT...Sub-freezing temperatures between 28 to 32 expected.

* WHERE...Central Oregon.

* WHEN...From 2 AM to 11 AM PDT Wednesday.

* 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

303 
WWUS76 KPDT 291232
NPWPDT

URGENT - WEATHER MESSAGE
National Weather Service Pendleton OR
532 AM PDT Wed Sep 29 2021

ORZ511-291800-
/O.CON.KPDT.FZ.W.0003.000000T0000Z-210929T1800Z/
Central Oregon-
Including the cities of Bend, Madras, Prineville, and Redmond
532 AM PDT Wed Sep 29 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 11 AM PDT THIS
MORNING...

* WHAT...Sub-freezing temperatures as low as 30.

* WHERE...Central Oregon.

* WHEN...Until 11 AM PDT this morning.

* 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

536 
WWUS76 KPDT 291627
NPWPDT

URGENT - WEATHER MESSAGE
National Weather Service Pendleton OR
927 AM PDT Wed Sep 29 2021

ORZ511-291730-
/O.CAN.KPDT.FZ.W.0003.000000T0000Z-210929T1800Z/
Central Oregon-
927 AM PDT Wed Sep 29 2021

...FREEZE WARNING IS CANCELLED...

Temperatures in Central Oregon have warmed to the upper 30s to mid
40s this morning so the freeze warning has been cancelled.

$$

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

Area Forecast Discussion
National Weather Service Pendleton OR
252 AM PDT Tue Sep 28 2021

.SHORT TERM...TUESDAY THROUGH THURSDAY...Current radar and
infrared satellite imagery showing the leading edge of the upper
level trough and associated cold front continuing to drive
through Eastern Oregon and into Idaho this morning. As this
occurs, showers will be more confined at elevation along the
Cascades and through the Blue Mountains, and will taper off
through the afternoon and early evening hours today. The trough
axis will pass through the area and eject to our northeast tonight
into Wednesday morning. Zonal, westerly flow aloft occurs in the
wake of the departing system Wednesday, as an upper level ridge
begins to build along the west coast. This ridge continues to
build into Thursday, but a dropping upper level trough from the
Gulf of Alaska will infiltrate the Pacific Northwest and erode the
ridge to provide showers to initiate along the Cascades Thursday
afternoon/evening. Eventually, the trough wins the battle, and
pushes the ridge east to provide a slight chance of showers to
cross through the area late Thursday into Friday morning. However,
moisture associated with the passing trough will be minimal due
to the slow exit of the earlier ridge.

An additional 0.01-0.03 inches will be possible through the day
today along the east slopes of the Cascades and the foothills of
the Blues, but 0.10-0.25 inches will be possible at elevation
along the Cascades and Blue Mountains. Cool temperatures will
accompany this trough, with highs only peaking in the mid to upper
60s for the Lower Columbia Basin and upper 40s to low 50s for the
mountains today. Lows tonight into Wednesday morning will be
frigid as temperatures bottom out in the upper 30s to low 40s for
lower elevations and around 30 degrees through Central Oregon.
Snow levels will hover between 5000-5500 ft tonight into
Wednesday morning before soaring into the 9000-10000 range
Wednesday afternoon/evening. High temperatures slowly rebound
back into the upper 60s Wednesday and in the mid 70s Thursday
across the Basin.

Guidance is in good agreement in the short term period, with
subtle differences between trough/ridge strength and the
initiation of the incoming ridge Wednesday. The GFS incurs a
stronger incoming trough today, but a slower and weaker ridge
Wednesday and Thursday. This results in the GFS being a slightly
wetter and windier outcome versus the ECMWF, albeit marginal. The
forecast reflects this blend, with a slight lean toward the GFS. 75

.LONG TERM...FRIDAY THROUGH MONDAY...The extended period is
characterized by a dropping upper level trough on Friday, before
an upper level ridge builds across the Pacific Northwest through
the weekend. This slow moving trough will back up against the
departing ridge to allow for a slight chance of showers along and
within the Blue Mountains during the late afternoon and early
evening hours. The offshore ridge infiltrates onshore just on the
heels of the departing system, and actually overtops the trough to
spin off a closed low to our east and also develops one off the
California coast Saturday. Locally, the upper level ridge builds
to produce drier conditions, warmer temperatures and calm winds.
High temperatures in the mid 60s are likely for lower elevations
Friday, before a warming trend initiates over the weekend to
return temperatures to near normal values. The ridge begins to
center over our area into Sunday and lingers into the beginning
part of the workweek to allow for these conditions to persist
through the remainder of the extended period.

Guidance is in fairly good agreement with the overall pattern
within the long term, but differences regarding trough timing,
strength, and speed exist. This is a result of the ridging behind
the trough, as the ECMWF incurs a stronger ridge which relates to
a quicker, drier, and weaker trough versus the GFS. Also, the
ridge builds quicker with the ECWMF scenario in the wake of the
departing trough early Saturday morning. Ensemble cluster analysis
highlights less overall spread with GEFS members, however the
ECMWF deterministic and ensemble means are more represented and in
line with the overall mean outcome. This leads to slightly more
confidence in the ECMWF scenario, leading to a drier Friday and a
faster and stronger warm up over the weekend and into the early
part of the workweek. 75

&&

.AVIATION...06Z TAFs...An area of light to moderate rain will
continue to affect taf sites kpdt and kalw until 08z and lcl mvfr
conditions are possible. Meanwhile mostly vfr conditions should
prevail at all taf sites despite showers into Tuesday. Sfc wind
gusts between 20 to 25 kts are possible for taf sites kpdt...kalw
after 08z.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  64  39  67  42 /  20  10   0   0
ALW  65  42  69  45 /  30  10   0   0
PSC  68  43  69  46 /  10   0   0   0
YKM  64  37  65  43 /  20   0  10  10
HRI  67  40  70  43 /  10   0   0   0
ELN  60  38  61  42 /  20   0  20  20
RDM  59  29  69  36 /  20   0   0   0
LGD  58  36  64  38 /  40  10   0   0
GCD  58  35  67  38 /  30  10   0   0
DLS  65  44  70  49 /  30  10  10  10

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

SHORT TERM...75
LONG TERM....75
AVIATION...97