Hello, my name is John Peck and I'm a meteorologist with the National Weather Service in Pendleton
Oregon. This presentation is an add-on to our previous eclipse presentation. It is geared
more toward the weather enthusiast who might find interest in seeing what the cloud cover
has looked like on eclipse day in the past.
While it is convenient to allow other agencies comb through data and produce pretty graphics
like these regarding average cloud cover it can be a bit more informative to go back and
actually look at what has happened yourself. The remainder of this presentation is just
a series of 104 historical satellite images taken near 11 am Pacific Daylight Time between
the 20th and 22nd of August dating back to 1979. I will only dwell on each image long
enough to give a very brief synopsis of what is going on in it. You can press the spacebar
to pause and then press it again to resume the video if you would like a better look.
The basic structure of the next 104 slides will be a brief synopsis of the cloud cover
and any weather inferred to be occurring in the upper right hand corner and a running
total of cloud cover occurrences in the bottom right as we move along. One note on these,
west of Cascades cloud cover implies overcast conditions over Salem rather than the coast coast
those locations do tend to be much cloudier. I've included this figure even though this
area is outside our area of responsibility here at Pendleton because of the impact clouds
west of the Cascades could have on traffic moving along the passes and I-84 into our
area. This first image depicts a bit of an opposite of that scenario, ample cloud cover
over most of our area that might encourage moving west across the Cascades to the coast
or east into Boise's area to get away from the clouds. This image represents one of the
two main causes of substantial cloudiness in our area in late August. An area of low
pressure just off the coast of Astoria with associated cold front draped through central
Oregon.
We're not really off to a promising start with a second mostly cloudy day right off
the bat. The sun would still be visible in and out of clouds especially in the southern
half of the path of totality.
This is more typical late August weather, clear skies east of the Cascades with low
clouds associated with the marine layer to the west. In this case it appears the stratus
layer has managed to burn off for portions of Salem just in time for the eclipse. I will
try not dwell too much on days where conditions are clear for all or most locations in our
area to hopefully keep this presentation as short as possible.
This looks like another good day for most locations where large masses of people are
expected to gather although there are a few to scattered mid-level clouds over portions
of the John Day are and eastern Blue Mountains.
Another day with just a few clouds over the John Day-Long Creek area, significant coastal
clouds wouldn't bode well for traffic on the pass highways.
This looks like a quality eclipse day
Our area is in the clear once again, we do start
to see one of the other big concerns for late August in this image though several smoke
plumes visible in northern California and southern Oregon. I have only included smoke
in the observed conditions when it appears to significantly impact the path of totality.
This image is from the next day and the smoke is even more evident in southern Oregon. While
it isn't present in the path of the eclipse, under typical late August conditions it can
be expected, if not during the eclipse certainly after due to human caused fire starts.
This would be a poor eclipse viewing day for many portions of the area with broken mid-level
cloud cover and scattered to broken low level cloud cover. If you happened to be in the
John Day to Seneca area on this day you would have lucked out and had the best possible
view in the Pacific Northwest.
Here's the first day in the series where we observe thunderstorms, or at least remnants
of them. The billowing clouds over the northern Blue Mountains are likely lightning producers
and the developing clouds in southeastern Oregon will likely be thunderstorms in the
next few hours. Viewing across western portions of our area would still be quite acceptable.
Back to typical blue skies with no issues in this slide.
Another great day
A few clouds over extreme eastern portions of our area, but not a great day for those
heading to Baker, Ontario or near Boise
Lots of low level cumulus here, while a situation like this would likely result in seeing a
lot of blue through the clouds catching glimpses of the sun may be difficult it will be
relatively low in the sky around 45 degrees above the horizon and the sides of these clouds
may block your view.
No issues here with eclipse viewing
No issues here other than the georeferenced on the image getting consistently worse
Just a few mid and high level clouds here, likely no significant impact to the view.
Another day with just a few clouds, some somewhat vigorous cumulus development over the blue
mountains and lower basin this early in the day may have led to thunderstorms a little
later in the afternoon.
No clouds in the path at eclipse time, some mid and high level clouds are threatening
to move into the path from the south though
Completely clear
Another clear day
Based on the images from previous days I would be inclined to believe that this is cloud
and not smoke. Clouds to the east from the previous day do suggest possible thunderstorms
in Idaho coincident with what looks like smoke plumes today.
Just a few mid-level clouds streaming through the area, potentially impacting the major
gathering points Redmond to Madras.
Completely clear, stratus starting to sneak up the coast
No significant clouds over our area here, very cloudy west of the Cascades
Substantial mid-level cloudiness apparent here, could probably still see the Sun through
many of these clouds outside of thicker cloud cover in immediate vicinity of the Cascades
Even more cloud cover here bordering on technically overcast, but still likely to be able to see
the sun through the clouds in many areas.
This would be another very poor day for our area with substantial mid and low level cloud
cover.
Another very poor day with much of the same, few breaks possible near Redmond
Back to reasonable viewing conditions for our area here
And back to clear skies
This is more like it, clear skies again
A few clouds over the eastern Blues but otherwise clear
And clear again
A few clouds around here, an area of low pressure lurking off the coast and ruining Salem's
eclipse day.
The same low has moved on-shore and is now ruining eastern portions of our area's eclipse
day, down slope winds are helping our western areas stay cloud free
Poor conditions for western portions of our area, only partly cloudy for the eastern half
though
Mostly cloudy here, in and out of clouds for most areas
Back to clear again!
Another clear day for our area, cloudy on the coast
Clear again for us, with a low off the coast
Mostly cloudy over far eastern portions of the area, partly cloudy in the west
Clear!
Clear for our area
Just a few clouds in extreme eastern portions of our area
Lost of mid-level clouds around, but not likely to be an eclipse spoiler
Clear
Clear
Clear, I like this trend
Spoke to soon, this appears to be remnants from convection from the previous evening
covering much of the area.
Back to clear
More clear
A few mid or high clouds floating through, not an issue for viewing.
Clear
Clear
Clear
Clear
Clear
Clear, do I dare say anything about the trend?
Ruined for the coast, big low coming on shore. Still looks good for our area.
Most of our area is in a hole in the clouds, better to be lucky than good
Fairly poor conditions here, especially in western portions of the area. With clouds
from the coast to highway 395 I wouldn't to be in traffic on this day
Clear over western portions, mostly cloudy to overcast over eastern portions, remain
flexible in your plans
Just a couple clouds
Clear, some smoke evident over the Cascades
Well, there's the source of the smoke, a major fire in the Cascades west of Madras.
Most cloud cover does stay out of our area.
Lots of clouds, lots of smoke. Not a good day
Back to clear conditions
Partly cloudy, big low off shore.
Probably the worst day I found in this exercise. Solid clouds from the coast through western
Idaho. As indicated in the previous slide this was caused by a big low off shore moving
in. If you have your heart set on seeing the eclipse, this scenario would likely have been
well forecast and afford the opportunity to drive east to Wyoming to get out of the clouds.
No cloud worries here
Or here
Just a few clouds over the Madras area
No cloud concerns here
Mid-level clouds across the southwest portions of the path, developing thunderstorms across
the northeast portions
No clouds in our area, but does appear to be smoke over the Blues possibly as a
result of the thunderstorms from the previous day
Very little chance of seeing the sun in our area here
Some stratocumulus clouds left over from the previous day
Very few clouds here
Breaks in clouds possible here, standing mountain wave clouds east of the Cascades, if you could
maneuver yourself into a clear spot it would likely stay clear
Another set of mostly mountain wave clouds
Just a few clouds
No clouds for our area
Clear again
And again
And again
Lots of mid-level cloud cover, but Sun likely visible through it
Just a few fair weather cumulus clouds
No clouds
No clouds
A narrow band of mid-level clouds telling Fossil it doesn't want it to see the eclipse
Another big fire evident west of Madras
Winds have shifted more westerly, smoke plume from fire west of Madras now covering much
of the eclipse path
Fire still going but smoke plume doesn't look quite as thick
Another year, another fire, this time in the Ochoco National Forest
This is a combination of smoke and mid level clouds
Thunderstorms across southwestern Oregon as well as a few buildups over the Cascades in
the path of totality. A chance of a shot with a lightning bolt and an eclipsed sun perhaps?
Partly to mostly cloudy, mostly semi-transparent cloud cover.
Quite a lot of stratocumulus cloud, with little vertical extent it probably wouldn't be
a huge issue with eclipse viewing
Clear, fires evident in the Washington Cascades
Clear, fires continue
VERY smokey across northern portions of the path, but clear.
Clear.
Clear.
Clear, looks like a fairly large fire east of La Grande
In summary, historically the Inland Northwest has been the most favorable area in the country
for being able to see the Sun during the late morning in late August. A majority of very
cloudy days are caused by migratory low pressure systems. National Weather Service offices
are able to produce high accuracy cloud forecasts several days in advance with these systems
for your planning purposes. Remember that safety should be your top priority when planning
your eclipse viewing trip. Thanks for sticking with me through these slides, you can now
crown yourself an official weather nerd. If you have any questions or comments on this
video please let us know via leaving a comment here, sending a message on Facebook, or Tweeting
at us @NWSPendleton. Thanks and have a great day.
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