Rod's Weather Headlines

With no rain in sight on the forecast models through July 22nd, it appears Portland's summer dry season kicked-off back on June 30th, after seeing more than 1.25 inches of rain over a 10 day stretch.  Natives to our area have long said that summer begins July 5th and the record book backs up the folklore.  Historically, Portland's driest weather of the year runs from July 11th - August 18th.  The roughly 5 week period averages less than a 20 percent rain chance each day and can go without a single drop of rain!

Here are the records for dry weather for PDX during the summer months:

July:  0.00 inches - 1967 (several years have seen only a trace, including 2013)

August:  Trace - 2012 and several other years

September:  Trace - 1993

Average combined rainfall over the three months of July, August and September is 2.79 inches.  The three month average is less than any single month from October through March! 

Forecast outlooks continue to call for above normal temperatures and below normal rainfall this summer.  Of course, below normal during the summer months means barely any rainfall at all through August. 

Tuesday turned out to be a "dog day" of summer, meaning just one hot day.  Yesterday's quick hitting   hot spell was the warmest temperature in Portland since PDX hit 100 degrees back on August 16th of 2012.  The airport's official high temperature Tuesday was 99 degrees at 4:14 p.m.  The record for the date stands at 105 degrees back in 1942.  You may remember last summer's hottest day was 97 degrees on June 30th.

Here are a few high temperature reports from Tuesday:  Salem 99 degrees, Beaverton 100, Gresham 97, Oregon City 101, Tigard 97, Hillsboro 97, Vancouver, 98, Ridgefield 100, Battle Ground 100 and McMinnville 98 degrees.  At the coast, Astoria hit 89 degrees, Tillamook 84 and Newport 75 degrees.  In the Gorge, Hood River 97 and The Dalles 100 degrees.  Up on Mt. Hood, Timberline Lodge warmed to 75 degrees Tuesday at 4:00 p.m.

Counting Tuesday, Portland as topped 90 degrees two days this year.  Our hot season with 90 degree temperatures often extends into September.  The latest in the season, PDX has topped out at 90 degrees is October 5th, back in 1980.  My summer forecast still calls for above normal temperatures with very little rainfall through mid-September.  I expect 15 or more 90 degrees days, meaning we have more than a dozen hot days to go!

Lightning safety rules should be refreshed in your mind each summer.  Lightning strike counting between 1990 - 2012 shows a dramatic increase across Oregon.  Data, mostly collected from eastern Oregon, shows an increase in yearly strikes, rising from 29,000 strikes to nearly 50,000 on average over the past twenty years. The good news is that the number of people killed from lightning strikes each year across the country has decreased since 2006.  The average number of people losing their lives each year to lightning is considered to be 50, but the last 5 years have seen national lightning deaths of 34 or less.  So far, 2014 has seen 7 fatalities, highlighted per state on the map below.

Here are a few lightning facts:

Lightning is a rapid discharge of electrical energy.  Each spark can span over 5 miles in length and reach temperatures hotter than the surface of the sun.  Water acts as a conductor of electricity, making lightning strikes over water deadly.  Every year, millions of lightning strikes fill our skies. 

Basic lightning safety:

1.  When you hear thunder, get out of the water

2.  Know that when you hear thunder, lightning is close enough to strike you.

3.  Only cars with windows up and a metal-topped roof are safe as shelter.

4.  Never take shelter under an isolated tree.

5.  Immediately get off hill tops or mountain ridges.  Remember, lightning strikes high objects.

6.  Never lie flat on the ground.

7.  Stay away from objects such as metal that conduct electricity.

Learn more about how people are struck at this link from the NWS:  www.lightningsafety.noaa.gov/struck.htm

Our cool & stormy weather feels like early spring, but summer is days away.  The summer solstice will occur this Saturday at 3:51 a.m. PDT.  At this time, the earth is tilted so that the north pole is at its closest point to the sun. (Yet, the earth will be at its farthest  distance from the sun, called the aphelion on July 4th.)  As a result, there will be more minutes of sunlight in the northern hemisphere than there are at any other time of the year. 

The word solstice is derived from the Latin sol-stitium, for sun standing.  The summer solstice is the time of the year when the sun stops its northern climb and stands briefly before turning back toward the equator. As seen from Portland, the sun will reach its highest northern point in the sky at 67.54 degrees from the horizon on June 20 and 21 at 1:12 p.m.  From March 21 until September 24, there are more hours of daylight than darkness.  After June 21, the days will gradually grow shorter until December 21, the winter solstice. 

Of course, the opposite is true across the southern hemisphere, where winter is arriving and June 21st will be the shortest day of the year.

You are invited to an OMSI Star Party to celebrate the new season.  Viewing will be Saturday evening at 9:00 p.m. at Rooster Rock and "Stub" Stewart Parks.  For more information call, 503-797-4000. 

Happy Summer Solstice!

The above report is courtesy of Jim Todd, OMSI Director of Space Science Education. 

The U.S. Drought Monitor report shows most of Oregon and much of Washington to be abnormally dry, with parts of southern Oregon declared as a moderate to severe drought.  Severe drought conditions are in place over southeastern Oregon.  Central Oregon, including Bend and the Two Bulls wildfire are near the transition line of moderate to severe drought conditions.  The city of Bend is less than 60 percent of normal precipitation since last fall.  Mostly dry weather since mid May has helped to intensify fire danger. 

The Forest Service in Oregon is expecting an active fire season due to dry weather and early snow melt.  All of California, Nevada and much of Oregon are likely to see drought conditions persist or intensify over the summer months.  Lightning strikes are a key factor in the number of fire starts and are difficult to forecast weeks in advance.  A predicted El Nino weather pattern for next winter could lead to below normal precipitation across the northwest.  In general, Washington State had a much better snowpack last winter than Oregon, which is one of the reasons for less concern of a bad wildfire season.

It has been determined that the Two Bulls Fire was human caused.  This is a reminder of how careful we all need to be as we enjoy the outdoors in the coming months. 

If summer outlooks from the National Weather Service are correct, Portland and much of the Northwest will melt under above normal temperatures this June, July and August.  The metro valley could experience its first hot summer since the record year of 2009. Normally, Portland experiences 55 days each year with 80 degree heat and 11 days reaching 90 or hotter.

While outlooks are not specific to high temperatures, one would conclude Portland will see a likelihood of 12-20 days with 90 degree heat in the coming months.  My research shows this summer's projected Enso pattern is consistent with past years of record heat here in the Willamette valley. The so called Enso outlooks show a neutral pattern this spring, developing into an El Nino this summer and possibly strengthening this fall.  This described pattern mirrors conditions in play during the record heat of 2009 when PDX set the all-time record for 90 degree days with 24.  The extreme heat summers of 2006 and 2003 had similar oceanic temperatures in play. 

As our region braces for a hot summer, June rainfall will be a key factor in shortening or extending this year's wildfire season.  The number of lightning strikes is unpredictable and a key factor in the number of fire starts.

Rod Hill

Portland's first 90 degree day of the year sets a new record for May 14th of 91 degrees.  The old record of 88 degrees was just two year ago, back in 2012.  No surprise to see 90 degree heat in mid-May, in fact most of Portland's daily record highs are now in the 90s.  Today surpassed May 1st when the mercury warmed to 89 degrees at the airport.  The earliest 100 degree day on record for Portland was May 28th back in 1983. 

Other record temperatures set today include 88 degrees in Newport, the old record was 78 back in 1912.  Astoria also set a record high, warming to 87 degrees, the old record was 82 back in 1939.  Salem's record high for today stands at 93.  The capital city warmed to 90 this afternoon.  Other high temperatures this afternoon include:

Seaside 91, Kelso 90, Scappoose 91, Vancouver 92, Troutdale 86, Hillsboro 89, McMinnville 89 and Hood River 84 degrees.  (These reported highs are as of 5:00 pm from the National Weather Service.)

Forecast models show slightly cooler temperatures for the metro valley Thursday.  However, a light southwest wind will bring higher humidity, meaning you might actually feel hotter, especially in the shade. 

A large slosh of warm water is migrating toward south America in the equatorial waters of the Pacific.  Latest observations indicate surface water temps  are 9 degrees Fahrenheit above normal.  If the warm water area holds together and continues to migrate to the east, an El Nino pattern would be expected next winter.  NOAA's Climate Prediction Center has issued an El Nino Watch, which means current oceanic and atmospheric conditions are favorable for the development of an El Nino within the next six months.

El Nino winters are known for warmer and drier than normal weather here in the Pacific Northwest.  A subtropical jet often develops across California, bringing heavy rains to the state and possibly Arizona, parts of Texas and the deep south. 

A detailed winter forecast for out local area is still months away, but I will be watching the equatorial Pacific water temperatures for strong clues of what we should expect. 

This week's hours of steady rain in the metro valley has been welcome snowfall on Mt. Hood, as resorts near the end of the 2013-2014 winter season.  Skibowl has closed for the season, Mt. Hood Meadows will end daily operations this Sunday, but continue 3-day weekend openings into May and Timberline will, as always keep limited runs open into the summer season.

This past week as seen 2 feet of snow at 6,000 feet and another 1 to 2 feet could fall through Thursday morning!  Lower elevations at pass level have seen 8-12 inches of new snow, although rising temperatures today will improve travel conditions and transition snow to rain at Government Camp.  All total, the test site on Mt. Hood reports a snow depth of 128 inches, which would melt into 57 inches of water.  The totals are considered 95 percent of average to date.  The snowpack typically builds on Mt. Hood through May 1st and begins the summer season melt off by mid-May if not before. 

Snowfall the last few days has built the Timberline Lodge base to 158 inches, which is to the inch the amount of snow on the ground one year ago.  Total snowfall for the season is down, but only slightly from the 2012-2013 season.  To date, Timberline reports 468 inches of total season snowfall, compared to 520 inches one year ago. 

We all know, this Cascade snow season got off to a slow start, but since February, the snow numbers have been impressive!  Dave Tragethon with Mt. Hood Meadows, says resort traffic was slow through January but has been average since the February snows began. A final day of operations at the resort scheduled for May 17th is actually later than last year.  Tragethon says, he always reminds people the Mt. Hood snow season is a marathon not a sprint.  In terms of climatology, the 2013-2014 season will go in the books as near normal, with plenty of water stored on the mountain.

Be sure and enjoy what may be the last big shot of heavy mountain snow, before the season transitions into summer.  As always, check the Mt. Hood Ski Forecast page for latest conditions and links to your favorite resorts. 

The outlook for drier and warmer than normal weather the final two weeks of April is on track!  Current forecast models show no big rain storms through the end of the month.  In fact, total new rainfall estimates show an inch of rain through April 30th which would leave Portland under 2.00" total for a month that averages 2.73" of precipitation. 

Forecast outlooks continue to call for warmer & drier than normal weather for the months of May and June.