Rod's Weather Headlines

The Portland record book shows the driest weeks of the year are typically July 11th - August 22nd.  With an exception or two, the climate daily rain chance is 5-15% through the stretch of days.  This summer has been dry even by our summer standards!  Dating back to July 3rd, PDX has recorded .02" of rain through the 25th of August!  This is the driest stretch over the mentioned days since I began keeping records in 1999!  Including the summer of 2003, when July recorded a trace for the entire month.  The historic daily rain chance averages 25% August 23rd through Sept. 13th.  After which, the odds of rain increase has we get into the first weeks of fall.  

With all the talk of cloudy mornings this summer and a lack of extreme heat compared to a year ago, the headline of how bone-dry we have been has gotten lost.  If the forecast holds true, much of the metro area will see passing rain showers this coming Monday.  The rain would be a welcome sight to your lawn and mine!

Below are a few headline notes from a weather conference earlier this year in Colorado.  The point of the information is not to debate the role of man, but to confirm that earth's climate is seeing what many are calling rapid change.  It should be noted, the planet's climate has always evolved and will continue to do so.  Many of the data sets measured today can be compared to estimates from thousands of years ago. The current phase of warming opens up a fascinating period of scientific research and speculation.  

1.  20% of all carbon dioxide released into the atmosphere has been burned since 1997.  

2.  A quarter of carbon dioxide released into the atmosphere will remain for 1-3,000 years.

3.  The United States currently releases twice the output of Europe.  

4.  Computer climate models are inconsistent toward the amount of warming over the coming 100 years, the            reason is the uncertainty of heat absorbed by the oceans.  

5. Sea level could rise 3 feet by the year 3,000, simply due to thermal expansion of warmer water                         temperature.

6.  Increased beach erosion due to rising sea level is already being seen in the Arctic.

7.  Current estimate for ice free summers over the Arctic is the year 2030.  

8.  January - July of this year, warmest global temperature on record.

9.  Good News:  Leading researcher believes warming temperatures will increase tropical storms by 1% at              most.  An increasing subtropical jet stream will produce shear and limit tropical activity.

1.        Is the planet in a warm cycle - yes
Just because we are currently off of the peaks of a few years back does not mean the warm cycle is over.  Overall, the global temperatures remain consistently above climate normal's.  Ice loss is still a concern.


2.        Do we know if humans played a role in our recent temperature spike??  No we do not and any speculation is just that - speculation.


3.        Has climate always changed and moved into varying cycles?  Yes!  In fact the next ice age is some 6 or 16,000 years away.  (I forget which?)



4.       Do scientist overwhelming believe that warming temperatures lead to stronger storms and climate change from fresh water glacial melt into the world's oceans?  Yes!



Fresh water runoff into the oceans, alters the salinity and therefore the flow of currents which leads to a change of the air flows aloft in the

Atmosphere.



5.        Do we know if CO2 emissions are leading to warming?  No.



Do we know if C02 in the atmosphere is currently well above expected levels??  Yes



Do we know if humans are emitting tons of C02 into the atmosphere?  Yes we are.



6.        Does it make sense to be a good custodian of our planet and atmosphere??  Yes

Based on the above, why wouldn't we want to limit pollution into the atmosphere??  I would support going green....just like I support not
throwing a coke a cola can out of my car when driving or parked.

In conclusion, if we are undergoing climate change, what a spectacular time to live and witness.  Of course, our latest warm spike could just be a 30 year natural cycle that will soon change.   Does anyone know ??   No   /  Lets say we in the beginning of long term climate change, could the trend be natural? Of course.

At the end of the day, we are just stupid humans who not as good at pre-telling earthquakes as animals.

Rod Hill

Headlines of this weeks heat wave:  Burn Ban for Clackamas county due to hot, dry and windy conditions, Air Quality or Smog Advisory in effect through the weekend.  People are asked to drive less.  The Heat Advisory is in effect through Monday.  90 degree temperatures look likely through Tuesday.  Typically, Heat Advisories are issued when the temperature and or heat index will reach 95 degrees or above for a period of several days.  If the forecast holds true, Portland will have nine 90 degree days when next Tuesday ends.  The annual average is 13 days.  90 degree temperatures are often reached into the month of September, so we could reach the yearly average, despite a cool start to our summer. Stay Cool! 

Tonight is the peak of the Perseid Meteor Shower.  Skies will be clear for best possible viewing!

New research discovers reason for our cool and cloudy summer.  The discovery is linked to El Nino, a warming of Pacific equatorial waters and La Nina, a cooling of the same water.  Last winter's pleasant and dry weather was linked to an El Nino Pattern.  Since June of this spring, the waters have been cooling and transitioning to a La Nina pattern, expected to continue through this coming winter.  New research details that when a rapid transition occurs during the early summer months from El Nino to La Nina, the result is a period of low pressure troughs near and over the Pacific Northwest.  This trough pattern which we have had all summer, produces a consistent northwest flow that leads to marine clouds and cool days.  This new research will for the first time, enable forecasters to predict the possibility of a cool summer whenever a rapid transition to La Nina is expected during the mentioned time frame.  This is a "big deal" because up until now, the science has offered very little prediction confidence for the summer season in general.  

The National Weather Service reports a 70% confidence level that La Nina conditions in Pacific waters will be in place by the end of this year.  Present sea surface temperatures are just shy of 2.0 degrees F below normal in the equatorial waters.  The transition into La Nina is believed to be taking place. Confidence level of this winter's forecast will depend on how strong the La Nina becomes.  The colder the Pacific waters, the greater the confidence of a cool, wet active winter season. Snow data continues to be too inconsistent to predict with any confidence.  The headline today is growing confidence of a return to more wet, cool days, with an active storm pattern November through January.  

Current outlook forecasts call for drier than normal weather with near average temperatures through the 20th of August.  Near normal temperatures are expected into the month of October along with normal to below rain totals.  November - January are predicted to be cool & wet for the Northwest.  Based on the above, lets hope for a nice early fall into October and expect to get hammered this November!

With all the complaining about our cloudy starts this summer, I went to the record book and looked at July 1st - August 5th going back to the year 2000.  Here is what I found: This year 20 of the 36 days had morning clouds over Portland. That works out to be 55% of the time.  The average number of cloudy starts dating back to 2000 is 13 days.  So this year, we have had an extra week of cloudy mornings.  20 cloudy mornings is the most since 2001 had 22 days through the same period.  Here are the last five year:  

July - August 5th 2010:  20 days

                       2009:  13

                       2008:  12

                       2007:  14

                       2006:  13

Celestial Triangle

When the sun goes down tonight, step outside and look west. Venus, Saturn, and Mars have converged to form a triangle in the sunset sky.   The three planets will remain in triangular formation for many nights to come, only the angles will change.  Tiny Mercury will be to the distant far lower right from the trio later in week.  Sunset for Portland starts around 8:38 p.m. PDT on August 1 up to 8:29 p.m. PDT by August 8.  Enjoy!  

I saw the triangle the other night and Mercury off to the right!  I looked straight up over downtown Portland and Mercury trailed off to the southwest.  

Northern lights may be visible tonight and Thursday.  You need to get way from the city lights and look to the north to have a chance.  Marine clouds have been arriving around midnight, so take a look before 11:00 pm to be safe.  The chance of seeing the lights are on the slim side, but you never know.

The July PDX climate report is out and as I have mentioned, the month is closer to normal than you would think:

Average High:  79, below normal -.3 degrees //  Av. Low:  56, below normal -1.0 degrees // Mean Temp:  67.5, below normal -.6 degrees

The above states July was within one degree of matching the climate average.  Total rain came early in the month:  .59", below normal -.13 inches.  We reached 90 degrees four times, which is normal.  By comparison, July 2009 was the 2nd hottest on record with a mean temperature of 73.6 degrees, warmer than this year by nearly 6 degrees!

Forecast outlooks show near normal weather expected August and September.  There is more data to support slightly cooler than normal.  No long heat waves are expected.