Rod's Weather Headlines

Before I begin, let me remind you that our wet weather since October 11th was not projected. In fact, October was forecast to see below normal rainfall. To date, Portland is on track to see more than 4.00" of total rainfall for the month, well above the climate average of 3.00 inches. The last two weeks have been a vivid reminder that abrupt changes in Northwest weather patterns often happen with little warning and no forecast of likelihood.

My 2014-2105 Winter Forecast hinges on the projection of a weak El Nino or Neutral Enso cycle, referring to equatorial ocean waters off the coast of South America being near or slightly warmer than normal for the season. The graphic shows the breakdown of winter precipitation since 1950 for the years in question.

Notice the nearly 50-50 percent split of dry seasons verses wet winters. Most of the years reviewed had little total snowfall. The graphic suggests little snow for this up-coming winter and no confidence in terms of below or above normal precipitation.

It is interesting that when I compared winter seasons following the top five hot summers, in terms of 90 degree days, I also found a 50-50 percent split between wet seasons and below normal rainfall years. Snow history also mirrored the weak El Nino years with most seasons seeing a few inches, but one year showing a solid 8" of snowfall! There are a handful of other parameters I gathered and calculated, but in a nut shell my best guess to prepare for this winter season is the following:

1.  Temperatures: Normal To Above.

2.  Precipitation: No Confidence To Predict A Wet Or Dry Winter.  However deviations from climate normals will likely hold within 4 inches for the season.  

3.  Valley Snow: Trace To 4", one 8" event looks possible

4.  Mt. Hood Snow: A Good Average Season With 500 Inches Total Snowfall..

The valley's last big wind storm occurred back in December 2006 when Salem had winds reaching 80 mph and the Portland metro had 70 mph gusts, while PDX spiked at 53 mph. The repeat cycle for winds reaching 70 mph or higher seems to be about 10-15 years, meaning Portland might go another year or two before we see another "big blow."

I am a big believer in following current weather trends. Here is what to watch for:

The past 10 years have shown a trend for as much rain during the spring as the winter months, meaning a downward trend in total rainfall for the months of November - February and an up tick for March - June. All but two of the last 11 Februarys have seen very low rain totals when compared to climate averages. Something else to watch for will be the average elevation of Mt. Hood snowfall. The freezing level makes all difference in a good verses bad ski season.

I hope you enjoyed reading my thoughts and research. In a nutshell, this winter will likely offer typical Northwest weather. Mostly mild temperatures and rainy days are expected with a possible snow event just for fun!

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MY 2014-2015 WINTER FORECAST: 

1. PRECIPITATION:  Little confidence to project.  Look for a few inches within the climate normal. 

2.  VALLEY SNOWFALL:  A few inches possible, the valley may see one big 8" event. 

3.  MT. HOOD SNOW:  A good, average season, total snowfall at Timberline near 500 inches. 

4.  ARCTIC OUTBREAK:  Good chance of one or two cold episodes. 

5.  WINDSTORMS:  Not due for anything more than a few 40-55 mph gusty wind events. 

Please send your questions and thoughts to my email:  rod@rodhillforecast.com

Thank you for reading, 

Meteorologist Rod Hill

A forecast for partly to mostly clear skies Tuesday overnight and early Wednesday morning should provide a decent view of this week's total Lunar Eclipse. The full moon will slide through the dark shadow of the Earth and for 58 minutes the only light hitting the moon with be the reddish glow from Earth's sunrises and sunsets. The eclipse will begin at 1:17 a.m. and complete at 5:32 Wednesday morning. Totality will last from 3:27 to 4:25 a.m.

A Lunar Eclipse is safe to watch with the naked eye. Binoculars and telescopes will enhance the view. At the time of totality, no one can predict the exact color to moon will turn, although an orange or reddish color is a good bet.

The public is invited to a viewing party, starting at 1:00 a.m. at Milo Mclver State Park in Estacada. Rose City Astronomers and Oregon Parks and Recreation will have telescopes set up for the free viewing party. OMSI Space Science Director Jim Todd, will be presenting informal talks about the eclipse and the autumn night sky. For more information, please check the OMSI website: http://www.omsi.edu/starparties

Meteorologist Rod Hill 

September continued Portland's hot summer. Climate numbers from the National Weather Service show September tied the all-time PDX record for mean temperature of 67.6 degrees. The average low last month was 56.5 degrees, which was the 2nd warmest on record. (Records at PDX date back to 1941.) Both the mean and low temperature average were more than 3 degrees above normal. The average high temperature of 78.7 degrees did not crack the list of top 5 warmest months. The trend of warm nights leading to records while hot afternoons fell short of record territory began back in July. Take a look:

July low temperature average: 4th place all-time at PDX.

August low temperature average: Warmest all-time at PDX.

September low temperature average: 2nd place all-time at PDX.

In each of the three months above, warm low temperatures set the pace for near and record mean temperature averages. The summer of 2014 did in fact finish with no daily record high temperatures. In contrast, September tied or set 4 daily low temperature records and the summer months of July, August and September combined to tie or break 11 daily low temperature records.

The weather pattern likely responsible for record nights and hot afternoons falling short of record territory was a south to southwest wind flow and few summer days with strong east winds. Warm air masses overall helped to keep 24 hour temperatures often above normal. Most of Portland's extreme record highs of 100 degrees or better have come with intense high pressure and east winds, a combination the valley seldom saw this past summer. It may be true, that often smoky skies also played a role in holding temperatures up at night and slightly cooler during the day, although many of the record low temperatures occurred prior to wildfire smoke covering the skies in August and September.

(Mean temperature is the average temperature of a 24 hour day.)

Meteorologist Rod Hill

Today's cloudy, wet weather is perfect for the first full day of fall and a reminder that summer has ended. Despite the talk of a long dry summer, the record book will remember Portland's warm season has typically dry with a little bit of rain. Precipitation totals show only one unusually dry month: June 2.33" - above normal, July 1.05" - above normal, August .01" - one of the driest in history, but not a record and September to date .10", with more rainy days to come.

Days of above normal temperatures and Portland's typical dry season combined for a long and active wildfire season.  Portland finished the summer season with no 100 degree temperatures and in fact no daily record high temperatures! What the Rose City did experience was 70 of 94 summer days with above normal temperatures or 74 percent! PDX warmed to 90 degrees 21 days which ties for 4th place all time, behind the 24 days of the record summer of 2009. It is also interesting that Portland's longest streak of 90 degree weather was a mere three days in a row. The numbers fall short of the summer of 2009 when temperatures peaked over 100 degrees several times, including 106 degrees on July 28th & 29th. The mentioned hot streak of 90 degree weather began July 25th and continued for 10 consecutive days!

Still PDX did set temperature records including the warmest August on record in terms of the average low and mean temperatures. July's low and mean temperature averages finished in 4th place all time.

Now that our summer has ended, it is time to dream of fall. Fall outlooks call for above normal temperatures and below normal rainfall through at least the first two weeks of November when taken as a whole.

Happy fall, I hope you enjoy this week's rain and look forward to changing colors.

Meteorologist Rod Hill

Colors are changing and fall is near! Summer ends and autumn begins this coming Monday, September 22, at 7:29 p.m. local time with the Autumnal Equinox. On that day, the north and south pole will be equal distances towards the sun at 93.2 million miles away. At the moment of the Equinox, the sun stands directly over the Earth's equator. As the a result, the Northern and Southern Hemispheres are illuminated equally. The word equinox has a Latin root, meaning equal night.

On the day of the equinox, it's easy to find due east and due west from your own backyard. Just go outside around sunrise 6:57 or sunset 6:20 and notice the location of the sun on the horizon with respect to familiar landmarks.

Happy Autumn!

The Visible Satellite photo clearly shows the smoke plume from the fire east of Estacada, blowing over the Willamette valley. If you look closely, you can see brown colors in the haze. If not for the fire, Portland's sky would be perfectly blue today.

The Air Quality Map from DEQ, show in green, healthy air for much of the Portland metro. The yellow circle indicates moderate air quality this afternoon over Salem and the orange marker near Oregon City shows unhealthy air for sensitive groups as you head toward the foothills of Clackamas county. The poor air quality is likely being caused by the wildfire burning in the Cascades.

East winds are much calmer today, but still blowing to 25 mph along I-84 in the gorge and gusty to 40 up at Crown Point. Fire danger continues to be considered critical. Hot temperatures and very dry air will keep Red Flag Warnings in place through early Tuesday morning. I expect cooler weather and calmer south winds this coming Tuesday afternoon. The forecast still shows promise of widespread rain showers on Thursday. Portland has not seen soaking rainfall since July 22nd & 23rd.

Meteorologist Rod Hill

Today's Portland high of 90 degrees or better becomes the 16th day this year, which matches my summer forecast of being the hottest since the record summer of 2009. Current forecast outlooks call for above normal temperatures and drier than normal weather this coming September, October and November for our region and much of the Northwest.  

NOAA is still projecting a developing El Nino this fall, but confidence of a moderate or strong El Nino phase is eroding. A week El Nino would give little confidence of what to expect this winter season. If neutral conditions hold, in terms of Pacific equatorial water temperatures, the possibility of an extreme weather event this winter would increase. Remember, the valley is due for a large windstorm, in terms of repeat statistics of such an event.

Forecast confidence for the winter season may not increase until early November. At that time, forecasters should know if Pacific water temperatures are warming or holding close to season averages.

Meteorologist Rod Hill

(My summer forecast called for 12-20 days of 90 degree heat or hotter here in Portland.  I mentioned 16 days as my projection target which would be the warmest summer season since the record year of 2009.  Today's hot weather verifies my summer outlook!)

Monday's high temperature of 93 degrees at PDX becomes the 10th, 90-degree day of 2014.  With 90 degree temperatures likely into the first 2-weeks of September, Portland is on pace to see 16 or more 90 degree days this summer, which would be the most since the record summer of 2009, when PDX sizzled, warming to 90 degrees or hotter a record 24 days!

Current forecast models show a return to 90 degree heat Monday of next week.  In fact, it looks possible that Portland will see several 90 degree temperature days next week and possibly warm to 100 for the 1st time since August of 2012.  The map below shows an above normal temperature projection for the Northwest through October. 

It is too soon to project the up-coming winter, but at this time a long summer and warm start to fall looks to be a good bet.

Meteorologist Rod Hill

Tuesday rainfall through 4:00 pm has reached .41" at PDX, which is a record amount for the calendar date.  Other records include Troutdale where .57" fell and Salem, where .10" was a new record in a usually dry month!  
An upper low center will pass overhead Wednesday bringing widespread rainfall reaching .50" or more.  Hail and thunderstorms will be possible.  The low center will also lower snow levels on Mt. Hood to near 6,000' by late afternoon.  Timberline Lodge could see a mix of snow.  
It is possible that 2-day rainfall over Portland will reach nearly an inch, which would be well above normal for our usual driest month of the year.  July has seen only a trace of rain in several years.  Average monthly rainfall is less then 3/4 of an inch. 
Dry weather will return during the day Thursday.