WINTER OUTLOOK 2016-2017

Before I announce my projection for the winter of 2016-2017, here is a quick word as to where we are coming from.  Last winter was as expected, a strong El Nino pattern that produced a healthy snowpack on Mt. Hood, much above normal rainfall for the Willamette Valley in terms of the water year dating back to October 1st and ending Sept. 30th and above normal temperatures overall.  Below are a few headlines for the water year:  

1.  Mt. Hood Test Site Snow Ending April 30th:  90" depth, 41.7" of water storage for 67% of normal.

2.  Portland (PDX) Total Water Year Precipitation Oct. 1st - Sept. 30th: 47.02" / 10.99" above normal

3.  Portland Season Snowfall:  1.3"

4.  Highest Wind Gust (PDX)  SW G 55 mph, December 21, 2015

5.  Portland Temperature average:  2.5 degrees above normal mean temperatures.

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The strong El Nino of last winter weakened during the spring and Enso Neutral Conditions are in place.  NOAA projects a 55-60% of Neutral conditions holding through the winter of 2016-2017.  My forecast projection work is based on data sets showing Neutral condtions, dating back to 1950.  I further examined Neutral seasons following a strong El Nino winter.  My outlook is based on averages of the above mentioned data sets. 

Here is my Winter Forecast for the Portland Metro Valley & Vancouver:  

1. Temperatures likely to be near normal or above by no more than 2.0 degrees.

2.  Rainfall: While a dry season is possible, odds favor rain totals near 37.90" / 1.87" above normal.  November and December are likely to combine for a wet start to the rainy season. 

3.  Valley Snowfall:  At least 1 or 2 mini-snow events dumping 3-6" of total snowfall are likely.

Also, I see an elevated chance to see an 8-12" snow event.  The historical average for this winter's pattern is 6" of total season snowfall.  However, odds are equal of seeing a big snow event as to seeing less than 3.00" for the year.  The December snow of 2008 that dumped 19" and the winter of 2003-2004 that produced 12.6" are in the data set. 

4.  Windstorms:  Odds are heightened for valley windstorms with south wind gusts reaching 50 mph or higher. The majority of Willamette Valley windstorms happen in Neutral and El Nino years.  Most recently, Neutral years brought the windstorms of December 2014, when PDX had a 67 mph wind gust, the highest since 1981 and the storm of December 2006, which had a blow of 80 mph in Salem and 70 in downtown Portland, but 53 at PDX.

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Perhaps most important to many is the Mt. Hood Snow Outlook.  My snow records for Mt Hood only go back to 2000.  Of these years, I found 8 seasons in the data set matching this up-coming winter scenario and 6 of the years had solid snowpacks!  The projected snowpack for this up-coming winter is 72% of average, which would be slightly higher than last winter.  I do want to point out that the 2 bad seasons I looked at include the record low snowpack season of 2014-2015.  In otherwords, there is reason to be cautious with the snow projection, but the best bet calls for a solid year with Timberline seeing more than 500" of total snowfall and Meadows more than 400 inches - both would be considered near normal.  Also, odds favor a good start to the season with a decent snowpack build during the month of December.

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My Seasonal Foreast track record dates back to 2001 and has a 67% accuracy rate, including my 2016 summer prediction of 16 total 90 degrees at PDX. The airport hit 90 degrees, 14 times this past summer.  

Industry standards for seasonal prediction is considered to be less than 50% for precipitation and 55% for temperature outlooks. 

-Rod Hill

 

Last weekend of September brings record cold

By Rod Hill on 30-Sep-19 17:42.

The wild weekend weather was highlighted with Sunday’s headline of the coldest September
day on record for the Rose City!  Downtown Portland recorded a high temperature of 49 degrees,
becoming the only September day in 145 years of record keeping to not reach 50 degrees.

Read more...

First possible fall freeze

By Rod Hill on 26-Sep-19 17:41.

Today’s weak cold front is the first push of colder air returning to the Northwest.

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EF-0 TORNADO CONFIRMED

By Rod Hill on 10-Sep-19 00:01.

NWS confirms an EF-0 tornado Sunday for three minutes, 6:44-6:47 pm in western Multnomah County. Winds estimated at 65 mph, path length 800 feet by 360 feet wide at maximum.

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Tuesday sets record high temperatures

By Rod Hill on 28-Aug-19 00:01.

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE PORTLAND OREGON
0425 PM PDT TUE AUG 27 2019

...RECORD HIGH TEMPERATURE SET ON AUGUST 27TH, 2019...

A RECORD HIGH TEMPERATURE OF 98 DEGREES WAS SET AT PORTLAND OR
TODAY.

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EF-O Tornado Confirmed in Portland

By Rod Hill on 03-Jul-19 00:55.

Monday July 1, 2019

National Weather Service confirms EF0 tornado, Sunday at 5:24 pm, lasting 6 minutes, 3 miles N/NE of downtown Portland. Winds estimated at 80 mph, a 1 mile storm path width max width of 40 yards.

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Tuesday Weather Shift To Bring Needed Rainfall

By Rod Hill on 13-May-19 10:16.

Monday will bring one more warm, sunny afternoon with highs in the 70s before a cool, showery weather pattern returns Tuesday. Right now, rain is likely to develop Tuesday afternoon and mostly end by the evening hours. Valley rainfall tomorrow could reach .25 inches with highs in the low 60s.

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Summer Outlook 2019

By Rod Hill on 01-May-19 22:06.

 
 
The outlook from the National Weather Service May through July projects all of the western United States to see above normal temperatures when averaged over the three month period.  The map on the right shows a below normal rainfall pattern for the same

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WINTER ADVISORY, SNOW LIKELY TONIGHT

By Rod Hill on 26-Feb-19 23:24.

THE NWS has issued a Winter Weather Advisory for Portland, Salem and all areas in purple on the map. This next round of snow starting mid to late evening and continuing through tomorrow morning may drop 1-3" of snow. The best chance of more than an inch will be in the hills and south of Portland.

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WINTER STORM WATCH TONIGHT - MONDAY

By Rod Hill on 24-Feb-19 14:55.

 
WINTER STORM WARNING SOUTH OF PORTLAND, INCLUDES SALEM
 
 
Below is the surface map mid-morning Monday from the GFS model. Note the  L center is
cutting across Crater Lake.

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Snow Likely For Portland

By Rod Hill on 08-Feb-19 00:00.

ALERT FOR LIKELY SATURDAY SNOW AND AGAIN SUNDAY NIGHT
 
Confidence remains high that lowest elevations of the I-5 corridor from Albany to Vancouver

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