Rod Hill's Winter Outlook 2017-2018

By Rod Hill on 25-Oct-17 20:20.

Like many forecasters that attempt long-range, seasonal forecast, I rely heavily on the projected Enso Cycle, which is a reference to projected water temperatures in the equatorial region of the Pacific Ocean.  A forecast for a period of NEUTRAL conditions, LA NINA or EL NINO plays a significant role in weather prediction.  NOAA's projection on October 17th, favors a 55-65% of a developing La Nina this Fall and Winter seasons. The outlook does leave the door open for present NEUTRAL conditions to continue.  

Other weather patterns I have examined for my prediction include winter's following hot summers in terms of 90 degree heat, years following 50" water seasons and winters following big snow seasons.  Last season's long list of big weather events has made my research for 2017-2018 my most difficult call, since I began seasonal outlook prediction back in 2001.  

Rod's Winter / Seasonal Outlook 2017-2018

 

  1.   Total Precipitation:  32 - 39"  /Odds favor by 67% a normal to below normal year.                           

        Would be 11-20" drier than last season.  Normal Water Year at PDX is 36 inches. 

  2.   Valley Temperatures:  1-3 degrees below normal  / Coldest months Dec. & Feb. 

  3.   Valley Snow:  No Confidence / data shows a 50% of a quiet year or a big season. 

        (My Hunch is that we slightly favor a quiet snow year with a trace to 2" of total snow)  

4.     Mt. Hood Snowpack:  A Great Season, 105% of Average or Higher!  

        Timberline 600-700" of total snowfall, Meadows at least 600", both amounts would better last year's 95% of normal  snowpack.

5.    Wind Storms:  No Reason to expect more than a few 50 mph gusts events

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My forecast accuracy for seasonal prediction dating back to 2001 is 66%.  Last winter I correctly predicted at least 5-6" of valley snow and called for a heightened chance of one big storm.  Although I called for an above normal water year, I did not see our 51" of moisture that came raining down. Industry standard for seasonal forecasting is closer to 55%.

Meteorologist Rod Hill

       

                                                         

        

 

 

       

                                                                             

        

 

Saturday Flooding Concerns

By Rod Hill on 20-Oct-17 10:40.

Forecast models show a long stretch of steady, heavy rainfall arriving Friday overnight and continuing into early Sunday morning.  New rainfall on top of what fell Thursday could equal 7" or more over the mountains (snow levels will rise back above 7,000 feet), 3-4" or more at the coast and at least 2.00" over Portland.  Some valley locations could see more than 3.00" of new rainfall over a 30-hour period!  

Intense rain rates with very heavy rainfall Saturday night will bring the greatest risk of street flooding, rising streams and increase the risk of landslides, especially in areas of the Gorge impacted by the Eagle Creek fire. 

Stay alert for possible high water.

Rod Hill

Mt. Hood First Snowfall

By Rod Hill on 19-Sep-17 09:46.

Mt. Hood picks up the first snowfall of the early fall season!  Timberline Lodge at 6,000' reports .27" of total moisture from Sunday night through Monday night.  Surface reports show 2-3" of wet snow on the ground.  Temperatures will hold near 32 degrees through Thursday morning, meaning new snow accumulations will be possible, but snow melt will likely occur as flakes try to stack up.  

(Below are resort observations Tuesday morning)

Mt. Hood Tuesday Morning

Snow levels near 5,000' through Wednesday night will mean all rain over HWY 26 and Government Camp.  Snowfall on the upper mountain will melt away this weekend as dry, warm weather returns.  Stay updated on my Mt. Hood Weather Page.

-Rod Hill

Hot back half of summer

By Rod Hill on 26-Aug-17 10:13.

Portland likely to see 90 degree heat this weekend with temps Sunday rising to near 100 degrees. As of Saturday morning, August 26th, PDX has hit 90 or better 15 days. With forecast models showing possible 90 degree heat through next Tuesday and again Labor Day weekend and another possible heat stretch around September 10th, the number of hot days may rise into the mid 20s, which would put the summer of 2017 on the list of hottest summers. Obviously, my projection of no more than 14 hot days (reaching 90 or better) is turning out to be way off! I simply did not see reason to expect what may be 12 sizzling days in the month of August. The most 90 degree days on record at PDX for August is 13 back in 1967. This month may challenge the record. Also, if Portland hits 90 or higher 25 times, this summer will be second to the hot year of 2015 when PDX hit 90, 29 times. Rod Hill

Rare heavy mid-May snowstorm

By Rod Hill on 17-May-17 10:35.

A rare snowy morning in May at Timberline Lodge. Not rare because of the snow, but rare because of the depth. According to auto-snow weather stations at 6,000’, Timberline has 28” of new snow over the past 36 hours! The Monday night - Tuesday night snowstorm hit Mt. Hood like a mid-winter dump and is quite rare for so late in the season. Snow levels during the storm dropped to just above 3,000 feet, bringing traction tires or chain requirements over Cascade passes. Today’s snow level will rise to 5,000’, bringing melting snow on HWY 26 at Government and improving travel conditions overall. Timberline has picked up more than 600” of snow this season, nearly 100” more than the winter of 2015-2016. Historical records for mid-May snowstorms are difficult to find, because most snowpack measurements end for the season on May 1st and this forecaster also stops logging the snowpack as May begins. Rod Hill

Trying to reach 70 degrees.

By Rod Hill on 21-Apr-17 07:38.

After a chilly 30 something start, much of the Willamette Valley and southwest Washington will warm to near 70 degrees this afternoon. Sunny skies and developing east winds will bring the warmth. Compared to April of 2016, we have been forced to hold our patience this spring for the arrival of warm weather. One year ago, Portland begin April with 76 degrees to start the month and saw temperatures rise to 89 degrees on the 19th. This year, 2017 has produced two 63 degrees, but nothing warmer as of this morning. This afternoon's high will be the warmest of the year to date and may reach 70. Today's record high is 82 degrees and the climate average is 62 degrees. The last time PDX touched 70 was October 8th. Enjoy today's sunshine, because showers return Saturday morning. Rod Hill (April 21, 2017)

February all-time record for rain in jeopardy

By Rod Hill on 20-Feb-17 08:15.

Heavy rain on this Monday morning, February 20th, has pushed total rainfall at PDX over 9.00" for the month and into 2nd place on the all-time February wet record list! Less than an inch of water is needed to break the all-time February rainfall record of 10.03" set back in 1996. It is likely that we will break the record, in fact we may do so this week. Total rainfall for the Water Year, starting October 1st and ending September 30th is now over 32.00 inches. Normal for the 12 month period is 36.03 inches. The surplus at this time is more than 11" to date, which is roughly 3 months of extra rain since October. Rod Hill

East winds to bring snow or ice

By Rod Hill on 31-Jan-17 07:46.

Cold east winds becoming gusty Tuesday night and blowing 40-50 mph near the gorge Wednesday and Thursday will set the stage for more winter weather over the Portland and Salem metro areas.  At this point, any moisture before Thursday night will be light and scattered, meaning no problems are expected.

Heavier snow looks possible Friday morning with a possible icy mix.  Forecast models show the potential of 2-4" of metro valley snow, which would cause closures. East winds could keep temps near freezing through Saturday morning with more snow or ice potential.  Saturday afternoon is expected to see south winds bring warming with a transition to all rain, except areas near or inside the Gorge.

-Rod Hill

ICE STORM WARNING FOR PORTLAND

By Rod Hill on 17-Jan-17 03:23.

ICE STORM WARNING FOR PORTLAND-VANCOUVER METRO AREAS UNTIL 10:00 PM TODAY.

12 NOON UPDATE:  A period of dry weather this morning has helped a fuel a warm up.  Most areas away from the Gorge and not getting hit with gusty east winds will see rain this afternoon with temps in the mid 30s and warmer.  This includes downtown Portland.  I continue to watch cold pockets in Clark county, but warming may take place.  Troutdale and other cold windy areas near the gorge should expect accumulating freezing rain ice this afternoon and tonight.   -Rod Hill

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Light freezing rain will begin 7:00 - 8:00 this morning. Areas away from the east wind will see less than .25" of ice accumulation and could see temps warm above 32 degrees by early afternoon. Gorge areas (Camas, Troutdale, Gresham etc.) likely to see bad ice accumulation up an inch. Freezing rain may last into Wednesday where east winds are blowing the hardest. Areas above 1,000' will see temps warm the fastest and turn to rain.

Salem to see light ice then all rain by the noon hour. Areas near and north of Woodland also should see warming temps by early afternoon.

ICE STORM WARNING UNTIL 6PM WEDNESDAY FOR THE GORGE, INCLUDING HOOD RIVER.  

Heavy ice accumulations in the Gorge may force I-84 closures.

FLOOD WATCH IN EFFECT THROUGH AT LEAST THURSDAY.  

Heavy rain likely Tuesday afternoon - Wednesday night, followed by more rain into the weekend. 

COAST HIGH WIND WARNING - TUESDAY AFTERNOON - WEDNESDAY MORNING.

Possible Freezing Rain, Flooding Concerns

By Rod Hill on 16-Jan-17 03:24.

Cold east winds, blowing out of the Gorge to set the stage for possible Tuesday morning freezing rain in Portland and Salem.   

Precipitation is expected to return early Tuesday morning and may fall as freezing rain, depending on temperatures.  Hours of freezing rain are possible into early afternoon and possibly longer near the gorge in places like Camas, Troutdale and Gresham.  Ice will be possible at elevations near and lower than 2,000 feet.  During the afternoon, south winds should bring warming temps, changing most of the valley to rain.

The Gorge will likely see a bad ice storm with 24 hours of possible ice accumualtion from freezing rain Tuesday into Wednesday afternoon.  Significant ice accumulations of .75" are expected.  Conditions could get bad enough for I-84 closures.  

Flooding rains and rapid snow melt continue to be a concern.  A FLOOD WATCH is posted for much of our region.  Inches of metro valley rain will fall Tuesday through Thursday. The metro valley could see 2-3" of rainfall, while 3-5" fall at the coast and 4-7" hit the Coast Range.  Rising snow levels to 8,000' will melt mountain snowpack while heavy rains fall.

 Keep updated as weather will be a top story through mid-week.

-Rod   /  January 16, 2017