Rod's Weather Headlines

I expect clear skies for Sunday evening's full, "SUPER" moon and total Lunar Eclipse.  The so-called Harvest Moon will be the closet full moon to earth of 2015, making it a "SUPER" moon.  At the satellite's closet point, the moon will be 221,753 miles from Earth.  The close proximetry will make the moon appear 14% larger and 30% brighter than a typical full moon.  Look for the moon rise in the eastern sky at 6:55 pm.  

The added bonus Sunday night will be a total Lunar Eclipse.  Between 7:11 and 8:21 pm, the moon will be completely in the dark shadow of the Earth.  The moon will likely have a reddish glow, as light from Earth's sunrise and sunsets illuminate the moon.  Lunar Eclipses are safe to view.  In fact a standard pair of binoculars will enhance viewing. 

Rod Hill, with special thanks to Jim Todd, OMSI Director of Space Science Education. 

Sunset tonight will be 8:23 and we should have a mix of partly cloudy skies or mostly clear conditions unless late day Cascade thunderstorms develop and throw cloud cover back over the metro valley. Experts say to look low in the northeast sky shortly after sunset.  Viewing increases later in the night and you are advised to simply look up to see so called shooting stars in all directions!  The meteors will be traveling at more than 1000 mph at a distance some 30-80 miles above ground.  

Tonight's shower is made possible as Earth travels through a debris path left by comet Swift-Tuttle back in 1992.  While tonight will be peak viewing, meteors will be occuring through the 25th of August. 

Rod Hill

July continues Portland's trend of hot summer weather!  The average high, low and mean temperatures at PDX for the month were all the second warmest on record:

AVERAGE HIGH:  86.7 - 6.1 degrees above normal

AVERAGE LOW:  61.1 - 3.3 degrees above normal

AVERAGE MEAN:  73.9  - 4.7 degrees above normal

Total rainfall for the month was near normal at .57", just .08" below average. 

You may recall that June set the record at PDX for being the warmest all-time in all three temperature categories.  Depending on August, we may be experiencing the warmest summer in Portland's recorded history. 

Forecast outlooks call for above normal temperatures during the months of August & September. 

Rod Hill

FORECAST UPDATE JULY 29TH:  FORECAST MODELS SHOW POSSIBLE 100 DEGREE TEMPS THURSDAY & FRIDAY, FOLLOWED BY 90s THIS WEEKEND.  MONDAY - TUESDAY COOL DOWN MAY BE "FOOLS GOLD", MEANING HOT AIR MAY STICK AROUND INTO TUESDAY.  KEEP UPDATED FOR 7-DAY CHANGES. 

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A forecast for 90 degree temperatures through this weekend and possibly lasting into next Tuesday or Wednesday could break the all-time record of 90 degree days for one year, set back in 2009.  The record is 24 days and Portland will hit 90 for the 19th time this year Wednesday, July 29th.  If the hot forecast holds, PDX would reach 90 for a record breaking 25th day next Tuesday, August 4th.  

While cooler days are in the forecast the back half of next week, 90 degree heat is common through the 1st 10-14 days of September and possible into early October!  All of this means, Portland has the potential to smash the all time record.  Current forecast outlooks call for above normal temperatures through October.  

The July record for 90 degree days is 14, set back in the hot summer of 2009.  PDX will hit 90 or better, each of the last 3 days of this month, making it 12 days total. 

A HEAT ADVISORY WILL BE IN EFFECT during the up-coming stretch of hot weather.  Please stay hydrated and protect your body with clothing, hats and sunscreen.  Fire danger continues to be very high. 

Rod Hill

It comes as little surprise that JUNE 2015 was the warmest on record at PDX in nearly every category!  

Here is the list of records:

1.  Highest average maxium temperature:  82.7 degrees, 9 degrees above normal.

2.  Highest average low temperature:  57.9 degrees, 4 degrees above normal. 

3.  Highest mean temperature:  70.3 degrees, nearly 7 degrees above normal. 

4.  The low temp of 71 degrees, June 27th was the warmest low temp for June - all time.

5.  The number of 90 degree days was the most on record:  9 - the old record was six 90 degree days.

(Total rainfall of .40" was the 6th driest on record at PDX)

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Let's hope for a cooler July.

Rod Hill

Portland and Salem are grabbing a spot in weather history for what some may say are all the wrong reasons. A combination of dry weather and near record hot temperatures so early in what is called meteorological summer may have bad consequences down the road as fire season looms.  

Let's begin with Portland's lack of spring rainfall. Dating back to April 1st, PDX has seen 2.74" of moisture, a total less than 50% of normal. With forecast charts showing little chance of significant rainfall through the end of June, Portland may go into summer with the least amount of April-June rainfall in more than 30 years! It is a well known climate fact, that metro valley precipitation in July and August comes primarily in scattered showers and thunderstorms and can total next to zero for each month. In other words, as fire season begins, Portland may be looking at a 5-month period of limited rainfall and increasingly dry conditions through August. The driest April - June on record at PDX occurred back in 1987, when only 3.71" of rain fell. I project this year's total will be 2.94" or less.

As for our 4-day heat wave, last Saturday through Tuesday, the National Weather Service reports it is one of the earliest stretches of 90 degree heat on record! The graphic shows Salem's run of four 90 degree days, including a high of 96 is the longest, early run of heat in 120 years! Portland hit 90 or higher three days in a row, becoming just the 4th such early heat wave in the last 75 years.

As to what it all means as we look forward, the answer is uncertain. Portland's summer rainfall is very sporadic and extremely dry weather is typical. Several temperature outlooks call for the Northwest to see well above normal summer temperatures. However, I believe it is unlikely that Portland will approach last year's total of 21 days reaching 90 or hotter.

Meteorologist Rod Hill

Clouds over the city and wet days to begin June are both good news, following the 5th driest May in the record book for PDX. Portland picked up .59" of rain last month, just 24 percent of normal for a month that typically sees nearly 2.50 inches. The forecast gives the Rose City a chance to pick up about 1/2 inches of total June rainfall through tomorrow. 

Despite a run of cool days last month, the temperature averages ended just shy of 3 degrees above normal, including the 3rd warmest low temp average for the month and the 5th warmest mean temp on record at the airport. 

By now, you may have seen this weekend's 7day forecast calling for the first 90 degree heat of the year. To date, Portland's warmest temperature of 2015 has been 85 degrees. Extended forecast models show temps cooling off next week and a stretch of below normal weather toward the middle of the month. Nothing unusual about seeing 90 degree weather in June. This forecaster still believes we have a chance to see a comfortable summer with near average 90 degree temperature days of a dozen or so. 

Fire season has begun and daily fire weather briefings are now taking place. The numerous lighting strikes of the past days have been accompanied by heavy, soaking rainfall, which of course is good news. So called dry lightning will be our worst fear this summer as temperature averages warm and a typical dry northwest summer kicks in.

(Live camera image of Portland, courtesty of KGW TV)

Meteorologist Rod Hill

Despite warm temperatures last winter, Portland will likely see a comfortable, Northwest summer! The National Weather Service projects above normal temperatures for all of the west through July and likely into August. (Shown in the brown shading.) However, my findings show temperature deviations likely to be close to normal with a slight edge toward an above normal average by one degree celsius for the three months of meteorological summer, (June, July & August).

Our current ENSO phase which looks at Pacific water temperatures, shows slightly warmer than normal readings. Looking at all summers with similar conditions dating back to 1950, roughly 40% of summer months were actually cooler than normal! When all years are averaged, the temperature expectation figures out to slightly warmer than normal. The data set used shows the average number of 90 degree days from May through September to be 10-15 days.  Eleven hot days of 90 or better is considered normal. Despite the record hot summer of 2009 with 24, 90 degree days and last summer's 21 hot days, the overall trend of hot summer days is actually down when looking at 30 year averages.

The rainfall forecast is harder to pinpoint. Keep in mind, July and August rainfall typically comes from scattered thunderstorms, which can drop an inch of water in one day, putting monthly totals above average. It is not unusual for July and August to see only 1-3 days each month with measurable rainfall. Notice the National Weather Service has much of the west in the "equal chance" category for precipitation. I project June has a 50-50% chance of seeing 2.00" of rainfall, which would be above normal. I expect July and August to see mainly dry weather, but keep in mind, we only need a thunderstorm or two to go in the record book as wet!

My personal seasonal outlook accuracy dating back to 2001 shows a rating of 63%, which is roughly 15% above industry standards. You may remember last summer, I projected the warmest summer since the record year of 2009, calling for up to 20 days of 90 degree heat - PDX ended up with 21 days.

To recap: I expect a pleasant summer, possibly slightly warmer than average temperatures, but no more than 15, 90-degree days. Rainfall could be above average for June with 2.00" falling, but July and August will see typical dry weather, minus possible downpours with scattered thunderstorms.

Meteorologist Rod Hill

Beautiful sunshine has returned along with expected 70 degree temperatures into the first of next week. Warmer overnight temps in the 40s are also in the forecast for the next 7 days. After that, the final days of April look wet with west breezes. All of this means Portland's freezing season is likely over and the frost free growing season has begun! Typically, the threat of 32 degree temperatures ends for the entire metro around the 1st of May.

The average final freeze for PDX is March 30th. However out-lying areas such as Hillsboro often experience frosty mornings through May 1st. Record lows of 32 degrees can be found for out-lying areas through mid-May, but are rare and not typical.

All of this means, it is likely safe to put out hanging baskets and plant flower beds with vegetation that will thrive with temperatures no colder than 35-40 degrees at night. Grass seed quickly germinates with most hours holding near and above 50 degrees each day.

If my projection is correct, the final freeze for PDX this spring was back on March 5th and the last hard freeze in the 20s was all the way back on January 2nd when the temperature dropped to 26 degrees!

Happy spring planting!

Meteorologist Rod Hill 

Colder spring weather has arrived! A cold front last night dropped snow levels to 3,000 feet, bringing wintry travel conditions to Government Camp as shown on the ODOT camera this morning. Timberline Lodge reports 5" of snow with more on the way! Heaviest snow showers could produce a snow mix near 2,000 feet. Here in the valley, we are in store for days of sun breaks and heavy scattered showers. Ominous skies at times may bring hail and lightning.

Colder spring weather has arrived! A cold front last night dropped snow levels to 3,000 feet, bringing wintry travel conditions to Government Camp as shown on the ODOT camera this morning. Timberline Lodge reports 5" of snow with more on the way! Heaviest snow showers could produce a snow mix near 2,000 feet. Here in the valley, we are in store for days of sun breaks and heavy scattered showers. Ominous skies at times may bring hail and lightning.

A reminder that Portland is doing fine in the rain department. March will likely wrap up roughly an inch of above normal for the month. Any snow on Mt. Hood is welcome, but at this point, the season snowpack is likely to remain below 50% of normal through the final report May 1st.

The big story I want to highlight is an abrupt change in our weather pattern. The precipitation outlook map shows western Oregon shaded in green, meaning above normal moisture is likely through the first two weeks of April! Daytime highs will likely average below normal, while overnight lows will be normal to above.

Forecasters started to talk about the abrupt change to cool wet weather last week. However, the monthly outlook for April issued several weeks ago, failed to pick up on the weather change. At this point, I have little confidence for the May and June forecast. More to come on our summer outlook in the weeks ahead.

Meteorologist Rod Hill