Rod's Weather Headlines

The latest reports say at least 66 dead in Alabama and 193 across the southeastern states.  These reports are preliminary and conflicting depending where you look, but are likely to go much higher.  Preliminary reports from the National Weather Service list 164 reports of tornadoes.  Many of these reports are likely from the same twister. Wednesday April 27th, all total saw 660 reports of severe weather.  

Wednesday's storms were fueled ahead of a strong jet core plunging south across the gulf coast states.  Jet stream winds that reach speeds between 80 & 200 mph clear out the air above, which forces surface air to rise and fill the void.  This lifting when added to other lifting agents such as a cold front or low pressure area often creates explosive storms.  The gulf coast states add to the severe weather potential when moist, unstable air from the gulf moves northward into the storm zone.  Some scientist believe changing weather patterns are pulling cold air from the Arctic farther southward more often.  If true, powerful jet streams will be created more often across the central and southern United States.  These jet cores during the spring, when clashing cold and warm air mass temperatures are often extreme, lead to severe weather outbreaks.  

As we head into the summer months, the greatest threat of severe weather will shift northward.  Severe storms will become more active across the upper plains and the great lakes in a typical year.

Video and tornado pictures from the Alabama storm can easily be found by searching the subject.  The Alabama tornado is likely to be an EF 4 or EF 5, meaning rotating winds in the vortex reached 200 mph or higher!

A friend of mine - Brian Schmit, put together the following research:

__________________________________________________

Period of record for Portland (PDX), 1949 - 2011

Least number of days above 60 degrees for any year before April 30th

1.  2011   /   5 days as of April 25th

2.  1955   /    9 days

3.  1975   /  10 days

4.  1967   /  11 days

5.  1950   /  13 days

6.  2008   /  15 days

______________________________

If the forecast holds true through this Saturday (April 30th), 2011 will have 6 days above 60 degrees through the month of April.  The least of any year since records began at PDX!

Anyone surprised?

Today's rainfall puts PDX over the top for the water year which runs Oct. 1st through September 30th.  The water year average is 37.07 inches.  As of 7:00 pm today, April 15th, Portland has received 37.46" of rain for the water year. Meaning, if we do not get another drop of rain, come Sept. 30th, the current water year would end above normal - wow!!

PDX has received 1.54" of rain over the past two days.  Thursday saw a daily rain record of .88" and today set a rain record with a total of .66" as of this evening.  The current April rain total is 3.17".  Normal for the entire month is 2.64 inches.  The wettest April at PDX was back in 1993 when 5.26" fell.  If we get to 4.05", this month would tie for 5th place on the wet list.  

Our wet spring has really been something up in the Cascades as well.  Timberline Lodge reports a base of 206" today, Skibowl has a base of 103", both are highs for the season.  Here in the valley, the current water year surplus is 8.89", also a high for the season.  The surplus means we have had roughly two extra months of rain since October!

Hang in there - the La Nina is weakening.  There is reason to believe our weather will dry out and return to normal around mid-May.  Normal would be very, very nice!  Still believing we will have a nice summer. 

MT. HOOD, OR (Immediate Release) -- Skiinfo collects ski resort data from all ski areas in Europe and North America - more than 2,000 in total - and according to their information, Mt. Hood Meadows received more snow than any other ski area on the planet the first week of April!

By the end of Thursday, April 7h, 2011 Mt. Hood Meadows had received a total snowfall of 121cm (just over four feet) in 7 days. Skiinfo awarded this snazzy certificate to Mt. Hood Meadows, which can be seen at it’s website skiinfo.com.

_______________________________________________________________________________________

Pretty amazing!  Over at Timberline Lodge, I keep a season record each year.  Last year, the lodge had a total of 405" of snowfall through the end of March.  This year, Timberline had received 572" by March 31st.  Of course, this April has been amazing! 

* The amounts I mentioned are total snowfall for the season, not depth on the ground.

This past Friday was a reminder that we can still see freezing temperatures in April.  PDX tied the days record low of 31 degrees.  The average final freeze for Portland is March 30th.  The record latest spring freeze is May 2, 1964. 

Colder locations such as Salem and Hillsboro typically see a few freezing starts through April 30th and have had freezing temperatures into the 2nd week of May. 

This coming week, I am watching Tuesday morning for possible freezing spots.  

_________________________________________________________

You may recall an earlier post where I documented an early final freeze average over the past 10 years.  Dating back to 2000, PDX has an average final spring freeze of March 15th.  This year is proving to be colder. 

Update:  March 31st , Three Records Fall This Month!

1.  23 consecutive days of measurable rainfall  - a new record.  The old record was 16 straight days back in 2003.  

2.  Portland (PDX) had measurable rainfall 28 of 31 days.  This is a new record for the most days with measurable rainfall in the month. The climate average for the entire month is 17 days.  The old record was March of 2003,  when 27 of 31 days saw .01" of rainfall.   

Total monthly rainfall is 6.43".  Monthly average is 3.71".  March 2011 is now the 5th wettest in the PDX records, dating back to 1941. The wettest March at PDX was 1957 when 7.52" fell.    

3.  March 31st becomes the latest in the year to reach 60 degrees at PDX for the first time.  The old record for the latest date to reach 60 was March 27th, back in 1955.  The all-time record at all reporting stations for the latest date to hit 60 degrees is April 9th, back in 1875.  

Interesting that the wet March of 2003 went on to have a very wet April, in fact the month holds the record for consecutive wet days at 13.  The good news is that, May & June of 2003 were both very, very dry and warm!  In case you are wondering, spring of 2003 was considered "neutral conditions".  This year, we are seeing a weakening La Nina.

___________________________________________________________

The above clearly illustrates how wet and cool this March has been!  

No surprise that the March 31st snow survey on Mt. Hood finds lots of snow.  The measuring site is located near 5,300 feet.  Total depth of the snow on the ground is 139".  The snow would melt into 52" of water - what is called the snow water equivalency. The Mt.  Hood site is 98% of normal for this time of the year.  The last measurement will be taken May 1st.  The entire season average is 65" of snow water equivalency.  Looks like we will end the season in great shape!

Statewide, Oregon is said to have a snowpack 127% of average.  Washington reports a snowpack 115% of average.  California - where much of this year's La Nina went, reports a snowpack 165% of average!

Drink up, we should have plenty of water this summer.

Two headlines will highlight this weekend:

1.  Spring Begins - The Vernal Equinox, Sunday March 20, 4:21 p.m. PDT

The north and south pole will be equal distances towards the sun (92.6 million miles away).  The sun will rise due east and     set due west.  As we head toward summer, the sun will rise and set farther to the north. 

2.  Full Moon Saturday - nick named the "Supermoon".  The moon will reach it's closest point to earth in 18 years, at a distance of 221,567 miles.  The close location will make the moon appear 14% larger than normal.  We will need a little luck to see the show! Moonrise Saturday:  7:57 pm / Sunday: 9:19 pm

Seismologists according to a report I read, have found no evidence connecting lunar perigees to heightened seismic               activity.          

Have a great weekend and happy spring - let's hope it is a good one!

NORTH OREGON COAST-CENTRAL OREGON COAST-SOUTH WASHINGTON COAST-
 INCLUDING THE CITIES OF...ASTORIA...CANNON BEACH...TILLAMOOK...
 LINCOLN CITY...NEWPORT...FLORENCE...RAYMOND...LONG BEACH...
 CATHLAMET
 341 AM PST FRI MAR 11 2011
 
 ...TSUNAMI WARNING REMAINS IN EFFECT FOR THE OREGON COAST...
 
 ...TSUNAMI ADVISORY REMAINS IN EFFECT FOR THE WASHINGTON COAST...
 
 A LARGE EARTHQUAKE WITH A MAGNITUDE OF 8.9 OCCURRED THURSDAY EVENING 
 IN EASTERN JAPAN. 
 
 A TSUNAMI HAS BEEN GENERATED IN JAPAN AND PARTS OF THE WESTERN 
 PACIFIC WHICH MAY ALSO CAUSE DAMAGE TO THE OREGON COAST. PERSONS IN 
 LOW LYING COASTAL AREAS SHOULD BE ALERT TO INSTRUCTIONS FROM THEIR 
 LOCAL EMERGENCY OFFICIALS. 
 
 LISTED BELOW ARE SOME PROJECTED ARRIVAL TIMES FOR THE INITIAL WAVE 
 FOR THE FOLLOWING LOCATIONS:
 
 CHARLESTON, OR 715 AM PST
 SEASIDE, OR    724 AM PST
  
 ESTIMATED WAVE AMPLITUDES ARE LISTED BELOW:
 
 LONG BEACH, WA:     0.4 METER  (1.3 FEET)
 CLATSOP SPIT, OR:   1.37 METER (4.5 FEET)
 CANNON BEACH, OR:   1.13 METER (3.7 FEET)
 OCEANSIDE, OR:      1.01 METER (3.3 FEET)
 
 TSUNAMI WAVE AMPLITUDES ARE EXPECTED TO PEAK TWO TO THREE HOURS 
 AFTER INITIAL ARRIVAL ALONG THE WEST COAST.
 
 ONCE AGAIN A TSUNAMI WARNING REMAINS IN EFFECT FOR THE OREGON COAST.
 
 A TSUNAMI ADVISORY REMAINS IN EFFECT FOR THE WASHINGTON COAST.
 
 A TSUNAMI WARNING MEANS THAT A TSUNAMI WITH A SIGNIFICANT WIDESPREAD 
 INUNDATION IS IMMINENT OR EXPECTED. WARNINGS INDICATE THAT 
 WIDESPREAD DANGEROUS COASTAL FLOODING ACCOMPANIED BY POWERFUL 
 CURRENT IS POSSIBLE AND MAY CONTINUE FOR SEVERAL HOURS AFTER THE 
 INITIAL WAVE ARRIVAL.
 
 TSUNAMI ADVISORIES MEAN THAT A TSUNAMI CAPABLE OF PRODUCING STRONG 
 CURRENTS OR WAVES DANGEROUS TO PERSONS IN OR VERY NEAR THE WATER IS 
 EXPECTED.  SIGNIFICANT WIDESPREAD INUNDATION IS NOT EXPECTED FOR 
 AREAS UNDER AN ADVISORY.  CURRENTS MAY BE HAZARDOUS TO SWIMMERS... 
 BOATS... AND COASTAL STRUCTURES AND MAY CONTINUE FOR SEVERAL HOURS 
 AFTER THE INITIAL WAVE ARRIVAL.
 
 THE NATIONAL WEATHER SERVICE WILL CONTINUE TO MONITOR THE
 SITUATION... AND WILL UPDATE THIS BULLETIN EVERY HOUR OR SOONER AS
 CONDITIONS WARRANT.
 
 PLEASE STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA SOURCE
 FOR ADDITIONAL INFORMATION
  
 

La Nina is finally showing signs of weakening, meaning Pacific waters are staring to warm in the equatorial area off of the coast of South America.  Projections have La Nina ending as soon as May 1st, followed by neutral conditions to begin summer.  

Forecast outlooks call for March to continue cooler than normal temperatures with above normal rainfall.

April is expected to be cool, but rainfall will likely be close to normal.

If the forecast holds, May would see normal temperatures and normal rainfall.

The above gives hope for a decent late spring and summer season.  Last spring and summer saw many cloudy days with temperatures cooler than previous years.  Remember, the stretch of cloudy, cool days was linked to a rapid transition from El Nino to La Nina, that took place late spring.  Fingers crossed, this summer will ripen tomatoes and deliver the sunny days many of us wait all year for!