May Report....and More!

A lot to cover in this post. It has been a while since I've last posted, probably because this past month has been a busy one. Let's start with my May report card!

Remember that this month's challenge was to accurately forecast the LOW temperature for Portland. Low temperatures can be a challenge given cloud cover and nocturnal radiation or how the day's heat escapes the atmosphere. Anyways...on to the results! May was one of the best months so far. Both high temperatures and conditions were at a 94% mark! Each category had one miss out of 18 forecasting days. The May challenge of low temperature came in at 88%. A confession, I don't often pay too much attention to the low temperatures each day. I do not forecast low temperatures out any further than the next day. There is more emphasis on the daily high temperature than the low. That's why people watch, right? June will be the half-way point of the year and I am going to bring on a big challenge. I will aim to have Portland's most accurate morning forecast. Using the normal criteria, I will chart each station's morning forecast (high temperatures only) and at the end of the month, we will see who's on top! At the end, you can choose who you trust for your morning forecasts!

May wrapped up "meteorological" Spring. It's how us weather geeks break down March-April-May. The graphic below sums up what has been a soggy three months!

March contributed a majority of the Spring rainfall, setting a record of 7.89"! April received 3.25" and we just finished up May with 3.37". The interesting thing about May is that we tied an all-time May record with 15 straight dry days! Despite just over two weeks of dry weather, we still finished ABOVE average for May rainfall! If we didn't have that dry stretch, we may have cracked the top 5 wettest May's but we will just have to settle for above-average. But this was a different "Spring" than a year ago. Spring 2012 was a warmer spring than 2011. Last year, Portland's first 80 degree day was June 4th. This year, we only had to wait until April 22nd to get to 80 degrees and we've hit it a couple more times since then; 5 times to be exact. Weekends have been rather nice over the last two months as well. Between April and May, Portland had four completely dry weekends! But is was the last Saturday in May that gave Portland one of its wettest hours. On the 26th, 1.03" of rain fell in 60 minuets! That 1.03" grand total ties Portland's wettest hour and set a daily rainfall record for May 26th. Ahhhh, Spring!

Coming next week, I'll have Portland's Spring in pictures. Some awesome photos that you won't want to miss!

Recapping and Looking Ahead

We're a third of the way through 2012 and I'd have to say that April was the best month so far! The main story from April was the amazing run of weekend weather that we had which included some record-breaking temperatures. On April 23rd, Portland hit 82 degrees! That broke the old record of 79. The very next day, our temperature was 64, resulting in an 18 degree difference between Monday and Tuesday! Pretty crazy to see temperatures in the 80's in April, let alone to see such a drastic two-day temperature change. The April weather pattern not only brought heat but some active weather as well. A few days late in the month had some thunderstorms hit the metro area and a few severe thunderstorms rocked parts of the southern Willamette Valley.

My challenge for April was to work on precipitation forecasting. As you will see, the results show that I still need some work. April breaks down like this (forecasts for 17 days): 88% conditions accuracy, 70% temperature accuracy and only 52% precipitation forecast accuracy.

Out of the 17 days worked, only one day were all three categories missed. I had called for some showers and sun-breaks on that day and wound up with a mostly cloudy and very wet day (nearly half an inch fell). There are so many precipitation models out there, it is tough to know which one to use under specific weather patterns. Different models tend to handle different patterns better than others, so the more experience the better. The takeaway message is that my forecast is down and April is a tough month to predict due to the potency of the spring atmosphere.

Looking ahead to May, my new challenge will be to tackle each daily LOW temperature. Speaking of May, lots of information is being released ahead of the approaching summer season. First is the push of Severe Weather Awareness by the National Weather Service. Spring and Summer is our most active weather seasons, where we average 2-3 tornadoes a year! Washington also averages the same amount of twisters and Idaho just a few more at 3-4. Easily overlooked, the Pacific Northwest once lead the nation in tornado deaths in 1972! Six were killed amongst hundreds injured on April 5th when a F3 tornado ripped through Vancouver. We are not immune to severe weather here!

CPC Summer Outlook

Many might ask if the brief run of 80-degree weather we had in April translates into a warmer summer? Portland reached 80 or better on back-to-back days in late April. We only average one day at 80 or above during the fourth month and the most its ever happened was 5 times in 2004! We set 3 temperature records in April during 2004 and then went on to set ZERO temperature records the following month. So whats in store for the summer? The Climate Prediction Center released this map showing temperature anomalies for the June-July-August period. 

Two things jump out at me after looking at this map. The first one is quite obvious. Well above-average temperatures are being predicted for the southwest this summer. This very well may be a record-breaking summer in parts of the desert SW. The second thing that I notice is that none of the continental US is predicted to be BELOW average temperatures. Might this be an indication of global climate change?