Tuesday, May 1, 2012

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?

No comments:

Post a Comment