El Niño Watch

The surface water of the Equatorial Pacific is showing signs of becoming warmer than average, which would indicate a transition to El Niño conditions. That region has remained "neutral" through May, but temperatures have been gradually rising for five months. By the end of May, sea surface temperatures were about +0.4° to +0.5°C in the critical region, which suggest the beginning of an El Niño. Read the entire ENSO Discussion.

Based on these recent trends, it is likely that the Equatorial Pacific will transition to El Niño conditions from June through August 2009. Read the latest weekly update here.

Our most recent ENSO episode was a La Niña from August 2007 to June of 2008. Since then, we have been in weak La Niña transitioning to neutral conditions through 2009 so far.

The last El Niño episode was July 2006 through February 2007.

What could El Niño mean for the Commonwealth? Well, not much. For a Summertime El Niño episode, not much deviation from average is documented for Virginia. In fact in the United States, only the Rocky Mountain West shows any substantial response in the Summer to an El Niño with wetter than average conditions. The U.S. tends to experience more noticeable climate impacts during a Winter El Niño event.

(Click to enlarge this graphic)

Well, what about impacts from El Niño on the Atlantic Hurricane Season? Research has shown that El Niño's wind profiles encourage the development of more eastern Pacific hurricanes, while hindering the development of Atlantic hurricanes. La Niña leads to the opposite, with fewer eastern Pacific hurricanes and more Atlantic hurricanes. Read here for a full discussion on ENSO's possible impact on tropical activity. So this means that the chances for the Atlantic and Gulf Coasts to receive a hurricane are reduced. However, this does not mean that hurricanes cannot form and do significant damage during an El Niño season.

--Carrie

Heavy Rain Monday Morning

Very heavy rainfall greeted many of you in Central Virginia for your Monday morning! Totals ranged from as little as a trace to as much as an inch or more in some spots. Officially at RIC, there was 0.43" accumulated. Farmville is an example of the higher totals, though, with 1.1" from this morning's rain.

There is a slight chance for scattered showers this afternoon, but we should be dry by this evening in all of Central Virginia. Tuesday looks dry before our next chance of rain and storms returns Wednesday and Thursday.

Brief Shift In Weather Pattern

We did it! We finally made it through a day without rain. Hope you enjoyed your Sunday!

We have an interesting weather pattern setting up for the start of the workweek. The general flow will be from the coast for Monday through Wednesday. This should keep temperatures a few degrees cooler than what we've seen for the past few days.



This will also bring in some moisture from the Atlantic. Consequently, spotty showers will be possible tomorrow and we should at least see some clouds on Tuesday and Wednesday. I'm still a little skeptical about our rain chances on Tuesday or Wednesday, but if you have outdoor plans, keep a close eye to the forecast and we will keep you updated!