Late February Weather Outlook

REVIEW:

A weak La Nina (cooler equatorial Pacific Ocean waters) is ongoing this winter. However, last winter we had a moderate to strong La Nina event. The stronger the event the greater the impact on our weather here. The tendency is for wetter conditions during La Nina events for winter and spring. However, the weaker the event then the more likely other factors will impact our weather. This is the case this winter. This winter we have had a positive North Atlantic Oscillation while last winter we had a negative North Atlantic Oscillation (NAO) . The NAO is is the relationship between the Greenland/Iceland low pressure and the Azores high pressure. Ocean temperatures are also a part of the equation. In the negative phase, it tends to be colder and snowier. In the positive phase, it tends to be warmer and wetter here for winter and early spring. NAO is having an influence on our weather pattern along with many other factors but given the weaker La Nina this winter it argues for a great chance that 2012 will be different than 2011.

Two week outlook:

The weather pattern looks to become more active with a series of storms the next 2 weeks. Expect temperatures to be close to normal with precipitation above normal, mostly rain with a little snow expected. 

March outlook:

Expect the overall pattern from winter to continue with warmer and wetter conditions.

Longer-term outlook:

La Nina is forecast to end in the spring. If NAO continues to be positive it will favor a trend of warmer than normal weather with the wet March transitioning to normal or even below normal rainfall by May. The official outlook for summer is equal chances for temperatures and rainfall but if La Nina ends and we keep a positive NAO it will favor close to normal temperatures with some periods of dry weather.

Summary:

The outlook favors more of the same into March with warmer and wetter conditions dominating with limited snow events. Changes may occur after that though.