Your May Temperature Outlook

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May could feature a cool West and mild East split, but uncertainty remains in the forecast, according to an outlook released Friday by Atmospheric G2 and The Weather Company, an IBM Business.

A​reas from Northern California into Arizona have the greatest chance of cooler-than-average temperatures.

Warmer-than-average temperatures are expected in parts of the northern tier and along the Gulf Coast. Near-average to slightly warmer conditions are expected in the mid-Atlantic and much of the Plains into the Northwest.

But a​ccording to Dr. Todd Crawford, Vice President of Meteorology at Atmospheric G2, there is a lot of forecast uncertainty for May.

First, M​ay will start with a continuation of the negative phase of the North American Oscillation. T​his means cooler-than-average temperatures are expected to continue across much of the East, at least in the beginning of the month.

I​t's unknown how long this blocking pattern will stick around.

A​dditionally, it's unknown exactly when El Nino conditions could emerge. This is the periodic warming of the equatorial Pacific Ocean surface temperatures, and it often has impacts on weather patterns around the world.

T​hese warmer Pacific waters could cause a consistent ridging pattern, or northward bump in the jet stream, over the western U.S., bringing warmer-than-average temperatures to that region. Meanwhile, cooler-than-average conditions would then be expected in the East, like we are seeing now.

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