Tag: El Nino

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Heavy Rains Hit Illinois

A large, slow-moving winter storm has dropped considerable rainfall across Illinois in the last few days. Here is the map of the amounts in the last 7 days, through this morning (12/28). Areas in shades of red are 5 to 8 inches, and follow Interstate 70 across Illinois. Areas in shades of yellow to light brown are 2 to 5 inches. I’ll post more when the rain finally ends.

AHPS Precipitation Analysis

And it’s still raining. There is the potential for another 0.75 to 1.25 inches expected in southern and central Illinois. Another 1.25 to 1.75 inches is expected in parts of northern and western Illinois before this system moves on.

Is this El Niño?

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Warmer-than-average December in Illinois

The NWS released their latest forecast for December and it is calling for very strong odds of a warmer-than-average December for Illinois and a large portion of the United States. They put the chances at 70 percent or higher in northern Illinois and the Great Lakes region. The odds are between 60 and 70 percent for the rest of Illinois. Those are about the strongest odds that I have ever seen in a monthly forecast.

This forecast for December is strongly supported by the various forecasts out to 14 days, which are also calling for very strong chances of above-average temperatures.

 

off15_temp

The precipitation forecast is not as striking – increased odds of wetter-than-average conditions in the south and along the East Coast. That’s a classic El Niño precipitation pattern in winter months for those regions.

off15_prcp

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Latest Seasonal Forecasts for Illinois – A Mild Winter?

The NWS Climate Prediction Center released their latest seasonal forecasts today. Here are the results for Illinois. The biggest news is that Illinois has an increased chance of above-average temperatures and below-average precipitation for the winter months of December, January, and February. This forecast is based largely on the developing El Niño in the Pacific Ocean.

While the forecast of a milder winter may sound appealing, I would not leave the winter coat in the closet and throw away the snow shovel just yet. Two things to consider are: 1) this is not a 100% guarantee, other factors come into play in determining our winter weather, and 2) even a mild winter can contain short periods of intense cold and abundant snowfall.

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More on the seasonal forecast

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El Nino and the Latest NWS Outlook for Summer, Fall, and Winter

Summary: According to the NWS Climate Prediction Center, El Niño has arrived and has a 90% chance of staying this summer and an 80% chance of remaining through the end of 2015. In terms of strength, this El Niño is expected to be weak to moderate. Illinois is expected to have an increased chance of cooler-than-average conditions in the late summer and on into fall.

The El Niño event has finally arrived and heavily influenced the NWS climate outlooks released this morning. For June (first figure, top row), the Southern Plains are expected to have an increased chance of cooler-than-average temperatures. A large part of the US is expected to have an increased chance of wetter-than-average precipitation, including the southern two-thirds of Illinois.

For the period June-August (first figure, second row), the increased chance for cooler-than-average conditions stretches northward and eastward and includes far western Illinois. The  increased chance for wetter-than-average conditions does not cover Illinois. This should not be a concern since no part of Illinois is in drought now.

Later forecasts for July-September, August-October, and September-November show in increased chance of cooler-than-average across Illinois (see second figure for the July-September temperatures). Continue reading “El Nino and the Latest NWS Outlook for Summer, Fall, and Winter”