Outlook for Spring and Summer from NWS

The new outlooks for March, Spring, and Summer from the National Weather Service’s Climate Prediction Center are out.  You can click on any map to see the larger version.
Overview: The NWS says that La Nina conditions continued through January and into early February across the equatorial Pacific Ocean, as indicated by oceanic and atmospheric observations. The CPC/IRI consensus ENSO forecast indicates that La Nina conditions are expected to decay rapidly and transition to ENSO-neutral conditions during Spring. ENSO-neutral conditions are favored to persist through at least the summer.

March

Parts of Illinois shaded in blue have an increased chance of colder than normal conditions. This is part of a larger area of expected colder conditions that extend from the Midwest westward and is a classic La Nina signal for this region. Current climate conditions do not favor colder or warmer than normal conditions in the rest of Illinois. Current climate conditions do not favor wetter or drier than normal conditions in Illinois in March.

March-April-May

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NWS Outlook for First Half of 2018

The NWS released their new outlooks for the first half of 2018. First of all, the NWS notes that La Niña conditions continue across the Pacific Ocean and will likely persist through the rest of winter. It will likely fade this spring, leading to so-called “ENSO-neutral” conditions, which will continue through summer. “ENSO-neutral” just means that we are between La Niña and El Niño conditions, in other words, neutral.

January

The shorter-range forecasts out to 14 days indicate a shift in the weather pattern bringing warmer and wetter than normal conditions across Illinois. By this Sunday we could be in the 40s and 50s in Illinois (left panel, below) while the prospects of rainfall are high with potential totals of 1/2 to 1 inch over the next 7 days (right panel).


Continue reading “NWS Outlook for First Half of 2018”

NWS Outlook for First Half of 2018

The NWS released their new outlooks for the first half of 2018. First of all, the NWS notes that La Niña conditions continue across the Pacific Ocean and will likely persist through the rest of winter. It will likely fade this spring, leading to so-called “ENSO-neutral” conditions, which will continue through summer. “ENSO-neutral” just means that we are between La Niña and El Niño conditions, in other words, neutral.

January

The shorter-range forecasts out to 14 days indicate a shift in the weather pattern bringing warmer and wetter than normal conditions across Illinois. By this Sunday we could be in the 40s and 50s in Illinois (left panel, below) while the prospects of rainfall are high with potential totals of 1/2 to 1 inch over the next 7 days (right panel).


Continue reading “NWS Outlook for First Half of 2018”

Outlook for Summer, Above Normal Temps

The NWS released their outlooks for the month of July and the 3-month period of July-September.
Illinois and much of the US has an increased chance of warmer-than-normal temperatures for both July and July-September (first column in the figure). Illinois has equal chances of being above, below, and near-normal on rainfall – a virtual coin toss. That is not a surprise on the rainfall. Most of our summertime rain is guided by local conditions and fast-changing weather patterns.
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Historical Trends for July
Temperatures: Historically in Illinois, daytime temperatures in July have become milder over time (first graph) while nighttime temperatures have become warmer over time (second graph). While the decreased heating during the day may be welcome, the increased warming at night can be problematic for humans, animals, and plants as they rest. The green line is a smoothed curve to help the eye see the underlying pattern of change from the variability of individual years. Continue reading “Outlook for Summer, Above Normal Temps”