April showers bring May flowers and we could certainly use a little rain around here -- but we may not get it.
As we like to say, “Climate is what you expect, and weather is what you get.” So, nothing is set in stone (recall the Tax Day floods?), but the climate forecast for the month is coming in dry and warm.
First, the average high in April is 73 degrees with the warmest we have on record being 96 degrees on April 30, 1946. Our coldest low dropped to 21 degrees on April 3, 1943, with our average being 53 degrees. So, very comfortable temperatures are generally the norm. Rainfall averages 3.41 inches but we are at a 50% rainfall deficit both for the month of March and for 2021.
The dry weather trend is likely to continue, according to the Climate Prediction Center:
And the temperatures have a 50% chance of being above normal:
Why this forecast?
The prediction factors are pretty simple: La Niña is still in effect, resulting in cooler temperatures in the Pacific along the U.S. West Coast and soil moisture is low. Have a look at those cool waters.
Cooler water means cooler air over the ocean and that means we don’t get a lot of warm, rising air which is needed to create clouds and rain. So, this clearly inhibits rainfall. With less cloud cover and rain, temperatures will naturally be warmer.
The soil moisture I talked about last Monday and the exceptional and extreme drought continues across much of the U.S. In fact, the drought continues to increase across the country, now spreading to northern states, New England and Florida:
Dry soil is warmer than wet soil and we may find ourselves getting into a cycle of “no rain = hotter, then hotter = no rain, then no rain = hotter, etc.” That is a positive feedback with negative results and exactly what we saw in 2011.
Finally, the other factor to consider is that we are simply seeing warmer days, and this decade’s trend continues thanks to climate change. You add it all up and we’re looking at a dry, warm April.