Last day of a too wet May

May 2018 fades away at midnight Thursday, leaving behind soggy grounds, washed out driveways and the usual daily threat of thunderstorms, possible flooding and more.

Persistent rain, flooding and damage even leaves our local ministers no longer claiming that the weather is “God’s will.”  God moved to a drier climate and is keeping out of sight.

Depending on where you measure rainfall totals for May in Southwestern Virginia, Mother Nature has dumped 8.5 to more than 10 inches on us.

Our message for her is simple and direct, involving use of a graphic four-letter word that, basically, tells her to go screw herself.

Officially, our rainfall ranks third in the list of all-time wet Mays, trailing 10.14 inches in 1940 and 10.13 inches in May.  Unofficially, some areas collected well over 10 inches during the past 30 days and we still have the 31st day remaining.

Cave Spring got 5 1/2 inches is the 24 hour period last Sunday and Monday  The “official” measurement at the Roanoke airport recorded less than 1/2 inch in the same period.

Why is it so wet outside.  Writes Don Petersen in  The Roanoke Times:

Why has it been so wet in the latter half of May? And is there any hope for it to be not so wet? First, let’s review what led up to this.

March and the first half of April featured a jet stream pattern with a deep southerly dig over the eastern U.S., which brought rounds of unseasonably cold weather and abnormally frequent snowfall for early spring.

Just before and after this period, strong summerlike high pressure over the eastern high pressure brought searing heat relative to the season — an 84-degree record February high for Roanoke and five days in the 90s in the first half of May.

Now, the pattern has got stuck in a new configuration, with the stronger jet stream winds retreating north to over Canada, and a trough of low pressure along and east of the Mississippi River funneling Gulf of Mexico moisture northward. This sluggish pattern has kept rain in our region much of the latter half of May.

The common denominator in the cold, the hot and the wet has been a “blocked” jet stream pattern that hangs up in various locations for several weeks, as opposed to a more progressive pattern that alternates between cool and warm, wet and dry every few days.

Will it continue?  Myatt adds:

The solution to our constant wetness may also lie in the pattern becoming blocked in a different configuration for a while.

There are growing signals that, moving into early June, a pattern similar to our March and April coldness could re-develop, with blocking high pressure over Greenland forcing the jet stream abnormally southward over the eastern United States.

How that manifests is a little different than it would in early spring. It’s not going to get cold and snow, but cooler than normal weather may develop for early to mid-June.

If a persistent northwest flow aloft develops, it could also dry us out considerably. If that flow stays more north of us, we could be left in more of a cool, damp period rather than drying out entirely.

That’s still the fuzzy, indefinite future. In the shorter term, we have plenty of moisture, a former almost tropical system, and a continued stagnant pattern that will almost certainly lead to more rain and possibly some locally heavy rain.

In other words, the jury is still out and anything can happen.

Keep an umbrella handy.

© 2004-2021 Blue Ridge Muse

© 2021 Blue Ridge Muse