While the Southwest Remains Dry, More Rain Is Ahead in Parts of the Soggy East

 Linda Lam

Published: August 13,2020

Additional rounds of rain are ahead for the rain-weary mid-Atlantic and Southeast into next week. Meanwhile, the Southwest, which could really benefit from precipitation, will remain bone-dry.

Below, we take a look at the wetter-than-average conditions that have prevailed in parts of the East and South this year and what is expected in the short-term.

Recent Wet Pattern in South, East and Dry in Southwest

The year started off wet across much of the South. Some locations, including Birmingham, Alabama, Jackson, Mississippi, and Greer, South Carolina, are experiencing surpluses of more than a foot of rainfall so far this year.

Recently, above-average rainfall has been focused in parts of the mid-Atlantic.

The upper-level weather pattern featuring a trough, or southward dip in the jet stream, over the eastern U.S. has been in place at times this year. This is a favorable situation for disturbances to bring precipitation to parts of the East. Cooler temperatures also can accompany this setup.

In addition, upper-level areas of low pressure have become cut off from the jet stream at times. We saw this in June when a cutoff low brought days of rain to portions of the Midwest and East.

Precipitation from Jan. 1-Aug. 12. The green and brown boxes indicate how much above- or below-average precipitation has been year-to-date.

As mentioned, August is off to a soggy start in the mid-Atlantic.

Hurricane Isaias brought heavy rainfall to parts of the mid-Atlantic and Northeast early in the month. However, much of New England didn't receive much rainfall and is experiencing drought conditions.

Rounds of rainfall have continued to impact the mid-Atlantic since then. Heavy rainfall prompted flash flooding in southern New Jersey, southeastern Pennsylvania, Maryland and Delaware on Wednesday.

Baltimore has picked up almost 6 inches more than average so far this month, while Richmond, Virginia, is close to 9 inches above average. This is the wettest start to August on record in Richmond and the second-wettest start in Philadelphia, according to the Southeast Regional Climate Center.

Precipitation and departure from Average for the first 12 days of August.

The story has been different in the Southwest.

The monsoon runs from June 15 through Sept. 30 and brings much-needed rainfall to the region.

But the monsoon has been missing so far this season. Drought conditions have expanded, and record heat continues to dominate the Southwest.

Meanwhile, the mid-Atlantic remains drought-free.

Areas in orange and red are experiencing drought conditions as of Tuesday, Aug. 11, 2020.

Wet Forecast

It looks like the rain won’t be going away over the next several days for areas of the country that do not need additional precipitation.

A more amplified jet stream will develop this weekend with a trough over the East and a ridge of high pressure over the West. In addition, an upper-level low in the East and a stalled front, along with a moist atmosphere, will result in periods of rain and thunderstorms into next week.

(MORE: Pattern Shift Develops This Weekend)

A brief break from the rainy pattern is possible early next week in parts of the mid-Atlantic and Southeast, but the chance of storms is once again expected to increase during the middle of next week.

Setup for more rain into next week.

Rainfall will be locally heavy at times, and many locations in the mid-Atlantic will see more than an inch of rain through this weekend.

Given the recent rainfall, flash flooding will be a concern. Never drive through water-covered roadways, as just six inches of water can cause a vehicle to stall or lose control.

(MORE: Types of Severe Weather to Watch for in Late Summer)

Precipitation Forecast

Meanwhile, the ridge of high pressure over the West will keep conditions hot and dry there.

Little to no precipitation is expected within the next week for most of the Southwest. Temperatures will also be far above average in the West, with numerous daily record highs expected to be broken into next week.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.