At a Glance
- The recent weather pattern has brought increasing worries of drought in parts of the West.
- Meanwhile, much of the South is experiencing above-average rainfall and flood concerns.
- Ice cover on the Great Lakes is below average and can lead to more erosion and lake effect snow.
- Blossoms are being observed earlier than usual and may be at risk if a freeze occurs.
The weather pattern that has dominated the Lower 48 since the start of 2020 is beginning to increase concerns of drought, flooding, lack of ice and early spring blossoms.
Below we take a closer look at why concerns will grow if this pattern persists.
Drought Growth
The track of the jet stream has kept parts of the Southwest drier than average since the start of the year. The jet stream has focused the storm track farther north into the Pacific Northwest and Canada, generally missing California.
This dry pattern has prompted abnormally dry areas to develop in portions of California, while drought has persisted in much of the Four Corners. Drought also remains in parts of Texas.
This is typically a wet time of year in California but little precipitation has been observed.
Downtown Los Angeles has measured only 0.32 inches since Jan. 1, which is over 3.5 inches less than average. February is the wettest month on average in much of Southern California but there are no real signs of significant precipitation headed for the Golden State into mid-February.
There has been a lack of snowfall, as well. The snow water equivalent (the amount of water in the snowpack) is only about 50 to 70 percent of average in the Sierra Nevada.
Portions of Arizona and New Mexico are also well below average in terms of snowpack, which is very important for water needs during the dry months.
If this dry pattern continues for the remainder of the wet season then the concern for drought and wildfires will increase heading into the summer.
South Flood Concerns
The recent upper level weather pattern has brought rounds of rain to the South as systems combine with moisture from the Gulf of Mexico.
A strong system brought very heavy rainfall to parts of the Southeast on Feb. 6, causing widespread flooding across the region.
Atlanta has seen about double its average precipitation so far this year, as of Feb. 7. Birmingham, Alabama, has seen more than a foot of rain and more than double its year to date average.
Jackson, Mississippi, is experiencing its second-wettest start to the year on record, according to the Southeast Regional Climate Center, with more than 15 inches measured.
The wet pattern looks to continue and more rainfall is ahead for the South and several rivers are already in moderate to major flood stage.
(MORE: Heavy Rain, Flood Threat Are Returning to the South)
Additional rainfall on saturated ground, combined with rivers and streams that are already running high, will increase the risk for more flooding.
Early Signs of Spring
Leaves and blossoms are often the first signs of spring and in parts of the South and West they are already beginning to appear.
Temperatures have been warmer than average for much of the East, South and parts of the West this winter and in some cases well above average.
The milder conditions have caused some plants and trees to start sprouting earlier than usual.
The map below shows that some parts of the South have seen spring leaf out more than 2 weeks early. Spring leaf out refers to when trees begin to produce leaves. Areas in the darkest red are two weeks or more ahead of schedule.
Virginia Beach, Virginia, and Charlotte, North Carolina, are 19 days early, according to USA National Phenology Network. In addition, this is the earliest that spring has sprung in parts of the Southeast in the 39-year record.
It is not just the South that had leaves and blossoms appear. A few areas in the West are also ahead of schedule, including Seattle, Washington, which is about 2 weeks early.
Since it is still early February, there remains a chance of frost and freeze conditions. This could damage plants and other greenery that have bloomed early if precautions are not taken.
(MORE: When Does the Last Freeze Typically Occur)
For most areas of the South the last freeze of the season usually occurs in March. This is also the case in much of the Southwest.
Lack of Ice Cover in the Great Lakes
Warm temperatures have also impacted the amount of ice that has formed this winter on the Great Lakes.
Only about 10% of the Great Lakes is covered in ice, as of Feb. 7, 2020. The average for this time of year is about 37% so coverage is about a third of what is typically expected.
Lake Erie is the shallowest of the Great Lakes and usually freezes fastest. By early February about 64% of Lake Erie typically is covered in ice, but this year there has been very little ice observed.
The lack of ice impacts the amount of evaporation that occurs. When ice forms, the cooling of surface waters results in a lot of evaporation, noted Lauren Fry, the U.S. Army Corps technical lead for Great Lakes hydrology. This means that with less ice, water levels on the lakes will remain high, increasing coastal flooding and erosion in the months ahead.
(MORE: Three Great Lakes Set High-Water Records in January)
In addition, the absence of ice leaves the shoreline vulnerable to erosion from waves that increase when strong winds occur.
The lack of ice also means that significant lake effect snow can still occur, since once ice forms moisture from the lake is no longer available.
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.
