This week is getting off to a shaky and dangerous start for people across the Great Plains. A few severe storms have already produced large hail in the Oklahoma and Texas Panhandles this morning (Monday, May 20, 2019), and several rounds of fairly widespread severe thunderstorms will likely slam neighborhoods from eastern New Mexico to Missouri the rest of today and tonight.
SONAR Critical Events: Severe thunderstorm and tornado threat areas for May 20 and May 21, 2019.
What to Expect
The atmosphere has become very unstable just east of a dry line near the New Mexico-Texas border. East of the dry line, storms are forecast to produce very large hail – up to tennis ball or baseball size – as well as destructive straight-line winds of 60 mph or stronger. Flash flooding will also be a good bet, so drivers may run into roadblocks.
The Storm Prediction Center (SPC) has issued a “High” risk of tornadoes for the following areas: the I-40 corridor from Amarillo, Texas to Oklahoma City; the I-27 corridor from Lubbock to Amarillo; and the I-44 corridor from Wichita Falls to Oklahoma City. On a scale of one to five, with five being the best odds for severe weather, a “High” risk is a five. The SPC rarely posts a High risk, so this is potentially a very serious situation.
Some tornadoes in the High risk zone could be strong – EF-3 or greater – and they may stay on the ground for a long time, what’s known as “long track” tornadoes. But other cities are also prone to tornadoes today through tonight. They could spin up as far south as Midland, Texas, as far north as Wichita, Kansas, and as far east as Ft. Smith, Arkansas and Tulsa, Oklahoma.
Drivers will need to pay attention to rapidly changing conditions and seek shelter as quickly as possible if necessary. It’s important to know the signs of a possible tornado that may be close by.
By Tuesday the risk for severe storms and tornadoes shifts eastward to the ArkLaTex region and portions of the Mississippi River Valley, including Little Rock and St. Louis. By this time the intensity of the severe storms should be much less than today’s expected outbreak. On Wednesday, isolated severe storms could hit some of the same areas in today’s threat zones.
Other Significant Weather This Week
Source: NOAA
Spots of heavy snowfall will develop across the Rockies later today through tonight, from northern New Mexico to southeastern Wyoming. This will affect drivers who have to haul through the high elevations along the I-25 corridor from around Santa Fe to Cheyenne and Laramie; as well as on the I-70 corridor from Grand Junction to just west of Denver. Heavy snow will come back to the northern Sierra Nevada tonight, in addition to the Cascades of far northern California and south-central Oregon. Chain controls are likely, and the National Weather Service (NWS) has issued a Winter Weather Advisory for these regions.
Look for more periods of snowfall across the Rockies and the Great Basin from Tuesday through Thursday. Teeth-chattering cold from well-below-normal temperatures will accompany the snowfall. Low temperatures most of the week will drop into the teens and 20s, so drivers will have to keep pouring winter additive into their diesel in order to prevent fuel gelling. In contrast, record-breaking heat in the 90s is possible across the Southeast during the second half of the week.
