Severe weather expected Sunday into Monday

(TULSA, Okla.) A significant severe weather event is expected to develop across eastern Oklahoma Sunday evening and spread east into northwest Arkansas overnight. A few tornadoes will be possible along with damaging wind gusts to 70 mph. Large hail to golf ball size will can also be expected, especially in the evening.

The better chances of severe weather across northeast Oklahoma will be between 6 pm and 11 pm, and into southeast Oklahoma and northwest Arkansas from 10 pm to 5 am. 

Surface instability looks to weaken late evening and overnight.

However, continued strong low level shear values and a low level jet will continue the severe potentials into far Eastern Oklahoma and Northwest Arkansas.

During this time, storms are forecast to become more linear with a transition to more of a damaging wind threat. However a tornado threat will remain possible, especially with the potential for quick spin ups along the leading line. These conditions will remain possible into the late overnight hours before weakening.

Precipitation should start to taper off from west to east across East Central and Southeast Oklahoma behind the frontal boundary and exit West Central Arkansas by mid morning Monday. Precipitation across Northeast Oklahoma underneath and near the surface low should start to taper off early morning Monday and exit far Northwest Arkansas by late morning Monday as the storm system lifts off to the northeast.

One other thing of note is the potential for periods of heavy rainfall through Sunday night. Precipitable water values in the 1.5 to 2 inch range combined with possible training of storms across Northeast Oklahoma will aid in rainfall amounts of 1-3+ inches by the time precipitation exits Monday morning. During the height of the precipitation, rain rates of 1-2 inches per hour are possible which will help to increase a localized flash flooding potential. Across the rest of the County Warning Area (CWA) rainfall rates along the front will allow for rainfall amounts of a half inch to locally over 1.5 inches.

Looking into the upcoming work week, the front that moves through Sunday night is forecast to lift back northward through the region Tuesday and increase moisture over the CWA ahead of another low pressure system predicted to move out into the Plains Tuesday night and Wednesday. In response, additional shower and thunderstorm chances are forecast through the week. The greater precipitation chances at this time are forecast Tuesday night into Wednesday as the surface frontal boundary stalls just to the northwest. Severe potentials will also be possible with this activity. Precipitation chances finally taper off Friday as the front and the upper level trof axis finally move through the region.

Temperatures this week look to fall back toward the seasonal average behind Sunday night’s front for the first part of the week and then cool again behind the late week front.

Sunday

A 20 percent chance of showers and thunderstorms after 4pm. Sunny, with a high near 87. South wind 15 to 20 mph, with gusts as high as 30 mph. 

Sunday Night

Showers and thunderstorms, mainly before 4am. Some of the storms could be severe. Low around 60. South wind 15 to 20 mph becoming west after midnight. Winds could gust as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between 2 and 3 inches possible. 

Monday

A 30 percent chance of showers and thunderstorms before 7am. Mostly cloudy through mid morning, then gradual clearing, with a high near 77. West wind 5 to 15 mph, with gusts as high as 20 mph. 

Monday Night

Mostly clear, with a low around 57. South wind around 5 mph. 

Tuesday

A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 81. Southeast wind 5 to 15 mph, with gusts as high as 25 mph. 

Tuesday Night

Showers and possibly a thunderstorm. Low around 69. Southeast wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 80%.

Wednesday

Showers and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. High near 80. Southwest wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 80%.

Wednesday Night

A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 61. Southwest wind 5 to 10 mph. 

Thursday

A 40 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 78. South wind 10 to 15 mph, with gusts as high as 25 mph. 

Thursday Night

A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 59. South wind 5 to 10 mph becoming north after midnight. 

Friday

A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 71. North wind 10 to 15 mph, with gusts as high as 25 mph. 

Friday Night

A 20 percent chance of showers. Partly cloudy, with a low around 49. North wind 10 to 15 mph, with gusts as high as 20 mph. 

Saturday

Sunny, with a high near 69. Northwest wind 10 to 15 mph, with gusts as high as 20 mph.