Thunderstorm chances increase mid-week

(TULSA, Okla.) Expect scattered clouds Sunday overnight, from about I-40 southward. I-40 northward mostly clear. With returning moisture, expect temperatures to be a little warmer than Sunday morning but still on the chilly side with temperatures in the mid to upper 40s. Fog will again be possible in the valleys across northwest Arkansas and northeast Oklahoma, though it appears to be less likely due to slightly higher wind speeds overnight.

High pressure departs the area Monday as the next storm system moves toward the region. This will allow for gusty winds to develop Monday and especially Tuesday across the area. With warm and generally dry conditions in place, expect limited fire weather danger for mainly northeast Oklahoma, where wind gusts may exceed 30 mph at times. Near critical grassland fire spread rates will be possible on Monday, though increasing moisture may limit this potential especially as we move into Tuesday.

Current data show a strong storm system moving into the central plains Tuesday afternoon. A trailing cold front from the surface low is still on track to move into the area late Tuesday night and into early Wednesday morning. This front will be working with moisture returning to the area, though it will be mostly modest with dew points ranging from the mid-50s in northeast Oklahoma to possibly the lower 60s along the Red River. This may inhibit development and overall coverage of showers and storms across the area. Instability, as a result, is fairly modest but should be enough to get the job done for a few thunderstorms.

Models toward the end of the week are coming into agreement with a broad area of dry northwesterly or west/northwesterly flow aloft over the area. Vorticity notably increases Friday and Saturday, mainly over the central plains, with some of that energy extending into the County Warning Area (CWA). 

As a result, showers and thunderstorms will be possible with a developing surface low in the central plains and a trailing cold front extending into the CWA. The timing and exact evolution of this system continues to be highly uncertain. For now, we’ve opted to keep chances for some showers and storms in the forecast for next weekend with the best chances on Sunday.

Monday

Sunny, with a high near 73. South wind 5 to 15 mph, with gusts as high as 20 mph.

Monday Night

Mostly clear, with a low around 55. South wind around 10 mph.

Tuesday

Sunny, with a high near 77. South wind 10 to 20 mph, with gusts as high as 25 mph.

Tuesday Night

A 20 percent chance of showers and thunderstorms after 1am. Mostly clear, with a low around 61. South wind 10 to 15 mph, with gusts as high as 20 mph.

Wednesday

Mostly sunny, with a high near 76. South wind around 10 mph becoming west in the afternoon. Winds could gust as high as 20 mph.

Wednesday Night

Clear, with a low around 50. Northwest wind around 5 mph.

Thursday

Sunny, with a high near 70. North wind 5 to 10 mph.

Thursday Night

Mostly clear, with a low around 48. North wind around 5 mph.

Friday

Sunny, with a high near 74. East wind around 5 mph becoming south in the afternoon.

Friday Night

Mostly clear, with a low around 55. Southeast wind around 5 mph.

Saturday

Mostly sunny, with a high near 75. South wind 10 to 15 mph, with gusts as high as 25 mph.

Saturday Night

A 20 percent chance of showers. Partly cloudy, with a low around 62. South wind 10 to 15 mph, with gusts as high as 20 mph.

Sunday

A 20 percent chance of showers. Mostly sunny, with a high near 77. South wind 15 to 20 mph, with gusts as high as 30 mph.