Severe Weather Likely

*** Severe Weather Likely West-Central/Northwest Oklahoma this evening ***

A cold front has made it's way to just north of I-40 this morning, and then extends north of OKC to east of Ponca City. This front will be the focusing area for severe weather in west-central and northwest Oklahoma this afternoon. The front is expected to stall near this area this morning with some small variance in positioning. Several ingredients for severe weather are in place. An upper level storm will approach the area this evening, with the majority of the lift across northwest Oklahoma with the main energy passing into Kansas. A dry line will be pushing into the Texas Panhandle. I agree with Kramar's AM forecast discussion out of Amarillo. I think the dry line could be approaching southwest Oklahoma this evening. The cold front should stay up across the northern Texas panhandle before making a surge southward this evening. This will bring the triple point further south into southwest Oklahoma. 6Z NAM shows CAPE of 2500 j/kg across southwest and west central Oklahoma with lifted index up to -6 this evening.

Upper level winds are very favorable for supercells. Despite northeast to easterly surface winds, a strong low level jet at 850 mb will begin developing this afternoon and strengthen into the overnight period. 700 mb winds increase after dark out of the south-southwest with 500 mb winds out of the west-southwest. This is a very favorable "turning with height" situation for tornadoes. Due to the increasing speeds, speed sheer will also be a concern through the evening. Any storm which rides across the warm front will be a favored cell for tornadic activity.
At this time, I would pinpoint a box around Arnett to Seiling to Clinton to Elk City as the highest potential, but again it depends on the exact positioning of the warm front. The supercells will likely ride just north of the warm front.
Thunderstorms become more likely tonight as the frontal system begins pushing southeast. It should be near the I-44 corridor overnight and some locally heavy rain may occur. The system continues to push east into Arkansas by morning.

A similar situation sets up for Arkansas Tuesday. The low level jet sets up over western Arkansas during the morning with strong southwesterly winds at 700 on top. CAPE looks to be high again and severe weather looks to be a good bet from north-central to southwest Arkansas. It should be a dry day across Oklahoma.

A warm front begins lifting north across Texas (the same front) on Wednesday. The front is expected to lift northward through southeast Oklahoma during the afternoon. Severe weather will be possible in the warm sector across western Arkansas and southeast Oklahoma. There may be some rain north of the front in central parts of the state as well. I am slightly concerned about training/flash flooding along the stalled front Wednesday night and Thursday morning. This would likely be around Ardmore to McAlester to Muskogee and into northwest Arkansas. A shortwave approaches around 7 pm. It will be in the area through at least sunrise. GFS shows a strong low level jet with speeds over 75 mph out of the south at 850 for Wednesday night into Thursday morning across southeast Oklahoma and western Arkansas so severe weather looks to be a possibility. 700 mb winds are strong all across Oklahoma and I cannot rule out a large area of rain behind the front. A broad cyclone (huge low) will accompany this system and move northeast of the area Friday. Thursday afternoon should begin a dry period that will last several days.
The weekend looks sunny with light and variable winds Saturday. Winds turn to the south on Sunday and it will become windy across northwest Oklahoma. Highs will start off in the upper 60s and reach the 70s by Sunday. The next chance of thunderstorms will start Tuesday and last through Wednesday of next week and severe weather looks likely again.
OKC 73 54/61 42/55 48/62 43/64 41/68 45/74 50/79 52/78 57/74
Winds/clouds 30% and breezy today, 50% tonight, 60% Wednesday evening, 50% Thursday morning and breezy. Mostly sunny to sunny Friday through the weekend, Breezy Sunday. Next Monday partly cloudy and breezy 10%, Tuesday overcast 20%, Wednesday partly cloudy 30%.
State forecast graphics at www.okcfox.com

Greg/Fox 25/Used with permission