Two Parts Storms, One Part Chilly Air

Tuesday, March 24th 2015, 3:14 pm
By: News On 6

March is a turbulent month for weather in Oklahoma.  We have a charged up jet stream with enough returning moisture and warmth to create the impending threat for storms.  With spring at hand, so is severe weather season and our first round is likely just hours away as I write this.

                A two-part storm threat is coming for Green Country starting with this afternoon (Tuesday).  A potent and compact wave in the upper levels of the atmosphere is sending a front into the area.  Once the CAP breaks and storms fire by late afternoon, the ingredients of wind shear and instability are there to make those cells quickly go severe.  Hail and high winds are the main threat. The surface level wind direction (more out of the southwest) isn't as conducive for low-level rotation, but we'll still be monitoring for all threats.  This will encompass areas along and east of Highway 69.  By 6pm (first map), I expect we'll have a broken line of storms somewhere from near Grove to Muskogee and perhaps all the way down to around McAlester. These will clear the region and weaken by late evening.

                The more widespread threat of severe weather returns Wednesday afternoon.  Our winds will quickly pivot back to the south in the morning hours allowing moisture and warmth to quickly return. Another wave of energy originating further northwest will send a stronger cold front our direction. As our instability peaks in the afternoon, that front should be poised just northwest of Tulsa, angling into southwestern Oklahoma.  Widespread storms will develop by mid-afternoon with a hail threat initially.  A brief tornado can't be ruled out, but these storms will rapidly evolve into a squall line by sunset and push southward.  The strong nature of the cold front will actually impede the storms as dense, cold air rushes beneath the updrafts to these storms, cutting them off from their inflow of energy from near the ground.  That takes away some of the potency of the storms and the risk for any tornadoes.  Still, a high wind and hail threat will continue into the night, ending from northwest to southeast.  The attached map shows the Storm Prediction Center's Outlook for enhanced severe weather over Oklahoma Wednesday.

                Cooler, stable air rushes into the region Thursday. We'll need to have those jackets handy as temperatures won't likely climb out of the 50s until Saturday afternoon. The bulk of the cold air stays just to our east, but there's still a minor risk of a frost or light freeze in a few spots by early Saturday morning.  We can't even rule out a snowflake or two over far northeastern Oklahoma Friday morning as a weak wave rotating around the large jet stream trough squeezes out enough moisture in just cold enough air. It's not exactly a return to winter, but a few days to remind us we're still in the early stages of spring when cold air still makes an appearance from time to time.  Those instances just become less harsh and not as long as the spring rolls on.

                We'll keep you updated as the storm threat ramps up over the next 36 hours. Be sure to follow me on Twitter: @GroganontheGO or on my Facebook page for the latest updates!