Severe Weather and Flooding Threat Returns to Green Country

Wave after wave of rain activity is overspreading Oklahoma with each downpour growing heavier than the last.  It’s a very active weather pattern over the next 36 hours and a telltale sign that El Niño is having an effect on our region. In fact, active periods of wet weather like this are anticipated over the next several months here in the Southern Plains.  We are still early enough in the colder season, however, that the threat of severe weather, not wintry weather, is the big issue at hand.

                As I write this on Sunday night, the second of several batches of rain is soaking the area. The rain will last, off and on, into Monday morning before tapering off.  There are essentially two impulses kicking off the widespread rain in this timeframe with the second one moving out by midday Monday.  The increasing moisture and low level jet stream will enhance the rainfall rates overnight and allow for a few claps of thunder to be heard across parts of the region.  This, however, is not the main event.

                On Monday afternoon, the deep trough (the main portion of this storm system) will move into the High Plains, setting up a classic dryline in the panhandle region.  Moisture will continue to surge north, keeping us locked into clouds. Enough instability (the heat and moisture combo at the surface) will allow storms to fire by mid to late afternoon Monday out west. These storms will tap into powerful winds aloft, which should allow them to quickly intensify and rotate in this very dynamic environment. Initially, these storms will be over far western Oklahoma while we see a lull in the rain. These storms will continue to grow and cause hail, high winds and a few tornadoes as they move east quickly.  Eventually, these will congeal into a squall line that will approach the Green Country Monday evening. The attached Outlook map shows the highest potential of severe storms to our west through the evening hours.

                We’ll see this final batch of storms arriving as early as midnight, posing a high wind and isolated tornado threat. Meanwhile, Green Country will be beneath a powerful low level jet stream again that evening, which should fire numerous showers and storms across the eastern half of the area. These could also be strong to severe. This train of moisture will continue to shift through the region Tuesday morning when another two to three inches of rain may occur.  That rain will fall on a nearly saturated soil by that point so flash flooding will be a possibility through midday Tuesday before the rain clears the area. The next map shows the total rain potential. Strong winds with the storms and even behind them could pose a risk for spotty power outages and tree damage.  Needless to say, this is another powerful storm system pushing right through the region!  By Tuesday night, we’ll be in the clear.

                The rest of the week will offer seasonable temperatures with mostly dry weather. A strong cold front is likely arriving early this next weekend. It’s the first good push of Arctic air into the region this season and our high temperatures may struggle to climb above 50° by early next week. Tulsa has yet to have its first official freeze of the season, just missing it by 1° last Friday morning. This cold front could finally plunge all of our lows below the freezing mark… coming 3 weeks later than normal for Tulsa. The latest first freeze for the city is November 28th. If this cold front doesn’t do it, then we could challenge that record.  However, the outlook 8 to 14 days out shows colder than normal readings likely in place. If it’s not a first good taste of winter, we may still end up with a chilly Turkey Day!

Be sure to follow me on Twitter: @GroganontheGO and on my Facebook page for the latest updates on this stormy weather.