It feels more like late May than late August. The mugginess is through the roof and we have repeated storm threats every few days. Caught in an unseasonably active jet stream pattern, our rain totals are keeping pace with the wettest years on record for Tulsa. As of late last week, we had already surpassed the average annual rainfall, meaning if we receive no more precipitation this year, 2019 will still be wetter than normal. More rainfall is on the way, but we have some serious heat to handle first.
Ahead of our next cold front will come a surge of hot air. It’s a one-day heat wave that will send our temperatures well into the 90s. The issue with Monday will be the heat combined with significant moisture pooling in the atmosphere. With a dewpoint in the “Ridiculous” category on our Muggy Meter, the heat index will likely top 110° by afternoon as shown below across much of Green Country. When you have days of rain and then a day of sunshine and heat, it’s hard to avoid a steam bath outdoors.
That heat and moisture will fuel strong to severe storms by Monday evening. As a cold front moves into the northeast Oklahoma around sunset, it is expected to quickly light up with thunderstorms. They could quickly reach severe limits with large hail and damaging winds. These storms will expand southward through the evening impacting areas along and south of I-44. For Tulsa, the main severe threat will come between 6pm and 10pm. The highest storm chances will be east of Tulsa, but most areas will likely see at least a good soaking. Any heavy downpours could also cause flash flooding, given our saturated soils. The tornado threat is fortunately low but cannot be ruled out. Below is the risk area for severe weather Monday night.
By Tuesday morning, most of the storms will have weakened and moved into southern Oklahoma. However, some lingering showers may pester us into Tuesday and even that night. However, that front will provide a significant cool-down and nice drop in the humidity. Midweek is shaping up to be fantastic with highs in the 80s and lows in the 60s.
Temperatures will creep upward again late this week, but not to anything hotter than normal for late August. Storm chances will also increase again as another disturbance drops southeastward into the area. The timing is not firmed up, but Friday night into Saturday offers the highest rain chances. The jet stream pattern shown above will favor this active weather this week, but transition to a more benign weather pattern as we head into September with the storm track shifting back to our north again. The second half of the holiday weekend will actually be quite pleasant with a chance to dry out. Outdoor plans for Labor Day look promising with sunshine and highs in the 80s.
We are heading into the heart of the Tropical season and so far, we have not had any major systems to speak of. However, newly-formed Tropical Storm Dorian could make a run at several locations across the Caribbean including Puerto Rico this week as a minimal hurricane. The forecast path is shown below. It is not currently expected to have a major impact on the mainland U.S. However, there are more tropical waves worth watching. If one of them can organize, it would have warmer than normal ocean water to fuel it. It could be an interesting month ahead.