New Month Brings New Weather Pattern

Sunday, May 31st 2015, 10:56 pm

By: News On 6

With nearly 20 days of recorded rainfall in Tulsa and 68 reports of tornadoes throughout the state, it's clear the month of May dealt our region more than its fair share of severe weather. 14.77” of rain fell in Tulsa and much more in southern Oklahoma. This makes it the 5^th wettest month in Tulsa history and THE wettest month in Oklahoma history. See the first attached map – that's a lot of water! Flooding of our lakes, rivers, and low-lying roadways was the result of this prolonged deluge, whose effects linger into this new month of June.

                The outlook is far better in the short-term as a much-needed stretch of dry weather shifts into the state. A ridge in the jet stream will stall over the central U.S. for a few days, allowing the sun to break out and the floodwaters to recede. However, it will also build the heat and all of that residual moisture in the air will translate to muggy conditions. Starting with Monday, our warm-up will begin as winds make a gradual switch back to the south. By Wednesday, our temperatures return to seasonal normal with lows in the mid-60s and highs in the mid-80s. By Friday, parts of Green Country will be pushing 90° with a heat index well over that. Yuck.

                Monday will far and away be the most pleasant day of the week with lower dewpoints (less mugginess), some sunshine, and mild temperatures. If your yard is dry enough to mow, I'd recommend doing it earlier rather than later simply due to the warming trend in the week to come. Most of our flooded rivers and streams have crested and will fall below flood stage by midweek. Lake levels are mostly steady or falling now, which is another promising trend. It will take a while before lakes like Keystone, Fort Gibson and Tenkiller (among others) become safe recreationally again.

                We're not exactly heading into the dry, doldrums of summer. Early June is one of the most common times for mesoscale convective complexes (MCS's) to push into our area. Those are large areas of storms followed by steady rains that generally form to our north and west and slide into our region nightly. That could begin as early as Friday, but appears to be more likely by the weekend or early next week. By that point, we'll have had a chance to allow our ground to recover from May's relentless rains, but severe weather and localized flooding could still be an issue. In fact, 8 to 14 days out, the Climate Prediction Center pegs our region for both cooler and wetter than normal conditions. (See the second map) This is a sign of a returning active pattern for the second week of June. El Niño is a likely culprit as it tends to send a moisture-filled subtropical jet stream over the southern U.S., sending storm system after storm system our way.

                All in all, June will likely treat us much better than May. Climatologically speaking, it's drier with less severe weather. However, we can't let our guard down as this break in the rain and storms will only last so long. Hopefully we'll manage at least a week's worth of dry weather before we start showing a colorful Radar screen over Oklahoma again.

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