Get ready for instant July!
Temperatures soared to 100 degrees Monday in Kansas and Nebraska as a hot dry air mass surged north.
Thermometers pushed into the 90s as close as Yankton, SD and northwest Iowa.
Heat surges north Monday.
The heat wave is part of a major shift in the upper air pattern over North America. Low pressure in the West and a developing ridge in the central U.S. are combining to pump warm air north.
Expect the warm front to lift north through Minnesota Tuesday. As it does the combination of warmer air and sunshine could be enough to push temperatures well into the 80s, with some locations pushing 90+ in southern Minnesota Tuesday.
We’ll feel some humidity Tuesday with dew points rising into the 60s.
Clash of the air masses: Omaha “Dry line?”
The low level moisture distribution is really interesting and somewhat unusual today in the Midwest.
Extremely dry desert air (with dew points below zero!) has surged northeast from Colorado and the southwest deserts into Kansas and Nebraska. Dew points in the 20s have pushed all the way north into Nebraska.
Meanwhile a humid Gulf of Mexico air mass is being sucked north through Iowa into South Dakota. Dew points are in the 60s, and it feels humid.
The stark contrast in these air masses is making for some interesting features on the surface weather map. The clash point is called a “dry line.” Dry lines are common in West Texas and Oklahoma, and they can be the focus for thunderstorm development.
Dry can lines act as cold fronts because the drier air is actually denser than moist air. When the dry line pushes into the more humid air it creates lift as the dense air lifts the lighter moist air above it.
Dew point overlay on visible satellite image. Desert dry air pushes northeast into more humid air mass.
We’ll have to watch to see if T-Storms can develop near the dry line in northwest Iowa tonight.
Best storm chances?
If storms do not develop in Iowa and move in tonight, it appears the best storm chances for Minnesota could come late Tuesday night and again late Wednesday night.
Updated SPC risk area Tuesday.
The atmosphere may just be too warm aloft Tuesday for storms to pop. Meteorologists call this “capping” as the atmosphere is capped aloft and storm development is prevented.
Bottom line…it should feel like July Tuesday. Look for temps in the 80s and maybe some 90s in southern Minnesota. Dew points in the 60s will make it feel like summer! The best chance for storms may come late Tuesday night.
How La Nina saved the West:
You may recall my visit to Lake Mead last fall and my post about the near record low and emergency water levels on Lake Mead.
Much of the Mountain West recorded record snows this past winter. A whopping 711 inches (59 feet!) fell on Snowbird, Utah. The Sierra in California piled up a record 61 feet of snow this past winter.
Governor Jerry Brown declared an end to California’s drought this spring as reservoirs surge with snowmelt.
Near Las Vegas, Lake Mead is recovering. Runoff from heavy snows in Colorado will allow 3.3 million acre feet of additional water to be released form Lake Powell downstream to Lake Mead. That’s 14 times the amount of water the Las Vegas Valley used last year.
Lake Mead In October. Note the bleached rocks showing high water of the past, and how far the lake has dropped exposing the Hoover Dam intake straws.
The increased flow is expected to raise the level of Lake Mead by around 20 feet by September. It may not end the potential for long term water crisis for Lake Mead, but it’s a great step in the right direction.
Hoover Dam spillway and hydroelectric power plant below the Dam. The new bridge arches gracefully over the canyon.