Another mild week of weather is in store across the much of the United States. A rather persistent upper-level ridge will continue to dominate the weather across the nation, although there will be an upper-level low over the Gulf Coast that will remain in place before intensifying as Memorial Day Weekend begins. While this ridge should allow for above-average temperatures flourish, the upper-low near the Southeast will keep the region, especially Florida, cooler than normal.
Temperatures so far this month have been well above normal, especially for the Central and Southern Plains as well as the Ohio River Valley. Temperatures in these regions have been as high as 15 degrees above-average. The contiguous United States’ average temperature to date stands at 63.22 degrees, which is 4.37 degrees above average.
On Sunday, a cold front will bring a period of below-average temperatures to much of the Plains. Temperatures will be 10 to 25 degrees below normal, from the Great Lakes back toward the Central Plains and down into much of the Southern Plains. The same goes for Florida and parts of Georgia and South Carolina due to the persistent rain. An onshore flow along the West Coast will also keep the immediate coast several degrees below normal. Meanwhile, the Gulf Coast up through the Ohio Valley, Mid-Atlantic, and Northeast will experience temperatures 5 to 15 degrees above-average for most locations. This will also be felt in the intermountain west. Some areas will approach up to 25 degrees above normal. Even a location or two in the Tennessee Valley may tie or break their daily record high, while many areas on the Florida Peninsula my actually reach record lows.
The cold front in the Plains will weaken, allowing warmer air to surge back in on Monday. A large part of the country will begin to experience summer-like temperatures. This includes the Northwest, Northern and Central Plains, Lower and Mid-Mississippi River Valleys, Mid-Atlantic and Northeast. Many of these areas can expect highs 5 to 10 degrees above normal, with up to 25 degrees above normal across the Northwest and in portions of the Dakotas. Temperatures won’t be record-breaking in those regions, but most locations will hit or exceed 75 degrees. A potent upper-level low moving into the Southwest is going to keep temperatures 25 degrees below average there. West Texas, eastern New Mexico, parts of the Southeast, and the Upper Midwest will generally be 5 to 15 degrees below their typical high temperature for this time of the year.
Now on Tuesday, we’ll continue to see the warmer temperatures peck away at the cooler air as the upper-level ridge really begins to dominate and strengthen, especially over the Western US. High temperatures will be up to 30 degrees above-average in the Northwest and the Northern Plains. We aren’t anticipating any record highs to be broken despite these anomalous temperatures. Otherwise, Tuesday will be quite similar to Monday, although the intensity of the below-average temperatures will not be as significant. The Upper Midwest will also see the return of milder temperatures.
On Wednesday, the warm air will continue to dominate over the cool air. The only areas expected to feel cooler than average temperatures will be the immediate Californian coast and Florida. Much of the remainder of the Southwest will be quite seasonable, while temperatures will be 15 to 30 degrees above-average in much of the Northwest, Northern Plains, and Midwest. Chicago will go from the 50s on Sunday to near-80 degrees on Wednesday. Generally, the Eastern US can expect highs 5 to 10 degrees above average. That means there will be a lot in the way of temperatures in the 70s and 80s. Down toward the Gulf Coast, highs in the 90s will be commonplace.
Even warmer air will stream in across the north in the Central US on Thursday. This is thanks to the intensification of the ridge, while a new upper-low approaches the Southwest coast. This dominant ridge will bring warmth coast-to-coast, with highs ranging from a few degrees to as much as 30 degrees above-average. The warmest of the air will remain locked in across the Northern Tier with the exception of the Northeast. The only areas expected to see below-normal temperatures are the Californian coast (due to an onshore flow), Florida (due to rain), and northern New England (due to a northwesterly flow).
Friday will be quite similar as Thursday. The unofficial start to summer, Memorial Day Weekend, will see an upper-level low move into the West coast, while a different low over the Gulf Coast intensifies. These will be responsible for bringing cooler than normal air to both the West and East Coast, while the Central US remains mild.