A trade organization for the major United States airlines is projecting a busy summer for travel. The AccuWeather.com 2012 Summer Forecast is projecting that parts of the nation will be very active due to thunderstorms.
While the state of the U.S. and global economy is debatable, Airlines for America (A4A) has released its summer travel forecast and is expecting the number of passengers on planes this summer to be comparable to last year or about 86% full.
If the A4A estimates are accurate and a high number of seats on alternate flights are already taken when passengers encounter delayed or canceled flights due to rough weather, they could find it harder to find alternate routes.
While just about any spot over the U.S. is capable of experiencing a disruptive pop-up garden variety thunderstorm during the afternoon and evening hours in the summer, we have pinpointed a few potential trouble spots. Some rather busy hubs are on the list.
According to Long Range Weather Expert Paul Pastelok, "Areas most likely to have frequent heavy thunderstorm activity during June and July extend from around Detroit and Cleveland to Washington, D.C., and Philadelphia."
Pastelok explained that a persistent dip in the jet stream is forecast during the first part of the summer from the Great Lakes into the Northeast.
Clusters of thunderstorms would tend to ride this river of air dividing cool conditions to its north from building warmth to its south.
Another potential trouble spot will be the Four Corners region during August into early September.
"A phenomenon known to Southwestern U.S. locals as the Monsoon should bring a bigger crop of showers and thunderstorms compared to recent years," Pastelok said.
In short, the Southwest U.S. Monsoon occurs when a flow of humid air from the eastern part of the Pacific Ocean and/or the Gulf of Mexico begins to ride over the region. Heating from the intense sun helps to create the flow in the first place, but also turns the atmosphere over, creating towering clouds and thunderstorms, which can unleash tremendous amounts of rain.
This often represents the primary source of moisture for the region, aside from mountain snowfall in the winter and runoff from that snowfall in the spring.
"We expect a zone of high pressure to set up farther north in the West later this summer, allowing the Monsoon to be more extensive," Pastelok said.
"It is possible the frequency of these storms may cause some problems at area airports from Phoenix to Las Vegas and perhaps a far to the northeast as Denver for a time later in the summer," he added.
On a final note, the area along the Atlantic Seaboard is also expected to turn wet late this summer as a high pressure area over the Atlantic clashes with a dip in the jet stream over the Midwest and Appalachians.
The setup could cause a convergence of tropical moisture somewhat similar to that of late summer 2011.
The density of airports within the I-95 to I-81 zone of potential drenching downpours could result in some rather widespread delays in already packed planes.
While the risk from microburst winds at airports is usually short-lived and detected by sophisticated (Doppler) radar, low cloud ceilings and poor visibility from heavy rain can cause longer-term delays, especially at the busiest hubs.
The stage is for severe thunderstorms to target parts of the Ohio Valley as the weekend comes to an end.
Dry days will be hard to come by in the northeastern United States for the first week of May as storm systems cause rain to frequent the region.
Residents of the southeastern United States may feel like the calendar has flipped ahead to Memorial Day weekend with warm and muggy weather in place for the start of May.
A stormy pattern will persist across the western Gulf Coast, threatening to trigger more flooding from Texas to Mississippi through at least Monday.
May is picking up where April left off with record-challenging warmth surging back into the northwestern United States.
Those looking to traveling or spending the bank holiday outdoors across the United Kingdom will face bouts of rain and wind, but dry conditions will follow by midweek.
Unusually late coating of snow in Washington, D.C., Baltimore and Philadelphia.
United States (1982)
May produced 365 tornadoes in the U.S., the highest number for any month since reliable records have been available, according to NOAA. The May figure topped by 90 the May 1965 high of 275.
Guangxi, China (1986)
Hailstones weighing up to 11 pounds killed 16 people and injured 125.