Pattern change: End in sight to Southeast misery; Midwest, Northeast to turn even cooler; Eastern weekend soaking
The Southeast has endured a long stretch of uncomfortable and record-breaking heat since last week, but there is hope ahead.
A change in the pattern will finally bring some much-needed relief from the ongoing heat wave. Meanwhile, the Midwest and Northeast will continue to find relatively cool conditions after a short tease of summer heat.
The jet stream will take a sharp southward dive over the East, squashing the eastern half of the area of high pressure that has set up over the southern U.S. This will in turn squash the heat wave, leading to cooler conditions.
At the same time as the southward dip in the jet stream slides over the East, the jet stream will lift northward over the Northwest, bringing a record-smashing heat wave to that region.
Temperatures will cool closer to average in the South and Mid-Atlantic while falling up to 15 degrees below average in parts of the Northeast and Midwest starting Friday.
Accompanying the pattern change will be a widespread area of rain and thunderstorms in much of the East this weekend.Southeast Relief
Much of the Southeast has been baking under a strong upper-level ridge of high pressure for more than a week. This has brought a stretch of hazy, hot and humid days.
Love the heat? Check out these photos from this year's summer season:
Heading into this weekend, high pressure will weaken as that southward dip in the jet stream moves into the East and a cold front moves into the Southeast. This will allow temperatures to return to closer to where they are expected to be for this time of year – much more comfortable than the last week or so.
Instead of highs 5 to 15 degrees warmer than average with temperatures soaring into the mid and upper 90s, highs may top out a smidge below late-June averages with temperatures topping out mainly in the 80s in the Southeast, perhaps even holding in the 70s in a few spots.
Low temperatures will also be slightly cooler, with temperatures dropping back into the 60s, which should feel downright refreshing after the recent torrid heat.
Atlanta has reached 90 degrees 10 out of the last 11 days with the mercury rising as high as 95 degrees. This weekend's highs are expected to be in the low to mid-80s, which will undoubtedly feel refreshing.
Raleigh, North Carolina has also seen a very warm June with the average temperature, which factors in both high and low temperatures, more than 3 degrees above average. The thermometer even reached 100 degrees on June 16, setting a new record for the date. Air conditioners may get a little break this weekend with highs in the 80s.
(MAPS: 10-Day Forecast)
Charleston, South Carolina experienced 10 consecutive days of temperatures reaching at least the mid-90s. Numerous record warm low temperatures have been set as well over the last few days as well. By this weekend highs will be in the 80s or low 90s and lows will drop back into the lower 70s.Cool Northeast, Midwest
Meanwhile, much of the Northeast and Midwest have not seen a long stretch of real summer heat – at least, not in summer. The end of spring was hot; in fact, it was the hottest May on record in the Northeast. In June, though, there have been a few brief periods of hot conditions, reminders of summer, but most locations have seen temperatures close to or slightly below average for this month.
The Mid-Atlantic is one of the areas that have seen a few rounds of heat, including Philadelphia which tied their record high on June 12 of 95 degrees.
This taste of summer, however, was short-lived as a cold front has pushed through the Northeast. This weekend, as the jet stream dips southward over the eastern U.S., cool conditions will be locked in as high temperatures will be up to 15 degrees below average.
(MAPS: Weekly Planner)
New York climbed to 89 degrees on Tuesday, but then high temperatures will drop into the 70s Friday through the weekend.
Boston has been fairly cool for June with the average high temperature more than 2.5 degrees cooler than average. Highs have only reached 80 degrees five times this June -- the average number of 80 degrees days in June is 11. Below-average temperatures are expected to dominate beginning late this week with highs only in the 60s Friday through the weekend. Average highs in Boston are near 80 degrees for the end of June.
The National Weather Service weather forecast office in Boston noted in a forecast discussion that "overall this is an atypical pattern for the beginning of summer. Looks just awful. Overall unseasonable with onshore east/northeast winds. Periods of wet weather at times."
Temperatures have also been cooler than average in the Midwest, including Chicago where highs may not reach the 80s from Thursday into part of next week (average highs should be in the mid-80s) and lows will even drop into the 50s.
Cool conditions have also been prevalent in Marquette, Michigan where the average temperature for June is more than 2 degrees below average. That trend is likely to continue to end the month as highs in the 60s and low 70s are expected (average high is in the mid-70s).
A noticeable temperature drop will take place in St. Louis as well. Highs will go from the mid-90s to near 80 degrees late week, along with noticeably lower humidity. A similar scenario is expected in Kansas City, where temperatures will struggle to reach 80 degrees late this week – a pleasant change to end June.
The incoming southward dip in the jet stream and an associated frontal system will tap plentiful moisture across the East from Friday through the weekend. As a result, showers and thunderstorms will be numerous during this time frame.
Friday night through Saturday night looks especially wet in the Northeast, with locally heavy rainfall and some flash flooding not out of the question. Showers will linger through Sunday in portions of the Northeast.
(MAPS: Daily Forecast)
Severe thunderstorms are possible Saturday from Virginia and West Virginia to the Carolinas and Gulf Coast.
The surface low-pressure system will also produce gusty winds in parts of the region, particularly near coastal areas where winds will blow onshore for a time as the low moves through.
We should also note that prior to this pattern change, showers and storms will impact the Mid-Atlantic due to a stalled west-to-east aligned front.