A stationary front stalled from the Central Plains through the Mid-Atlantic midweek will be the main driver of much of the weather across the nation during this time period. This front often acts as a focal point, allowing for the development of heavy, flooding rains and severe thunderstorms. It will also acts as a separator between the warmer and cooler than normal air temperatures.
Parts of the Northeast and Midwest experienced record heat on Monday. In Albany, the capital of New York, the day ended up being the fourth hottest day on record. Topping off at 97 degrees, this was the warmest temperature since July of 2012 and was just a few degrees from the all-time record high of 100 degrees in recorded history.
This Tuesday, the northern Mid-Atlantic region, New England, Great Lakes, and Upper Midwest will all experience relief from the heat the remainder of the week. High temperatures will be in the 70s and 80s across these areas. Some areas will even struggle to get out of the 60s, especially along the lakefronts due to the cooler waters of the Great Lakes. These temperatures will range from near-average in the Northeast to up to 15 degrees below normal in the Upper Midwest. All of these areas are located north of the stationary front.
South of the front is the complete opposite: near-record heat. Despite the southward progression of the front since Monday, the upper-level ridge will remain dominate over the Southeast and its effect will span as far north and west as the Central Plains. High temperatures will generally be 5 to 10 degrees above average in these areas, but parts of the Mid-Atlantic and Carolinas will experience temperatures upwards of 15 degrees above their typical high temperature for this time of the year. Actual high temperatures will generally be in the 90s, but it will feel more like about 100 degrees thanks to the addition of humidity. Dew points will be between 65 and 75 degrees, which indicates a sticky to even oppressive air mass. Daily record high temperatures may even be broken in a few cities in the Carolinas.
Due to this heat Tuesday, Heat Advisories are in effect from the Tidewater of Virginia southward through the coastal Carolinas. There are also Heat Advisories in effect for parts of Missouri and Illinois as well as an Excessive Heat Warning for the Saint Louis metro. Heat indices in the city and surrounding areas will like surpass 100 degrees.
The area of intense heat will shrink further on Wednesday thanks to the slow southward movement of the front as well as the prevalence of clouds, rain, and thunderstorms across the Midwest and Ohio River Valley. Temperatures from the northern and central Rocky Mountains into the Central Plains will be quite cool for this time of the year, reaching levels of up to 20 degrees below normal. It is summer, however, so despite the cooler than normal conditions, it will still be rather warm. Temperatures to the east from the Midwest through the Northeast will be a few degrees within average. Actual high temperatures will generally hold into the 70s and 80s.
The heat will persist across the southern Mid-Atlantic and Southeast, however, on Wednesday. Now while temperatures of up to 10 degrees above average doesn’t sound significant, it will be across this part of the county. This is because average high temperatures for this time of the year are in the mid to upper 80s. Add about 10 degrees to that and temperatures will near the century mark. It will at least feel like 100 degrees thanks to the added moisture, which will make for very uncomfortable conditions. Columbia is currently forecast to max out at 100 degrees.
Thursday will be quite similar as the warmer air continues to gradually erode. Temperatures will remain up to 20 degrees below average in the Central Plains while milder temperatures beginning to stream back into the Rocky Mountains. Most of the Central US will feel temperatures a few degrees on the cooler side of average. The same will apply to the Midwest, Great Lakes, and Northeast. Again, it won’t be chilly out because it is summer, and Thursday is actually the first day of meteorological summer. Actual highs will be in the 70s and 80s for most areas,
The Southeast will remain toasty on Thursday. High temperatures into the 90s and possibly low 100s will be in the cards for a third day in a row. Florida will also be hot with widespread highs in the low to mid 90s. Florida is hot year-round, but it is actually unusual for temperatures to hit the 90s for multiple days in a row, which will be the case for at least the next five days.
As we get into the weekend, cooler than normal temperatures will persist across much of the Northern Tier. The coolest of air relative to average will remain in the Central Plains and back into the Rocky Mountains by Sunday. The Northeast and Midwest will be more seasonable while the Southern Tier remains mild with highs of up to 10 degrees above average. High temperatures in the 90s to low 100s will be commonplace from the Southwest through the Southeast.