Long-Duration Heat Wave In Midwest, Northeast | Weather.com
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- A heat dome is developing over the eastern U.S., leading to a long-duration heat wave
- Daily record highs and warm lows are likely.
- Above-average highs combined with the humidity and little overnight relief will lead to dangerous heat conditions.
A long-duration, dangerous heat wave is likely to smash records in the Midwest and Northeast throughout this week. In some areas, the longevity of the heat that’s forecast has not been seen in decades, according to NOAA’s Weather Prediction Center.
Below, we break down what to expect.
Highs Will Set Records
Highs soaring toward the middle 90s will spread from the southern Great Lakes and Ohio Valley into the Northeast during the first half of this week. This heat will persist through the end of the week in many of these same areas.
Widespread daily record highs will be set beginning Monday and likely lasting into Saturday. A few cities that could set new records at times through Saturday include Detroit, Cincinnati, Cleveland, Pittsburgh, Philadelphia, Boston and Hartford.
Forecast Highs Compared To Average
Dew points will also increase, meaning it will feel sticky and humid. When the humidity is added to the hotter-than-average temperatures, feels-like temperatures will be even higher. In some areas that means the heat index will rise into the upper 90s or lower 100s.
There Won’t Be Much Relief Overnight
Don’t expect a break from the heat overnight, either. Low temperatures will only dip into the 70s for most locations. A spot or two may be stuck near 80 degrees overnight.
Daily record-warm lows likely will be widespread.
A few locations that could see record warmth overnight include Grand Rapids, Cleveland, Pittsburgh, Philadelphia, Syracuse and Albany.
Forecast Morning Lows
This Heat Will Be Dangerous
The hot daytime temperatures over several days, when combined with very warm low temperatures and humid conditions, will raise the risk of heat illness.
On the map below, areas in orange indicate where people sensitive to heat may be affected Thursday. The red areas are where anyone without effective cooling and/or adequate hydration could be impacted. Purple areas are of the most concern and show where the excessive heat may have wider impacts.
You can see the heat risk maps for other days this week at this link.
Heat illness is a serious concern. Please take necessary precautions to be ready for the upcoming heat.
(Data: NOAA)
What’s Behind The Upcoming Heat And How Long Will It Last?
The jet stream has pushed northward and a strong ridge of high pressure, or heat dome, is developing over East.
That setup is allowing above-average temperatures to spread north and eastward. In addition, a southerly flow will bring an increase in humidity.
This general pattern may stick around for a while. But, some relief might arrive in parts of the Great Lakes, New England and upstate New York this weekend. Areas from the mid-Atlantic to the Ohio Valley will remain hot during that time.
Linda Lam is a lead meteorologist at weather.com. Growing up in Massachusetts she developed a fascination for winter storms and hurricanes that led her to pursue a career in meteorology.
