…Prolonged and intense heat wave continues into Friday from Midwest to
Mid-Atlantic…
…Unsettled weather could produce severe weather and excessive rainfall
for parts of the Central and Eastern U.S….
Extreme heat warnings and heat advisories remain in effect for portions of
the Mid-Atlantic, Ohio Valley and the Southeast through today–impacting
approximately 130 million people. The Ohio Valley is still expected to
experience the most prolonged and notable effects from this heat wave. The
duration of this heat remains dangerous to anyone without effective
cooling and/or adequate hydration as heat related illnesses increase
significantly during extreme longer duration heat. Continue to limit
outdoor time, stay hydrated, and take action when you see symptoms of heat
exhaustion and heat stroke. The extreme heat will moderate across the
Mid-Atlantic tonight followed by Friday for the Ohio Valley, due to the
weakening ridge aloft.
A quasi-stationary surface front draped across the northern tier,
shortwave energy riding along the boundary and warm unstable air present
at the surface will contribute to scattered to organized thunderstorm
activity across much of the Eastern half of the country over the next
several days. There’s a slight risk (at least 15%) of excessive rainfall
leading to flash flooding over parts of eastern Kansas up into Iowa,
Wisconsin and northern Michigan/U.P.. The Storm Prediction Center also
issued a slight risk (level 2/5) for a small area encompassing
northeastern Iowa, far southeastern Minnesota and southwestern Wisconsin,
where isolated wind damage will be possible. The threat for flash flooding
shifts into the interior Northeast on Friday where a surface wave riding
along a warm front will lift up into the region. A slight risk of
excessive rainfall is in place across northeastern Upstate New York, and
northern Vermont/New Hampshire. A new convective threat develops over the
Northern Plains on Friday out ahead of a longwave trough and an emerging
surface low pressure system. SPC issued a slight risk for parts of the
Dakotas and far north-central Nebraska, where large hail and locally
damaging winds are forecast.
A degrading upper low will retrograde into the Southeast Coast over the
next couple of days. Scattered showers and thunderstorms are expected from
the Southeast up into the Mid-Atlantic, where some storms could produce
sporadic/isolated wind damage, according to SPC. Continued cloudy and
rainy conditions could produce localized flash flooding in New Mexico
through Friday, but will also keep temperatures down between 10-20 degrees
below average.
Kebede
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
