…Flash flooding and severe weather threat continues over the Midwest the
next couple of days…
…Potentially dangerous heat anticipated across the southern Plains,
lower Mississippi Valley, and Gulf Coast…
A low pressure/frontal system traversing the center of the country
continues to help trigger rounds of showers and thunderstorms leading to
the threat of some flash flooding and severe weather. The low pressure
center is forecast to gradually push eastward through the Upper Midwest
today and reach the Great Lakes by the end of the week. A broad warm
sector supported by plentiful moisture, instability, and deep-layer shear
will allow for storms to potentially turn severe and contain heavy
rainfall throughout Missouri, Illinois, and into the lower Ohio Valley.
Storms should redevelop during the afternoon, increasing in coverage into
the evening, with a Slight Risk (level 2/4) of Excessive Rainfall in
effect given the threat for some intense downpours and potential training
convection leading to instances of flash flooding. A Slight Risk (level
2/5) of severe weather similarly covers the chance for some instances of
large hail and damaging winds. The system will push into the Lower Great
Lakes and Ohio/Tennessee Valleys by Friday and Saturday, with storms
likely to spread as far east as the Appalachians and Mid-Atlantic. Some
chances of isolated flash flooding and severe weather are forecast.
Heat will remain the major weather story throughout much of the
south-central U.S. into the beginning of this weekend and likely beyond.
Widespread highs into the upper 90s and triple digits are forecast to span
from the Southwest to the central Gulf Coast. Elevated humidity levels
will soar heat indices up to around 110 degrees for areas outside of the
Southwest and southern High Plains. However, actual high temperatures in
these more arid regions will be higher and well into the triple digits for
some locations. Low temperatures are anticipated to only drop into the
upper 70s and 80s for many locations, which could break several daily
records. This level of heat can affect anyone without effective cooling
and/or adequate hydration. Therefore, it is imperative to follow proper
heat safety and check on vulnerable individuals.
Elsewhere, some showers and storms will continue over New England as an
upper-level low churns over Nova Scotia. To the south, portions of
central/south Florida will also see scattered storm chances the next
couple of days as a cold front slowly pushes through. Some thunderstorms
will also be possible with a shortwave passing over portions of the
northern Great Basin today and into the northern Rockies by tonight.
Monsoonal moisture and storm chances are set to return to the Southwest
and central Great Basin by Saturday, where isolated flash flooding is the
greatest concern. Forecast high temperatures are expected to generally be
around average along the East Coast with mid- to upper 80s expected. Areas
of the Great Lakes/Upper Midwest behind the passing storm system will be
cooler with highs in the 70s. More temperatures near or above average are
expected over the northern/central Plains with highs in the 80s and 90s.
Highs across the northern tier of the West will remain below average, with
70s for the Pacific Northwest and low 80s into the northern Great Basin,
warming closer to average into the central Great Basin with mid-80s to low
90s.
Snell
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
