Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
304 PM EDT Sun Jun 26 2022
Valid 00Z Mon Jun 27 2022 - 00Z Wed Jun 29 2022
...Heavy rain and flash flooding possible across much of the Southwest and
southern Rockies over the next few days...
...Isolated severe thunderstorms are possible throughout the Lower Great
Lakes, upper Ohio Valley, and Tennessee Valley through this evening...
...A break in the heat and humidity expected to arrive across the South,
but with heat continuing to build throughout much of the West...
Additional rounds of showers and thunderstorms are likely to impact the
Southwest and southern Rockies into tonight as moisture remains in place
along with a front extending from West Texas to Arizona. Much of this
region will gladly welcome more rain, given the longer term drought
conditions that are in place, but locally there will continue to be
sufficient heavy rain to result in some flash flooding. A Slight Risk
(level 2/4) of excessive rainfall has been issued for much of
central/northern New Mexico and southern Colorado through tonight to
highlight this concern, with a Slight Risk also maintained for Monday over
west-central to northern New Mexico. Additional rainfall totals of 1 to 2
inches, with locally higher amounts, could lead to rapid runoff and
flooding concerns particularly near burn scars. The threat of widespread
shower and thunderstorm activity is expected to gradually diminish and
shift southward on Tuesday.
A cold front advancing across the eastern and southern U.S. will create
the potential for isolated severe thunderstorms through this evening, with
the greatest threat extending from the Lower Great Lakes to the Tennessee
Valley. A few storms could contain damaging wind gusts, frequent lighting,
and heavy rain. An isolated threat of flash flooding will also extend
along much of the cold front as it reaches the East Coast on Monday.
Meanwhile, a hot and sultry airmass initially across the Deep South and
Southeast will be supportive of scattered afternoon and evening
thunderstorms through early this week as the aforementioned cold front
slowly settles down across this region. Slow-moving thunderstorms will
have the capability of producing intense rainfall rates and isolated flash
flooding.
A gradual frontal passage should occur for much of the South over the next
couple of days, and this should bring about a break in the recent high
heat and humidity. High temperatures for Monday and Tuesday should trend
down closer to normal across the Gulf Coast states, but turn below normal
across the southern Plains and adjacent areas of the lower Mississippi
Valley and Mid-South. Conversely, for the West, a building upper-level
ridge will allow for highs to surge into the 90s and near 100 degrees from
central California through the Intermountain West and into the Pacific
Northwest. The greatest high temperature anomalies will be over the
Pacific Northwest where daytime highs will be as much as 20 to 25 degrees
above normal for this time of the year. Heat Advisories remain in effect
across large areas of Washington, western Oregon, and northern California,
as well as areas farther south including the San Joaquin Valley and
southern California. The heat will be relatively short-lived over the
Northwest, as an approaching storm system and associated cold front
crosses the region and ushers in cooler air by Tuesday.
Orrison
Graphics are available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php