…There’s a Slight Risk of Excessive Rainfall leading to Flash Flooding
over much of the Four Corners region tonight…
…Record heat begins to relent over the Southern Plains this weekend…
…Critical Fire Risk and Red Flag Warnings in effect across much of the
Great Basin…
An upper-level ridge over the Great Plains will support monsoon storms in
the Four Corners region and a waning heat wave in the Southern Plains.
Ongoing monsoonal storms in the Four Corners are expected to continue into
this evening. There’s some Flash Flooding threat, as depicted by our
Slight Risk (at least 15%) of Excessive Rainfall, over portions of
northeastern Arizona, northwestern New Mexico, central-southern Utah, and
southwestern Colorado. Slot Canyons are particularly vulnerable to Flash
Flooding. The flash flooding threat dwindles a bit heading into the
weekend as the upper-ridge shifts slightly eastward and an anomalous
closed low enters the West.
The upper ridge will begin to dislodge from its centered position over the
Southern Plains and shift eastward this weekend. In the meantime, high
temperatures in the upper 90s to 100s and lows in the 70s and low 80s will
continue to plague much of western Texas/Oklahoma through Saturday. These
conditions will tie or break existing temperature records. Things begin to
moderate later this weekend when the upper ridge shifts begins to shift
eastward. The deep and anomalous upper low will contribute to
significantly below average temperatures for much of the West over the
next couple of days. High temperatures in the 60s on Friday will represent
20-30 degree negative anomalies over portions of southwestern Oregon and
northern California. Numerous minimum high temperature records will likely
be tied or broken, particularly over sections of California’s Central
Valley and the Great Basin.
In addition to the record cold in the West, the upper low will strengthen
the wind field (surface winds approaching 25mph) in the Great Basin while
maintaining the dry airmass in place, This will support a Critical Fire
weather threat for portions of southern/eastern Nevada, southern Idaho and
western Utah through Friday. Elsewhere tonight, some front range storms
may develop and propagate from northeastern Colorado into southwestern
Nebraska and northwestern Kansas where the Storm Prediction Center has a
Slight Risk (level 2/5) of Severe Thunderstorms depicted.
Kebede
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
