…Record-breaking heat remains across California and the Southwest
through this weekend, while briefly overspreading portions of the Plains
and Midwest on Saturday…
…Strong winds and dangerous fire weather conditions are forecast from
the northern/central Rockies into the Plains on Saturday…
…Locally heavy rainfall will be possible across the immediate Gulf Coast
through Saturday, with more of a focus toward the Florida Peninsula by
late Sunday…
A record-breaking late-season heat wave continues over portions of
central/southern California and the Desert Southwest this weekend as
upper-level ridging persists over the region. Forecast highs will once
again soar into the upper 90s to low 100s outside of immediate coastal
areas in central/southern California and into the 100s to low 110s into
the Desert Southwest. Numerous daily record-tying/breaking highs will
likely be reached again following days of new record daily temperatures.
Heat-related advisories and warnings are in place as this persistent level
of major to extreme heat remains a danger to anyone without adequate
air-conditioning/hydration and those spending greater time outdoors. After
a brief period of more seasonable temperatures to the north following a
cold frontal passage, highs will trend above average again for most of the
rest of the Interior West by Sunday, with 70s into the northern Great
Basin/Rockies and 80s for the central Great Basin. Further to the east
over the central U.S., a brief period of upper-level ridging and strong
southerly flow ahead of an approaching system will bring some hotter high
temperatures to portions of the Midwest and Central Plains on Saturday.
Forecast highs into the low to mid-90s are upwards of 20 degrees above
average, and some record-tying/breaking temperatures possible here as
well. An approaching cold front will bring cooler, more seasonable air on
Sunday with highs back down into the 70s. The Southern Plains will remain
hot and above average south of the front through the weekend with upper
80s and low 90s forecast.
As noted, an upper-level wave will move quickly along the northern-tier of
the country this weekend with an accompanying surface frontal system. Lee
cyclogenesis east of the Rockies has led to a rapidly deepening area of
low pressure just north of the U.S./Canadian border, with a tightening
pressure gradient leading to widespread very strong, gusty winds across
the northern/central Rockies and into the northern/central Plains.
Wind-related advisories and warnings are in place for gusts upwards of
60-70 mph through Saturday. In addition, very dry conditions combined with
the gusty winds with cold frontal passage will also bring a significant
risk of wildfires. The Storm Prediction Center has highlighted areas from
northern Colorado/southern Wyoming into central Nebraska and southern
South Dakota with a Critical Risk of fire weather (level 2/3). Widespread
Red Flag Warnings and Fire Weather Watches cover much of the rest of the
region due to wildfire risk. Greater moisture further east will lead to
some showers and storms ahead of the frontal system over the Upper Great
Lakes by Saturday afternoon. Some moderate rainfall will be possible, and
strong dynamic forcing with the system could lead to some more potent
thunderstorms. A Slight Risk of severe weather (level 2/5) has been
introduced from the Storm Prediction Center in northeastern Wisconsin
mainly for the threat of some large hail. The system will continue into
the Northeast Sunday afternoon/evening with more showers and thunderstorms
expected.
An area of low pressure over the southwestern Gulf of Mexico and
increasing Gulf moisture will lead to periods of thunderstorms producing
locally heavy rainfall along the immediate Gulf Coast and eastward along a
surface trough/weak frontal boundary across the Florida Peninsula this
weekend. While storms may be generally ill-focused for any potential
flooding threat, a couple areas will see a low but non-zero risk. More
concentrated storms along a coastal trough nearby the far south Texas Gulf
Coast could lead to some isolated flash flooding on Saturday. Another
focus will be along and ahead of the weak frontal boundary through the
central Florida Peninsula on Sunday, with some isolated flash flooding
possible along the Florida Gulf Coast and South Florida. The National
Hurricane Center (NHC) continues to monitor this area of low pressure for
potential tropical development, though if something were to develop this
remains more likely after the current forecast period into next week.
Putnam
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php