…Precipitation in southern California will ease wildfire conditions but
could result in localized debris flows and flash flooding…
…Elevated wildfire concerns over portions of Arizona this weekend…
A deep upper low and associated frontal system are working their way south
across the western U.S., bringing snow from the Great Basin east to the
Rockies and central High Plains. The upper low is forecast to gradually
stall, resulting in persistent low pressure over the Southwest through
Monday. As low pressure strengthens, winds and precipitation will increase
across the region. Strong gusty winds and dry conditions will likely
result in elevated wildfire concerns over portions of Arizona while
precipitation eases fire weather conditions in southern California. Due to
increased sensitivity from recent wildfires, moderate to locally heavy
rain could result in debris flows and flash flooding in or around burn
scars in southern California.
East of the Rockies, low pressure tracking along the U.S.-Canada border
will push a couple of frontal systems south across the Central U.S. while
high pressure builds over the Southeast today. The leading front will
extend from the southern Plains to the Great Lakes, but precipitation
chances will be limited to the southern Plains and Great Lakes regions.
The second front will trigger snow showers over the northern Plains and
Upper Midwest today before catching up with the leading front this
afternoon. The southern portion of the front will slowly sag towards the
Gulf Coast Sunday into Monday while the northern portion pushes across the
Northeast and Mid-Atlantic. Shower and thunderstorm chances will continue
in the southern Plains and spread into the Lower Mississippi Valley and
Southeast. Locally heavy rainfall may lead to isolated instances of flash
flooding on Sunday for portions of the Texas Gulf Coast and Lower
Mississippi Valley. Wintry precipitation chances will also spread into the
northern/central Appalachians and interior New England, with the locally
heavy snow possible in northern New York downwind of Lake Ontario.
Today will mark the start of a warming trend in temperatures along the
Gulf and East Coasts. High temperatures will generally be 5-15 degrees
below average this afternoon, then return to near average values Sunday
and Monday. A cooler air mass will move across the Central U.S. in the
wake of a cold front this weekend, with the coldest anomalies expected in
the Rockies and High Plains where temperatures will be 15-25 degrees below
average today. An eastward moving warm front will bring above average
temperatures to the north-Central U.S. by Monday. West of the Rockies,
temperatures will generally be below average under the influence of the
upper low, and precipitation and cloud cover will result in highs falling
to 10-20 degrees below average in the Southwest.
Dolan
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
Leave a Reply