Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Sun Oct 21 2018
Valid 12Z Sun Oct 21 2018 - 12Z Tue Oct 23 2018
...Heavy rainfall threat continues for South Texas...
...Below normal temperatures for the eastern U.S. as most of the western
U.S. stays warm and dry...
As the cold front that pushed across the East Coast continues to move
farther into the Atlantic, surface high pressure will build across the
eastern U.S. Dry conditions will settle for the second half of the weekend
and into the early workweek. However, a mix of light snow and rain showers
can be expected for the lower Great Lakes today. Most of the rainfall
activity will occur in South Texas as a stationary front stays put off the
middle and south Texas Coast. Copious amounts of moisture will be pulled
across the Rio Grande Valley, and will give way to showers and
thunderstorms. The heaviest rainfall will occur off the coast in Mexico;
however, some localized flooding is possible near the Texas/Mexican border
adjacent to the coast. Consequently, a flash flood watch is in effect for
the Brownsville region. By Monday, low pressure will begin to lift
northward--thus, the heavy rainfall will also lift north across
south-central Texas and into southeast Texas. This axis of heavy rainfall
will begin to shift eastward toward the central Gulf Coast by Tuesday.
Some of this activity could produce localized flash flooding.
High temperatures will continue to stay below normal across the eastern
and southern U.S. today and overnight. The foothills of North Carolina
will receive the first freeze of the year overnight Sunday and into
Monday--with much of the Tennessee Valley and portions of the Southeast.
By Monday, high temperatures will rebound to near normal. The exception
will be Texas as the rainfall activity expected to occur in south and
south-central Texas will keep high temperatures in the upper 50s to low
60s--which is nearly 25 degrees below normal. An upper level trough will
move toward the Four Corners today, ushering in moisture that will lead to
scattered showers and thunderstorms across the Southwest and Central Great
Basin. As the trough pushes inland, the rainfall will shift east in the
Four Corners region. Otherwise, dry conditions and above normal
temperatures are expected for the rest of the western U.S.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php