Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
438 AM EDT Sun Apr 20 2014
Valid 12Z Sun Apr 20 2014 - 12Z Tue Apr 22 2014
...Heavy rainfall across the coastal Carolinas will finally wind down...
...Severe thunderstorms will be possible across West and Central Texas
through late Monday...
The configuration of the upper jet will continue to be split in nature
which will feature an active southern and northern stream. Such a setup is
forecast to persist through early next week before a much higher amplitude
pattern evolves thereafter. The current state of the atmosphere consists
of a strong closed low along the Carolina coast which has been responsible
for a multi-day heavy rainfall event. With the best moisture content now
over the offshore waters, the event has finally begun to wind down with
scattered activity expected along the coastal Carolinas on Easter Sunday.
Another disturbance within the active southern stream has helped foster
the growth of numerous showers and thunderstorms across the Four Corners
region and Southern Plains. Some of the more organized convection should
spawn along a north to south oriented trof extending through West/Central
Texas. Given sufficient daytime heating across the Lone Star state, the
atmosphere should be rather unstable which may lead to the development of
some severe thunderstorms. The Storm Prediction Center outlook suggests
this is the case with severe weather possible on Sunday in the vicinity of
Lubbock and Midland, Texas with the threat moving into Central Texas by
the following day.
The northern branch of the upper jet will also be a key contributor to the
weather during the next couple of days. An upper trof currently skirting
the Upper Intermountain West will continue sliding eastward with minimal
change in intensity expected. While the wintry precipitation will be
locked to locations north of the international border with Canada, the
system should be an active rain producer. Low-level convergence along the
approaching cold front will aid in the development of numerous showers and
thunderstorms across the middle of the country. All of this activity is
forecast to slide eastward reaching the Ohio/Tennessee Valleys by late
Monday to early Tuesday.
The upper pattern will become much more amplified by the time Monday
evening arrives with a deep upper trof just offshore of the West Coast.
Onshore flow combined with frontal and orographic lift will help spread
widespread precipitation from Northern California up into the Pacific
Northwest. Through Tuesday morning, the WPC winter weather desk is
advertising around 2 to 4 inches of snow across the Oregon Cascades.
With regard to temperatures, it should be rather mild across the middle of
the U.S. Persistent southerly flow pushing into the Northern Plains/Upper
Midwest will raise the mercury well into the 70s on Sunday. A drop in the
temperatures is expected by early next week once the cold front passes
through but readings should still hold steady in the upper 50s/lower 60s.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php