Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
432 AM EDT Sat Apr 19 2014
Valid 12Z Sat Apr 19 2014 - 12Z Mon Apr 21 2014
...Heavy rainfall will be possible across the coastal Carolinas throughout
...A threat for severe weather looms across areas of West Texas on
A split flow regime will continue across the country with both streams
being fairly active during the period. A pair of systems in the southern
branch of the jet are forecast to be active precipitation producers this
weekend. The lead upper trof currently spreading moderate to heavy
rainfall to the Southeastern U.S. is expected to remain a slow mover as
the closed low wobbles slowly toward the east. The approaching system
should continue to have access to plenty of moisture off the Gulf of
Mexico and subtropical Atlantic waters. Ample vertical lift along the slow
moving cold front combined with dynamics aloft with the upper low will
continue to aid in the production of heavy rainfall throughout the
weekend. The WPC precipitation forecast suggests amounts may approach the
2 to 4 inches the next 48 hours across the lower North Carolina coast. Any
regions that receive a long duration of high rainfall rates may see the
possibility of flash flooding.
The other system within the southern stream is a slow moving closed low
currently crossing the California/Arizona border. The disturbance should
eventually evolve into more of an open wave as it migrates into the Four
Corners region on Saturday. A disorganized area of showers and
thunderstorms should develop with no real focus visible at the surface.
Orographics should play a role in local enhancements across the Southern
Rockies. Given the unstable air mass this system will be encountering
across the Southern High Plains, there will be a threat for severe weather
over West Texas on Sunday.
Looking to the north, an active northern stream of the jet will carry a
series of systems eastward with decent separation between each
disturbance. While there is sufficient amplitude in the upper flow to
allow colder air to work its way southward, it should not make it beyond
Northeastern Minnesota/Upper Peninsula of Michigan while most of the
wintry impacts will be north of the international border. Precipitation
overrunning the warm front should bring a mixture of freezing rain and
snow to sections of Northeastern Minnesota and possibly into portions of
the Upper Peninsula of Michigan. Otherwise, light to moderate rain will
fall from the Central Plains and into the Middle Mississippi Valley along
a slow moving cold front.
Across the Pacific Northwest, the series of disturbances migrating through
the region should bring periods of rain to the lower elevations and snow
across the Washington Cascades as the low-level flow becomes more onshore.
The general lack of cold air should limit snowfall amounts to only 4 to 6
inches across this range through Monday morning.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php