Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
216 PM EDT Wed Apr 10 2019
Valid 12Z Sat Apr 13 2019 - 12Z Wed Apr 17 2019
...Lead Heavy Rainfall Threat for the Mid-Lower Mississippi/Ohio
Valleys and South...
...A Second Storm Threat through the West to the East-Central U.S.
next week...
...Weather Highlights/Hazards and Guidance/Predictabillity
Assessment...
A major system exits the Southwest/Southern Rockies to the
southern Plains and mid-lower MS/OH Valleys this weekend, bringing
widespread enhanced rains/deepening Gulf moisture with potential
of excessive rainfall, flash flooding, and strong to severe lead
warm sector convection over the South. The potent low and wrapped
precipitation will track over the Northeast Monday as its trailing
cold front works precipitation/convection underneath arcoss the
southeast and eastern states before exiting into the Gulf of
Mexico and western Atlantic. A composite blend of the overall
compatable 06 UTC GFS and 00 UTC ECMWF/UKMET seems to offer a
reasonable depiction of the storm.
Meanwhile upstream, models/ensembles overall agree to bring
another potent mid-upper level trough/ample height falls/frontal
precipitation into the West Coast Sunday with a subsequent
emphasis digging down across the West to the snowy Rockies into
Mon-Tue before emerging over the Plains into next midweek. The
model and ensemble signal is growing in support of this scenario
with GFS/ECMWF and GEFS leading the way with more pronounced
southern stream flow separation that has been the case with recent
systems. This suggests potential for downstream southern Plains
storm genesis next Wed that portends a renewed lead return flow of
deepening Gulf moisture and an enhancing precipitation/convection
shield and flooding threat over an east-central U.S. already
wettened by the lead storm.
Schichtel
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and
the Northern Great Basin, Sun-Tue, Apr 14-Apr 16.
- Heavy precipitation across portions of the Central Rockies, the
Central Great Basin, the Northern Rockies, the Northern Great
Basin, and the Northern Plains, Mon-Tue, Apr 15-Apr 16.
- Heavy precipitation across portions of the Northern Rockies and
the Northern Great Basin, Sun-Mon, Apr 14-Apr 15.
- Heavy rain across portions of the Mid-Atlantic, the Lower
Mississippi Valley, the Central Appalachians, the Tennessee
Valley, the Great Lakes, the Middle Mississippi Valley, the
Northeast, the Southern Appalachians, the Southeast, the Southern
Plains, and the Ohio Valley, Sat-Sun, Apr 13-Apr 14.
- Heavy rain across portions of the Lower Mississippi Valley, the
Tennessee Valley, the Middle Mississippi Valley, the Southern
Appalachians, the Southeast, the Southern Plains, and the Ohio
Valley, Wed, Apr 17.
- Heavy rain across portions of the Northeast, Mon-Tue, Apr 15-Apr
16.
- Heavy snow across portions of the Northeast, Mon-Tue, Apr 15-Apr
16.
- Severe weather across portions of the Southeast, the Lower
Mississippi Valley, the Southern Plains, and the Tennessee Valley,
Sat, Apr 13.
- Severe weather across portions of the Southeast, the
Mid-Atlantic, the Southern Appalachians, and the Tennessee Valley,
Sun, Apr 14.
- Flooding possible across portions of the Middle Mississippi
Valley, the Great Lakes, the Upper Mississippi Valley, and the
Northern Plains.
- Flooding occurring or imminent across portions of the Lower
Mississippi Valley, the Northern Plains, the Tennessee Valley, the
Northern Rockies, the Middle Mississippi Valley, the Northern
Great Basin, the Upper Mississippi Valley, the Pacific Northwest,
and the Ohio Valley.
- Flooding likely across portions of the Central Plains, the
Northern Plains, the Northern Great Basin, the Middle Mississippi
Valley, the Upper Mississippi Valley, and the Southern Plains.
- Much below normal temperatures across portions of the Central
Plains, the Central Rockies, the Northern Plains, the Southern
Rockies, the Upper Mississippi Valley, and the Southern Plains,
Sat-Sun, Apr 13-Apr 14.
Additional 3-7 Day Hazards information can be found on the WPC
medium range hazards chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation, winter weather outlook probabilities
and heat indices are at:
https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml