Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
158 AM EDT Wed Apr 17 2019
Valid 12Z Sat Apr 20 2019 - 12Z Wed Apr 24 2019
...Overview and Guidance Preferences...
Upper pattern will transition toward much more zonal flow next
week after a vigorous system exits out of the Northeast this
weekend. Models and ensembles show decreasing agreement on the
flow, which is expected given the short wavelengths. As such,
trended from a multi-deterministic model blend to start the
forecast (Sat/Sun) to a 50/50 deterministic/ensemble blend of the
latest guidance for next week. Relatively weak systems will rule
the pattern next week focused from the southern Plains
northeastward/eastward and also in the Pacific Northwest with
another front moving into WA/OR around Tuesday.
...Weather Highlights/Threats...
Wrapped-up system in the east will be on the way out with a focus
for modest rain into primarily Maine on Saturday before moving
into Canada. This may linger into Sunday depending on how long it
takes the upper trough to actually clear the area. Western front
will spur some light rain over the Plains Sun/Mon and slowly push
southward and eastward, gradually increasing in amounts as Gulf
moisture continues to lift into the region. Temperatures will
generally trend milder than average for most of the lower 48 given
the quasi-zonal flow next week.
Fracasso
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