Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
1159 AM EDT Sat Jun 22 2019
Valid 12Z Tue Jun 25 2019 - 12Z Sat Jun 29 2019
...Weather Highlights/Threats...
An amplified/closed upper low will slowly rotate over a
cooled/unsettled Pacific Northwest next week. This anomalous
system will support lead frontal passage underneath across the
central Great Basin/Rockies, with lead N-central U.S. system
genesis and return moisture/instability fueling organized
convection mid-later next week. A summertime upper ridge will
meanwhile build underneath over a warming central U.S. A lead
system will lift northeastward through the Great Lakes/Northeast
as its trailing cold front stalls and then dissipates over the
Southeast, still remaining a local focus for thunderstorms.
Several reinforcing impulses and surface fronts feed into the
Great Lakes/Northeast in the wake of the lead system to focus
additional convective swaths. Upper ridging initially over
Southeast and Gulf of Mexico will be replaced by an inverted Gulf
Coast states upper trough by later next week. Slow translation and
deep moisture pooling in a moist southeasterly low-level fetch
will favor an uncertain and localized heavy downpours threat over
the Gulf Coast states/Southeast.
...Guidance/Predictability Assessment...
Models and ensembles are in better than normal agreement through
medium range time scales, bolstering forecast confidence. The WPC
medium range product suite was primarily derived from a composite
blend of the latest GFS/ECMWF/UKMET/Canadian days 3-5 then latest
GFS/GEFS and ECMWF/ECMWF ensemble mean days 6/7.
Schichtel
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