Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
1247 AM EDT Wed Jun 19 2019
Valid 12Z Sat Jun 22 2019 - 12Z Wed Jun 26 2019
...Weather Highlights/Threats...
Expect with deep layer southerly flow advecting warm air north
across most areas east of the MS Valley to see heat building
across the Southeast/TN Valley/Oh Valley/Appalachians, continuing
up into the Northeast early next week. Expect hot warm sector
temperatures under this ridge including a risk of record warm
minimum values mainly for the eastern southern Plains and lower MS
Valley.
The systems present a threat of strong to severe/MCS convection
and locally heavy rains in areas with pooling
moisture/instability. The rainfall focus Sat and Sun is forecast
to be from eastern KS and OK across the MS valley into the Great
Lakes and central Appalachians.
On Mon 24 Jun and Tue 25 Jun the showers/storms are expected to
focus from east Texas across the Arklatex to the lower MS Valley,
Ohio and TN Valleys and Appalachians.
...Guidance/Predictability Assessment...
The WPC medium range product suite was derived from a composite
blend of compatible guidance from the 12 UTC GFS/18z GEFS and 12
UTC operational ECMWF/12z ECMWF ensemble mean guidance. This
maintains good WPC continuity for the large scale evolution of
systems across the country.
The models agree on the large scale pattern of the initial
northern Plains closed low moving north into Canada by early next
week and a high amplitude southeast ridge persisting.
Next week, a new closed low develops and moves southeast from
offshore British Columbia into the Pacific northwest or adjacent
coastal waters by the middle of next week. This persistent and
slow moving circulation allows the deep layer ridge to rebuild
over TX and NM. There is less spread than normal for these
forecasts, lending the situation to a consensus based approach.
Petersen
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