Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4
000
FXUS02 KWBC 130530
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
129 AM EDT Mon Jul 13 2020

Valid 12Z Thu Jul 16 2020 - 12Z Mon Jul 20 2020

...Hot temperatures to continue into next week east of the
Rockies...

...Overview and Guidance/Predictability Assessment...

Strong upper high south of the Gulf of Alaska will favor continued
troughing over the Pacific Northwest and expansive ridging over
the central/eastern US. This summertime pattern will keep the
storm track along the Canadian border with progressive westerly
flow and above normal temperatures for most areas of the lower 48.
Ensembles remain in great agreement after a bit of a departure in
the GEFS from the steadfast ECMWF ensembles. Blend of the 12Z/18Z
deterministic sufficed to start with the system pushing out of the
Great Lakes and into the Northeast. Trended toward the 12Z
ECMWF/ECMWF ensemble mean and 18Z GEFS mean as the GFS appeared
too quick across Canada (even in progressive flow) and the
Canadian was too flat across the northeast Pacific.

...Weather Pattern/Hazard Highlights...

A cold front will push through the eastern Great Lakes Thursday
with a chance of showers/thunderstorms and locally heavy rain. The
unsettled weather will continue along and to the south of the
boundary (Ohio Valley/Midwest/Mid-Atlantic) and into the Northeast
with overall light to modest rainfall amounts. Generally dry
conditions are expected elsewhere over the CONUS except Florida
which will see afternoon showers/storms and perhaps over the
southern Rockies on the west side of the upper high to the
northern Plains next week. The relative lack of rainfall across
the West and Plains during the next week in combination with
summertime heat is expected to worsen/expand drought conditions in
those areas.

Temperatures will be near to below normal over the Pacific
Northwest and along the coast through California, but close to
normal over the rest of the West. Temperatures remain near record
highs over parts of New Mexico and Texas later this week with
widespread 100+ readings, but a few degrees cooler than in the
short term. Above normal temperatures are likely from West Texas
through the central Plains, Great Lakes, and into the Northeast by
the weekend (5-10 deg above normal). Widespread highs in the 90s
are expected with higher heat indices over 100F from Oklahoma
eastward through the Southeast.

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

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.