Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
158 AM EST Fri Nov 08 2019
Valid 12Z Mon Nov 11 2019 - 12Z Fri Nov 15 2019
...Record cold next week with an inland Northeast heavy snow
threat...
...Pattern Overview and Guidance/Predictability Assessment...
Upper ridging over western Canada and also near the Azores will
favor broad troughing over the eastern 2/3rds of the CONUS next
week. Concurrently, a lost upper low near Baja California will
slowly push across northern Mexico to eventually rejoin the
southern edge of the westerlies late next week. The
models/ensembles were in good agreement on the larger/synoptic
scale but differed in timing/track/strength of the embedded
systems. Overall the 12Z ECMWF and the 18Z GFS clustered fairly
well with their ensemble means and each other to form a starting
point for the forecast. System of interest on Tuesday near Long
Island/Block Island will lift into Nova Scotia/New Brunswick with
modest to perhaps locally heavy snow for interior/northern New
England.
...Weather Highlights/Threats...
Cold Canadian high pressure will spill out of eastern Montana
Monday morning through the Central Plains and into the Ohio Valley
by Wednesday, bringing in well below average temperatures that
will likely break daily records across a sizable area of the
eastern half of the CONUS Mon-Wed. Conversely, some record highs
are possible on Monday over northern California under the upper
axis. Front in the east will carry low pressure just off New
England with a swath of snow to the northwest of the track and
lake-effect snows for the Great Lakes with very cold temperatures
aloft over still warm water. Temperatures will moderate for later
in the week as the high moves offshore and weakens, but highs will
remain about 10-15 degrees below average along and east of the
Mississippi into next Friday. West of the Rockies, temperatures
will stay above average by about 5-10 degrees. Precipitation could
expand across the Gulf Coast late next week as the upper low once
over western Mexico moves eastward along the I-10 corridor
coincident with a weaker front to its north.
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