Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
255 PM 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...
The general pattern across the CONUS next week is expected to
feature upper ridging over the western U.S. and Canada with
downstream troughing over much of the central/eastern CONUS. A
slow moving upper level low will gradually move across Mexico and
into the Gulf toward of the end of next week. Overall, forecast
models and predictability were average to slightly above average
in the large scale with the usual timing/track/strength
differences noted. The anomalous deep trough mid-week will induce
a surface low along the U.S. East Coast and bring a threat of
heavy snow for interior/northern New England. Model guidance has
come into enough of an agreement that for Day 3-4 (Mon-Tue), a
blend of the available deterministic guidance was used. Beyond
that time frame, the 00Z ECMWF and 06Z GFS offered enough utility
to be incorporated, with increasing percentages of the latest
ECENS/GEFS means toward Day 7.
...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. By the end of the
week, the upper low once over Mexico reaches the Gulf and its
interaction with a stalled/lingering frontal boundary could spread
precipitation along the Gulf Coast with possible low pressure
developing.
Fracasso/Taylor
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
- Heavy snow across portions of the Upper Great Lakes, Mon, Nov 11.
- Heavy snow across portions of the Northeast and the Lower Great
Lakes, Mon-Tue, Nov 11-Nov 12.
- Flooding occurring or imminent across portions of the Middle
Mississippi Valley and the Northern Plains.
- Flooding likely across portions of the Northern Plains.
- Much below normal temperatures across much of the Great Plains
to East Coast, Tue-Thu, Nov 12-Nov 14.
- Much below normal temperatures across portions of the Northern
Plains and the Northern Rockies, Mon, Nov 11.
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