Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
514 PM EDT Thu Oct 10 2019
Valid 12Z Sun Oct 13 2019 - 12Z Thu Oct 17 2019
...Pattern Overview and Guidance/Uncertainty Assessment...
The deep closed upper low over the Upper Midwest Sunday will
slowly lift toward James Bay early next week, keeping cyclonic
flow over the eastern CONUS. Another shortwave trough and its
associated cold front drops through the Pacific Northwest and
eventually through the Plains Tuesday and then into the Northeast
U.S. mid to late week. Another pair of fronts will then approach
the Pacific Northwest by the end of the forecast period.
For this cycle, the 00Z ECMWF and ECENS mean were the primary
component of the model blend preference. For Day 3-4, model spread
was low enough to include the deterministic runs of the
ECMWF/GFS/CMC/UKMET, with inclusion of both the 00Z and 06Z GFS.
By Day 5-7, uncertainty increases, particularly across the
northeast Pacific, as the extratropical transition of Hagibis
impacts the overall synoptic pattern. An ensemble blend weighted
toward the 00Z ECENS mean was used for Day 6-7.
...Weather Highlights/Threats...
A stalled front across the Southeast and Gulf Coast region will be
the focus for showers and thunderstorms Sunday through Tuesday
with slightly above normal precipitable water values in place.
Moisture may be lifted into the region from eastern Pacific
sources, but questions remain on how much influence there may be
with a weakening area of disturbed weather. Another approaching
front and low pressure sweeping the central/eastern US on Wed-Thur
will be the focus for rainfall from the lower Mississippi Valley
toward the mid-Atlantic and Northeast.
Below normal temperatures will persist late this weekend into
early next week across the northern Plains. Moderation is expected
toward the middle of next week. The South will see above average
temperatures through mid-week followed by near normal to slightly
below normal as Canadian high pressure sweeps through the eastern
CONUS.
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
Hazards:
- Heavy rain across portions of the Northeast, the Pacific
Northwest, the Northern Mid-Atlantic, California, and the Lower
Great Lakes, Wed-Thu, Oct 16-Oct 17.
- Heavy rain across portions of the Southeast, the Southern
Mid-Atlantic, the Lower Mississippi Valley, the Southern
Appalachians, and the Tennessee Valley, Mon-Wed, Oct 14-Oct 16.
- Flooding possible across portions of the Plains, the
Upper/Middle Mississippi Valley, and the Great Lakes.
- Flooding occurring or imminent across portions of the
Northern/Central Plains, the Upper/Middle Mississippi Valley, and
the Great Lakes.
- Flooding likely across portions of the Middle Mississippi Valley
and the Northern Plains.
- Much below normal temperatures across portions of the
Northern/Central Plains, the Upper/Middle Mississippi Valley, and
the Great Lakes, Sun-Wed, Oct 13-Oct 16.
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