Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
258 AM EDT Wed Aug 7 2024
Valid 12Z Sat Aug 10 2024 - 12Z Wed Aug 14 2024
...Excessive Heat lingers over portions of Texas and the central
Gulf Coast this weekend into next week...
...Overview...
The remnants of Debby are now forecast to lift out of the Northeast
rather quickly on Saturday with now only limited heavy rain
concerns for New England.
Upstream over the West and central states, upper ridging centered
over Texas will maintain monsoonal flow over the Southwest this
weekend into next week with heat concerns persisting from Texas to
the central Gulf Coast. Minor troughing over the Pacific Northwest
will linger through the period.
...Guidance/Predictability Assessment...
There is finally consensus among global guidance with the 00Z suite
now that the GFS is much quicker in its exit of Debby through the
Northeast on Saturday. However, the 18Z GFS was still much slower
with Debby remnants, so it was largely excluded from the forecast
blend that went into the Days 4-7 fronts and pressures. The 12Z
ECMWF was heavily favored in that forecast blend and for QPF a
general blend of the 01Z NBM with the 12Z ECMWF/CMC and some UKMET
was used.
...Weather/Hazards Highlights...
The quicker exit of Debby-related rainfall from the Northeast on
Saturday warranted dropping the Slight over New England in favor
of a more restricted Marginal.
Monsoonal moisture on the western side of the ridge will keep a
wet and unsettled pattern in place from the Four Corners region
northward into the Rockies/High Plains through this weekend .
Marginal EROs are in effect for parts of the Southwest/Four Corners
for Days 4/5.
Guidance continues to agree organized activity Saturday/Sunday
that originates in the lee of the CO Rockies and track southeast
over
portions of southern KS/much of OK into the Ozarks. Marginal Risks
are in effect for both Days 4 and 5 as a result.
Above seasonal normal temperatures persist over Texas to the
central Gulf coast this weekend into next week down stream of a
ridge axis over west Texas. Below normal temperatures over central
U.S. persists behind a cold front this weekend/Monday before return
flow brings temps back toward normal.
Jackson
Additional 3-7 Day Hazard information can be found on the WPC
medium
range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:
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/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw