Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
254 AM EDT Mon Jul 6 2026

Valid 12Z Thu Jul 09 2026 - 12Z Mon Jul 13 2026


...Major Heatwave focus over the Southeast U.S. and building over
the Southwest/West-Central U.S. through this week and beyond...

                
...Pattern Overview...

An upper-level ridge develops over the Central U.S. through this
weekend, while a series of shortwaves move through the Great Lakes
and Northeast/Mid-Atlantic. This pattern will promote a major
heatwave across the Southern U.S.. Mean troughing keeps
temperatures at or below average across the Eastern
Pacific/Pacific Northwest.


...Guidance/Predictability Assessment...

Models are in reasonably good agreement regarding the 500 mb
pattern across the CONUS during the medium range period. A general
model blend consisting of most of the available deterministic and
Ai guidance is used on days 3 and 4 before ensemble means are
gradually incorporated into the blend through the rest of the
period.


...Weather/Hazards Highlights...

A major heat wave is expected to expand beneath a growing upper-
level ridge in the Central/Southern U.S.. This heat wave will
spread from the Southeast to the Southern Plains and into the
Central Rockies by the weekend. Heat indices between 105-115 are
expected across the South. Troughing in the Northeast/Mid-Atlantic
will support continued hot/moist southerly flow into the Florida
Peninsula, in particular, where there's a growing concern for
extreme heat risk beginning on Wednesday and continuing into the
weekend. No overnight relief from hot temperatures will affect
anyone without adequate cooling/hydration as well as health
systems, industries and infrastructure.

Scattered showers and thunderstorms will gradually spread south
through the Mississippi Valley, Midwest and Mid- Atlantic before
stalling out over the South late this week and into the weekend.

Meanwhile, monsoonal moisture may start to increase over at least
Arizona late-week/weekend as the upper high lifts farther north
into Utah/Colorado. Ridge amplification may also lead to some
downstream strong convection for the Southern Rockies/Plains given
summertime airmass and growing upper diffluence/weaknesses.


Kebede


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, excessive rainfall outlook,
winter weather outlook probabilities, heat indices and Key Messages
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/#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