Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
254 PM EDT Sun Jun 14 2026

Valid 12Z Wed Jun 17 2026 - 12Z Sun Jun 21 2026


...Hazardous Heat shift from the West/Southwest to the South....

...Excessive Rain/Flooding threat from the Midwest to the South
and Gulf Coast...


...Pattern Overview and Guidance/Predictability Assessment...

The guidance continues to show a fairly agreeable large scale
pattern across the CONUS for the period, featuring an initially
amplified pattern which should flatten with time by next weekend.
There remains a lot of uncertainty in the details, especially
pertaining to smaller scale shortwaves reinforcing a Great Lakes to
Eastern U.S. trough, and with energies moving through the
Northwest to Northern tier. The biggest source of uncertainty
though surrounds a vort of energy out of the Northwest Gulf, which
the NHC currently shows a low (30 percent) probability of tropical
development. The vast majority of the guidance shows the presence
of this feature, tropical or not, but intensity and timing vary
widely and remains highly uncertain. This is a low confidence
forecast, with high impact potential, and will continue to be
monitored closely.

WPC favored a general blend of the deterministic guidance for the
first half of the period, transitioning towards majority ensemble
mean guidance Day 5 and beyond to account for uncertainty in the
forecast, especially across the South. This keeps the new forecast
for today in line with continuity.


...Weather/Hazards Highlights...

A wavy front will settle and trail back from the Southeast U.S.
through the Gulf Coast and southern Rockies/Plains this week and
provide a focus for heavy rain and thunderstorms. Regardless of any
sort of tropical development in the northwest Gulf, deep tropical
moisture return and instability will interact with the generally
west to east oriented front to fuel a heavy rainfall/flash flooding
threat to include potential for the repeat/training of activity.
The WPC Day 4/5 Excessive Rainfall Outlook (ERO) for
Wednesday/Thursday show Marginal to Slight Risk areas for flooding
for the western to central Gulf Coast/lower Mississippi Valley,
with heavy rainfall potential beyond as the feature possibly moves
eastward into Southeast.

Farther north, a heavy rain and thunderstorm threat is meanwhile
also slated mid-later week as a series of energetic and progressive
northern stream shortwave and surface lows/fronts dig from the
north-central U.S. through the Midwest/Ohio Valley states. WPC Day
4/Wednesday and Day 5/Thursday ERO Marginal and Slight Risk areas
shift slowly southeastward over the region. There are also
coinciding SPC severe weather threat areas to monitor there and to
the Mid-Atlantic. Threat potential may persist later next week as
systems refire activity, but also expand focus into the south-
central U.S./Mid-South and into the East with frontal push.

Early week ridging over the West will lead to much above normal
temperatures and a moderate to locally major HeatRisk, especially
into parts of the Southwest. With time, the heat will spread into
the south-central U.S. with moderate to major HeatRisk expected for
parts of central Texas. Locally elevated heat threats look to
overspread the Gulf Coast and Southeast/Florida to also monitor.

Schichtel/Santorelli


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