FXUS02 KWBC 020648

PMDEPD



Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

248 AM EDT Wed Jul 2 2025



Valid 12Z Sat Jul 05 2025 - 12Z Wed Jul 09 2025





...Heavy Rain/Flash flooding threat for Florida as well as from 

the north-central Plains to the Midwest this holiday weekend...



...Hazardous heat and humidity to spread from the Midwest this 

holiday weekend to the Mid-Atlantic/Northeast early next week as

sweltering heat lingers for the South and builds over the West...





...Pattern Overview...



Upper troughing over the Northeast will eject into the Canadian 

Maritimes over the holiday weekend as multiple Pacific shortwaves 

dig into a West Coast mean upper trough which will help to keep it 

in place heading into next week. In between, a building upper ridge

will spread a threat of hazardous heat and humidity from the 

Midwest this holiday weekend to the Mid-Atlantic/Northeast early 

next week as a hot summer airmass lingers over the South and builds

over the Southwest/West. Meanwhile, a series of strong to severe 

convection forcing and heavy rain fueling impulses will progress 

atop the ridge from the north-central U.S. to the Midwest and into

the Northeast. Meanwhile, tropical moisture will fuel some heavy 

downpours along/south of a slowly weakening Florida front over the 

weekend in a region with local precursor heavy rains and tropical 

moisture, with any organization being monitorred by the NHC.



...Guidance/Predictability Assessment



The WPC medium range product suite was derived from a composite

blend of compatible GEFS/ECMWF/Canadian ensemble mean guidance 

along with WPC coninuity and the National Blend of Models. 

Forecast spread increases over time within average seasonal norms,

but ensemble mean usage mutes individual system depictions given 

uncertainty, especially in the Gulf and offshore the Southeast 

U.S. given slowly growing but still limited NHC support. Recent

model runs have been less than stellar from run to run with the 

handling of this option in particular, especially the Canadian.



...Weather/Hazards Highlights...



Tropical moisture and instability will support heavy convective 

downpours along/south of a lingering front across Florida through 

the upcoming holiday weekend. WPC Excessive Rainfall Outlook (ERO) 

Marginal Risk areas are shown for Day 4/Saturday and Day 5/Sunday 

for west-central Florida as preceded by heavy rainfall. Guidance 

has varied QPF over Florida and uncertain onshore inflow solutions

into east-central Gulf and Southeast coastal areas as contingent 

on tropical development potential the NHC continues to monitor.



Periodic strong to severe storms/MCS will offer periodic heavy 

rain/runoff threats to focus from the north-central U.S. to the 

Midwest this weekend as upper trough/impulse energies work on the 

northern periphery of the main central U.S. upper ridge where 

moisture/instability tends to be lifted near a wavy draping front. 

WPC ERO Marginal Risk areas are depicted for Day 4/Saturday and 

downstream for Day 5/Sunday. Into early-mid next week, showers and 

embedded thunderstorms will focus near the slow moving front into 

the Northeast/Mid-Atlantic, but also refire back across the north- 

central states where ejecting upper-level waves will interact with

moisture and instability pooling frontal zones.



Meanwhile, a broadening upper ridge will spread a hazardous heat 

and humidity threat from the Midwest this holiday weekend to the 

Mid-Atlantic/Northeast into next week as a hot summer airmass 

lingers broadly over the South and builds up across the West.





Schichtel





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





































































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