RadioMan763™
HOME - GET A SCANNER RADIO - MENU
National Weather Service
Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
327 AM EDT Fri Jun 5 2026
Valid 12Z Mon Jun 08 2026 - 12Z Fri Jun 12 2026
...Overview...
An amplified ridge will dominate much of eastern U.S. while a shortwave energy will move across northern U.S. supporting multiple rounds of showers and thunderstorms across the Plains into the Mississippi Valley and across the Ohio/Tennessee Valley. Meanwhile, troughing over the Pacific Northwest will maintain a corridor of moisture across the northern tier, while bringing cooler temperatures to parts of western U.S. Anomalous warmth from the Plains through the Great Lakes and much of the East will continue to build through the week.
...Guidance/Predictability Assessment...
Models continue to show decent cluster with the trough over the West and broad ridging across much of eastern U.S. By mid-period, the shortwave energies embedded in the trough over the West Coast begin to diverge within the models, especially with the GFS, as it ejects eastward. These subtle impulses will likely determine the placement and intensity of mesoscale convective systems across the Northern Plains, Upper Midwest, and Great Lakes. The ensemble spread remains relatively small after Day 5. Therefore, the forecast favored a blend between ECMWF/GFS/CMC/EC-AIFS/UKMET, with less weight towards the GFS. Towards the latter portion of the forecast, the ensemble means were incorporated to smooth out timing and placement differences.
...Weather/Hazards Highlights...
At the surface, a series of low pressure systems and frontal boundaries moving across the Plains into the Upper Great Lakes will support scattered showers and thunderstorms across much of the Mississippi Valley and Upper Great Lakes on Monday into Tuesday. Several shortwave disturbances embedded within the west-northwest flow aloft will support clusters of thunderstorms. Increasing moisture transport from the Gulf combined with sufficient instability along the boundary could bring chances for high rainfall rates. Therefore, Day 4/Monday Slight Risk of excessive rainfall are in place to account for flash flooding concerns across parts of Tennessee/Ohio Valley into the Mississippi Valley, while the Marginal Risk continues to highlight parts of the Central Plains, the Upper Great Lakes, Upper Midwest, and Southeast.
The frontal passage will slowly move into the Ohio/Tennessee Valley and parts of the Mid-Atlantic by Tuesday, bringing chances for showers and thunderstorms eastward, while southerly flow continues to pool warm moisture along the boundary. Therefore, a Marginal Risk was placed for Day 5/Tuesday excessive rainfall outlook across parts of the Great Lakes into parts of Southeast. In addition, a secondary Marginal Risk is placed over the Northern Plains, where increased instability may interact with a secondary frontal boundary producing organized convection and heavy rainfall rates.
Over into the Southeast, persistent warm moisture combined with sea- breeze interaction will maintain daily thunderstorm chances across Florida and portions of the Gulf Coast, which may lead to locally heavy rainfall.
Troughing over the Pacific Northwest and a surface low with a trailing cold front will bring cooler conditions and chances for scattered showers and thunderstorms on Monday into Tuesday. By midweek, the frontal boundary pushes further southeastward and will interact with a second frontal boundary over Northern Rockies/Plains. The frontal boundary will gradually drape into the Upper Midwest, bringing additional showers and thunderstorms across the northern tier through Thursday.
Temperatures will trend below normal over the Pacific Northwest and along the West Coast as the trough continues to move inland. The remainder of CONUS will experience above seasonal temperatures with north-central U.S. seeing the greatest anomaly with 15-25 degrees above normal temperatures.
Oudit