Top Weather Stories of the Week
Forecast Discussion: June 29 – July 5, 2025
Overview
The past week has been dominated by a persistent heat dome across much of the United States, driving record-breaking temperatures and oppressive humidity. However, as we move into the period from Sunday, June 29 to Saturday, July 5, 2025, the forecast indicates a gradual dissipation of this extreme heat in many areas, particularly in the Midwest, Northeast, and Mid-Atlantic. Meanwhile, severe weather threats, including thunderstorms and potential flash flooding, will remain a concern across portions of the Central and Eastern U.S. Additionally, tropical activity in the Gulf of America and the Atlantic is showing signs of potential development, which could bring significant impacts to the Southeast and Gulf Coast by the end of the week. Below, let’s discuss the top weather stories for the upcoming week, focusing on the dissipation of excessive heat, severe weather threats, and tropical developments.
1. Dissipation of Excessive Heat
The extreme heat wave that has gripped much of the U.S., affecting over 200 million people with temperatures above 90°F and heat indices in the triple digits, is finally showing signs of relief. A heat dome, characterized by a strong high-pressure system aloft, has been responsible for record-breaking temperatures across the Midwest, Ohio Valley, Northeast, Mid-Atlantic, and Southeast. Cities like Rapid City, South Dakota (98°F), Minneapolis (97°F), and parts of the Northeast have tied or broken daily temperature records. This heat has been exacerbated by high humidity, pushing heat indices to dangerous levels and elevating the risk of heat-related illnesses, particularly for vulnerable populations without adequate cooling.
Forecast Evolution
Sunday, June 29 – Monday, June 30: The heat dome begins to weaken as an upper-level trough moves into the Great Lakes and Northeast, allowing cooler air to filter into these regions. The Midwest, including Chicago, Milwaukee, and Minneapolis, will see temperatures drop from the upper 90s to the mid-80s by Monday. The Northeast and Mid-Atlantic, including New York and Washington, D.C., will experience a similar cooling trend, with highs retreating to the mid-80s to low 90s. However, the Southeast, Mid-South, and Plains will remain hot, with temperatures still exceeding 90°F and heat indices approaching 100°F due to lingering high humidity.
Tuesday, July 1 – Wednesday, July 2: The cooling trend continues to spread southward, with the heat dome shifting westward. The Southeast, including Florida, Georgia, and the Carolinas, will see temperatures closer to seasonal averages (mid-80s to low 90s) by midweek. The Plains and Upper Midwest will experience a brief respite, though the Desert Southwest and parts of Texas will continue to see above-average temperatures in the mid-90s to low 100s.
Thursday, July 3 – Saturday, July 5: While the most intense heat begins to subside across the eastern two-thirds of the U.S., a secondary surge of warm air may develop in the West, particularly in California, Nevada, and Arizona, where temperatures could again climb into the upper 90s to low 100s. The Southeast and Gulf Coast may see a return of above-average temperatures by the weekend, driven by southerly winds and high ocean temperatures in the Gulf of America, potentially exacerbated by tropical activity discussed below.
Impacts
The gradual dissipation of the heat dome will reduce the risk of heat-related illnesses, which have been a significant concern, especially in urban areas like New York City and Chicago, where infrastructure strains (e.g., power outages and hospital cooling issues) were reported. However, the Southeast and Gulf Coast will remain vulnerable to heat stress through midweek due to persistent high humidity. Local regulations in heat-prone cities like Tucson and states like California are helping mitigate risks, but the prolonged heat has already taken a toll on public health and infrastructure.
2. Severe Weather Threats
Severe thunderstorms, heavy rainfall, and potential flash flooding are expected across portions of the Central and Eastern U.S. through the weekend, driven by a combination of frontal boundaries, upper-level impulses, and abundant moisture. The Storm Prediction Center (SPC) has highlighted areas of concern, particularly in the Upper Mississippi Valley, Northern Plains, and Southeast.
Forecast Details
Sunday, June 29: A Slight Risk (Level 2/5) of severe thunderstorms is in effect for the Upper Mississippi Valley and Northern/Central Plains, including parts of Minnesota, Iowa, and Nebraska. Primary threats include large hail (1-2 inches in diameter), damaging winds (>58 mph), and isolated tornadoes. Heavy rainfall, with 1-2 inches possible in a short period, raises concerns for flash flooding, particularly in urban areas. The Southeast, including the Tennessee Valley and Gulf Coast, will see scattered thunderstorms fueled by daytime heating and high moisture content, with a Marginal Risk of excessive rainfall.
Monday, June 30: The severe weather threat shifts eastward to the Upper Great Lakes and Upper/Middle Mississippi Valley, with a Slight Risk in effect for parts of Wisconsin, Michigan, and Illinois. Similar hazards—large hail, damaging winds, and isolated tornadoes—are expected. Heavy rain (2-4 inches) could lead to flash flooding, especially in areas with saturated soils from prior storms. The Southeast will continue to experience scattered thunderstorms, with a focus on coastal areas from Florida to the Carolinas.
Tuesday, July 1 – Wednesday, July 2: The severe weather threat expands to include the Northeast, Mid-Atlantic, and Southeast, with a Marginal Risk of excessive rainfall extending from the Appalachians to the Gulf Coast. Thunderstorms may produce heavy downpours (1-3 inches), leading to urban flooding risks in cities like Miami, Fort Lauderdale, and Charleston. The central Gulf Coast is particularly at risk for heavier rain (3-5 inches) due to moisture from a potential tropical system (see below).
Thursday, July 3 – Saturday, July 5: Severe weather threats diminish in the Midwest and Northeast as the frontal boundary weakens, but the Southeast and Gulf Coast remain at risk for heavy rain and thunderstorms, particularly if tropical development occurs. The SPC notes a potential for derechos (widespread, long-lived windstorms) in the northern Plains, Ohio Valley, and Tennessee Valley earlier in the summer, but this risk appears lower for this period unless tropical systems enhance instability.
Impacts
The combination of severe thunderstorms and heavy rainfall poses risks of flash flooding, particularly in urban areas and regions with poor drainage, such as Miami and Fort Lauderdale. Damaging winds and hail could disrupt outdoor plans, including Independence Day celebrations, and pose risks to infrastructure. The potential for isolated tornadoes, while low, requires vigilance in the Upper Midwest and Plains.
3. Tropical Activity in the Atlantic and Gulf of America
The Atlantic hurricane season, which began on June 1, is showing signs of increased activity in the Gulf of America and along the Southeast coast. Tropical Depression Two (T.D. 2) has formed in the Bay of Campeche and is expected to become Tropical Storm Barry before making landfall in Mexico by Sunday night or Monday, June 30. Additionally, the National Hurricane Center (NHC) is monitoring a potential low-pressure system near the southeastern U.S. Atlantic and Gulf coasts for possible tropical or subtropical development by the end of the week.
Current Systems
Tropical Depression Two (Bay of Campeche): As of this evening, June 29, Tropical Storm Barry is located in the southwestern Gulf with landfall imminent in along the southeast coast of Mexico. The system is moving northwest and will weaken rapidly upon landfall due to interaction with mountainous terrain. Impacts along the Texas Gulf Coast include increased moisture, leading to a 60% chance of showers and storms, slightly elevated seas, and enhanced rip currents through Monday. Saharan dust moving into Southeast Texas by Monday may limit further development in the region.
Eastern Pacific Activity: In the eastern Pacific, Tropical Storm Erick has weakened to a low-pressure system after making landfall in southern Mexico as a Category 4 hurricane. It will produce 3-6 inches of rainfall, with flooding risks in southwest Mexico. Another system off the coast of Panama has a low risk of development next week, but it will not impact the U.S..
Forecast for Potential Development
Sunday, June 29 – Tuesday, July 1: No significant tropical development is expected in the Atlantic beyond T.D. 2, as Saharan dust suppresses activity across the basin. The NHC notes a quiet Atlantic with no tropical cyclone formation expected over the next 7 days, partly due to the dust cloud affecting Southeast Texas and the Gulf Coast.
Wednesday, July 2 – Saturday, July 5: The NHC has highlighted a 20% chance of tropical or subtropical development near the southeastern U.S. Atlantic and Gulf coasts by the end of the week, potentially over the 4th of July weekend. This system could form from a remnant frontal boundary interacting with very warm Gulf waters (above-average sea surface temperatures). Model guidance suggests energy may become trapped in the northeast Gulf or off the Southeast coast, leading to slow development. Heavy rainfall (3-5 inches) is possible, regardless of development, posing a flooding risk for Florida, southern Georgia, and the Carolinas. Impacts could include flash flooding, rip currents, and coastal flooding.
Long-Term Outlook: The above-average sea surface temperatures in the Gulf and western Atlantic, combined with ENSO-neutral conditions, create a conducive environment for tropical cyclone formation. The NHC’s extended forecast tools, including the Global Tropical Hazards Outlook, suggest continued monitoring of the western Caribbean and Gulf for potential development into mid-July.
Impacts
The primary concern for the Gulf Coast and Southeast is heavy rainfall and potential flooding, even if a system remains weak or subtropical. Cities like Miami, Fort Lauderdale, and Charleston are at risk for urban flooding, with building seas and rip currents posing hazards for coastal activities over the holiday weekend. If a tropical system develops, it could enhance severe weather threats, including tornadoes, along the Gulf Coast. The NHC’s upgraded forecasting tools, including a 5% improvement in tracking and intensity forecasts, will provide communities with more preparation time.
Additional Notes
Saharan Dust: A large Saharan dust cloud moving into Southeast Texas and the Gulf Coast will limit tropical development early in the week but may create colorful sunrises and sunsets. The dust could also impact air quality in Texas and Florida.
Climate Context: The excessive heat and active hurricane season are consistent with climate change trends, which increase the frequency and intensity of extreme weather events. The warming atmosphere holds more moisture, contributing to heavier rainfall and flooding risks.
Preparation: With the 4th of July weekend approaching, residents in the Southeast and Gulf Coast should monitor forecasts closely for potential tropical impacts. Coastal areas should prepare for rip currents and possible coastal flooding, while urban centers should be ready for flash flooding risks.
Conclusion
The week of June 29 to July 5, 2025, marks a transition from extreme heat to more seasonable temperatures across much of the U.S., with the Midwest, Northeast, and Mid-Atlantic seeing the most significant relief. Severe thunderstorms and heavy rainfall will pose ongoing risks, particularly in the Upper Midwest, Plains, and Southeast, with flash flooding a primary concern. In the tropics, T.D. 2 in the Gulf of America will bring minor impacts to Texas before weakening, while a potential low-pressure system near the Southeast coast could develop into a tropical or subtropical system by the holiday weekend, increasing rainfall and coastal hazards. As always, staying informed through NHC and local Weather Forecast Office updates will be critical for safety and preparedness.