Short-term heavy rainfall and other severe convective weather are expected in the central and eastern United States and Mexico

Under the combined influence of the subtropical high-pressure system and a shortwave trough (Fig. 1), moderate to heavy rainfall is expected to sweep from west to east across regions including northern Mexico, the central and eastern United States, and southern Canada from June 24 to 28. Specifically, parts of Sonora and Chihuahua in Mexico, northeastern Nebraska, southeastern Minnesota, Wisconsin in the United States, and southeastern Ontario in Canada are likely to experience heavy downpours or severe storms, with cumulative rainfall reaching 40 - 130 mm (Fig. 2). Some areas will be accompanied by short-term heavy rainfall, thunderstorms with strong winds, and tornadoes, indicating severe convective weather conditions (Fig. 3).

Additionally, influenced by a tropical disturbance, moderate to heavy rainfall is forecast along Mexico’s western coastal areas from June 29 to July 1, with localized heavy downpours or intense rainfall, accompanied by winds of 4 to 6 on the Beaufort scale, and gusts exceeding 8 on the Beaufort scale (Fig. 4).

Figure 1  Average Geopotential Height at 500 hPa (contours, Units: dagpm) and Wind Field at 850 hPa (wind barbs, units: m/s) from June 24 to 28, 2025

Figure 2  Forecasted Accumulated Precipitation from June 24 to 28, 2025 (Unit: mm)

Figure 3  Forecast of 850 hPa Wind Field (wind barbs, units: m/s) and K-Index (shaded, units: °C) at 1200 UTC on June 27, 2025

Figure 4  Forecasted Accumulated Precipitation from June 29 to July 1, 2025 (Unit: mm)

Author: Hu Yingying                                 Reviewer: Niu Ruoyun 

English reviewer:Wang Yi                                                                       Issue approver:Dai kan