Heavy rainfall  Expected in the Central and Eastern United States and Southern Mexico

Over the past week, heavy rainfall has been observed in southern Canada, eastern and southern United States, and most  of Mexico, with cumulative precipitation ranging from 100 to 250 mm and exceeding 300 mm in some areas. Notably, localized rainfall totals surpassed 500 mm in central and southeastern Texas, northern Virginia in the United States, as well as in central Nuevo León, northern Michoacán, southwestern Veracruz, northeastern Chiapas, and northwestern Yucatán in Mexico (Fig. 1).

Over the next three days, influenced by an upper-level trough (Fig. 2), parts of southeastern Canada, central and eastern United States are expected to experience moderate to heavy rain, with localized severe or extreme downpours (90-140 mm). These conditions will be accompanied by severe convective weather, including short-duration heavy rain, thunderstorm winds, and hail (Fig. 3). Starting June 21, under the influence of a subtropical high, some regions in the central and eastern United States will see temperatures exceeding 35°C from west to east. Additionally, affected by a tropical depression, from June 18 to 21, most of Central America will face heavy to torrential rain, with southern Mexico, central and northern Guatemala, and southeastern Belize experiencing localized extreme downpours (120-300 mm).

Figure 1: Accumulated Rainfall from June 9 to 16, 2025 (Unit: mm)

Figure 2: 500 hPa Geopotential Height (contours, units: dagpm) and 850 hPa Wind Field (wind barbs, units: m/s) at 1200 UTC on June 19, 2025

Figure 3: Forecasted Accumulated Precipitation from June 17 to 20, 2025 (Unit: mm)

Author: Min Yue                                 Reviewer: Ma Jie 

English reviewer:Wang Yi                                                    Issue approver:Dai Kan