Widespread Severe Convective Weather Expected in Northern Central United States

Over the past week, widespread severe convective weather has been observed across the central United States, with the largest hailstone diameter recorded at 12.7 cm, breaking historical records. It is expected that over the next two days, a high-altitude cold vortex will rapidly move eastward, and the upper-level jet stream will enhance the dynamic uplift and moisture transport conditions in the north-central U.S. The combination of strong wind shear and unstable energy will lead to extensive severe convective weather in the north-central region, affecting areas from Minnesota, western Wisconsin, through Iowa, and extending to eastern Kansas and western Missouri. Parts of these regions are likely to experience tornadoes, hail, and other severe convective phenomena. Additionally, a large area of rain and snow is forecasted for southeastern Canada and northeastern U.S., with heavy to torrential rain expected in the central and eastern U.S., including torrential downpours in South Dakota, Oklahoma, and other areas.

Figure 1 500 hPa Geopotential Height (contours) and 850 hPa Wind Field (wind barbs, color-filled for wind speed) at 1200 UTC, April 27, 2025

Figure 2 Forecasted Accumulated Precipitation for April 28-29, 2025 (Unit: mm)

Author: Hu Yingying                                 Reviewer: Zhou Ningfang 

English reviewer:Wang Yi                                                                       Issue approver:Dai Kan