Fig. 1: Current NOAA/NWS weather watch, warnings and advisories.
Discussion: A collision of extremes in the Midwest U.S. this morning. Extreme rainfall leads to flash flooding in Indiana and Ohio overnight (Fig. 1). A flood watch extends from Indiana to West Virginia. Just south of the heavy rain belt, an Excessive Heat Warning is issued for the Missouri to Tennessee Valley(s). In this zone, high temperatures near 100F last through tomorrow with heat index near 110F. The lack of much recovery at night leads to rising heat stress on local electric grids and agriculture. A Heat Advisory remains across much of the Mid-south U.S. plus the eastern Carolinas to southeast Virginia.
There is more severe weather and excessive rainfall on the way! Severe thunderstorms featuring damaging wind and hail strikes Montana and the Mid-Atlantic States westward to the Lower Ohio Valley (Fig. 2). Excessive rain causing flooding stretches across the U.S. Corn Belt eastward into Maryland (Fig. 3). On Thursday, severe weather develops (again) across Montana and Mid-Atlantic States adding the Interior Southeast U.S. (Fig. 4). The excessive rainfall zone tomorrow returns to the Midwest U.S. and extends to the Carolinas (Fig. 5). Finally, additional strong to severe storms dominate the East-central U.S. to Carolinas on Friday (Fig. 6). Excessive rain and flood risk regenerates in the Lower Ohio Valley (Fig. 7). NOAA/WPC indicates 1-4 in. of rain with high spots of 5 in. from Iowa to North Carolina in their 72-hour forecast (Fig. 8).
Fig. 2-3: NOAA/SPC severe weather outlook and NOAA/WPC excessive rainfall/flood risk areas for today.
Fig. 4-5: NOAA/SPC severe weather outlook and NOAA/WPC excessive rainfall/flood risk areas for Thursday.
Fig. 6-7: NOAA/SPC severe weather outlook and NOAA/WPC excessive rainfall/flood risk areas for Friday.
Fig. 8: NOAA/WPC 72-hour rainfall forecast across the U.S.
Fig. 9: Using all operational models, the consensus of population weight CDD forecast through July 21st is indicated and compared with yesterday’s forecast and 30-yer/10-year normal.