Late Season Northern U.S. Snow Cover Deepens, Likely To Last Into May
04/23/2023, 11:10 am EDTA Wet Spring for Europe to the Black Sea; Southwest Europe Drought Developing
04/30/2023, 12:44 pm EDTFig. 1: NOAA weather watch, warning, and advisory areas.
Discussion: A Freeze Warning for low temperatures mostly in the upper 20’s (-2 to -4C) is in effect for the Ohio Valley with a Frost Advisory issued for the Tennessee Valley and Lower Missouri Valley (Fig. 1). The freeze/frost extends to Pennsylvania. Meanwhile, ongoing Flood Warnings for snowmelt are in place for eastern North Dakota and northeast Minnesota. The latest 5-day significant river flood forecast by NOAA extends the current flooding southward across eastern South Dakota, much of Minnesota, and to near St. Louis along the Mississippi River (Fig. 2). The northern Great Plains (western U.S. mountains and Southern Canada) snow depth remain prohibitive (Fig. 3). Chilly temperatures remain in the forecast through the next 10 days with some easing of the chill possible in the 11-15-day forecast although forecast confidence is low. The rainfall forecast is best illustrated by the NOAA/WPC 7-day outlook which indicates heavy rain most concentrated on Oklahoma rather than Kansas (Fig. 4).
Fig. 2: NOAA 5-day significant river flood risk outlook.
Fig. 3: U.S. snow cover and snow depth daily analysis valid April 23, 2023.
Fig. 4: NOAA/WPC 7-day quantitative precipitation forecast.