Forecast Details for Saint Marys, IA

Recent Locations: Riverside, CA Norton, VA Saint Marys, IA

This Afternoon: A 10 percent chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 80. Southwest wind around 9 mph.

Tonight: A 40 percent chance of showers and thunderstorms, mainly after 10pm. Mostly cloudy, with a low around 65. Southeast wind 6 to 8 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Tuesday: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1pm. Some of the storms could be severe and produce heavy rainfall. High near 82. Windy, with a southeast wind 10 to 15 mph increasing to 20 to 25 mph in the afternoon. Winds could gust as high as 38 mph. Chance of precipitation is 80%. New rainfall amounts between three quarters and one inch possible.

Tuesday Night: Showers and possibly a thunderstorm before 7pm, then a slight chance of showers and thunderstorms between 7pm and 1am. Some of the storms could be severe. Low around 52. Windy, with a west wind 17 to 22 mph decreasing to 11 to 16 mph after midnight. Winds could gust as high as 33 mph. Chance of precipitation is 80%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Wednesday: A 20 percent chance of showers before 1pm. Mostly sunny, with a high near 72. West northwest wind 10 to 14 mph, with gusts as high as 20 mph.

Wednesday Night: Mostly clear, with a low around 50.

Thursday: Sunny, with a high near 77.

Thursday Night: A 30 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 58.

Friday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 78. Chance of precipitation is 60%.

Friday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 55. Chance of precipitation is 60%.

Saturday: Mostly sunny, with a high near 76.

Saturday Night: A 30 percent chance of showers. Partly cloudy, with a low around 56.

Sunday: A 30 percent chance of showers. Mostly sunny, with a high near 78.

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Weather Topic: What is Rain?

Home - Education - Precipitation - Rain

Rain Next Topic: Shelf Clouds

Precipitation in the form of water droplets is called rain. Rain generally has a tendency to fall with less intensity over a greater period of time, and when rainfall is more severe it is usually less sustained.

Rain is the most common form of precipitation and happens with greater frequency depending on the season and regional influences. Cities have been shown to have an observable effect on rainfall, due to an effect called the urban heat island. Compared to upwind, monthly rainfall between twenty and forty miles downwind of cities is 30% greater.

Next Topic: Shelf Clouds

Weather Topic: What is Sleet?

Home - Education - Precipitation - Sleet

Sleet Next Topic: Snow

Sleet is a form of precipitation in which small ice pellets are the primary components. These ice pellets are smaller and more translucent than hailstones, and harder than graupel. Sleet is caused by specific atmospheric conditions and therefore typically doesn't last for extended periods of time.

The condition which leads to sleet formation requires a warmer body of air to be wedged in between two sub-freezing bodies of air. When snow falls through a warmer layer of air it melts, and as it falls through the next sub-freezing body of air it freezes again, forming ice pellets known as sleet. In some cases, water droplets don't have time to freeze before reaching the surface and the result is freezing rain.

Next Topic: Snow