For most, the cool pattern will result in temperatures averaging 10 to 15 degrees Fahrenheit below early May averages, which could lead to a frost or freeze - or even wet snowflakes.
As of 2 p.m. Sunday afternoon, this was the NWS map for Frost Advisory/Freeze Watch areas for Sunday night into Monday morning.
For those concerned about their plants and conditions, the weather service has an internet site at weather.gov/StateCollege that will keep those concerned alerted to the advisory.
The forecast for the week of May 7 shows an increase in temperature as the week passes, ending with a warm, albeit rainy, Friday and Saturday at 15 degrees.
Friday will be cloudier, but the rain will stay just south and west of viewing area until Friday night. That is when we expect temperatures to be the coldest. The advisory is in effect because the temperature will be around zero and could harm plants.
Russia: Syrian safe zones plan to take effect at midnight
Captain Jeff Davis of the Pentagon would not say if the U.S. military would honour the zones and promise not to fly over them. The largest de-escalation zone includes Idlib province and adjoining districts of Hama, Aleppo and Latakia provinces.
At this temperature, damage to most plants may be minimal, and only affect a leaf or two.
Wednesday will be mostly sunny with a high of 65 and a low of 45.
Partly sunny to cloudy skies will transition into patchy clouds overnight.
For the weekend, the projection is for Mother's Day possible showers and drizzle, but a high of 64 and a low of 48.