The National Weather Service is forecasting a 40 percent chance of thunderstorms for Saturday, a day filled with activities as lots of folks across the region kick off the holiday weekend. The day won't be a total washout (the latest run of the GFS forecast model shows only 0.04" of rain through Saturday evening; that is very unreliable because it doesn't pick up on convective precipitation well and thunderstorms are just that -- a single thunderstorm would dump well over that amount of rain, but it does indicate the scattered nature of the storms for Saturday). However, any storm that does develop will have a slight chance of becoming severe.
NOAA's Storm Prediction Center in Norman, Okla., has placed all of East Tennessee and the Cumberlands under a "slight risk" for severe weather on Saturday. Take a look:
Generally speaking, a "slight risk" for severe weather means there is a 15 percent chance that a severe thunderstorm could strike.
Chances are, not everyone is going to see rain on Saturday, and pinpointing exactly where the storms set up is an impossibility at this juncture. But as the day progresses, the diurnal heat will create instability that could help strong storms fire. The SPC says that atmospheric factors will "promote a risk for large hail, damaging winds and an isolated tornado. Storms may merge into clusters with time with a continued severe risk Saturday evening."
NWS-Morristown has issued a hazardous weather outlook for both Saturday and Sunday, saying strong to severe thunderstorms are possible each afternoon as a "very moist and unstable airmass moves into the area." The primary threat on each day, the NWS says, will be damaging winds and hail.
Overall, the Memorial Day weekend is looking wetter than it was just 24 hours ago, when it appeared that the bulk of the holiday weekend precipitation would be contained to Sunday evening and Sunday night. Thunderstorm chances will increase Saturday night, and Sunday looks like pretty much everyone will see rain. Thunderstorm chances on Memorial Day are now up to 40 percent, as models increase the amount of precipitation falling on the holiday.
Precipitation chances begin to diminish as everyone heads back to work on Tuesday (figures, right?) with high temps in the mid 70s and low temps in the mid 50s for the rest of the week -- which is pretty much normal for this time of year. The hottest weather of the season (to date) still appears to be on the way as we get several days into June.
Eye to the Sky is a weather blog by Independent Herald editor Ben Garrett. Garrett is a weather enthusiast who has long blogged about interesting weather on his personal website. He is not a professional forecaster or a meteorologist and information on this blog should not be considered a substitute for forecasts, advisories or other products from the National Weather Service.