Meteorological summer begins Tuesday and Mother Nature has a few plans for the Potomac Highlands going forward through June. Will temperatures soar to record highs or will rain provide frequent heat relief?
Let’s examine how the pattern will shake out.
We hope you are enjoying the cool Memorial Day weekend weather because June will begin much warmer. We expect a frontal system to bring showers and a few thunderstorms within June’s first week followed by a brief shot at somewhat cooler temperatures. The next threat for rain will come just before the middle of the month and then the final seven days of June will feature occasional showers and thunderstorms.
We’re moving into the height of the severe weather season. Traditionally, June is the second most active month for thunderstorms with gusty winds, hail and yes, even tornadoes. Historically, in June, the 11th to the 24th between 4 p.m. and 6 p.m. is the most favored timeframe for thunderstorms. We think June 10, 13 and 27 holds the best chance for severe weather in the Potomac Highlands.
Agriculture interests hope for enough rain to keep the crops healthy and hydrated in June. Only eight of the previous 20 Junes have produced less than 4.24 inches, which is Allegany County’s average rainfall for the year’s sixth month. We expect rainfall to trend near average, so the Potomac Highlands will likely not see significant dry spells that would cause crop stress. Flash flooding, on the other hand, is usually very localized. If it does occur this month, the best chance is June 13 and 28. The U.S. Route 220 corridor is climatology favored for flash flooding.
June is the first month of the Atlantic hurricane season. We don’t expect any early season tropical storm or hurricane to bring rain to the region in June. Should a tropical system develop in June, the Lower Mississippi Valley and Southeast Atlantic Coast will see rainfall.
Now that we have discussed the rainfall trends, let’s examine temperatures. As the zone of upper-level winds, known as the jet stream, lifts north, cold fronts become less frequent in the summer. The source for thunderstorms comes from weak and diffuse upper-level systems that detach from the jet stream. We are forecasting one early month cold front to provide heat and humidity relief between June 4-6. The warmest stretch of weather in June will be period leading up to the summer solstice, June 14-20.
When the numbers are crunched at the end of June, we expect the average low and high temperature to exceed average. The only chance for a daily record high to be shattered will be around June 20. Allegany County’s most recent 30-year climate data shows the monthly average low and high temperature is 57 degrees and 81 degrees, respectively. Garrett County averages a monthly low temperature of 54 degrees and a high temperature of 76 degrees.
Looking ahead through the remainder of summer, we expect near to slightly below average rainfall in July and August with warmer than average conditions. We’ll discuss the specifics for July at the end of June and look ahead to August at the end of July.
If you have a summer vacation planned, enjoy! Beware, however, the UV Index will often reach 8 to 10 in June, July and August. Apply sunblock, wear light-reflective clothing and a wide-brimmed hat when outside and seek shade as often as possible. Keep in mind that if you are outside between 11 a.m. and 4 p.m., regardless if it’s June 2 or Aug. 31, a sunburn can happen in 15 to 25 minutes. It may be tempting to stay outside longer on a cloudy day but 80% of the solar radiation can penetrate cloud cover and a sunburn can catch you off guard.
The 2022 edition of the Hagerstown Town and Country Almanack will be available later this summer. Please feel free to reach out to me if you are interested in purchasing a copy and as always if you have any weather-related questions, my contact information is below.
Chad Merrill is a Cumberland native and meteorologist who serves as the Hagerstown Town and Country Almanack weather prognosticator and senior meteorologist at Earth Networks in Germantown. Merrill previously was a meteorologist with WDVM (formerly known as NBC25) in Hagerstown and WJAC-TV in Johnstown, Pennsylvania.