Roanoke’s high temperature today (Saturday) failed to reach 80 degrees for the third consecutive day. Blacksburg, which has had only two 80-plus days among the first 16 days of this month, barely stayed out of the 40s for a low (50) on Saturday morning. You know those kind of temperatures can’t hold on forever in June. Summerlike temperatures are expected to return to the region during the coming week, with Roanoke likely seeing its first 90s of 2012 in the Wednesday-Friday time frame (map at left is projected temperature for Thursday), perhaps as early as Tuesday. Locations south and east of Roanoke will be in the 90s, with mid-upper 80s to the west. This will be because of an area of high pressure expected to build over the region in the middle part of next week (Wednesday weather map shows high centered almost directly overhead), allowing several days of hot sunshine and relatively dry air.
Between the current cooler regime (another sunny day of 50s lows and 70s to low 80s highs on Sunday — Happy Father’s Day!) and the coming hot one, some showers and storms may be possible from Sunday night through Tuesday as we’ll be between high pressure systems that are capping the atmosphere and not allowing surface moisture to build aloft into precipitation-making clouds. Moisture creeping in from the south, perhaps somewhat stirred by a weak cold front passing well north of us, will help feed a few showers and storms, especially during peak daytime heating over the mountains.
This will not be a long-term heat wave, as a cold front is likely to move in by Friday or Saturday of next week to quickly break the hot spell. Also something to watch is the potential for a tropical low in the Gulf of Mexico, which has been consistently depicted on forecast models, such as today’s 12Z GFS for next Saturday, the 23rd (linked here). Most model projections have favored the western Gulf for this activity. It’s something on the horizon to monitor, though still too far out to be a definite feature, and certainly too far out for any detailed forecasts.