Good morning and happy Hump Day!
The rain and somewhat cooler weather that this week has brought already is expected to continue through the end of the workweek, with the chances for rain diminishing gradually through Friday. The weekend should bring with it about average temperatures and the typical chance for afternoon showers and thunderstorms for the region, with a possible uptick in rain chances by the middle of next week…
Current Synoptic Picture
Currently, an upper-level trough is situated over the Northeastern United States, with the base of the trough extending as far south as the Southeast – resulting in the negative 500mb height anomalies across the region. In the Northwest, a broad upper-level ridge is resulting in positive 500mb height anomalies for much of the Northwest and the northern Great Plains.
In the Southeast, the general troughiness and enhanced upper-level diffluent flow (shown by the purple contours in the image below) is providing sufficient lift for the development of widespread showers and thunderstorms, which has already led to many reports of flash flooding in locations where thunderstorms have trained over the area.
Through Friday
Through the end of the workweek, this general pattern will continue, with an upper-level trough to the north and a building ridge in the Southwest forcing shortwave after shortwave to pass over the region, bringing numerous showers and thunderstorms to the area. Even though the pattern is in good agreement between the two global weather models, there are still some differences between the two, with the American GFS model being the drier solution.
Even with this uncertainty, a general 1-3″ of rain can be expected through Friday, with some locations receiving up to 6″ as a result of persistent rains from training thunderstorms. Due to the widespread rain and troughing in the region, temperatures will remain about 5-10 degrees below average as well, with highs in the low-to-mid-80s and lows around 70F.
The Weekend through The Middle of Next Week
As the upper-level low in the Northeast begins to move out of the region Friday evening, and the sub-tropical ridge in the Western Atlantic starts to build back into the Southeast, the threat for widespread rain will gradually diminish, returning to a typical diurnal cycle – that is, thunderstorms forming during the afternoon, and dissipating overnight.
This will result in temperatures returning to normal for the weekend, with highs in the mid-to-upper 80s expected across the region, with lows bottom out in the low 70s.
By the middle of next week, models are in good agreement of another pattern change, with an upper-level low expected to approach the Northeast. This may enhance shower and thunderstorm activity across the region (per yesterday’s operational 18z GFS run), however both the GFS and ECMWF ensemble solutions keep this feature well off to the north.
Day-to-Day Forecast
Today
Expect cloudy skies with a 100-percent chance of potentially heavy rain and thunderstorms throughout the day. Expect high temperatures in the upper 70s to near 80F. Due to the heavy rains and already saturated soils, flooding is possible in some locations.
Tonight
Expect cloudy skies with a 70-percent chance of showers and thunderstorms throughout the night. Low temperatures in the low 70s are expected. Due to the widespread heavy rainfall possible across the region, flooding is possible in some locations.
Tomorrow
Expect mostly cloudy to cloudy skies with a 90-percent chance of showers and thunderstorms throughout the day, but most likely in the afternoon hours. High temperatures in the upper 70s to low 80s are likely. Due to the heavy rains, flooding is possible in some locations.
Tomorrow Night
Expect mostly cloudy to cloudy skies with a 60-percent chance of showers and thunderstorms, especially in the evening. Low temperatures in the low 70s are expected.
Friday
Expect partly to mostly cloudy skies with a 70-percent chance of an afternoon shower or thunderstorm. High temperatures in the upper 70s to low 80s is expected.
Friday Night
Partly to mostly cloudy skies are expected, with a 50-percent chance of a shower or thunderstorm, especially in the evening. Lows in the low 70s are likely.
Saturday
Partly to mostly cloudy skies are forecast, with a 50-percent chance of an afternoon storm. Expect high temperatures in the low-to-mid-80s.
Saturday Night
Partly cloudy skies with a 40-percent chance of a shower or thunderstorm are forecast, especially in the evening. Expect low temperatures in the low 70s.
Sunday
Partly to mostly cloudy skies are forecast, with a 60-percent chance of an afternoon storm. Expect high temperatures in the low-to-mid-80s.
Sunday Night
Partly cloudy skies with a 40-percent chance of a shower or thunderstorm are forecast, especially in the evening. Expect low temperatures in the low 70s.
Monday
Partly to mostly cloudy skies are forecast, with a 60-percent chance of an afternoon storm. Expect high temperatures in the low-to-mid-80s.
Monday Night
Partly cloudy skies with a 40-percent chance of a shower or thunderstorm are forecast, especially in the evening. Expect low temperatures in the low-to-mid-70s.
Tuesday
Partly to mostly cloudy skies are forecast, with a 60-percent chance of an afternoon storm. Expect high temperatures in the low-to-mid-80s.
Tuesday Night
Partly cloudy skies with a 50-percent chance of a shower or thunderstorm are forecast, especially in the evening. Expect low temperatures in the low-to-mid-70s.
