Forecast Discussion

Synopsis...

High pressure will remain in control through Friday, keeping temperatures 10-15 degrees above normal.  A shortwave 500mb trough will bring a cold front through the region Friday night and early Saturday, ushering in refreshingly cooler temperatures.  Earl looks to remain off shore but bring some clouds for the early part of the weekend and breezy conditions.

Short Term (through Wednesday)...

Dewpoints will remain in the 60s and 70s today which will create hot and humid conditions throughout the state.  We expect fog in the morning in some locations this week as well.  Persistence looks like the best forecast through Friday with temperatures reaching into the upper 80s and mid 90s.  Nighttime lows will be in the upper 50s and low to mid 60s.  GFS and NAM MOS guidance looks fairly accurate through the week.

Long Term (Thurs-Sat)

Continued hot and humid temperatures on Thurs/Fri with a few more clouds by Friday due to Earl.  A cold front will sweep through the region on Friday night/Saturday.  Although we will see a drop in temperatures behind the front on a brisk northwesterly flow, the precipitation and RH values associated with the FROPA (frontal passage) do not look very impressive.  Therefore, we have kept the state dry on Saturday with the exception of Northwest/North Central.  Orographic lift along with cold air aloft should create sufficient instability for a few showers in these regions.  Saturday's temperatures are the most interesting during the period and should be monitored closely over subsequent shifts.  GFS MOS had Bradford only getting to 57 on Saturday!  In general, it seems like the eastern half of the state will be warmer than the western half of the state where the cold front will have already passed through earlier in the morning on Saturday.  One potential wrinkle however is the proximity of Earl to the coast.  A closer track would promote more clouds in eastern zones and keep temperatures cooler.

-Dan DePodwin

Head of Forecasting Operations