All good things..and so forth
It was tremendous while it lasted. Who could have imagined autumn weather this time of year, with a low temperature this morning – Aug. 16 – of 54 degrees at the UMW weather station in Fredericksburg? My vote would be for at least six weeks more of the same, but the sad truth is that today is the beginning of the end of our beautiful weather with reality just around the corner. We will see sunshine and dry weather today with a high in the upper 70s but conditions will go downhill tonight.
A surface high pressure is drifting northeastward across the Great Lakes into New England while a low pressure center rides north along the same frontal boundary that pushed through Fredericksburg earlier this week. This one/two punch will result in a return of humidity, clouds, and chances of rain beginning Saturday and continuing through Monday. The surface wind flow around these two weather systems will be out of the east and northeast off the cool Atlantic waters, ushering in the annoying cold air damming phenomenon also known as “the wedge,” which typically brings persistent low overcast and intermittent light rainfall. The setup is illustrated in this model forecast graphic for Saturday morning (the blue line shows the axis of the wedge):
Temperatures will top out in the mid-70s this weekend but the higher humidity will be painfully obvious after our three days of August glory. To make matters more interesting the addition of a slug of Gulf of Mexico moisture into the weather mix could mean significant rainfall for us this weekend. At the moment the heaviest deluge looks to pass across the Tidewater region but a slight trajectory shift could spill more moisture over the ‘Burg. Either way you might want to dig out the umbrellas again and keep them handy the next three days.
Meanwhile Tropical Storm Erin has formed just off the African coast over the eastern Atlantic and another potential tropical system is currently located over the Yucatan Peninsula of Mexico. As we approach the peak of the Atlantic hurricane season in mid-September I expect the number of named storms will ratchet upward rather quickly. We’ll all have to keep an eye on the tropics over the next couple of months.
So, to recap: enjoy the delightful weather today but ready those umbrellas for the weekend!