Friday, June 29, 2012

From Storms To Heat

After this morning's wake up call from Mother Nature, we're going from yesterday's frying pan to today's oven.  There are a couple of flies in the ointment regarding today's heat -- the first of which is how quickly we clear out this morning -- I would guess we see sun west of the city by 8:30, 9 AM and sun at the Shore by 10.  Assuming that takes place, we shouldn't lose too much potential heating from the day today.  If skies clear out more slowly, that may change.

Once we go sunny, it should remain mainly sunny for the duration of the day.  It doesn't look like we see much in the way of clouds nor in the way of any pop up thunder later on as the atmosphere will become "capped" and basically prevent significant cloud or shower development.  That sets the stage for the oven.

The other question is how much humidity remains in place.  Assuming winds pick up later, we should mix out some humidity and see dew point values hang in the lower half of the 60's...very similar to what we experienced during our heat events last week.  While it will produce heat index values of 100-105, it will not be much worse than the air temperature this afternoon.   However, any higher dew point values may result in a heat index value that pushes above 105.

All that together, it's going to be a nasty day as we approach 100 and see some bank thermometers probably exceed that mark through the region.  Today's record is 102...probably out of reach in Philly but some places like Atlantic City or Wilmington (records of 98) have a better shot of hitting their record today.  Heat continues through the weekend but there will be another shot of thunderstorms on Saturday night as another wave of energy pushing through like the one we got this morning.