For Wednesday into Friday, temperatures look to reach 90 degrees or better making this a probable heat wave for much of the region. Dew points will be in the mid and upper sixties and this should place heat index values into the excessive heat category (100 to 105 degrees), especially for the urban corridor. The raw numbers show that there is a possibility that on Wednesday or Thursday, Philadelphia could reach into the upper nineties with full sunshine. At this point, I have capped temperatures in the mid-nineties. While thunderstorms are forecast for Friday due to the frontal passage, when there is excessive heat and humidity, sometimes a very isolated…but very strong…thunderstorm pops up and therefore don’t be surprised to see a rogue storm on Wednesday or Thursday.
Saturday, June 16, 2012
Forecast for Sunday, June 17, 2012
High pressure will remain in control of the weather conditions into Father’s Day on Sunday. A warm front should move across the region Monday into Tuesday Morning. The warm front may have a few scattered showers or thunderstorms associated with it. The warm front moves well to the north by Wednesday and we are in store for excessive heat as a Bermuda High Pressure system sets up shop delivering a strong south-southwest flow. A strong cold front is expected to bust the heat on Friday. There is a chance that the cold front moves in during the peak heating hours and dynamics at this point do look favorable for the development of scattered strong thunderstorms.