Sunday, July 14, 2013

Heat Warnings For Philly & Immediate Burbs Start Tomorrow

The region's entering the first of a several day run of 90 degree weather, likely including our hottest days of the year coming up on Tuesday and Wednesday as temperatures get above 95 on at least one, if not both, days.  Combine that heat with dew points that will be in the upper half of the 60's or lower 70's, you have the recipe of ingredients that will produce heat index values around or above 100 (the threshold for excessive heat warnings in Philly) for at least the next few days.  Excessive heat warnings are out for the immediate Philadelphia metro, with heat advisories likely to follow for the outlying areas as we move towards midweek.

The hottest days of this upcoming stretch may be Tuesday, Wednesday, or Friday.  Tuesday and Wednesday have a higher level of confidence in mid/upper 90's heat, with Friday a bit less certain as of now given model inconsistency in breaking the heat ridge down and sending a cool front through.  There's a good deal of waffling on Friday's level of heat but the possibility of mid and upper 90's type heat does exist for that day as well.

This may very well be our hottest weather of the year -- probably not going to hit 100 on the thermometer except at your local bank or thermometer that tends to continually run warm.  That said, having several days of this is not going to be a cup of tea that we want to deal with.

In terms of stretches of 90 degree heat, this stretch has the potential of running as long as seven days.  It will be significantly shorter than last July's 12 day heat wave (and 15 out of 16 days), nor will it likely feature the 100 degree weather last July's heat produced.  It still will be hot though!