Sunday, April 20, 2008

Wild Temperature Challenge Continues

Those of you who regularly visit Phillyweather.net know that the Temperature Challenge is a snapshot of a five day forecast, graded for accuracy to see how well the TV stations and the National Weather Service stack up to reality.

This is the 7th Temperature Challenge I've done and this is probably the first one with as much variability in the weather as I have seen since I started these in July. Temperatures have gone much warmer than expected each of the first three days of the challenge from what was forecast on Thursday night. As a result there have been rather large errors in forecasts for the three days of the challenge, with Sunday bringing a twenty degree forecast error by NBC 10 from what was forecast on their Thursday night forecast. When comparing the actual high temperature of 77 on Sunday to forecasts made on Saturday night, only Fox 29 was within five degrees of actual and when compared to Thursday night's forecast, only CBS 3 and Fox 29 were within ten degrees.

Thanks to stronger than expected high pressure to our northeast the progression of the upper level low was halted which limited our rainfall. Thanks also to dry air aloft we were able to see a few hours of sunshine today which allowed our temperatures to climb into the 70's in parts of the region.

You can see Saturday's and Sunday's results below.