ChescoWx

With some lower spots with a chance to have their first freezing temperature attached is the average, earliest and latest dates on record.

With some lower spots with a chance to have their first freezing temperature attached is the average, earliest and latest dates on record.

Of note 54 years ago today back in 1972 Chester County was experiencing a rare early season snow event that left as much as 3.0" of snow at Morgantown. After a little rain yesterday with between 0.1" to 0.3" falling, today our high temperatures were reached at midnight. Daytime temperatures today will remain in the upper 40's to Low 50's which is about 10 to 15 degrees below normal daytime highs for mid-October. The NWS has issued a freeze warning for tonight with temperatures near freezing or below in valley locations to just above freezing on the ridge tops. Temperatures will run 4 to 8 degrees below normal through Monday before we return to near normal by Tuesday, but by Saturday we drop to about 4 degrees below normal. We look to stay dry through Saturday according to the ChescoWx model.

Of note 54 years ago today back in 1972 Chester County was experiencing a rare early season snow event that left as much as 3.0" of snow at Morgantown. After a little rain yesterday with between 0.1" to 0.3" falling, today our high temperatures were reached at midnight. Daytime temperatures today will remain in the upper 40's to Low 50's which is about 10 to 15 degrees below normal daytime highs for mid-October. The NWS has issued a freeze warning for tonight with temperatures near freezing or below in valley locations to just above freezing on the ridge tops. Temperatures will run 4 to 8 degrees below normal through Monday before we return to near normal by Tuesday, but by Saturday we drop to about 4 degrees below normal. We look to stay dry through Saturday according to the ChescoWx model.

Not that much rain so far today here in Chesco

Enjoy today! Highs should reach the mid to upper 70's which is about 10 degrees above normal. A strong cold front will cross the region tonight with a line of storms during the evening hours. Temperatures will fall from the upper 50's at midnight to lows in the upper 40's by morning. Behind the front is some very chilly air for mid-October. Temperatures during the day tomorrow will struggle to escape the 40's across the ridges with low 50's in the valleys. By Sunday morning we should see lows in the mid 30's with a freeze possible in the colder valleys! Temperatures will run well below normal through Monday before we return to near normal by Tuesday. We look to stay dry through the new work week according to the ChescoWx model. In weather history on this date in 2009 the county high only averaged 41 degrees...the coldest October 16th since records began in 1890!

Enjoy today! Highs should reach the mid to upper 70's which is about 10 degrees above normal. A strong cold front will cross the region tonight with a line of storms during the evening hours. Temperatures will fall from the upper 50's at midnight to lows in the upper 40's by morning. Behind the front is some very chilly air for mid-October. Temperatures during the day tomorrow will struggle to escape the 40's across the ridges with low 50's in the valleys. By Sunday morning we should see lows in the mid 30's with a freeze possible in the colder valleys! Temperatures will run well below normal through Monday before we return to near normal by Tuesday. We look to stay dry through the new work week according to the ChescoWx model. In weather history on this date in 2009 the county high only averaged 41 degrees...the coldest October 16th since records began in 1890!

Of note 72 years ago today back in 1954 Chester County was on the last day of a 2 day storm that left as much as 1.60" of rain at Coatesville 1SW. This was the remnants of Hurricane Hazel which tracked within about 80 miles of the county. Today we should see highs in the upper 60's to near 70 which is about 5 degrees above normal with lows tonight in the 50's. Temperatures will run about 11 degrees above normal Friday but by Saturday we drop to 4 to 9 degrees below normal, before we return to near normal by Tuesday. By Sunday morning lows will be in the low to mid 30's with a freeze possible in the colder valleys! Our best chance of rain is Friday with around 0.30" according to the ChescoWx model.

Of note 72 years ago today back in 1954 Chester County was on the last day of a 2 day storm that left as much as 1.60" of rain at Coatesville 1SW. This was the remnants of Hurricane Hazel which tracked within about 80 miles of the county. Today we should see highs in the upper 60's to near 70 which is about 5 degrees above normal with lows tonight in the 50's. Temperatures will run about 11 degrees above normal Friday but by Saturday we drop to 4 to 9 degrees below normal, before we return to near normal by Tuesday. By Sunday morning lows will be in the low to mid 30's with a freeze possible in the colder valleys! Our best chance of rain is Friday with around 0.30" according to the ChescoWx model.

How does the ChescoWx East Nantmeal forecast stack up against the National Weather Service? After 7 weeks of scoring every forecast against what actually happened, the temperature results are pretty clear! Since August 22 we have verified 50 days and about 2,800 high and low temperature forecasts, each one matched up against the NWS forecast for the same day issued at the same time. ChescoWx was closer on temperatures on 45 of the 50 days. The NWS was closer on 4 and 1 was dead even. The typical ChescoWx miss was about 1.8 degrees. The typical NWS miss was about 3.0 degrees. For tomorrow's forecast the gap is widest... about 1 degree for ChescoWx vs about 2.5 degrees for the NWS. The edge holds out through day 6 and the two are basically even by day 7. About 8 in 10 ChescoWx forecasts landed within 3 degrees of the actual temperature vs about 6 in 10 for the NWS. Much of the NWS gap is a warm lean on daytime highs of about 3 degrees in our backyard. Rainfall is a different story. On the 10 days with measurable rain the NWS did a bit better, and both forecasts badly missed our two biggest rain events (1.66" on September 3 and 2.42" on October 11). Rain is where we are focused on improving next. Fair caveat... 50 days of late summer and early fall is a start, not a final verdict. We will keep scoring every forecast through the winter, and snow will be the real test! The live scorecard is on the Current Weather page here: https://chescowx.com/current-weather/ Let me know if any questions!

How does the ChescoWx East Nantmeal forecast stack up against the National Weather Service? After 7 weeks of scoring every forecast against what actually happened, the temperature results are pretty clear! Since August 22 we have verified 50 days and about 2,800 high and low temperature forecasts, each one matched up against the NWS forecast for the same day issued at the same time. ChescoWx was closer on temperatures on 45 of the 50 days. The NWS was closer on 4 and 1 was dead even. The typical ChescoWx miss was about 1.8 degrees. The typical NWS miss was about 3.0 degrees. For tomorrow's forecast the gap is widest... about 1 degree for ChescoWx vs about 2.5 degrees for the NWS. The edge holds out through day 6 and the two are basically even by day 7. About 8 in 10 ChescoWx forecasts landed within 3 degrees of the actual temperature vs about 6 in 10 for the NWS. Much of the NWS gap is a warm lean on daytime highs of about 3 degrees in our backyard. Rainfall is a different story. On the 10 days with measurable rain the NWS did a bit better, and both forecasts badly missed our two biggest rain events (1.66" on September 3 and 2.42" on October 11). Rain is where we are focused on improving next. Fair caveat... 50 days of late summer and early fall is a start, not a final verdict. We will keep scoring every forecast through the winter, and snow will be the real test! The live scorecard is on the Current Weather page here: https://chescowx.com/current-weather/ Let me know if any questions!

Not much rain this AM

Extended Ensemble outlook (not a forecast) shows a cooler trend than normal for last week of October and into the first couple weeks of November.

Extended Ensemble outlook (not a forecast) shows a cooler trend than normal for last week of October and into the first couple weeks of November.

Of note 141 years ago today back in 1885 Chester County was on the last day of a 3 day storm that left as much as 2.48" of rain at West Chester 2NW. This was the remnants of an unnamed tropical storm which tracked within about 100 miles of the county. Today we should see highs in the upper 70's to low 80's which is about 15 degrees above normal with lows tonight in the low to mid 50's. Temperatures will run 5 to 10 degrees above normal through Friday but by Saturday we drop to 4 to 8 degrees below normal, before we return to near normal by Tuesday. By Sunday morning lows will be in the low to mid 30's with a freeze possible in the colder valleys! Our best chance of rain is Friday with around 0.31" according to the ChescoWx model.