ChescoWx

The NAM for now has the low actually almost going right up the GS Parkway. If verification is a move 25 miles east - I would tug that thump of early accumulating snow down a bit into Chester County.....now if it is 25 miles further inland....really quick turn to rain. Either way rain should wash any accumulations away as far North as Tamaqua

My current idea IP to rain - Delaware and Eastern Chester 0.5" to 1.0" - Western Chester and Western Montgomery Counties 2-4” Northern Bucks and Lehigh Valley 5"-9” Poconos 7"-11" NE PA

Dry the next 2 days with slightly below normal temps in the upper 30's for highs across the County. Clouds will increase with snow arriving Thursday AM...we should see a quick turn over to rain from southeast to northwest during the mid-morning hours. Up to an inch of snow is the current early NWS forecast. Some models have up to 3" for NW sections of Chester County but we don't shovel models. The record high for today is 69.7 set in 2015. The record low is 2 above zero from 1988. Record rainfall is the 4.21" that fell back in 1909. Daily snow record is 6.8" from 1915.

Dry and seasonably chilly start to the work week through Wednesday. It looks like a major storm will impact the area with our first nor'easter of the season starting on Thursday. As always the exact track of the storm will determine how much if any snow or ice we get before any change to rain. The record high for today is 69 degrees from 2015. Our record low is 2 degrees above zero set in 1988. The rain record is 1.98" from 1993. Our daily snow record is the 3" from 1916.

I thought I would post the analysis of White Christmas chances for the Philly burbs of Chester County PA. We have about a 26% chance of at least 1" of snow on the ground come Christmas morning.

A chilly light rain is falling this morning across much of Chester County. Up to 0.25" of rain could fall in some spots today. Clearing tonight and then dry through Wednesday. It looks snow may arrive on Wednesday night into Thursday morning. However, models today now show a pretty quick change to rain...but as we have said expect models to bounce around a bit before we get some consensus by mid-week. The record high for today is 68 degrees from way back in 1897. The record low is 2 above zero from 1968. The daily rain record is the 1.95" from 2002. Record snow is the 9" that fell today back in 1960.

Just to keep it real - we are far from snow starved based on climatology. While last year was a below average 20.5" of snow for Chester County the prior winter we received 52.2" of snow - well above our normal snowfall in at least the western Philly burbs of 36" - combined the last 2 years we are spot on average! Also we have averaged above normal precipitation over the last 4 straight years.

Nice December day today with slightly below normal temps. Chance for some light snow developing toward daybreak on Sunday changing to rain during the morning and ending mixed with snow again during the evening. Dry and chilly during the mid-week before snow chances increase with some potential for a significant storm starting on Wednesday night into Thursday. Details of course TBD but something to watch and we will during the week. The record high for today is 70 degrees set in 1946. The record low is 1 degree above zero set today in 1910. Our daily rain record is the 1.90" from 1952. Daily snow record is the 5.9" that fell in 1904.

Euro with over a foot in some spots of Bucks and Lehigh counties - see above...of course just a model run but close

As we track model snow totals for the season - here is our 1st nice weenie map between now and Christmas Eve.

We are starting a pattern today of seasonably cold temperatures that should last through much of the holiday season. In addition there will be multiple chances of rain and snow every few days during this stretch. The first such chance will be with some snow possibly arriving by Sunday AM changing to rain. More mixed wintry precipitation could arrive Wednesday night. The latest US Model (GFS) hints at a major snowstorm by next weekend....but we don't shovel models! The record high for today is the 71 degrees from 1966 (during the following 3 weeks almost 3 feet of snow would fall including over 20" with lightning on Christmas Eve 1966) The record low for today is 6 degrees from 1989. Record rain is the 1.80" from 2009. Our record snow was the 7.8" that fell today in 2005.

12z trends look to be going north....on to next "event" or rumor of event!

Today looks to be our last above normal temp day for quite a while. Our temperatures looks to average near to below normal for most days between now and Christmas Day. There will also be multiple chances of some wintry weather. The first chance will be some snow mixing in with rain on Sunday into Sunday night and again on Wednesday. Mainly higher spots in the county over 550 ft will have chances to see some minor small accumulations on non-paved surfaces. The record high for today is 70 degrees from 1980. Our record low is 12 degrees from 1959. Daily rain record is the 1.94" from 1978. The daily snow record is 4.7" from 1917.

South trend continues... GFS trend 2022.12.07.mp4

South trend on the EPS continues

Latest Euro shows a touch of snow over spots of Chester County come Friday night into early Saturday morning....not a "plowable" event!

Looking like we might see some wintry changes with the 12z runs this AM.....southwest trends to continue??

We have picked up 1.12" of rain since yesterday morning. With 0.11" since midnight. Some additional showers are possible and continued mild today. The main change to the longer term forecast is a prolonged period of normal to slightly below temperatures for mid to late December with even some wet snow chances toward Saturday morning. Our record high for today is 78 degrees set in 1998. The record low is 1 above zero set in 1926. The daily rain mark is the 2.04" that fell in 1914. Daily snow record is the 8.0" that fell today in 1959.

A stretch of unsettled weather starts today with rain and wet snow chances every day through Saturday. Temps start mild but trend colder by Thursday night when we could see some mixing with snow. We should dry out by Saturday afternoon. The record high for today is 73 degrees from 1998. The record low is 8 degrees above zero from 1902. Record rain is the 1.47" in 2013. Record daily snow is the 6.7" that fell today in 1910.

Always enjoy posts from our own Larry Cosgrove....still remember his days on Channel 17 (especially during the Blizzard of 1996) his thoughts on the upcoming pattern change and impacts "There are two key drivers to the evolving pattern in North America. One is the building and retrogression of a blocking ridge in Greenland, which looks to shift into Nunavut AR in the third week of this month. The ridge displaces the current Arctic cold pool and 500MB vortex, and forces the chill to stream into coverage to the right of the Continental Divide. Another factor favoring a more wintry look to the lower 48 states is the southern branch jet stream. Aided by an energy/moisture input form the Madden-Julian Oscillation, and already nudging into the American Southwest, the subtropical wind field will contain disturbances that will wear down the heat ridge complex straddling the southern Gulf of Mexico. The initial impulse should bring heavy rain and thunderstorms in the near term in a belt close to Interstate 40 (Oklahoma City OK to Wilmington NC). But the second and third storms will be stronger, tap into colder air next week, and may yank the snow line further south into the Ohio Valley and middle/upper Appalachia by December 15. If model projections of the ridge complex near the Arctic Circle verify, we may see another two storms riding the rim of a very cold air mass over the eastern two-thirds of the U.S. between December16-25. The CFS platform suggests that this configuration will last until about January 8 2023, then give way to what looks to be a very impressive, ten to fourteen day "January Thaw"."