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chescopawxman

WXSIM Weather Simulator Forecasts

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Wxsim not terribly enthused with 6z model forecasts at this time....

Saturday: Partly cloudy in the morning, becoming mostly cloudy to cloudy in the
 afternoon. Patchy light fog in the morning. A chance of rain in the afternoon.
 High 44. Wind east around 2 mph in the morning, becoming south-southeast in the
 afternoon. Chance of precipitation 30 percent. Precipitation mostly less than a
 tenth of an inch.
 
 Saturday night: Dense overcast in the evening, becoming mostly cloudy to cloudy
 after midnight. Patchy light fog in the evening, then light to moderate fog
 after midnight. A mix of rain and snow likely in the evening, then a chance of
 snow after midnight. Low 30. Wind south-southeast around 2 mph in the evening,
 becoming west after midnight. Chance of precipitation 70 percent. Precipitation
 (liquid equivalent) mostly between a quarter and half an inch. Snow accumulation
 about half an inch.

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With the 18z suite WXSIM has increased the event to 2 to 4 inches total

 

Saturday: Partly to mostly sunny in the morning, becoming cloudy in the
 afternoon. A chance of a mix of snow and rain in the afternoon. High 42. Wind
 east around 3 mph in the morning, becoming south-southeast in the afternoon.
 Chance of precipitation 40 percent. Precipitation (liquid equivalent) mostly
 less than a tenth of an inch. Snow accumulation about half an inch.
 
 Saturday night: Dense overcast in the evening, becoming mostly cloudy to cloudy
 after midnight. Light to moderate fog after midnight. Snow likely in the
 evening, then a chance of snow after midnight. Low 26. Wind south around 2 mph
 in the evening, becoming west-southwest after midnight. Chance of precipitation
 70 percent. Precipitation (liquid equivalent) mostly around half an inch. Snow
 accumulation 2 to 3 inches.

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1 hour ago, chescopawxman said:

With the 18z suite WXSIM has increased the event to 2 to 4 inches total

 

Saturday: Partly to mostly sunny in the morning, becoming cloudy in the
 afternoon. A chance of a mix of snow and rain in the afternoon. High 42. Wind
 east around 3 mph in the morning, becoming south-southeast in the afternoon.
 Chance of precipitation 40 percent. Precipitation (liquid equivalent) mostly
 less than a tenth of an inch. Snow accumulation about half an inch.
 
 Saturday night: Dense overcast in the evening, becoming mostly cloudy to cloudy
 after midnight. Light to moderate fog after midnight. Snow likely in the
 evening, then a chance of snow after midnight. Low 26. Wind south around 2 mph
 in the evening, becoming west-southwest after midnight. Chance of precipitation
 70 percent. Precipitation (liquid equivalent) mostly around half an inch. Snow
 accumulation 2 to 3 inches.

I'm leaning 4-5" in our neck of the woods due to rates and frozen ground surface after tonight.

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14 hours ago, iceman56 said:

I'm leaning 4-5" in our neck of the woods due to rates and frozen ground surface after tonight.

Looks like WXSIM agreeing with you with now 5" to 6" of snow forecasted

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6 hours ago, chescopawxman said:

Looks like WXSIM agreeing with you with now 5" to 6" of snow forecasted

Right now I'm enjoying the heavy snow and subsiding traffic on 100 as it's going to be hell on this road for the next year between construction and PECO.

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My WXSIM forecast for NW Chester County has the rain changing to snow by around 2pm tomorrow with around 3" before ending by 9pm. That said this will obviously be a very tricky forecast. If you are under heavier bands the precipitation will go to snow pretty easily....during lulls back to drizzle. Elevation will also play a significant role tomorrow. For spots in Chester and Berks county at 600 ft ASL or above I would expect more accumulation...especially if any of those bands rotate from NE to SW over those locales. The winds of course will likely be the biggest story - have your generators ready to go...I've got mine ready to go! stay safe 

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Nice job by the Wxsim with the last storm....just about spot on!

Now for the next one - the WXSIM with 12z data has 6" to 8" of snow for NW Chester County from Tuesday late night through Wednesday. It will change...but something to keep an eye on. Mainly rain for now in my NWS P&C

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Latest WXSIM local forecasting tool with 12z NAM and 6z GFS for East Nantmeal Twp still shows snow starting Tuesday by 830pm and snow most of Wednesday with approaching 6" of snow before ending. Somewhat colder storm than last time. Forecast will change but something to keep an eye on...

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Wxsim with both GFS and NAM 12z bumps up snow totals for NW Chester County to around 8" with a start time of 8pm and all over by Wednesday evening

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WXSIM for NW Chester County with 18z GFS/NAM of course goes to 8" to 12" of snow with the mid-week system

Tuesday night: Cloudy in the evening, becoming dense overcast after midnight. A
 chance of a mix of snow and rain in the evening, then snow likely after
 midnight. Low 30. Wind chill ranging from 23 to 38. Wind southeast around 7 mph.
 Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly
 around half an inch. Snow accumulation around 2 inches.
 
 Wednesday: Dense overcast. Patchy light fog. Snow likely. High 33. Wind chill
 around 23. Wind east-southeast around 8 mph in the morning, becoming northeast
 in the afternoon. Chance of precipitation 80 percent. Precipitation (liquid
 equivalent) mostly around an inch. Snow accumulation 6 to 10 inches.

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Latest 12z GFS/NAM blend via WXSIM for NW Chester County has snow arriving Tuesday evening with moderate snow by 8pm temp at 35 degrees. Heavy snow by midnight temp at 32 degrees. At 7am there is 3" of snow on the ground with Heavy snow by 9am. Accumulations reach 10" by 1pm and we finish up by 6pm with around 17" of snow. Temps during the day will stay between 30.5 to 31.5 - total liquid equivalent 1.92"

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Latest WXSIM with 6z NAM/GFS for NW Chester County has a mix of light rain/snow arriving by 6pm temp around 38. Becoming all snow by 830 tmep 33.9. Heavy snow by 1130pm with about an inch by midnight with temps at 31.5. Moderate snow becoming heavy toward morning with 3" on the ground by 730am. Heavy snow most of the morning with 10" on the ground by 1230pm. Snow continues till about 630pm with total snow accumulations around 14" and 1.69" w.e.

 

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Wxsim for NW Chester County Pa has 3" to 5" for wave 1 and 6" to 10" for wave 2 for a total of 9" to 15". If this comes to pass we will exceed my preseason snow forecast for NW Chesco of 50"....but as a man wiser than I once said - we do not shovel model output!

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WXSIM not quite as impressed with totals as my current point and click for here in NW Chester County....but we shall see

Today: Dense overcast. A chance of snow in the morning, then snow likely in the
 afternoon. High 36. Wind chill around 25. Wind north-northeast around 9 mph,
 gusting to 19 mph. Chance of precipitation 70 percent. Precipitation (liquid
 equivalent) mostly around a quarter of an inch. Snow accumulation about an inch.
 
 Tonight: Dense overcast. A mix of snow and sleet likely. Low 29. Wind chill as
 low as 20. Wind north-northeast around 8 mph, gusting to 16 mph. Chance of
 precipitation 60 percent. Precipitation (liquid equivalent) mostly less than a
 quarter of an inch. Snow or ice (on ground) accumulation about a quarter inch.
 
 Wednesday: Dense overcast. Patchy light fog in the afternoon. Snow likely. High
 31. Wind chill around 20. Wind north-northeast around 10 mph, gusting to 17 mph.
 Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly
 around half an inch. Snow accumulation 3 to 5 inches.
 
 Wednesday night: Dense overcast. Patchy light fog. A chance of snow in the
 evening, then a slight chance of snow after midnight. Low 29. Wind chill as low
 as 20. Wind north-northeast around 10 mph, gusting to 16 mph, in the evening,
 becoming north-northwest after midnight. Chance of precipitation 50 percent.
 Precipitation (liquid equivalent) mostly around a tenth of an inch. Snow
 accumulation about a quarter inch.
 

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Wxsim has our Christmas Eve day snow starting late on the 23rd with it continuing until around 6am Christmas Eve morning with 1/4 to 1/2" of snow with temps just below freezing

 

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For our minor snow event for Jan 12-13 - Local Wxsim model for NW Chester County PA has flurries late PM tomorrow with Light snow by 9pm with 1" of snow by 3am and another 1.3" before ending at 9am for a total of 2.3" - more toward Southern Chester County and South Jersey.

Currently Clear 25.1 with a DP of 9.8 degrees

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Latest Wxsim with 06z data from GFS/NAM continues to paint 2.3" of snow for NW Chesco - snow begins by 8pm and is all over by 11am Sunday AM 

Our AM Low today was 17.9 - our coldest AM reading since the 13.8 low on the 23rd of November

Current Obs mostly clear Temp 19.1

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The latest Wxsim run with 12z (NAM/GFS) data of course has bumped up totals thanks to the bogus NAM run - now has 1.5" of snow by 7am tomorrow with snow increasing in intensity later tomorrow PM with 3.0" by 4pm - 5.0" at 9pm and ending up with 6.8" of snow by 1am Monday morning. This will correct with the 18z runs

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18z Wxsim has light snow off and on through 7pm tomorrow night with 3.3" of total snow here in NW Chester County PA

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Wxsim has 2 snow events this week for NW Chesco - 1st up in Thursday night into Friday AM with 2.0" of snow - then snow arriving on Saturday early evening continuing through midday on Sunday with 12.0" of snow before ending

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Latest Wxsim with 12z data up to 3" of snow by Friday AM in NW Chesco. Regarding weekend storm 

Has a brief period of snow arriving by 4pm Saturday quickly going to moderate sleet and than ZR with about 1.00" falling as frozen before temps rise above 0c around midnight. Than Heavy rain with another 1.40" falling with temps rising to 38 by 7am Sunday wind shifts to NW by 9am and temp fall below freezing by early PM.

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With the 6z models coming in colder the Wxsim is now reflecting this - so after 2 or 3" of snow tomorrow night. It has S+ arriving Saturday by 6pm transitioning to a period of heavy sleet with 3" to 4" of snow/ip accumulation before a change to ZR with 1.18" falling as frozen before a change to all rain by 2am. Then another 1.60" of rain with temps at about 34-35 degrees before a change back to sleet and then snow before ending. Wxsim also shows more heavy snow arriving Tuesday night into Wed AM with the early potential of several more inches of snow.

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Latest Wxsim with 6z data shows snow by 9pm tonight with 2.0" before ending by 6am tomorrow. Then Snow arrives Saturday afternoon becoming moderate to heavy becoming heavy sleet by 6pm with 3.0" to 5.0" of Snow/IP before changing to ZR by 9:30pm - ZR till midnight with 0.40" falling as ZR. Then temps warm above freezing at midnight with heavy rain falling through 9am with another 1.70" of rain before ending around 9am Sunday morning

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Wxsim updated with 12z data remained nearly the same as the 6z GFS/NAM for NW Chesco (similar temps/less precip - added a little snow at end)

S+ by 3pm Saturday with Heavy IP by 6pm - total snow/sleet 3" to 4" - Temps stay below freezing till near midnight with 1.36" falling as frozen. Than another inch or so of rain before changing to snow before ending

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Wxsim with 18z data from NAM/GFS trended slightly colder as temps now only get as high as 33 degrees here is the rundown

Snow by 2pm Saturday S+ by 3pm mixing sleet by 4pm some heavy sleet through 6pm with 4" to 6" of snow/sleet accumulation before a turn to ZR which continues till 1130pm with another 0.90" falling as ZR - temps than rise to just above freezing thru 8am with 0.40" of rain and 0.5" of ice accreteion

before a mix with sleet and snow and then all snow by 9am with another 1" of snow before ending

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