Central PA Summer 2026 Discussion/Obs Thread

[Itstrainingtime]

18 minutes ago, pawatch said:

64 degrees this morning!

Interesting...I got down to 62 all the way down here. 

[canderson]

Heat advisories up for Tuesday - not sure why they didn’t automatically extend through Wednesday. . 

[Itstrainingtime]

1 hour ago, canderson said:

Heat advisories up for Tuesday - not sure why they didn’t automatically extend through Wednesday. . 

I think they're going to hoist an Excessive Heat Warning for Wednesday later today or tomorrow. 

[ChescoWx]

Several of our valley locations this morning saw lows down into the 50's with the ridges remaining in lower 60's. The lowest I could find was 56.3 at the Warwick DEOS. Today will be our 6th below normal temperature day over the last 8 days. We turn that around tomorrow with highs well into the 80's with 90's in the valley spots. Widespread 90's on Wednesday before we back off several degrees by Thursday. So not many spots across Chesco will get to "enjoy" the so called "heat wave" this week. By next weekend we return to near normal temperatures with increasing chances of some showers.

[Mount Joy Snowman]

3 hours ago, Itstrainingtime said:

Interesting...I got down to 62 all the way down here. 

Low of 62 here as well. 

[Itstrainingtime]

2 hours ago, canderson said:

Heat advisories up for Tuesday - not sure why they didn’t automatically extend through Wednesday. . 

Also interesting that according to CTP's morning graphics that York and Lancaster counties are to have the LOWEST Heat Index values tomorrow in their forecast area. On Wednesday, York and Lancaster will be the highest. 

[mahantango#1]

3 hours ago, canderson said:

Heat advisories up for Tuesday - not sure why they didn’t automatically extend through Wednesday. . 

It's the element of surprise. Just like winter snowstorms you go to bed feeling confident that NWS has an advisory out for 1 to 3 in of snow tomorrow. But you wake up tomorrow morning and it's a winter storm warning for 10 to 14 inches.

[canderson]

24 minutes ago, mahantango#1 said:

It's the element of surprise. Just like winter snowstorms you go to bed feeling confident that NWS has an advisory out for 1 to 3 in of snow tomorrow. But you wake up tomorrow morning and it's a winter storm warning for 10 to 14 inches.

And then the ground truth is a dusting

[pawatch]

5 hours ago, Itstrainingtime said:

Interesting...I got down to 62 all the way down here. 

Sunday I was down to 60. This morning I was a little surprised it only made to 64.

Weather and temperatures have been all over the place.

[ChescoWx]

So cool (at least to me). Over on a local Facebook Page they posted the below article from 1930 about the original trained NWS Cooperative Observer for Coatesville PA - WT Gordon. Mr. Gordon (1888-1930) at that time he was looking to retire from observing the weather... but keep his legacy of accurate weather and climate reporting for Coatesville PA alive. Some of you may not know this but back in 1998 I actually purchased all of the handwritten NWS COOP pages from the NWS for Coatesville 1SW for every month from 1894 through 1948 (I know I am a weather nerd!) At the time this data was not available on the internet so during my many plane trips for work and in my spare time I transcribed by hand each and every day for all of those years into an excel spreadsheet the handwritten daily observations for those 54 years. When that was completed I accessed the data from 1948 through 1998 that was available on line to complete the data set for the NWS COOP stations of Coatesville 1SW (1893-1982) and Coatesville 2W (1983-2007). 

 

[Yardstickgozinya]

21 hours ago, Yardstickgozinya said:

According to last night's spc 4 AM update, some of the overlaps deterministic guidance was originally  picking up on are in jeopardy. Timing issues. 

Given the increasing uncertainty as to the location of the surface
   boundary on Friday and the overall quality of the severe weather
   environment, unconditional 15% severe probabilities for Friday are
   removed with this forecast. It is possible that severe probabilities
   may be reintroduced in later outlooks should it become apparent that
   the surface boundary washes out earlier than expected and quality
   low-level moisture is able to return sooner.

   That said, the front should begin to dissipate by Saturday in
   response to a mid-level trough digging southeast across the Great
   Lakes. This will allow rich boundary-layer moisture to advect
   northeastward into the Mid-Atlantic and southern New England. This
   increase in boundary-layer moisture and strong diurnal heating will
   allow for afternoon MUCAPE values between 1000-2000 J/kg, perhaps
   locally higher on Saturday and into Sunday. 

   This unstable and vertically sheared environment will be ripe for
   thunderstorm/severe thunderstorm development ahead of any digging
   mid-level trough. However, as alluded to previously, the timing,
   magnitude, and number of these troughs is highly variable within the
   ensemble guidance, leading to too little confidence to pinpoint
   where and when unconditional severe probabilities should be added.
   As confidence in the timing, track, and strength of these embedded
   troughs becomes clear, severe probabilities will likely be needed
   somewhere across the region stretching from the Upper Midwest
   southeast into the Mid-Atlantic for one or more days.