Central PA Summer 2026 Discussion/Obs Thread

[ChescoWx]

Plenty of 40's for lows this AM across the area with our overall chilliest morning since back on June 2nd. The coldest reading was the 42.7 at Warwick DEOS. Below normal temperatures look to continue today before we start a warming trend that peaks on Thursday before we turn cooler again for the weekend and looking ahead we see some unseasonably chilly air by early next week. Highs may not get to far above 60 degrees for some of the higher spots by next Tuesday. Our next rain chances hold off till Sunday.

[Superstorm]

46.6F at the Lancaster homestead this morning.

[WmsptWx]

Went to let the dogs out this morning and saw my breath. At 10:54 it is still 55°F currently. That was a fast crash.

[canderson]

Sitting outside having lunch. It’s gorgeous. 

[Yardstickgozinya]

18 hours ago, TheDreamTraveler said:

Finally some action...

Yes. as of today they have increased the chance of further formation to 40 to 60% In the next seven days, and it's moving W to WNW. We may end up having to keep an eye this puppy. 

[TheDreamTraveler]

9 hours ago, Yardstickgozinya said:

Yes. as of today they have increased the chance of further formation to 40 to 60% In the next seven days, and it's moving W to WNW. We may end up having to keep an eye this puppy. 

I was just updating myself on that area just now and NHC lowered it back down to 30% in the next 7 days lol. That's just how inhospitable the Atlantic's been this year. It's really crazy how hard it is for anything to form. I'd love at least one decent hurricane to track but maybe I'll get lucky with something in October hopefully if this one doesn't pan out. I think we're entering 5 days in a row now since September 11th when we beat the record for the latest forming hurricane in the satellite era and every day just keeps adding onto that record.

[Mount Joy Snowman]

57 upon leaving the house. Some humidity returns for a couple days but all in all not bad. Not much rain to be had. 

[pawatch]

56 degrees this morning .
 

[mahantango#1]

53 this morning.

[mahantango#1]

 

Wxrisk.com

9 hours ago ·

 

 

 

** ALERT ** 1ST POSSIBLE Coastal LOW of the Season SEPT 23-25 then 1st SERIOUS Cold air Blast SEPT 26-28

[ChescoWx]

Our beautiful autumnal weather continues with temperatures warming to a few degrees above normal both today and tomorrow with Highs not far from 80 degrees. We then start a sharp cooling trend over the weekend and into the new work week with temperatures by next week according to the ChescoWx forecast only in the low to mid 60's by the start of next week. The NWS forecast has those days about 10 degrees warmer – let’s see who is closer. Rain chances ramp up by late Saturday night into Sunday and Monday.

[WmsptWx]

3 hours ago, mahantango#1 said:

 

Wxrisk.com

9 hours ago ·

 

 

 

** ALERT ** 1ST POSSIBLE Coastal LOW of the Season SEPT 23-25 then 1st SERIOUS Cold air Blast SEPT 26-28

Did David intend to make that look like an Emergency Alert System scare graphic? LOL

[canderson]

89 for the high. Quite gross. 
 

I need rain desperately bad. My garden is brown. 

[pawatch]

67 degrees this morning . Some rain showers on the way.

Need to keep that grass growing 
 

[Yardstickgozinya]

https://forecast.weather.gov/product.php?site=CTP&issuedby=CTP&product=AFD&format=CI&version=1&glossary=1&highlight=off

Highlight Changed Discussion --

115
FXUS61 KCTP 170747
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
347 AM EDT Thu Sep 17 2026

.WHAT HAS CHANGED...
* Level 1 excessive rain risk expanded to all of CPA for today
* Cooler temperature moderation next week

&&

.KEY MESSAGES...
1) Very humid with locally heavy rainfall possible this
afternoon

&&

.DISCUSSION...
KEY MESSAGE 1: Very humid with locally heavy rainfall possible
this afternoon

Highly anomalous moisture for this time of year (NAEFS mean
pwat values near climatological maximum percentiles) pooling
around the periphery of subtropical high over the southern
Plains and lower MS Valley will interact with a surface cold
front moving slowly south/southeastward from the lower Great
Lakes to produce periods of showers and a few locally heavy
thunderstorms across Pennsylvania later today. 17/00Z HREF
indicates the potential for spot rain amounts of 2-3 inches.
It`s very likely that most of central PA picks up some rainfall
by tonight. However, we do not anticipate an all-day rain/washout.
Cloud trends remain a tough call with early morning convection
over north central PA, but fcst instability this afternoon across
south central PA will be more than supportive for thunderstorm
development. SPC continues to maintain a general (non-severe)
convective outlook for today which is likely due to the lack of
deep layer shear (displaced farther to the north) and poor mid
level lapse rates (very moist, tall/skinny soundings with warm
cloud depths greater than 10kft).

Another taste of Fall is on the way for the end of the week
with noticeably cooler and much drier/less humid air poised to
return behind the front (Td crashing into the 40s/50s). Expect a
crisp and cool overnight Friday into Saturday morning with some
upper 30s possible across the northern tier. Dry/fair wx
conditions are forecast to start the weekend and last through
the day on Saturday followed by periods of potentially heavy
rainfall Saturday night through early next week. Both NAEFS and
ECMWF SATs show at least 90th percentile PWs returning the the
region which is supportive for at least a marginal excessive
rain signal. NBM temps have also cooled/moderated quite a bit
Mon-Wed with most locations struggling to exceed 70F for
daytime highs.

[Yardstickgozinya]

On 9/15/2026 at 10:49 PM, TheDreamTraveler said:

I was just updating myself on that area just now and NHC lowered it back down to 30% in the next 7 days lol. That's just how inhospitable the Atlantic's been this year. It's really crazy how hard it is for anything to form. I'd love at least one decent hurricane to track but maybe I'll get lucky with something in October hopefully if this one doesn't pan out. I think we're entering 5 days in a row now since September 11th when we beat the record for the latest forming hurricane in the satellite era and every day just keeps adding onto that record.

Latest update from the NHC said that thunderstorms have become better organized and may continue to do so over the coming days. They must have decided to raise it back up to 40% chance of development over the next 7 days. It's to  keep moving west over the next 24 hours, then possibly turn to the south.