TheClimateChanger

Oh, sorry. I didn't know. I don't really pay much attention to him, but he had been posting a lot so I thought I'd take a look at his data for recent decades. Just thought it was interesting his data shows more recent warming than NOAA.

Decided to take a deep dive in this Chester County stuff for the period 2007-2024. @ChescoWxtook a look at his station compared to the CRN station in Avondale last summer. But I wanted to take a deeper dive. Chescowx.com hadn't updated all of the numbers for 2025, so I limited the analysis to 2007-2024. Here's what I found: Interesting how much lower the slope of the trendline appears in the official values for Chester County (~7.5F/century) over that timeframe, relative to that of the individual stations. The CRN site shows a warming of about ~12.6F/century. PHL airport warms at ~12.1F/century. Paul's backyard reflects a warming of ~11.1F/century. His composite average for the county was at ~10.4F/century. But the NCEI official numbers check in much lower for recent warming. Will have to see whether this continues... if this continues for even another half decade or so, I would expect Paul's composite averaging to start producing higher temperature means than NCEI. Recent years, the two estimates have been nearly the same (within ~.1F or so), whereas in the late 2000s, NCEI's value was often about 0.5F higher than Paul's.

Lol, this is a weird forecast for a severe thunderstorm warning.

Really impressive stuff here. Some notable high temperature rankings from the Midwest. Rockford, IL: 41.8F (3rd) Dubuque, IA: 41.4F (4th) Moline, IL: 46.5F (4th) Rochester, MN: 37.5F (4th) Cedar Rapids, IA: 45.5F (2nd) Des Moines, IA: 50.0F (2nd) Sioux City, IA: 53.9F (1st) Omaha, NE: 55.8F (1st) Minneapolis, MN: 37.8F (6th) Saint Cloud, MN: 35.1F (7th) Green Bay, WI: 34.1F (9th) Even warmer over the Plains! Giving the great torch of February 2017 a run for its money on the national means.

@donsutherland1 @bluewave

These old snowfall records are so ridiculously lowballed. Snow depth increased by 34" from the 4th to the 14th on just 34.2" of "official" snow. So there was literally no melting, sublimation or compaction over that entire time. What a joke.

Wow, that first one is crazy. I had to look it up to verify. What struck me is how ridiculously lowballed these snowfall totals must have been. From the 4th through the 14th, snow depth climbed 34 inches on only 34.2" of "official" snow. No way that's possible. There had to be some combination of melting, compaction and sublimation.

Certainly going to be difficult to see any sustained cold with that AO index.

For further context, regarding high temps. NCEI (nClimDiv) had us at +2.96°F for December & January, while PRISM has February at an unbelievable +6.12°F for the first half of the month. The record for DJF is +3.16°F, also from 2023-2024. So this is nearly guaranteed to be broken as well, unless the current forecast for the second half of the month is WAY off.

Thanks for the update, Don. Going to be a close call as to whether we break the record for warmest winter in the CONUS, set just 2 years ago (2023-2024). Right now, I'm projecting this to finish as the second warmest on record, but it's not out of the question that we set a new record. December-January averaged +2.25°F relative to 1991-2020 on NCEI's nClimDiv, and +2.71°F relative to 1991-2020 in the U.S. Climate Reference Network (all rural, non-adjusted) dataset. The record is +3.42°F in nClimDiv and +3.52° in U.S. CRN, from 2023-2024 (in each case). Second place is +2.73°F set in 2015-2016 for nClimDiv. PRISM's analysis has us at +4.70°F for February for the first half of February. Obviously, this is an *unofficial* value. But that would place us at approx. +3.07°F if it held up through the end of the month (with averaging by month) or about +3.01°F (with averaging by day) in the official nClimDiv records. It would also place us around +3.37°F in USCRN (averaged by month) or 3.33°F (averaged by day). Although I would expect the (IMO, more accurate) USCRN anomaly to come in higher than PRISM's estimate. What's intriguing to me is it looks like there is room to run even higher in the second half of February with these projections. A final anomaly around +6°F (or a bit higher) would be sufficient to set a new record even in the official nClimDiv dataset. But like I said, right now, I'm conservatively projecting this to finish as second warmest on record. I do think we will set a new record for warmest AVERAGE MAX TEMP, however... unusually large diurnal ranges (i.e., somewhat cooler lows) are holding the means back a bit. In terms of satellite TLT temperatures, this winter is pretty much guaranteed to be the warmest in the US48 band in the UAH analysis (with complete records back to the winter of 1978-1979). December & January were the warmest on record by a HUGE margin, so that one is pretty much already in the bag with another warm month.

For the season as a whole (December & January), NCEI's nClimDiv had us at 6th warmest. Max temps have been running warmer in general for several months, which is a departure from the usual case. For max temps, December & January were 4th warmest for the CONUS. Interestingly, the US Climate Reference Network has this as the warmest December & January (since 2005 & using nClimDiv for 1895-2004), as does the US48 TLT satellite-based anomaly from UAH. By my calculation, February would need to check in around 5.8F above normal to set a new record warm winter for the CONUS or about 3.7F for second warmest. The latter is certainly plausible. I mean the former is possible as well but would require some bigtime positive anomalies (full-blown Feb. 2017/March 2012 torching). I think max temps have the better odds to finish as warmest on record, not sure we get there in the means. It looks like a lock for warmest on record for USCRN (all rural, pristine sited stations with better equipment - e.g., redundant temp. sensors) and in the UAH satellite record. Looks like a new max temp record in the official NCEI records is also a lock. Just need to finish around +3.6F for that one, and we're near +5.2F for the first 10 days (PRISM) with that number likely to climb in coming days.

I'm extremely impressed by this start to February, particularly for high temperatures. Unusually large diurnal ranges are keeping the mean temperatures in check to an extent, but max temps have been soaring. With the current forecast, odds look very good for a top 10 warm February nationally, perhaps top 5. Average high temps are well within striking distance of a number two finish (1954's +7.34F over 1991-2020 mean would be a stretch).

Current 25-year average for March is currently 5.9":

I don't know how you had that date memorized. Anyways, up to 60F now (-5F to +55F).

Hard to believe it was -5F yesterday morning! Must be one of the bigger day-to-day swings on record.

Up to 50F now. First over 40F reading since January 14th (48F), and first 50F since the 13th.

One of the anti-Weathergamis is not like the others! You can see how the relative lack of variability in the summer versus the winter leads to many more unique combinations occurring in the wintertime than the summer. Spring and fall, of course, are more changeable in general, so they have the lowest number of common high/low pairings. Interesting data!

If you follow me enough, you know I like to include USCRN data as well. We built a parallel climate network with pristinely-sited, rural weather stations, including features such as multiple redundant temperature sensors, but it's rarely discussed. For context, this was largely constructed based on criticisms such as the ones presented frequently in this forum that the "official" numbers were inflated due to urban heating and/or adjustments. Of course, the reality is USCRN has consistently exhibited MORE warming than nClimDiv in the period of overlap. Over the last several months, the divergence has grown significantly. Heck, if you follow me closely enough, you probably know I even have a theory as to why that is... Anyways, USCRN agrees with the satellite data, finding this to be the WARMEST winter to date on record for the CONUS. The two month anomaly is up to +2.705F, compared to 2023-2024's anomaly of +2.630F in the USCRN dataset.

Some more on the winter anomalies:

Weathergami for NYC on Saturday. First 27/6 combo on record.

BVI has been below .75 mile visibility since 6:15, down to .25 mile at 7:55 am. https://forecast.weather.gov/data/obhistory/KBVI.html

At the worst, I couldn’t even see my neighbor’s outdoor lighting. Visibility must have been 50-100 yards.

It’s absolutely insane here right now. Near zero visibility.

Weatherbug was showing a couple strikes near New Castle earlier.

Lightning has been detected in the snow squall.