Jns2183

I present an interactive exploration of the weather from 2 stations 3.3 miles apart, one on a ridge the other on the lowlands with just a Susquehanna separating them. Note that is not my real last name I just didn't want to put my last name out there right now. https://jns182wx.github.io/kmdt-cxy-analysis/ Sent from my SM-S731U using Tapatalk

Outside the modern era was surprisingly hard to find times those two stations overlap and had good data but I did it was from 1948 to 1965 and I finished that analysis last night along with instead of just doing daily I did an hour by hour one because I had hourly data for that era and for this era so I will have a comparison up soon. Sent from my SM-S731U using Tapatalk

MDT vs. CXY: Quantifying the Bias Between Harrisburg's Two ASOS Stations (and Why It Matters for the Pre-1991 Record) Something that doesn't get talked about much in discussions of Harrisburg climatology is that the "official" record changed stations in October 1991 — from Capital City Airport (CXY, Fairview Township, York County) to Harrisburg International (MDT, Lower Swatara Township, Dauphin County/Susquehanna floodplain) — and that switch was made with no homogeneity adjustment whatsoever. The ThreadEx composite that most people pull from ACIS just splices them together at that date and calls it a day. I decided to actually quantify the bias using the 2001–2025 overlap period, when both stations were running reliably as ASOS units. 25 years of IEM daily data, both stations. Here's what I found. --- PRECIPITATION MDT runs wetter than CXY every single month except April, with an annual median ratio of 1.106 — meaning MDT receives roughly 11% more precipitation per year (43.3" vs. 38.4" mean over the overlap). The ratio is most consistent and statistically tight in winter (DJF ratio 1.126, tight bootstrap CI), which makes sense — synoptic-scale systems produce more uniform precipitation and the floodplain position at MDT reliably enhances totals. The widest uncertainty is in the summer convective months (Jun–Sep CI spans nearly 0.3), reflecting the high year-to-year variance when a single tropical remnant or MCS can hit one site much harder than the other. September has the largest single-month ratio at 1.164. April is the odd one out at 0.988 — essentially no bias. Spring frontal/stratiform precipitation appears to be the most spatially uniform regime between these two sites. The implication for ThreadEx is that the unadjusted splice at October 1991 introduces approximately an 11% step-down in precipitation when you cross back into the pre-1991 CXY period. Any trend analysis using that composite without adjustment is going to be systematically affected. --- TEMPERATURE The temperature story is more interesting than the precipitation one. Max temp is straightforward — MDT runs cooler than CXY all 12 months, ranging from −0.19°F in summer to −0.97°F in January. River valley moderating daytime heating, nothing surprising. Min temp is where it gets physically interesting: the offset reverses sign seasonally. MDT runs cooler than CXY in winter (as low as −0.71°F in February) but warmer in summer (+1.09°F in July). The crossover is right around April, which is near zero (+0.03°F). What you're seeing is the competing effects of cold air drainage into the Susquehanna floodplain in winter (making MDT colder at night) versus the river's thermal mass keeping the MDT boundary layer warmer on summer nights. CXY sits on a ridge position in Fairview Township at ~106m and apparently drains cold air off efficiently in winter while losing the river's moderating influence in summer. It's a textbook valley-versus-upland nocturnal temperature signature and it comes through cleanly in 25 years of data. --- DEWPOINT AND RH MDT runs higher dewpoint and RH than CXY all 12 months — no sign reversal here. The Susquehanna just keeps MDT moister year-round. The RH offset is largest in winter (DJF +3.68%) and smallest in summer (JJA +1.69%), which probably reflects the relative importance of the river moisture source versus atmospheric moisture demand across seasons. --- PRACTICAL UPSHOT If you're doing any work with the Harrisburg long-period record — trend studies, climatological normals, CAD research, whatever — and you're pulling ThreadEx without thinking about this, you should be aware of the discontinuity. The pre-1991 CXY record can be adjusted to MDT-equivalent using monthly multiplicative ratios for precipitation and additive offsets for temperature/dewpoint, derived from the overlap period. The adjustment is stable enough (particularly in the cool season) that I'm reasonably confident applying it back through the CXY record to 1939. Happy to share the Excel adjustment factor table if anyone wants — monthly ratios with bootstrap CIs, plus seasonal summaries broken out by DJF/MAM/JJA/SON. Sent from my SM-S731U using Tapatalk

At a certain point you can't hand hold the public. They either start to get it or they experience the consequences of not. My take is they are going to do whatever they want and if it goes wrong in any way they look to first person other than themselves to blame. Whatever it is that introduced this rot into our cultures era specific mindset needs to be ruthlessly scrubbed out. Sent from my SM-S731U using Tapatalk

Are you able to open the PDF I linked to from my Google drive,? Sent from my SM-S731U using Tapatalk

The graphics cards are ridiculous. I found a refurbished DELL LATITUDE 7420 i5 2.60GHz 16GB RAM 256GB SSD 14" laptop for $225 a few weeks ago and scooped it up. So much easier to use for lots of weather stuff than my phone. I just checked and same computer is already $50 more. Sent from my SM-S731U using Tapatalk

Unless someone has a mobile Doppler radar in the backyard any velocity signature around here he's going to be up in the mid levels around 5,000 to 6,000 ft just due to the the tilt of the radar Sent from my SM-S731U using Tapatalk

Looks like CAD almost with the position of the CIN Sent from my SM-S731U using Tapatalk

Here is a PDF of every tornado, severe storm, flood warning CTP issued May 25-28, 2011. To say they were busy with being understatement it's 345 pages. Page 136 and I think page 305 give or take five pages is where some good stuff is. I'm hosted on my Google drive so here's a link. https://drive.google.com/file/d/1rZ-v0WQLuBEK60otdrIPOwoibLsrBwgf/view?usp=drivesdk It was made by IEM raccoon https://mesonet.agron.iastate.edu/raccoon/?wfo=CTP&radar=CCX&product=N0Q&wtype%5B%5D=FF&wtype%5B%5D=SQ&wtype%5B%5D=SV&wtype%5B%5D=TO&year=2011&month1=5&day1=10&hour1=0&month2=3&day2=27&hour2=23 Outside is the greatest thing ever in existence for weather data. Australia spent 20 hours exploring it and I'm just now starting to understand everything it can do it truly is the best thing out there by far. Sent from my SM-S731U using Tapatalk

We can cross off the good old tornado watch to accumulating snow in under 12 hours off the bucket list. I can imagine this happening in a plains a lot more often than out here Sent from my SM-S731U using Tapatalk

If only we had some winter of 2010 type blocking stalling that front out right now and a small little shortwave riding up the front at the sc/nc border and a little gun powder via upper air low flying in from the southwest we would feasting because that shortwave would be also with this baraclinic boundary. 30 miles 30; degrees. On that fanciful note the snow is starting to mix in @MAG5035 When is the last time I set up like that had us cash in? Sent from my SM-S731U using Tapatalk

The temperature dropped over 13'degrees within 10 seconds when it hit. Impressive Sent from my SM-S731U using Tapatalk

The frontal storms were far worse wind wise. I had the pleasure of being outside when it hit due to a little huskey puppy that after taking a deuce decided the cool breeze was too good to leave despite the rain and took off running around the yard. Sent from my SM-S731U using Tapatalk

Thundersnow out south @MAG5035 Sent from my SM-S731U using Tapatalk

I predict this line upcoming packs more of a punch then first one Sent from my SM-S731U using Tapatalk

Has the moron shut down his Facebook yet? I hope all the idiots who make meteorologist job hell turn their rotting brains on that dude. Sent from my SM-S731U using Tapatalk

Hopefully I have enough time to like to sit down stitch those weirdos together for for 2011. The archive goes back to 1995. So if you have other dates your interested in let me know. I've spent the last month on a learning binge trying to piece together the ridiculously fragmented data and archive environment of weather data available and tools as well. Far more daunting then I thought but I produced basically 30 pages of a guide for myself. I think in going to take on trying to get a copy of AWIPS the nws made public to run on an AWS server so that I can run out the graphics power necessary to run it per hour use basis. 20 bucks a month is a lot better than spending $5,000 to build something that can run it. That's the main software that is that the workstations of the national weather service that brings in all the desperate data feeds that they've almost made totally public now. I even got authorization to use part of there MADIS feed Sent from my SM-S731U using Tapatalk

I never saw such green sky or have such an feeling something was off. But I was young and dumb so of course I stayed on a porch and watched funnel go pretty damn close above me. It touched down not long after Sent from my SM-S731U using Tapatalk

Here is a link to the raw base reflectivity files. You have to follow the directions below the view them and I can't until I get back home today. It's a bit of a process. https://www.ncei.noaa.gov/pub/has/HAS012685643/0001/ Link above is the directory to them I'm hoping to have the velocity ones a bit later Since these are raw data files, you will need one of the following free tools to view the actual radar images: NOAA Weather and Climate Toolkit (Recommended): This is the official software from NOAA. It is a Java-based desktop app that allows you to drag and drop these files and turn them into maps, animations, or even export them as Google Earth (KML) files. https://www.ncei.noaa.gov/products/weather-climate-toolkit Sent from my SM-S731U using Tapatalk

5/26/2011 I believe was the date. I was in Carlisle then. I ordered radar from inventory. Hopefully will have in an hour Sent from my SM-S731U using Tapatalk

Very rarely do we eat get severe to work out in May and June this time of day let alone March Sent from my SM-S731U using Tapatalk

Outside a tropical system the only times around here I've experienced true severe has been when we have a stong NW flow, dewpoint in upper 60's+. Temperature right around 80, and a clear almost bright skies under a solid cap till late afternoon when a huge jet stream slams into us causing upper air divergence and extremely rapid storm development 30-50 miles to my northwest. Outside of those very particular circumstances it's meh Sent from my SM-S731U using Tapatalk

We are getting barely any lightning with these. Sent from my SM-S731U using Tapatalk

I was thinking of you making these. It's like a tale of two different universes. If someone can explain it, hats off. Sent from my SM-S731U using Tapatalk