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🌧 100-Gauge Pixel Variance — Camp Hill, PA → KCCX

What your 4 nearest gauges will realistically show vs. what the radar reported
Range to KCCX
73.8 mi / 118.8 km
Super-res pixel
0.830 mi² / 2.15 km²
Legacy pixel
1.660 mi² / 4.30 km²
Super-res gauge spacing
481 ft → nearest 4 at 340 ft
Legacy gauge spacing
680 ft → nearest 4 at 481 ft
⚠️ Super-res vs Legacy pixel: The dBZ value is IDENTICAL — same physical beam, same atmosphere. The only difference is pixel area (2.15 vs 4.30 km²), gauge spacing (481 vs 680 ft), and your 4 nearest gauges (340 vs 481 ft away). Variance across the pixel is essentially the same; your near-4 gauges are just slightly more correlated in super-res.
RADAR REPORTS: 0.50" — Pixel mean rainfall
Precip Category SDCV Pixel P5Pixel P95 Your 4 Nearest Gauges
— italic = description low end high end P10 (Super / Legacy) P90 (Super / Legacy)
1. Widespread synoptic / warm-frontal 0.050"0.10 0.422"0.586" 0.483" / 0.481"0.518" / 0.520"
Laminar large-scale ascent. Your 4 gauges nearly identical. Radar probably right.
2. Stratiform nimbostratus 0.080"0.16 0.380"0.641" 0.471" / 0.468"0.530" / 0.533"
Steady rain. Minor spread. Bright band not an issue. Best radar scenario.
3. Stratiform + melting-layer bright band 0.110"0.22 0.341"0.698" 0.458" / 0.454"0.543" / 0.547"
Melting layer undulates. Radar may over-report. Your near-4 still fairly tight.
4. Mixed stratiform / convective trailing 0.175"0.35 0.270"0.826" 0.428" / 0.422"0.576" / 0.582"
Rain shafts beginning. Pixel-wide spread notable. Your 4 still within ~0.15" of each other.
5. Convective — distant cell (5–10 mi away) 0.260"0.52 0.198"0.992" 0.384" / 0.376"0.627" / 0.636"
5:1 range across pixel possible. Your near-4 spread to ~0.25". Radar mean getting suspect.
6. Convective — moderate cell over pixel 0.350"0.70 0.145"1.157" 0.334" / 0.324"0.691" / 0.703"
8:1 range across pixel. Near-4 spread ~0.37". One gauge could read 2× another neighbor.
7. Convective — intense core directly over pixel 0.500"1.00 0.090"1.391" 0.250" / 0.238"0.810" / 0.826"
15:1 pixel range. Near-4 spread ~0.57". You could read 0.25" while neighbor reads 0.80". Radar 0.50" is almost fiction.
8. Extreme / flash flood / training cells 0.700"1.40 0.052"1.613" 0.157" / 0.146"0.965" / 0.983"
31:1 pixel range. Near-4 spread ~0.82". Gauges 340 ft apart can disagree by 6:1. Radar number is a suggestion.
9. Snow — light stratiform 0.070"0.14 0.394"0.623" 0.475" / 0.473"0.526" / 0.528"
Most uniform precip type. Radar likely overestimates (bright band, Z-R invalid for snow).
10. Snow — heavy banded / orographic 0.235"0.47 0.217"0.944" 0.398" / 0.391"0.611" / 0.619"
Band edge within pixel = one side hammered, other side light. Near-4 spread ~0.22".
RADAR REPORTS: 1.00" — Pixel mean rainfall
Precip Category SDCV Pixel P5Pixel P95 Your 4 Nearest Gauges
— italic = description low end high end P10 (Super / Legacy) P90 (Super / Legacy)
1. Widespread synoptic / warm-frontal 0.100"0.10 0.844"1.172" 0.965" / 0.963"1.035" / 1.038"
Radar and all 4 gauges nearly agree. This is the textbook validation scenario.
2. Stratiform nimbostratus 0.160"0.16 0.760"1.283" 0.942" / 0.938"1.060" / 1.065"
Near-4 spread ~0.12". All 4 gauges within a dime of each other. Acceptable agreement.
3. Stratiform + melting-layer bright band 0.220"0.22 0.683"1.397" 0.917" / 0.910"1.086" / 1.093"
Near-4 spread ~0.18". Radar likely inflated by 15-30% due to bright band enhancement.
4. Mixed stratiform / convective trailing 0.350"0.35 0.540"1.651" 0.856" / 0.846"1.152" / 1.163"
Near-4 spread ~0.31". Pixel range 3:1. Validation starting to get messy.
5. Convective — distant cell (5–10 mi away) 0.520"0.52 0.397"1.984" 0.768" / 0.753"1.255" / 1.272"
Near-4 spread ~0.50". Pixel range 5:1. Single gauge validation is scientifically unreliable.
6. Convective — moderate cell over pixel 0.700"0.70 0.290"2.315" 0.668" / 0.649"1.382" / 1.405"
Near-4 spread ~0.73". Pixel range 8:1. You could read 0.67" while 340 ft neighbor reads 1.38".
7. Convective — intense core directly over pixel 1.000"1.00 0.180"2.781" 0.500" / 0.476"1.620" / 1.651"
Near-4 spread ~1.15". You could read 0.50" while 340 ft neighbor reads 1.62". Radar 1.00" could be anywhere.
8. Extreme / flash flood / training cells 1.400"1.40 0.105"3.225" 0.314" / 0.292"1.930" / 1.966"
Near-4 spread ~1.64". 30:1 pixel range. One gauge reads 0.30", 340 ft away reads 1.93". Radar is a rumor.
9. Snow — light stratiform 0.140"0.14 0.788"1.245" 0.950" / 0.947"1.051" / 1.054"
Near-4 spread ~0.10". Spatially uniform but Z-R for snow is ±50% anyway. Good spatial, bad physics.
10. Snow — heavy banded / orographic 0.470"0.47 0.434"1.887" 0.795" / 0.782"1.223" / 1.238"
Near-4 spread ~0.44". Band edge effect. One side of pixel in 2"+ band. Other side sees 0.40". Classic PA winter.
Column Key:
SD = standard deviation across all 100 gauges in pixel  |  CV = coefficient of variation (literature-based by precip type)  |  Pixel P5 = only 5 of 100 gauges read lower than this  |  Pixel P95 = only 5 of 100 gauges read higher than this

Near-4 P10 = lower bound of your 4 closest gauges (340 ft super / 481 ft legacy)  |  Near-4 P90 = upper bound of your 4 closest gauges

Super-res vs Legacy near-4: Differences are small (gauges are 340 vs 481 ft away). At those scales spatial correlation is high even in convection. The pixel-wide P5/P95 is identical for both — same beam, same dBZ, same physics. Distribution assumed lognormal. Local CV compressed by proximity factor (0.25–0.60 × pixel CV) derived from exponential spatial correlation model.
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