Single radar / Pennsylvania

State College radar KCCX

The weather service radar at State College, Pennsylvania, alone: each picture it makes from its own scans, at four tilts from its lowest up, every few minutes. Reflectivity, velocity, storm relative velocity, correlation coefficient and differential reflectivity, the storms it tracks and where they are headed, and how high its beam passes. How to read them.

Latest scan: 6:29 AM UTC
Scanning: Precipitation mode, pattern 215
Tilts: 0.5°, 1.3°, 2.4°, 3.1°
Stands at: 40.923°N 78.004°W, 2,405 ft above sea level
Reaches: 286 mi with reflectivity, 186 mi with velocity, 143 mi with storm relative velocity

KCCX on the map

Storms it tracks

The radar follows each storm cell from scan to scan, measures the way it is moving, and puts it ahead 15 to 60 minutes. Each is drawn on the map above, its track to the hour ahead marked each quarter hour.

Storm cells KCCX tracks, from its scan of 6:23 AM UTC
Storm	Where	Moving	In 30 minutes	In 60 minutes	Last forecast off by
W0	8 mi west of Meyersdale, PA99 mi from the radar, bearing 219°	Toward the north northeast at 17 mph	7 mi south southwest of Somerset, PA	-	2.3 mi
Z8	6 mi east southeast of Bear Rocks, PA91 mi from the radar, bearing 232°	Toward the north northeast at 49 mph	-	-	3.8 mi
M1	6 mi north northwest of Westernport, MD111 mi from the radar, bearing 212°	First seen this scan	-	-	0 mi
J0	3 mi west southwest of Berlin, PA89 mi from the radar, bearing 217°	Toward the northeast at 38 mph	7 mi south of Windber, PA	4 mi east southeast of Portage, PA	0.6 mi
A1	3 mi east southeast of Troy, PA88 mi from the radar, bearing 48°	Toward the northeast at 47 mph	7 mi east of Athens, PA	-	1.4 mi
O1	1 mi south southwest of Bethel Park, PA115 mi from the radar, bearing 249°	First seen this scan	-	-	0 mi
B8	At Bloomsburg, PA81 mi from the radar, bearing 85°	Toward the northeast at 37 mph	9 mi west northwest of Glen Lyon, PA	-	1.5 mi
D9	6 mi northeast of Clymer, PA51 mi from the radar, bearing 255°	Toward the northeast at 32 mph	9 mi south southeast of Sykesville, PA	7 mi east southeast of Treasure Lake, PA	1.2 mi
S8	4 mi southeast of Orchard Hills, PA82 mi from the radar, bearing 252°	Toward the northeast at 38 mph	11 mi northwest of Chevy Chase Heights, PA	4 mi northwest of Punxsutawney, PA	0.1 mi
K5	At Bedford, PA68 mi from the radar, bearing 203°	Toward the northeast at 47 mph	7 mi east southeast of Martinsburg, PA	7 mi east northeast of Huntingdon, PA	0.3 mi
V0	9 mi northeast of Orchard Hills, PA76 mi from the radar, bearing 257°	First seen this scan	-	-	0 mi
X5	9 mi southeast of Mount Union, PA46 mi from the radar, bearing 165°	Toward the northeast at 38 mph	6 mi south of Lewistown, PA	11 mi east of Milroy, PA	0.6 mi
Y0	2 mi southeast of Evans City, PA107 mi from the radar, bearing 264°	Toward the northeast at 20 mph	At Butler, PA	-	1.7 mi
Y8	6 mi west southwest of McConnellsburg, PA71 mi from the radar, bearing 184°	Toward the east at 25 mph	-	-	6.3 mi
F8	3 mi west northwest of Catawissa, PA78 mi from the radar, bearing 87°	First seen this scan	-	-	0 mi
Y9	6 mi south southwest of Blossburg, PA66 mi from the radar, bearing 44°	First seen this scan	-	-	0 mi
A5	5 mi east of Saxonburg, PA91 mi from the radar, bearing 263°	First seen this scan	-	-	0 mi
D1	9 mi northwest of Mansfield, PA81 mi from the radar, bearing 32°	Toward the northeast at 38 mph	3 mi south of Big Flats, NY	11 mi east southeast of Montour Falls, NY	0.2 mi
I1	10 mi west of Hancock, MD86 mi from the radar, bearing 193°	Toward the east southeast at 26 mph	-	-	3.6 mi
E1	4 mi east northeast of Milton, PA64 mi from the radar, bearing 82°	Toward the northeast at 53 mph	89 mi east northeast of the radar	-	1.8 mi
P6	9 mi east northeast of McConnellsburg, PA67 mi from the radar, bearing 172°	First seen this scan	-	-	0 mi
O0	13 mi north of Cumberland, MD84 mi from the radar, bearing 207°	Toward the northeast at 54 mph	9 mi south of Claysburg, PA	-	1.4 mi
H1	2 mi south of Robinwood, MD93 mi from the radar, bearing 169°	First seen this scan	-	-	0 mi
P0	At Black Lick, PA70 mi from the radar, bearing 244°	First seen this scan	-	-	0 mi
M0	48 mi north northeast of the radar48 mi from the radar, bearing 20°	Toward the northeast at 15 mph	54 mi north northeast of the radar	-	2.2 mi
U7	13 mi east northeast of Clearfield, PA17 mi from the radar, bearing 318°	Toward the northeast at 41 mph	-	-	2.6 mi
T7	7 mi west southwest of Belleville, PA27 mi from the radar, bearing 161°	Toward the northeast at 40 mph	3 mi northeast of Milroy, PA	-	1.5 mi
Z0	5 mi south southwest of Ashland, PA85 mi from the radar, bearing 99°	First seen this scan	-	-	0 mi
X1	7 mi east northeast of Berlin, PA81 mi from the radar, bearing 213°	First seen this scan	-	-	0 mi
O9	4 mi west southwest of Jonestown, PA84 mi from the radar, bearing 115°	Toward the northeast at 41 mph	1 mi west of Friedensburg, PA	At Tamaqua, PA	0.6 mi
L0	8 mi west northwest of Punxsutawney, PA58 mi from the radar, bearing 276°	Toward the northeast at 37 mph	4 mi southwest of Brockway, PA	-	1.7 mi
K0	2 mi west of Vinco, PA59 mi from the radar, bearing 233°	First seen this scan	-	-	0 mi
G0	14 mi west southwest of Wellsboro, PA59 mi from the radar, bearing 23°	First seen this scan	-	-	0 mi
D2	14 mi east of Kittanning, PA66 mi from the radar, bearing 265°	First seen this scan	-	-	0 mi

How high it sees

The beam leaves the radar tilted up and the earth curves away under it, so the farther from the radar, the higher it passes. Rain or snow falling under the lowest beam is not seen: far from the radar, shallow snow and drizzle can fall unseen. The heights are the standard ones, the air bending the beam as the weather service’s own rule takes it.

The middle of each tilt’s beam, in feet above the radar’s antenna, and how wide the beam has grown
Tilt	25 mi	50 mi	100 mi	150 mi	200 mi
0.5°	1,500 ft	3,600 ft	9,600 ft	18,200 ft	29,200 ft
1.3°	3,300 ft	7,200 ft	17,000 ft	29,300 ft	44,000 ft
2.4°	5,800 ft	12,300 ft	27,200 ft	44,500 ft	64,400 ft
3.1°	7,500 ft	15,600 ft	33,600 ft	54,200 ft	77,400 ft
Width	2,200 ft	4,400 ft	8,800 ft	13,100 ft	17,500 ft

How to read the pictures

Reflectivity: How strongly rain, snow and hail send the pulse back, in dBZ: the stronger, the heavier.
Velocity: The wind along the beam, in mph: green toward the radar, red away. Where the two meet tightly, the wind turns.
Storm relative velocity: The same wind with the storms’ own motion taken away, so a storm’s turning stands out: a tight pair of green and red is a rotating storm.
Correlation coefficient: How alike the returns of one pulse are, 0 to 1: rain and snow near 1, hail and melting snow lower, and debris a tornado lifts well below 0.8.
Differential reflectivity: How much wider than tall what falls is, in dB: large flat raindrops read high, hail and dry snow near 0.

Each picture is one tilt of one scan, as the radar sent it: its lowest tilt first, then three above it, the angles its scan pattern sets. A picture at a higher tilt sees higher into a storm, and farther over the ground at each distance. Press a point on the map to read the value there.

As data: /radar/now.json?show=sref&site=KCCX, the times of its frames, and /radar/s/KCCX/storms.json, the storms it tracks.