Single radar / Delaware

Dover AFB radar KDOX

The weather service radar at Dover AFB, Delaware, 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: 6:28 AM UTC
Scanning: Precipitation mode, pattern 212
Tilts: 0.5°, 1.3°, 2.4°, 3.1°
Stands at: 38.826°N 75.440°W, 50 ft above sea level
Reaches: 286 mi with reflectivity, 186 mi with velocity, 143 mi with storm relative velocity

KDOX 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 KDOX tracks, from its scan of 6:24 AM UTC
Storm	Where	Moving	In 30 minutes	In 60 minutes	Last forecast off by
B9	157 mi north northwest of the radar157 mi from the radar, bearing 334°	First seen this scan	-	-	0 mi
X8	155 mi north northwest of the radar155 mi from the radar, bearing 340°	Toward the northeast at 21 mph	159 mi north northwest of the radar	-	1.2 mi
H3	132 mi northwest of the radar132 mi from the radar, bearing 322°	Toward the northeast at 35 mph	136 mi north northwest of the radar	142 mi north northwest of the radar	0.7 mi
T8	124 mi north northwest of the radar124 mi from the radar, bearing 332°	Toward the northeast at 47 mph	131 mi north northwest of the radar	143 mi north of the radar	0.8 mi
Y6	147 mi southwest of the radar147 mi from the radar, bearing 225°	Toward the northeast at 25 mph	135 mi southwest of the radar	122 mi southwest of the radar	0.7 mi
A8	182 mi west northwest of the radar182 mi from the radar, bearing 298°	Toward the north northeast at 33 mph	-	-	2.8 mi
C9	152 mi north northwest of the radar152 mi from the radar, bearing 328°	First seen this scan	-	-	0 mi
V8	150 mi north northwest of the radar150 mi from the radar, bearing 345°	Toward the east northeast at 26 mph	150 mi north of the radar	-	1.6 mi
Y7	119 mi west southwest of the radar119 mi from the radar, bearing 251°	Toward the northeast at 29 mph	106 mi west southwest of the radar	7 mi west southwest of La Plata, MD	0.5 mi
M8	148 mi west northwest of the radar149 mi from the radar, bearing 303°	Toward the northeast at 31 mph	145 mi northwest of the radar	-	1.5 mi
D9	144 mi west of the radar144 mi from the radar, bearing 277°	First seen this scan	-	-	0 mi
U8	154 mi west of the radar154 mi from the radar, bearing 273°	Toward the north northeast at 51 mph	147 mi west northwest of the radar	-	1.3 mi
P8	2 mi east of St. James, MD131 mi from the radar, bearing 294°	Toward the northeast at 31 mph	-	-	3.3 mi
E9	110 mi west of the radar111 mi from the radar, bearing 266°	First seen this scan	-	-	0 mi
F9	160 mi west southwest of the radar160 mi from the radar, bearing 248°	First seen this scan	-	-	0 mi
I8	12 mi south of Poolesville, MD108 mi from the radar, bearing 276°	Toward the north northeast at 49 mph	-	-	3.7 mi
G9	138 mi southwest of the radar138 mi from the radar, bearing 227°	First seen this scan	-	-	0 mi
D8	148 mi southwest of the radar149 mi from the radar, bearing 217°	Toward the northeast at 29 mph	135 mi southwest of the radar	120 mi southwest of the radar	0.6 mi
H9	139 mi west southwest of the radar139 mi from the radar, bearing 244°	First seen this scan	-	-	0 mi
I9	15 mi southwest of Cabin John, MD104 mi from the radar, bearing 271°	First seen this scan	-	-	0 mi
A7	132 mi west southwest of the radar132 mi from the radar, bearing 250°	Toward the north at 32 mph	125 mi west southwest of the radar	122 mi west of the radar	0.5 mi
J9	5 mi northeast of Paramount-Long Meadow, MD134 mi from the radar, bearing 299°	First seen this scan	-	-	0 mi
K9	6 mi north northwest of Poolesville, MD111 mi from the radar, bearing 285°	First seen this scan	-	-	0 mi
Q8	132 mi west of the radar132 mi from the radar, bearing 266°	Toward the north northeast at 40 mph	125 mi west of the radar	-	1 mi
L9	112 mi west southwest of the radar112 mi from the radar, bearing 256°	First seen this scan	-	-	0 mi
M9	127 mi southwest of the radar127 mi from the radar, bearing 236°	First seen this scan	-	-	0 mi
N9	114 mi north northwest of the radar114 mi from the radar, bearing 328°	First seen this scan	-	-	0 mi
Q2	94 mi north northwest of the radar94 mi from the radar, bearing 327°	Toward the northeast at 36 mph	100 mi north northwest of the radar	108 mi north northwest of the radar	0.8 mi
A9	4 mi north northwest of Reisterstown, MD89 mi from the radar, bearing 302°	Toward the northeast at 24 mph	8 mi east northeast of Hampstead, MD	-	0.9 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=KDOX, the times of its frames, and /radar/s/KDOX/storms.json, the storms it tracks.