Single radar / Kentucky

Jackson, KY radar KJKL

The weather service radar at Jackson, KY, Kentucky, 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 212
Tilts: 0.5°, 1.3°, 2.4°, 3.1°
Stands at: 37.591°N 83.313°W, 1,364 ft above sea level
Reaches: 286 mi with reflectivity, 186 mi with velocity, 143 mi with storm relative velocity

KJKL 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 KJKL tracks, from its scan of 6:24 AM UTC
Storm	Where	Moving	In 30 minutes	In 60 minutes	Last forecast off by
W1	3 mi south southwest of Sissonville, WV107 mi from the radar, bearing 56°	Toward the north northeast at 47 mph	9 mi west southwest of Spencer, WV	-	1 mi
M1	5 mi south of Ripley, WV117 mi from the radar, bearing 47°	Toward the north northeast at 48 mph	9 mi south southwest of Mineralwells, WV	7 mi west southwest of St. Marys, WV	0.8 mi
X4	105 mi east southeast of the radar105 mi from the radar, bearing 111°	Toward the north at 49 mph	3 mi south southeast of Welch, WV	7 mi northeast of Oceana, WV	0.5 mi
R0	87 mi east southeast of the radar88 mi from the radar, bearing 106°	Toward the north northeast at 48 mph	10 mi south southwest of Oceana, WV	98 mi east northeast of the radar	0.8 mi
X5	4 mi east southeast of Ravenswood, WV128 mi from the radar, bearing 43°	First seen this scan	-	-	0 mi
A8	12 mi north northeast of Buffalo, WV112 mi from the radar, bearing 42°	First seen this scan	-	-	0 mi
U4	3 mi southwest of Mosheim, TN100 mi from the radar, bearing 170°	Toward the north at 37 mph	2 mi northeast of Rogersville, TN	14 mi north northwest of Surgoinsville, TN	0.9 mi
Q2	6 mi north of Mount Carmel, TN75 mi from the radar, bearing 151°	Toward the north at 60 mph	8 mi south southeast of Jenkins, KY	2 mi northeast of Pikeville, KY	0.2 mi
Z4	4 mi north northeast of Harlan, KY48 mi from the radar, bearing 178°	Toward the north at 43 mph	5 mi south southwest of Hazard, KY	11 mi east southeast of Jackson, KY	0.3 mi
K6	3 mi south southwest of Rogersville, TN86 mi from the radar, bearing 169°	Toward the northwest at 25 mph	-	-	3 mi
B7	2 mi east southeast of Alum Creek, WV96 mi from the radar, bearing 60°	Toward the north northeast at 45 mph	7 mi north of Sissonville, WV	-	1.2 mi
T7	9 mi south southeast of Cumberland, KY55 mi from the radar, bearing 158°	Toward the north at 33 mph	8 mi north of Cumberland, KY	-	1.3 mi
N5	12 mi south southwest of Harlan, KY62 mi from the radar, bearing 186°	Toward the north at 63 mph	14 mi west southwest of Hazard, KY	-	1.5 mi
P4	2 mi north of Sneedville, TN71 mi from the radar, bearing 176°	Toward the north northeast at 41 mph	11 mi east of Harlan, KY	9 mi west of Whitesburg, KY	0.2 mi
A4	2 mi west of Hazard, KY24 mi from the radar, bearing 168°	First seen this scan	-	-	0 mi
L8	11 mi northwest of Cumberland, KY37 mi from the radar, bearing 166°	Toward the north at 47 mph	13 mi north northeast of Hazard, KY	-	1.6 mi
S5	7 mi north northeast of Russell Springs, KY100 mi from the radar, bearing 253°	Toward the north northwest at 28 mph	-	-	2.1 mi
J5	5 mi east northeast of Whitesburg, KY44 mi from the radar, bearing 134°	Toward the north at 59 mph	5 mi west northwest of Coal Run Village, KY	-	1.4 mi
V3	1 mi southwest of Mullens, WV105 mi from the radar, bearing 90°	First seen this scan	-	-	0 mi
U0	2 mi southwest of Mount Carmel, TN81 mi from the radar, bearing 154°	First seen this scan	-	-	0 mi
Z6	6 mi west of Coal Run Village, KY36 mi from the radar, bearing 96°	Toward the north northeast at 46 mph	15 mi east of Paintsville, KY	4 mi south of Wayne, WV	0.6 mi
T4	5 mi east northeast of Liberty, KY86 mi from the radar, bearing 259°	First seen this scan	-	-	0 mi
N4	3 mi south southwest of Madison, WV85 mi from the radar, bearing 69°	Toward the north northeast at 47 mph	2 mi west of Charleston, WV	13 mi southwest of Spencer, WV	0.5 mi
O7	64 mi southeast of the radar64 mi from the radar, bearing 124°	First seen this scan	-	-	0 mi
Z3	8 mi south southeast of Welch, WV99 mi from the radar, bearing 100°	Toward the north at 58 mph	-	-	5.1 mi
X3	1 mi north of Culloden, WV90 mi from the radar, bearing 49°	Toward the north at 44 mph	9 mi north of Buffalo, WV	-	1.4 mi
G8	13 mi northwest of Mount Carmel, TN67 mi from the radar, bearing 155°	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=KJKL, the times of its frames, and /radar/s/KJKL/storms.json, the storms it tracks.