Active: November 6—30; Maximum: November 17, 09h30m UT (nodal crossing
at λ⊙ = 235.27°), but see below; ZHR = 15?;
Radiant: α = 152°, δ = +22°; Radiant drift: see Table 6;
V∞ = 71 km/s; r = 2.5;
TFC: α = 140°, δ = +35° and α = 129°, δ = +6° (β > 35° N);
or α = 156°, δ = −3° and α = 129°, δ = +6° (β < 35° N).
IFC: α = 120°, δ = +40° before 0h local time (β > 40° N);
α = 120°, δ = +20° before 4h local time and α = 160°, δ = 0° after 4h local time (β > 0° N);
α = 120°, δ = +10° before 0h local time and α = 160°, δ = −10° (β < 0° N).
The most recent perihelion passage of the Leonids’ parent comet, 55P/Tempel-Tuttle, in 1998 may be nearly 15 years ago now, but the shower’s activity has continued to be fascinatingly variable from year to year recently. This year seems unlikely to produce enhanced rates, but there may be more than one peak. Apart from the nodal timing above, Mikhail Maslov has suggested that there could be a peak with ZHRs of ∼ 5—10 at 21h UT on November 17, followed by another increase to ZHRs of ∼ 10—15, probably of below-average brightness meteors, on November 20, at ∼ 06h UT (the latter due to the 1400 AD dust-trail).
ZHRs for the nodal peak are liable to be "normal", so probably about 15±5. November’s waxing Moon is excellent news for either date, as it will set before or soon after the time the Leonid radiant first becomes usefully-observable, by local midnight or so north of the equator, afterwards for places further south. All observing methods can be employed. While these potential maximum timings do not exclude all others, if they prove correct, the two November 17 ones would be best-detectable from North American, and Middle East to Asian longitudes respectively, while that on November 20 would be similarly available from places between eastern North America east to extreme western North African longitudes.