aurora il

now:

No precipitation in the next 30 minutes

hourly:

temperaturechance of precipitation

highest precipitation chance is 40% around 1:00 pm (chance rain showers)

forecast:

extended:

bars span the daily low to the daily high, tinted by expected conditions; the strip under each day is the chance of precipitation. 9 of 16 days show measurable precipitation; wettest is thu 9/17 at 0.49 in (rain showers).

the first week overlaps the official forecast above and is the better number to trust; past about ten days treat this as a trend, not a forecast.

radar:

aurora

aurora

nearest NEXRAD site is KLOT. images are refreshed by the poller and cached here, so nothing on this page makes a request to a third party.

windmap:

each line follows the wind from where it starts, so the lines show the shape of the flow rather than any one reading: where they crowd together the wind is confluent, where they turn sharply there is usually a trough or a front. color is speed, the dot on each line is its downwind end, and the marker is aurora. grid average 10 mph. computed from a 7 by 5 sample grid, drawn once on the server. there is no animation because there is no javascript on this page.

detail:

trace:

temperaturedewpoint

wind:

sustainedgusts · faint spokes on the dial are the last 18 direction reports, newest brightest

pressure:

falling pressure generally precedes unsettled weather; a rapid rise behind a front brings the clearing and the wind shift.

humidity:

station:

discussion:

the reasoning behind the numbers, written by the forecaster on duty. worth reading when the models disagree.

normals:

today's high ranks 7th warmest out of 30 years of 12 sep on record here

running totals:

degree days use the daily mean against a 65°F base for heating and cooling and a 50°F base capped at 86°F for growing, which is the convention utilities and growers quote.

year:

the pale band is the normal high to low range for each date; each bar is that day's actual range, tinted by how far its mean ran from normal.

air:

airnow, official reporting area:

source: Open-Meteo (CAMS). a modelled value for this point, not a monitor reading.

water:

gauge height over the last week. observations from USGS; flood thresholds, where shown, from the NWS National Water Prediction Service.

rainreports:

1 of 10 reported measurable precipitation, the wettest 0.04 in. these are hand-read gauges from volunteers.

hazards:

local: within 120 miles, any magnitude

nothing on record for this window, which is the usual state of affairs.

us: united states, magnitude 4.0 and above

world: worldwide, magnitude 6.0 and above

space:

stable paths, no storm effects.

planetary k index, three days. 5 and above is a geomagnetic storm.

hf bands, daylight here:

this is a heuristic from flux, k index and whether the sun is up here, not an ionospheric model. it will not know about a sporadic e opening on 6m or a gray line path that is wide open. for real planning use VOACAP.

sun:

sunmoon · bands below the horizon are civil, nautical and astronomical twilight

the moon is down by full darkness tonight.

moon:

upcoming phases:

sky:

magnitudes are approximate; lower is brighter, and anything under about +6 is naked eye from a dark site. saturn ignores ring tilt, which can move it a few tenths either way.

satellites:

magnitude is approximate and lower is brighter; the ISS varies by about a magnitude with the angle of its panels. brightness fades as a satellite enters the earth's shadow, which is usually why a pass ends while it is still high in the sky. directions are where to look on the horizon.

planetarium:

satellite passes are the next visible pass for each tracked object, not a position right now: the glyph sits at the peak, and the faint part of the arc is where the satellite is above the horizon but in the earth's shadow, so too dark to see. point at any object or track to bring it forward and fade the rest. use the toggles above to hide whole groups. each body is drawn at its current position, with its track for the next 24 hours in the same color. dots on a track are whole hours, labeled every six. the faded part of a track is below the horizon. sizes follow real apparent diameter but on a compressed scale.

events:

upcoming:

comets brighter than magnitude 12:

positions computed here from Minor Planet Center orbital elements, not fetched per object. comet brightness predictions are notoriously optimistic: treat the magnitude as a rough guide, and anything fainter than about 8 needs a telescope.

minor planets:

asteroid close approaches:

source: JPL Center for Near Earth Object Studies. one lunar distance is 384,400 km. none of these are on a collision course; close approach lists exist because they are the routine traffic, not because anything is coming.

seasons:

meteor showers: