Weather

Observed radar. The national NEXRAD base-reflectivity composite (N0Q, about 1 km, 5-minute updates), mosaicked from the WSR-88D network by the Iowa Environmental Mesonet. Slider frames run every 10 minutes for the latest 2 hours.

HRRR forecast. Simulated 1 km AGL reflectivity from the HRRR (NOAA's 3 km hourly-cycled convection-allowing model), on the same dBZ scale as the observed radar.

TLE. Time-lagged ensemble: the pixelwise mean over the last 3 or 6 hourly HRRR runs valid at the same time, averaged either in log space, ⟨dBZ⟩ (no echo = −32.5 dBZ floor, the default), or in linear reflectivity, ⟨Z⟩ (no echo = 0).

Precipitation accumulation. MRMS (Multi-Radar Multi-Sensor) precipitation estimates, about 1 km: 24, 48 and 72-hour totals ending at the labeled hour, updated hourly. The 6-day total is the latest 72-hour total plus the 72-hour total ending 72 hours earlier; pixels missing from either are left blank.

GOES. GOES-West (GOES-18) or GOES-East (GOES-19), selected by longitude. True color is composited in the browser from red (0.64 µm, 0.5 km), blue (0.47 µm) and a synthetic green G = 0.45 R + 0.10 NIR + 0.45 B (NIR = 0.86 µm), on a 0.5 km grid. Clean IR is the 10.3 µm band at 2 km resolution, colored by brightness temperature.

The grey mask and the data region. Radar, HRRR, the ensemble mean, precipitation accumulation and GOES are all fetched for one region. The grey mask covers everything outside what is actually loaded; when it appears, a button offers to refetch every field for the current view.

Sources. Imagery via the Iowa Environmental Mesonet (data: NOAA/NWS). Forecast numbers via Open-Meteo (NBM), api.weather.gov (NWS forecast, alerts and the forecast discussions), IEM's MOS API (NBS/NBE bulletins), NOAA's open-data archive on AWS (NBP percentile bulletins), and NOAA SWPC (Kp forecast, OVATION).

Source. Two NBM station bulletins from the same cycle, at the same station as the forecast above, fetched from NOAA's open-data archive: the hourly bulletin (NBH), which reaches 25 hours, and the short-range bulletin (NBS), 3-hourly to about 70 hours. The chart uses NBH up to the last 00, 06, 12 or 18 UTC it reaches (the dotted line) and NBS after it. Both are issued every hour.

Temperature. The line is the bulletin temperature (TMP) and the shading spans one standard deviation (TSD) above and below it. The bulletin gives the standard deviation in whole °F.

Precipitation. Left of the dotted line, each bar is the probability of at least 0.01 in (0.25 mm) of precipitation in that hour (P01). Right of it, each lighter, outlined bar is the probability for its whole 6-hour period (P06), which is at least the probability for any one hour within it. Hover or tap for the NBM amount for the hour or period and the thunderstorm probability.

Wind. The line is the bulletin's 10 m wind speed (WSP) and the shading spans one standard deviation (WSD) above and below it, cut off at zero: speed cannot be negative, and the bulletin gives only the two numbers, so no distribution is assumed below the line. The dashed line is the gust (GST). The bulletin also gives a standard deviation for the gust, which is not drawn. The arrows along the top point the way the wind is blowing, every 3 hours (the bulletin's WDR is the direction it blows from). The bulletin gives speeds in whole knots.

Panels. Daily maximum and minimum temperature on a broken y-axis, with 24-hour precipitation below. Each day's maximum glyph sits at 17:00 local and each minimum at 04:00. Daily extremes are taken over the local calendar day (midnight to midnight). The bulletin values describe the NBM's daytime and overnight window products (TXN).

NBM temperature distributions. The sienna violins are the NBM forecast density for each day's maximum and minimum, drawn through the NBM's 10/25/50/75/90th percentiles from the probabilistic station bulletin (NBP), fetched from NOAA's open-data archive. The shape therefore follows the blend's own distribution. The center line marks the bulletin mean. Density uses one shared scale across all days and both temperature panels. Where the NBP bulletin is unavailable the violin is a Gaussian from the NBS/NBE mean and σ, and the legend states which is in effect.

NBM precipitation. The bottom panel shows the NBP 24-hour precipitation distribution for each 12Z–12Z period, with each violin at the center of its period. The label is the median, shown when nonzero. Hover or tap for the amounts exceeded with 90, 75, 50, 25 and 10% probability, and the probability of no precipitation. A flat tick at zero means all bulletin percentiles are zero.

Thunderstorm probability. The sienna percentage is the NBM's highest 6-hour thunderstorm probability within that 12Z–12Z period, from the station bulletin, shown only above 20%. The probability of thunder at some point in the 24 hours is at least this value. It is independent of the precipitation label: either can appear without the other.

Climatology. Grey bands are the empirical 5–95% and 25–75% percentile ranges and the grey line is the mean, computed per day of year with ±7-day pooling over the last 30 complete years (1996–2025), with quality checks on every maximum/minimum pair. The stations are those in the climate explorer below: KSAF, Santa Fe 2, KABQ, KSLC and Moab. The chart uses the nearest of these within 40 km of the point and within the elevation gate; where none qualifies, no climatology is shown.

NWS dot. The NWS forecast, the same value as the headline on the day cards.

NOAA Climate Prediction Center outlooks fetched from their site.

The forecasters' written reasoning. The area forecast discussion (AFD) is issued several times a day by the NWS office whose area contains the mapped point, and covers about a week. The extended forecast discussion is the Weather Prediction Center's national discussion for days 3–7. The 6–10 and 8–14 day discussion is the Climate Prediction Center's discussion of the outlook maps under Long range, issued daily around 3 pm Eastern. Only the AFD is local; the other two are national.

The original line wraps are removed so the text reflows; paragraph breaks, section headers and tables are kept as issued. Fetched from api.weather.gov.

Monitor. Hourly measurements from the nearest reporting AirNow monitor. AirNow collects the readings of state, tribal and local air-quality agencies. Monitors more than from the mapped point are not used; with none in range this section is hidden. Site locations come from AirNow's monitoring-site index.

Units and colours. PM2.5 in µg/m³ and ozone in parts per billion, as reported. Bars are coloured by the US Air Quality Index (AQI) category of the concentration:

The AQI is defined on 24-hour averages for PM2.5 and 8-hour averages for ozone, so an hourly bar's colour is not the official daily AQI reported on airnow.gov. The dashed line marks the top of the Good category.

Gaps. A missing bar is a missing measurement; gaps are not filled. Hourly data are published about 35 minutes after the hour, so the latest hour or two may be missing.

The strip at the top of the page is the latest routine airport observation (METAR) at , via IEM, refetched every 10 minutes. METARs are issued hourly, with extra reports when conditions change significantly, so an observation up to about an hour old is normal. The table is the last 7 complete days at the same station: calendar-day maximum and minimum, precipitation, and peak gust. Sunrise and sunset times are computed from the page's coordinates using standard solar-position equations. The moon glyph shows the current phase. Hover for its name and illuminated fraction.

Station. The climatology station used by the 7-day charts, . Recent months are fetched live from that station's daily record and compared against its own history.

Monthly means and normals. Mean temperature is the average of the daily midpoints, (max+min)/2. Normals are that station's 30 most recent complete years (1996–2025) for the same calendar month, and the percentile is the empirical rank of the month within those values. Quality checks are applied.

Records set or tied at this location in the last three months, from the National Weather Service Record Event Report (RER), read from the Iowa Environmental Mesonet's archive.

Reading it. Station climatologies overlaid across one year: one colour per station, one panel per quantity. The marks match the DRAW buttons: thin line, the median; bands, the middle 50% and middle 90% of days; dotted lines, the extremes; thick line ending in a dot, the selected year (this year by default). The readout in each panel's corner gives each station's values at the cursor in that order. The cursor starts on today and follows the pointer, or a tap on touch screens. All statistics are medians and percentiles, not means, computed for each day of the year with ±7 days pooled, over the last 30 complete years (1996–2025).

Difference. With exactly two stations selected, the readout adds a last line: first station minus second, for the median and the selected year.

Frost adds the freezing line, 32 °F (0 °C), to the minimum panel and, for each station, the dates of the last spring freeze and the first fall freeze (minimum at or below freezing): a bar from the 10th to the 90th percentile of the date across the 30 years, with a tick at the median. The dates are listed under the chart. Years with no freeze in that half of the year are excluded and counted.

Precipitation is the running total from the start of the year, as in NRCS SNOTEL plots: each year's total to date, then the median and bands across years for each day. The YEAR buttons set the start: January 1, or October 1 for the water year (written 2025–26). Years with more than ten days missing a gauge report are excluded, and the note under the chart gives how many remain; missing days in the remaining years count as dry.

Snowfall is the running total of reported snowfall, computed the same way. Fewer years usually qualify. Snow depth is not shown.

Extremes are the lowest and highest values within ±7 days of the date over the 30 years, not all-time records.

Year draws one observed year from the Iowa Environmental Mesonet's daily archive: this year, unless another is picked beside the button. It shows daily maximum, minimum and range, and the running precipitation and snowfall totals, through yesterday, with the same quality checks as the climatology. When the cursor is past the last observed day, the readout shows the latest value and its date.

Stations. The chart opens on the station for this page's location: the one the 7-day charts use, or the nearest station when none is close enough for them. Add others to compare from the dropdown beside it, and click a station to remove it. KSAF (Santa Fe airport), KABQ (Albuquerque Sunport) and KSLC (Salt Lake City airport) are automated airport stations (ASOS). Santa Fe 2, about 8 km from the Santa Fe Plaza, and Moab are NWS cooperative observer stations. Hover a station for its source. Record years and elevations are listed under the chart.