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Heat haze rippling above an empty athletic field in late afternoon with stadium light towers behind, the hero photograph of the Flash heat and WBGT page

Flash heat and WBGT · Hourly forecast · 1×1 km cells

WBGT and heat forecasts planned beside your on-site sensor, not instead of it.

Flash forecasts wet-bulb globe temperature, heat index, air temperature and dew point for every 1×1 km cell, hourly. Your sensor still makes the policy call. Flash tells you at noon what it will read at 4 pm.

No hardware · runs beside any WBGT meter you already own · For schools, athletics, construction, events and utilities

Illustrative example · Not live weather

Field B sensor 84.2 °F · 12:40

Flash WBGT forecast for Practice Field B: hourly bars from the 84.2 sensor reading at 12:40 to an 88.1 peak at 4 pm, against the GHSA bands at 82, 87, 90 and 92 degrees82 · discretion87 · 2 h max90 · 1 h max92 · no outdoor84.2Now85.01 pm86.62 pm87.83 pm88.14 pm87.35 pm85.96 pmWBGT forecast
Peak 88.1 °F at 4:00 pm, under 87 after 5:20 pm. The policy call stays with your sensor; the plan is made at noon.

What it predicts · Four heat parameters · One grid

What does Flash predict for heat?

Four parameters per 1×1 km cell, from the same engine and the same run as the lightning and hail products. Forecast hourly.

Illustrative example · not live weather · Practice Field B · Now → 6 pm

  • WBGT forecast for Practice Field B, illustrative: 84.2 °F now, peaking at 88.1 °F at 4 pm, 85.9 °F at 6 pm.

    Hourly forecast

    WBGT forecast

    The number your sensor will read at 4 pm, known at noon. Shown against the GHSA bands or your own thresholds, per field.

  • Heat index for Practice Field B, illustrative: 99.5 °F now, peaking at 106.5 °F at 4 pm, 103.4 °F at 6 pm.

    Hourly forecast · 1×1 km

    Heat index

    For crews, events and utilities that plan by heat index rather than WBGT, on the same cells and the same run.

  • Air temperature for Practice Field B, illustrative: 90.8 °F now, peaking at 95.6 °F at 5 pm, 94.2 °F at 6 pm.

    Hourly forecast · 1×1 km

    Air temperature

    Per 1×1 km cell, so the stadium and the practice field two miles away get their own numbers, not the airport's.

  • Dew point for Practice Field B, illustrative: 73.2 °F now, peaking at 74.3 °F at 3 pm, 72.8 °F at 6 pm.

    Hourly forecast · 1×1 km

    Dew point

    The humidity half of the WBGT story, and the reason two afternoons with the same air temperature can land in different bands.

Forecast vs measurement · The schools rule

Forecast or measurement: which one decides?

GHSA reads the meter on the field, and each state sets its own method. Flash does not replace it. Policy compliance uses the reading your state requires; planning uses Flash.

Which decisions the on-site sensor makes and which the Flash forecast makes
The decisionYour on-site sensorFlash forecast
Stop or modify practice right nowYour on-site sensorDecides.Policy compliance reads the meter on the field.Flash forecastSupports.Shows whether the next hour is rising or falling, so a pause is a plan.
Plan today's practice timeYour on-site sensorCannot.It reads the present only.Flash forecastDecides.Hourly forecast; move practice before the band changes.
Compare fields before assigning sessionsYour on-site sensorCannot.No outlook, no per-field difference.Flash forecastDecides.Forecast per 1×1 km cell; the shaded field and the turf field get their own numbers.
Warn trainers before the band changesYour on-site sensorAlarms as it crosses.The threshold is already behind you.Flash forecastAlerts ahead.Push, SMS or Skye when the forecast will cross 82, 87, 90 or 92, before it does.
Log the decision for the districtYour on-site sensorThe reading.Whatever the meter said when someone wrote it down.Flash forecastReading and forecast, side by side.Timestamped in the Command Center log with who made the call.
An empty athletic field at first light with dew on the grass and a sideline equipment cart, the morning hour when the WBGT forecast is used to plan the day

Planning day · The noon call

The plan is made at noon. The sensor still makes the policy call at 4 pm.

Plan made · Flash forecast 88.1 °F at 4 pmSensor reads the field · policy call

Who it is for · Heat safety software for four jobs

Who plans with the WBGT forecast?

Anyone who has to decide hours before the heat arrives, and prove afterwards that the decision was made on the numbers.

Empty athletic practice field at dusk in late-summer haze, the hour evening practice moves to when the WBGT forecast tops 87

Athletic directors and trainers: Field B · 88.1 °F at 4 pm · move practice

  • GHSA or state bands per field, practice moved before 87, both trainers notified, the reading and the forecast in the log.

    Schools
  • Heat index and WBGT per site for crew rotation and water breaks, with the record the owner's rep asks for.

    Construction
  • Start times, hydration stations and shade planned against the WBGT forecast for the venue's own cell, not the morning news.

    Talk to us about your venue
  • Line crews and restoration shifts planned by cell, so the hottest hour of the day is not also the hardest job.

    Talk to us about your crews

Skye · Illustrative example · Not live weather

Ask Flash about Thursday’s practice.

Skye, Flash Weather's AI weather agent, reads the same WBGT cells and the same run as this page, then answers or acts in the calendar and the phones your staff already use. A person confirms before anything moves; every action is logged.

How Skye works

Athletic director · Practice Field B · Tuesday 12:04

“Move Thursday practice if WBGT tops 87.”

IF WBGT > 87 °F → move practiceTriggered

Asked in Microsoft Teams, from the phone, between two meetings.

88.1 forecast at 4 pm. Practice moved to 5:30 in Google Calendar; trainers notified.

87 °F88.1 · 4 pm5:30–7:00Noon2 pm4 pm6 pm7 pm87 °F88.1 · 4 pm5:30–7:00Noon2 pm4 pm6 pm7 pm

Thursday's outlook for Practice Field B reaches 88.1 °F WBGT at 4:00 pm and stays above 87 until 5:20. Your GHSA policy caps practice at two hours in that band, so the 5:30–7:00 pm slot keeps the full session.

  • Action · Google Calendar: practice moved to 5:30
  • SMS · 2 trainers
  • Source · cell 3391 · 12:02 run
  • Confirmed by the AD before the change

State policy · GHSA and its siblings

Which state heat policy applies to you?

Flash ships the GHSA activity bands at 82, 87, 90 and 92 °F WBGT by default and lets you set your own state’s or district’s thresholds per field. Georgia’s policy is written up in full; the sibling pages follow the same format.

Empty aluminium bleachers beside a high school running track under a hazy late-summer sky, the venues state heat policies govern

Your state sets the bands. Flash ships them.

Georgia · GHSA

  1. 82 °Fthree 4-minute breaks per hour
  2. 87 °F2 h max, four breaks
  3. 90 °F1 h max, no pads
  4. 92 °Fno outdoor workouts
Read the Georgia policy
GAFLNCSCAL

Specifications · One set of numbers

What exactly does the heat model deliver?

The same figures appear on the pricing page and in the order form. Scoring method for every parameter: accuracy method.

ForecastValue
Forecast intervalHourly
ParametersWBGT, heat index, air temperature, dew point, per field
Resolution1×1 km grid cells
Inputs30+ integrated data signals, the same engine and run as the lightning and hail products
Policy bandsGHSA 82 / 87 / 90 / 92 °F by default; custom thresholds per field
DeliveryValue
ChannelsApp, SMS, email, Command Center, API and webhooks, Skye
SkyeAsk in plain language; the agent calls the same API and acts in your tools Skye
HardwareNone. Runs beside any WBGT meter you already own
CoverageContinental U.S.
Decision logSensor reading and forecast side by side, timestamped, with who made the call
ScoringScored against ground truth; method and figures on the accuracy page, never quoted unqualified Accuracy method

FAQ

What do athletic directors ask before they switch?

The four questions that come up on every heat demo, answered with the same numbers as the spec table above.

No. GHSA requires the reading from a scientifically approved WBGT instrument at the practice site, and other states set their own method; that reading stays your compliance record. Flash plans beside it: it tells you at noon what the meter will read at 4 pm, per field, so the decision is made before the band changes.

Hourly bands through the day and a five-day outlook, on the same 1×1 km cell as your lightning alerts, modeled on your own fields rather than the nearest airport. Set your thresholds per field and the forecast shows when each one will be crossed.

The GHSA bands at 82, 87, 90 and 92 °F by default. Set your own state's or district's thresholds per field and the outlook, the alerts and Skye all use them.

Only through Skye, and only after a person confirms. The agent proposes the new slot, shows the cell and the run it read, and writes to your calendar when you say yes. Every change is logged.

Book a demo · No sensors required for the forecast

See your own sites on the map before the next storm.

We'll load your locations, replay last season's strikes against Flash's predictions, and show you the alert log your safety officer would have received.