Aviation API
29 MSL Prognosis Chart with Relative Humidity
The mean sea level (MSL) and relative humidity (RH) charts are generated from UKMO model data (17 km resolution).
The model runs occur twice per day at 00Z and 12Z.
These charts provide a 2 day forecast and are available in 6-hourly timesteps out to H+72 and 12-hourly timesteps from H+72 out to H+120.
In addition to displaying mean sea level, areas of relative humidity at surface level are also shown. The areas shown are those where RH is above 80% (the data displayed is classified as 80, 97 or 100%).
29.1 Latest Prognosis set for a Location
Request the latest set of prognosis charts for the specified region. At this time the only region accepted is nz-spac (New Zealand and South Pacific area).
29.1.1 API Call:
GET /aviation/v2/chart/msl/prognosis/{region}/rh/latest29.1.2 Path Parameters:
| Path Parameter | Example | Description |
|---|---|---|
| Region | nz-spac | A supported region code. The region code must be lowercase. This parameter is Mandatory. |
29.1.3 Example:
This example would return the latest set of prognosis charts. 6 hourly from 00 through to 72 and then 12 hourly out to 120 hours.
GET /aviation/v2/chart/msl/prognosis/nz-spac/rh/latest29.1.4 API Response:
{
"version": "1.0",
"issue-time": "2025-09-08T22:40:26Z",
"path": "/aviation/v2/chart/msl/prognosis/nz-spac/rh/latest",
"response": [
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509081200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "000",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-08T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509081800_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "006",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-08T18:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "18"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509090000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "012",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509090600_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "018",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T06:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "06"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509091200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "024",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509091800_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "030",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T18:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "18"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509100000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "036",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509100600_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "042",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T06:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "06"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509101200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "048",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509101800_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "054",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T18:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "18"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509110000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "060",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-11T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509110600_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "066",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-11T06:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "06"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509111200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "072",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-11T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509120000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "084",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-12T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509121200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "096",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-12T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509130000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "108",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-13T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509131200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "120",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-13T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
}
]
}29.2 Prognosis set for a Location for the next n hours
Request the prognosis charts for the specified region that have a valid at time which is within the next n hours specified At this time the only region accepted is nz-spac (New Zealand and South Pacific area).
29.2.1 API Call:
GET /aviation/v2/chart/msl/prognosis/{region}/rh/next/{n}/hours29.2.2 Path Parameters:
| Path Parameter | Example | Description |
|---|---|---|
| region | nz-spac | A supported region code. The region code must be lowercase. This parameter is Mandatory. |
| n | 48 | The number of hours of charts to be returned. This can be up to 120 hours. This parameter is Mandatory. |
29.2.3 Example:
This example would return the prognosis charts that have a valid at time which is within [request time] -3 hours and [request time] + 48 hours.
GET /aviation/v2/chart/msl/prognosis/nz-spac/rh/next/48/hours29.2.4 API Response:
{
"version": "1.0",
"issue-time": "2025-09-08T22:44:50Z",
"path": "/aviation/v2/chart/msl/prognosis/nz-spac/rh/next/48/hours",
"response": [
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509090000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "012",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509090600_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "018",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T06:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "06"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509091200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "024",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509091800_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "030",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-09T18:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "18"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509100000_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "036",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T00:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "00"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509100600_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "042",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T06:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "06"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509101200_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "048",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T12:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "12"
},
{
"met:locator": "https://api.metservice.com/aviation/assets/chart/msl/nz-spac/rh/2025/09/08/12/202509081200_202509101800_202509082020.gif",
"met:analysis-time": "2025-09-08T12:00:00Z",
"met:product-name": "chart",
"met:domain": "aviation",
"met:issue-time": "2025-09-08T20:20:00Z",
"av:chart-type": "mslp-rh",
"met:prognosis-period": "054",
"av:msl-region": "nz-spac",
"met:valid-at": "2025-09-10T18:00:00Z",
"av:msl-type": "prognosis",
"met:validity": "18"
}
]
}