Using GPT to read weather charts

andrew · 27-05-2024 8:31pm #1

Apologies if this has been done already! And for the avoidance of doubt, what I'm about to post is not automatically generated, except where indicated in the quotes.

Anyway - I thought I'd start a thread about using GPT to read weather charts. Some of you might have experience with old(ish) versions of GPT which don't really have 'vision' capabilities. But newer models - e.g. GPT4o - do have that ability, and it allows them to 'look at' and interpret all manner of images - including weather charts. Those models are now becoming generally available.

To that end I've made a 'GPT' - which is a specific instance (for want of a better word) of GPT - which has a detailed set of instructions that tell it what to do. In this case, I've told it interpret weather charts, and given it quite a long set of instructions so that it has the different kind of charts in mind, and so that it produces well structured outputs.

The outputs can be fairly long. And the instructions could probably be improved. But by way of explaining what this model can do, I gave it the following chart from the "Charts ( Up to T120 ) Spring 2024" thread. You can see the output below:

weather chart.png

The model's first response was as follows:

The uploaded image is a temperature chart for the 500 hPa level, showing temperatures in degrees Celsius. This type of chart is useful for understanding the temperature distribution at approximately 5,500 meters (18,000 feet) above sea level, which is important for analyzing mid-tropospheric weather patterns and identifying areas of rising or sinking air.
Chart Identification:
Model Used: ECMWF IFS HRES (European Centre for Medium-Range Weather Forecasts Integrated Forecasting System High Resolution)
Type of Chart: Temperature Chart at the 500 hPa level
Time Frame: The model run was from 05/23/2024 at 12:00 UTC, and the forecast is valid for 01:00 PM IST on 05/26/2024.
Chart Interpretation:
Isobars and Temperature Gradients: The chart shows isotherms (lines of equal temperature) with a color gradient indicating temperature values. The temperatures range from approximately -57°C to 9°C.
Predicted Conditions:Cold temperatures (below -40°C) are evident over parts of northern and eastern Europe, including regions like Moscow, Helsinki, and Stockholm.Milder temperatures (around -10°C to -5°C) are observed over central Europe, including areas like Berlin, Warsaw, and Prague.Warmer temperatures (above -5°C) are seen over southern Europe, particularly around the Mediterranean regions such as Spain, Italy, and Greece.
Weather Features:The temperature distribution indicates the presence of cold air masses over the north and relatively warmer air masses over the south.There is a noticeable temperature gradient across Europe, which may suggest the presence of upper-level troughs and ridges influencing the weather patterns.
Forecast:The colder regions in the north are likely experiencing high-pressure systems aloft, leading to subsidence and clearer weather.Warmer regions in the south may be under the influence of low-pressure systems or warmer air advection, which could result in more dynamic and potentially unsettled weather.
Regional Relevance:
Local Impact:For northern Europe (e.g., Scandinavia, Russia), expect cooler temperatures aloft, which could contribute to cold surface weather and possibly stable conditions.Central Europe (e.g., Germany, Poland) will experience moderate temperatures at this level, suggesting relatively normal conditions for this time of year.Southern Europe (e.g., Spain, Italy, Greece) can expect warmer temperatures aloft, which might contribute to warmer surface conditions and potentially more active weather patterns, including possible convection.
Meteorological Terms:
500 hPa Level: This pressure level is used to represent the mid-troposphere, crucial for understanding larger-scale weather patterns.
Isotherms: Lines of constant temperature, which help in identifying temperature gradients and fronts in the upper atmosphere.
If you have any specific regions or details you would like to focus on further, please let me know!

Clearly it didn't identify the cold air over Ireland. But after saying "what is the forecast 500 hpa temperature over Ireland?" I got the following response:

The forecasted 500 hPa temperature over Ireland, as depicted in the chart, is around -25°C to -20°C. The specific color gradient for Ireland falls within the light green to cyan range, indicating these temperature values. This suggests relatively cold temperatures at the mid-tropospheric level over Ireland on the forecasted date.

and when asked to provide a forecast it said

The 500 hPa temperature forecast for Ireland being around -25°C to -20°C provides several insights into the weather conditions you can expect:
Implications for the Weather Forecast:
Mid-Tropospheric Temperature:Cold Air Aloft: The temperatures at 500 hPa being significantly below freezing suggest the presence of cold air in the mid-troposphere. This typically indicates the presence of an upper-level trough or low-pressure system aloft.
Stability and Weather Conditions:Potential for Instability: Cold air aloft, when combined with relatively warmer surface temperatures, can create an unstable atmosphere. This instability can lead to the development of showers and potentially thunderstorms, especially if there is sufficient moisture.Cloud Cover and Precipitation: The presence of cold air at this level can lead to increased cloud cover and precipitation. The specific type of precipitation (rain, sleet, or snow) would depend on the surface temperatures and the thermal profile of the lower atmosphere.
Surface Weather Impact:Cooler Surface Temperatures: The cold temperatures at 500 hPa can also have a cooling effect on the surface temperatures. This is particularly true if the cold air is accompanied by a high-pressure system at the surface, which can lead to clear skies and radiational cooling at night.Possible Windy Conditions: If an upper-level low or trough is present, it can lead to windy conditions at the surface as the atmosphere tries to balance out the pressure differences.
General Forecast for Ireland:Cool and Unsettled Weather: Expect cool and possibly unsettled weather conditions. There might be periods of showers, and given the cold air aloft, some of these could be heavy or thundery.Clear Nights with Frost Potential: If there are clear skies, especially at night, the cooling effect can lead to frost formation, particularly in rural and sheltered areas.
Summary:
The forecast of -25°C to -20°C at the 500 hPa level over Ireland suggests the potential for cooler, unstable weather with a likelihood of showers and possibly thunderstorms. Surface temperatures may be cooler than average, and windy conditions could be expected if associated with an upper-level trough or low-pressure system.

Anyway - keen to know what people think. If not this particular instance (which you can play with here if you have a paid subscription) then I'd be interested to know what people think of the potential of this kind of tool. It seems like there's a lot of generalist models out there which can perform well as specialists, once they're prompted well enough. Maybe helping weather forecasters is one of those areas.

Meteorite58 · 27-05-2024 9:25pm

I have no experience with GPT but find it interesting, don't know how useful it could be say if put up against the ECMWF. Can you give it a number of charts, different parameters all at once to get a forecast.

andrew · 27-05-2024 9:45pm

https://www.boards.ie/discussion/comment/122191406#Comment_122191406

Happy to give that a shot. I don't have the expertise to put together a sensible set of charts and parameters but if you have some in mind (or know where I'd find that information) happy to throw 'em in.

I haven't really tried asking it to synthesise a view from several charts. I suspect that would be a challenge, as it does a better job synthesizing quantitative data. In terms of comparing its output to an actual model, like ECMWF, my sense is that since GPT's output is more qualitative it might be hard to compare the two. But one can always ask it to!

Supercell · 28-05-2024 10:09am

I uploaded the same image to Google Gemini and got the following disappointing response, maybe my prompting could be better :

No, you cannot get a forecast for Ireland at ground level from the image. The image is a temperature map for Europe at high altitude. It likely shows air pressure patterns at a specific altitude, not actual temperatures on the ground.

For an accurate weather forecast, you can visit a weather website or app

adocholiday · 28-05-2024 11:12am

https://www.boards.ie/discussion/comment/122191478#Comment_122191478

This is an interesting experiment and I'm keen to see how it evolves but you're probably going to need a lot more inputs to get anything meaningful from it by way of forecasting.

Forecasting is usually based on the evolution of particular weather patterns so giving it one chart without context likely won't give much in the way of accurate forecasting. That chart you gave it only shows the forecasted temperature at 500hPa at a very specific time but how is it evolving? Is it getting cooler or hotter? What way are the air masses moving? What are the pressure gradients? The main factors that affect weather are temperature, atmospheric pressure, humidity, cloudiness, precipitation, wind speed and direction. Each one of those things in addition to other contributory factors has to be considered in making a forecast. There are sites to get all of that info from various models, I tend to use Meteologix. It can be a lot of work to extract all you need to get GPT to analyse them and summarise them all.

If it's of interest, ECMWF has made their AI powered model available for public use. You can select it on Meteologix and see it's output for those various factors above.

andrew · 29-05-2024 6:07pm

OK, I've gone ahead and asked for a forecast, using the following charts and the prompt: "Take a deep breath and think step by step. Analyse these weather charts sequentially and then produce a 3 day forecast for Ireland, taking into account the information displayed in the charts"

To produce a 3-day weather forecast for Ireland based on the provided charts, let's analyze each chart sequentially.
1. Mean Sea Level Pressure (MSLP)
Chart Description: Displays areas of high and low pressure, with isobars indicating pressure gradients.
Key Observations:A high-pressure system (1030 hPa) is situated west of Ireland.Isobars are fairly spaced around Ireland, indicating moderate pressure gradients.
2. Temperature at Surface Level
Chart Description: Shows surface temperature distribution in degrees Celsius.
Key Observations:Ireland's surface temperatures range between 12°C to 15°C.Warmer temperatures are noted towards the southeast of Europe, while cooler temperatures prevail to the northwest.
3. Wind Gusts (6h)
Chart Description: Indicates wind gust speeds over a 6-hour period in km/h.
Key Observations:Wind gusts around Ireland range from 30 to 50 km/h.Stronger gusts are noted along the western coasts of Ireland.
4. Precipitation (24h)
Chart Description: Shows accumulated precipitation over a 24-hour period in mm.
Key Observations:Light to moderate precipitation is expected across Ireland.Heavier precipitation is indicated in regions to the southeast of Ireland.
5. Temperature at 850 hPa
Chart Description: Displays temperatures at approximately 1,500 meters above sea level.
Key Observations:Temperatures at 850 hPa over Ireland range from 0°C to 6°C.Cooler air masses are noted to the northwest, with warmer air towards the south.
6. Geopotential Height at 500 hPa
Chart Description: Shows the height of the 500 hPa pressure level, indicating upper atmospheric conditions.
Key Observations:A trough is present over Ireland, indicating an area of lower geopotential height.This trough is associated with cooler temperatures and potential instability.
3-Day Weather Forecast for Ireland
Day 1: May 30, 2024
Pressure: The high-pressure system west of Ireland will bring relatively stable conditions.
Temperature: Surface temperatures between 12°C to 15°C.
Wind: Moderate gusts (30-50 km/h), particularly along the western coasts.
Precipitation: Light to moderate rain expected, especially in the western and northern parts.
Day 2: May 31, 2024
Pressure: The high-pressure system remains dominant, continuing stable conditions.
Temperature: Slight increase in temperatures, ranging from 13°C to 16°C.
Wind: Continued moderate wind gusts, potentially increasing in coastal areas.
Precipitation: Scattered light showers, with most of the country experiencing dry spells.
Day 3: June 1, 2024
Pressure: High-pressure influence starts to weaken as the trough approaches.
Temperature: Temperatures remain steady, between 12°C to 15°C.
Wind: Winds may strengthen slightly as the pressure gradient tightens.
Precipitation: Increased likelihood of rain as the trough brings more unstable air, particularly in western regions.
Summary
Ireland will experience relatively stable weather over the next three days, with high pressure dominating initially, leading to moderate temperatures, scattered showers, and moderate wind gusts. Towards the third day, expect a slight increase in precipitation due to the approaching trough.

My sense is that it's at least reading the charts correctly, insofar as it's accurately identifying temperatures and pressures etc. I'm not qualified to comment on the quality of the forecast but for reference here's Met Eireann's current forecast for May 31.

Friday: High pressure firmly in charge with settled and mainly dry weather throughout. Sunshine will turn a little hazy later in the afternoon however as a touch of cloud builds across northern counties. Highest temperatures of 16 to 20 degrees in light northerly breezes.

Some bits (high pressure system remains dominant/high pressure firmly in charge) seem similar at least!

Supercell · 30-05-2024 9:22am

https://www.boards.ie/discussion/comment/122199081#Comment_122199081

Thats really impressive, nice work!

andrew · 30-05-2024 4:40pm

As it happens as of today OpenAI have made GPTs free to people without a subscription. So the 'GPT' I used to do this is now available to anyone who'd like to mess around with it and see what it's good / bad at. It's likely to be bad at things that are adjacent to things it's also very good at!

Using GPT to read weather charts

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