Atm Sci 690 Weather Discussion –Forecasting Guidelines

The purpose of this page is to present some guidelines for making a good short-term (24 hour) weather briefing. Essentially, there are three important questions that need to be considered in making a briefing: (1) What are the important weather features over the time period and area of interest (content)? (2) Who is my audience and what information do they need to make decisions? (3) How can I effectively (Credibility) deliver the information (presentation)?

Making a forecast

Step 1: Examine the available observations and forecasts with an eye toward the “big” picture. Start specifically with national observations, national surface maps, current radar loops, satellite loops and initialized model charts. It’s important for you to have a solid understanding of what is happening right now. Why is it raining right now? Why is it sunny right now? Why is it hot right now?

Step 2: Especially in this class, apply your understanding of meteorological theory and begin making some projections as to what may happen in the next 12 hours. Based on your evaluation of current conditions and your understanding of the laws that govern vertical motion, you should be able to make some assumptions as to what might happen to the weather features in the short term.

Step 3: Begin interrogating the various models. Make sure you don’t just look at one model, but use a number of models to form a consensus of the overall larger scale evolution of the atmosphere. After looking at the observations from across the country and making some assumptions based on theory, you should be able to get a sense for where the models may be in error or may be in good consensus.

Step 4:Make your forecast! Once you have a “feel” for the model strengths and weaknesses, look at the forecast area details. What weather variables are you forecasting? Are there topographic effects or lake effects that may cause some uncertainties? What does model uncertainty mean for your forecast in this area? You need to now put your evaluation of the atmosphere and possible future events, into concrete form for a client. Make your forecast and be ready to answer questions to any uncertainties that may exist.

Step 5: Learn from the results. Whether it is a failed forecast or a great forecast, always pay close attention to how your forecast verified the following day. If you do not look to see what happened and how your forecast fared, you will never become a great forecaster. Shake off the missed forecasts, but always make sure you have a long memory when it comes to your forecast verification. In time you will see things in the model that you know bust in real life (ex. strong SW wind in spring and summer for the plains). That will give you Confidence in your future forecasting.

Atm Sci 690 Weather Discussion –Briefing Guidelines

Consider content first.

Step 1: Examine the national observations and forecast data with an eye towards the “big” picture. What isgoing on now and during the forecast period at the synoptic scale (say, areas the size of half the United States) that might affect my forecast site? In other words, you need to identify the weather feature that will govern the forecast (e.g. a low pressure system with a cold front that may move through the area; an anticyclone bringing clear skies and light winds, enhancing diurnal radiative effects, etc.)?

Step 2: Identify the important questions regarding that weather feature (e.g. how fast is the low/front moving; is it rapidly evolving; how consistent are the forecast models in handling the evolution of the system; how well do the forecasts agree with the observations so far, etc.)? Given that uncertainty is always a feature of weather forecasts, understanding the sources of that uncertainty is at least as important as the forecast itself. Clients spending thousands of dollars need to evaluate risk and uncertainty. Knowing that source of uncertainty will help you share information that is helpful to your client.

Step 3: Are there local features that might have an important role through interaction with the synoptic scale weather feature (e.g. land/water boundaries affecting the flow of air and associated temperatures; local topographic features – mountains/valleys/hills that might trap or funnel air, etc.)?

Next, consider presentation.

Step 1: Organize your “delivery” around the governing weather feature. For example if conditions have been fair due to the presence of an anticyclone, but a low pressure system is developing upstream and will replace it during the forecast period, talk about the current conditions that resulted from the anticyclone and segue into the transition associated with the approaching cyclone.

Step 2:Briefer #1 will take responsibility for the current state of the atmosphere including an evaluation of current national conditions as well as conditions in the forecast area. Briefer #2 will take responsibility for delivering the forecast portion of the briefing. So briefer #1 should pay some attention to what is upstream, what the uncertainties might be and how that may affect the forecast. Briefer #2 should then relate the current conditions to the forecasts: for example, how are the models handling the present situation (or how have they been handling it) You will want to incorporate some of the methods from the “Forecast guidelines” into this presentation.

Step 3: Both briefers need to identify the visual materials that you will use in your briefing presentation. The particular combination of internet materials will vary greatly, depending on the particular forecast situation, data availability and particular client you are forecasting. Make sure that you have alternate sources of information – this means that you MUST KNOW WHERE TO FIND THE INFORMATION THAT YOU NEED.

Step 4: Talk about the “HOW” and the “WHY” as well as the “WHAT”. For example, because the low is approaching but heading north of the forecast site, the winds will be changing from light to east/southeast and then south, bringing in warm, moist air to the region. Physically, why is the low heading north? How might that change? Because of the track, what is the expected weather?

Step 5: Talk to your audience (class). Project your voice. If you have given yourselves sufficient time for preparation, you should be confident in what you have to say. You must know WHOM you are talking too. Remember that the technical briefing will be geared to a professor. Make sure you back up your statements with solid meteorological thoughts and theory. When you deliver your forecast, remember that you are talking to a client that is very interested in what you have to say. Speak with confidence, but be ready to share uncertainties in the forecast that can affect the profitability of the clients operation. Remember that is why they are paying you; to help them make the best economic decision possible.

Note:If the two briefers have not worked together on their briefing it will be very easy to see. If you have not afforded yourself time to go through the forecast process, it will easily show. For new meteorologists confidence is s something that comes with experience. However, regardless of experience, confidence will come from being well versed in the current and forecast situation and the kind of information/data that you are to present. Give yourself the time to do the briefings well.