FAQs

Worldwide Meteorological Data

MET DATA PRICING

Frequently Asked Questions

1. Why should I use data from meteorological models like WRF & MM5?
There are several reasons why you should consider purchasing prognostic meteorological model data:

- There are no met stations available in your area
- There is no other representative met station site available for your site
- The available station data is out of date
- The available station data does not have a sufficient number of years
- The available station data does not meet data quality standards (e.g. poor treatment of calms)
2. What is the difference between WRF and MM5?
WRF and MM5 are both mesoscale meteorological models. Both models are still in use today however, WRF was developed as an evolutionary successor to the MM5 model and incorporates current state-of-the-science atmospheric physics improvements. Check with your regulatory agency to verify which model they prefer.
3. How is WRF or MM5 data different from station data with regards to low wind conditions?
The majority of meteorological data is collected from airport met stations. An airports primary concern is high wind speeds which may affect aircraft. Therefore, low wind speeds are often not recorded with sufficient accuracy for air dispersion modeling purposes. This is of particular concern for air dispersion modeling because low wind speeds often result in higher concentrations. The WRF and MM5 models avoid this issue as all wind speeds are calculated with equal accuracy.
4. What is the period of met data provided?
Lakes Environmental can provide one or multiple years of WRF- or MM5-processed met data, depending on what your requirements are. The most common period requested for regulatory purposes is five consecutive years of meteorological data. For information on the years available for each type of data, please visit our met services overview page.
5. What information is needed for placing an order for meteorological data?
When requesting a quote, the following information should be provided regarding the requested location:

- Latitude and longitude for the center point of your site
- City name and country name
- Time zone
- Time period required

Please visit our met data order page for further information.
6. What are the fees for an order?
Lakes Environmental offers highly competitive pricing for our meteorological data products. Simply fill out our quotation request form on our met data order page to receive a quotation.
7. How long will it take to get my order?
This will depend on the number of orders we are currently processing, and the period the WRF or MM5 data is to cover. Most orders can be completed in 1 to 3 business days. We can provide you with an estimated delivery date at time of order.
8. What is the anemometer height/reference height of the surface station?
The anemometer height is calculated by our Certified Consulting Meteorologist when processing the data. You will be provided with the anemometer height once your data is complete.
9. How do WRF or MM5 produce the wind field?
The data that we provide to our clients uses meteorological data provided by a vast global network of meteorological stations and satellite data which have been reanalyzed and gridded into a format suitable for input to the meteorological model. They then use state-of-the-science atmospheric physics conservation equations to calculate how the wind field would behave in between grid cells. Many additional factors are accounted for in the models including terrain and land use as they also influence the wind field for a given location.
10. What boundary conditions are used to generate the wind fields in WRF or MM5?
WRF and MM5 use 1km by 1km gridded land use to estimate surface properties (surface boundary conditions). It also uses the pre-processed wind field for the global weather simulations to obtain the initial time boundary condition at t=0 and at other times as well.

FAQs for CALMET-Ready and CALPUFF-Ready Data

1. What is the difference on wind fields provided by WRF/MM5 and CALMET?
Meteorological models including WRF and MM5 use state-of-the-science atmospheric physics conservation equations and account for more refined parameterizations for processes that cannot be simulated directly. For these reasons WRF and MM5 are classified as prognostic models. CALMET uses a simple mass conservation approach and does not solve the momentum, energy, or moisture conservation equations used by MM5 and WRF. CALMET is classified as a diagnostic model.
2. What is the difference between the CALMET-Ready and CALPUFF-Ready products?
Our CALMET-Ready data products are the output of the CALWRF and CALMM5 models which format prognostic model output for use in the CALMET diagnostic model. The user is then required to run CALMET in order to produce meteorological data for input to the CALPUFF model.

Our CALPUFF-Ready data has been processed using the USEPA’s Mesoscale Model Interface Program (MMIF) to produce data which can be directly input to CALPUFF thus bypassing CALMET entirely.

FAQs for AERMET/AERMOD-Ready Data

1. How are data extracted from MM5 or WRF?
The project location coordinates provided by the customer are used as the center point to define the modeling domain for WRF or MM5. The model is executed using a 12km or 4km grid cell domain depending on which option you specify during ordering, and data are extracted for the single grid cell containing the requested coordinate. Since output from the models represent grid cell averages, data from the extracted cell is representative of any point within the bounded grid cell.

FAQs for AERMOD-Ready Station Data (USA)

1. What versions of AERMET, AERSURFACE, and AERMINUTE are used?
Our system uses the latest releases of all preprocessors made available by the USEPA.
2. What happens if the selected surface station does not have ASOS wind data?
AERMINUTE can only be run for Automated Surface Observing System (ASOS) stations where 1-minute and 5-minute wind data are available. If the user-selected station is not an ASOS station, AERMINUTE is bypassed.
3. How are input parameters for AERSURFACE determined?
Our team of expert meteorologists (including a Certified Consulting Meteorologist certified by the American Meteorological Society) rely on experience and regulatory knowledge to select defensible values for surface moisture condition, snow cover, and additional model options. We also use data from the National Centers for Environmental Information (formerly NCDC) to support our decisions.
4. The regulatory agency requested all of the input files used to create the .SFC and .PFL files. Can you provide these?
Yes! Send us an email with your order number and we will send you the data required by your regulatory agency.
5. Will my order follow the specific guidelines of the local / state / regional regulatory authority that will review the data?
Because guidelines on how meteorological data are to be processed are many and have subtle variations, it is the customer’s responsibility to make our team aware of any specific requests for your order. When filling out the quote request, customers can include such information in the Additional Comments section before submittal. Our meteorologists will then review these comments and fulfill your order as requested.