Frequently Asked Questions

Some of the things we're most commonly asked about the Maryland Mesonet project, along with some information we think it's important to share!  Feel free to browse all the questions, or select from one of the general topic sections in the dropdown menu below:

What does "mesoscale" mean?

In meteorology, "mesoscale" refers to weather events ranging from 1 to 150 miles in size. These mesoscale events last anywhere from several minutes to several hours. Thunderstorms, wind gusts, derechos, heat bursts, refreezing, frontal boundaries, and the inside structures of tropical cyclones are all examples of mesoscale weather events.

So a "mesonet" is...?

...a network of automated weather stations built specifically to detect and monitor those mesoscale events, yes! "Mesocale" + "Network" = "Mesonet"

Our mesonet will be made of a set of high quality, closely spaced (~10 miles apart) weather monitoring stations and data collection systems that take samples rapidly (about once every second!) across the state to give a detailed, granular picture of events in real time. This data can then help improve lead time on weather alerts and advance emergency preparedness.

How many mesonets are there in the U.S.?

The country currently has 28 other mesonets! They're especially common in Midwest and Great Plains states, serving as tools for helping predict severe weather in "Tornado Alley."

The National Mesonet Program can be reached via its website ( )

Who are the partners involved in developing our mesonet?

The Maryland Mesonet is a partnership project between the University of Maryland College Park, the Maryland Department of Emergency Management, and the Maryland Environmental Service.

What is the goal of the Maryland Mesonet?

The Maryland Mesonet aims to develop and operate a world-class atmospheric monitoring system to
deliver reliable, timely information to residents and enhance critical public safety decision-making. By doing that, our broader goal is to improve the state's emergency preparedness by improving the regional weather forecast and increasing the lead time for emergency weather preparation.

Example:  If we expect a heavy rainfall event, and we're concerned about potential flooding, we can check our hydrologic sensors in these towers. If they tell us the soil is already saturated and not likely to absorb much more water, then the Maryland Department of Emergency Management can issue a flood alert much more quickly than they could without such precise information.

Why is the Maryland Mesonet so important?

Our mesonet is important because it lets us see and predict better, which helps keep Marylanders safe - especially those in small communities that national or regional forecasts might not be able to see in detail.

Since 1990, Maryland's experienced 25 federally declared disasters, with an average cost of $19M per event - and 88% of Maryland's counties have seen 10 or more disasters declared. Many of these disasters have come with very little notice and caused significant loss of life and livelihood in small communities across the state. Some examples you might remember include:
  • The 1998 Frostburg tornado
  • The 2001 tornado outbreak
  • The 2002 LaPlata tornado
  • The 2012 derecho
  • The 2016 + 2018 Ellicott City floods
One reason many of these events are hard to detect or predict well in advance is simply due to gaps in the federal observing system, but an even more central challenge to local forecasting is Maryland's own diverse geography.

In Western Maryland, deep valleys and high terrain alternate to produce numerous micro-climates, each potentially different from the broader regional picture (think: trapping cold air in the winter and creating freezing fog in a specific valley). The mid-Maryland urban corridor between US Route 15 and Interstate 95 has some of the densest population on the east coast, meaning that a shift in a forecasted event's path of just five miles can affect up to 2 million residents. Southern and Eastern Maryland together possess thousands of miles of coastline and numerous small towns, all uniquely at risk of tidal flooding and storm surge.

Having our own network of local monitoring sites giving rapid data on all of these different locations will make it substantially easier to both stay aware of these many regional weather situations and to give more accurate predictions (and better, more customized warnings) to each.

Plus, having a repository of real-time and archived statewide weather information at this level of detail has its own obvious benefits for scientific and research purposes. Based on the examples of other mesonets across the U.S., we can expect it to help us learn more about Maryland's weather patterns, geographic influences (e.g., "What effect does the Bay have?"), and surface weather...and thereby improve our overall meteorological forecasting, agricultural productivity, engineering and climate research, social and behavioral science projects, and more.

What benefits are going to come from the project?

Better and more frequent data from the Maryland Mesonet can help weather forecasters with...
  • Detecting fine-scale meteorological phenomena that might otherwise fall into the gaps of the current observing system
  • Creating a more comprehensive and accurate picture of atmospheric conditions, which is essential for reliable forecasting
  • Monitoring community-level weather conditions in nearly real-time
  • Improving situational awareness during rapidly changing weather conditions
  • Supporting decision making for local officials (e.g., public health, school closings, etc.)
  • Reducing delays in the production of National Weather Service alerts (e.g, watches, warnings, advisories, etc.) and briefings
  • Quantifying the impacts that natural hazards can have/have had on critical infrastructure
  • Enhancing public safety planning and identifying long-term community risks
  • Better informing requests for Presidential Disaster Declarations
  • Enhancing their tracking of climate, drought, air quality, fire weather, and other conditions
  • Providing an accurate "ground truth," especially in coastal and rural environments

How will specific sectors benefit from having a mesonet?

A few examples include...
  • AGRICULTURE:  Better monitoring of precipitation, soil moisture depth profiles leading to more efficient planting
  • EDUCATION: Real-time data access in schools/colleges leading to more STEM subject interest, options for studying and projects
  • UTILITIES: More precise data on local temperature, wind chill, humidity, etc. leading to more efficient resource allocation
  • GREEN ENERGY: Better solar radiation and wind speed/direction data allowing optimal siting of solar, wind power generation
  • ENVIRONMENT: Better meteorological data and air quality models leading to better informed assessments and decisions regarding environmental policy
  • TRANSPORTATION: Granular precipitation, temperature, and wind data allowing better decisions of road closures, public transit routing, etc. for safety 
  • TOURISM: More frequent and detailed weather data leading to more informed building, timing, promotional decisions for Maryland tourist destinations and events

What are the components of the mesonet stations?

Each station will consist of a 30ft (~10m) tower equipped with sensors to measure wind speed and direction, solar radiation, air temperature, relative humidity, air pressure, snow depth, rainfall totals, soil moisture levels, and soil temperature at several points within the upper 1m soil layer.

What kind of specific measurements will those be used for?

The following will all be collected in real time:
  • Wind speed + direction
  • Air temperature
  • Relative humidity
  • Barometric pressure
  • Solar radiation
  • Snow depth
  • Rainfall intensity + amount
  • Soil moisture + temperature
In turn, these measurements will be used to direct other quantities, such as roadway conditions, agricultural values, heat index, wind chill, and dew points...along with summary data (maximums, minimums, ranges, averages, daily totals, long-term trends, etc.) about all of the above.

The above-ground measurements will be sampled every one second, except for air pressure (sampled every 12 seconds) and rainfall or snow depth (sampled only when the relevant events are happening). These data points will be averaged and reported every minute.

The below-ground measurements will be sampled every 3 to 1800 seconds, then averaged and reported every 5 to 30 minutes.

All of this data is transferred wirelessly to a central server, where it can then be displayed on the web in a user-friendly format with visualizations, maps, charts, and archives - as well as disseminated to stakeholders like fire departments, farmers, emergency managers, etc. It will also be shared with the National Weather Service for weather model ingestion, verification, and early detection and warning uses.

How will the data collection actually happen?

The National Weather Service operates a system called the Meteorological Assimilation Data Ingest System ( MADIS ), which is designed to ingest and compile a large amount of non-federal data from myriad contributors across the states and private sector. The Maryland Mesonet data will also be collected via MADIS.

Once collected, it'll go downstream into forecast and warning systems, then out to our forecasters in the field, other forecasters and users, data analytics tools, and the broader weather enterprise.

How will the data improve regional forecasting?

By increasing the amount of data points (via the many site locations spread across the state), the geographical coverage, and the speed at which they report their measurements, we can help create a picture of the weather environment that has fewer blind spots and refreshes more often. That means we can catch more fine-scale events as they happen, better predict when they're likely to happen, and get more accurate information to those dealing with them when they do.

Is the data going to be publicly available, as well?

Yes! As stations are constructed and come online, all of the data they feed into the mesonet will be made available via the Maryland Mesonet website.

How many mesonet weather stations will be installed?

We currently plan to have at least three weather stations in each Maryland county. In fact, we've already started selecting our first sites!

The site selection process is happening in two phases:

First is an initial build-out of 28 sites (at least one per county) pre-selected based on finding the regions in each county with a history of extreme total daily precipitation that frequently exceeds 2+ inches/day.

Second is a step-by-step expansion, in which we'll select locations for the remaining stations based on modeling analysis.

If all goes smoothly, the first phase (deploying the initial 28 stations) is expected to be complete by the end of Summer 2024.

What are the conditions for a station site that can be considered representative of the local area?

It's important to locate the stations at sites that are representative of the mesoscale environment and to minimize the influence of any potential sources of mesoscale bias. To do that, we need our sites to meet the following conditions:

FOOTPRINT: The site should be a flat, natural surface at least 33 square feet large (~10 square meters). Surrounding vegetation and structures need to be a distance from the tower that is at least 10 times their height (e.g., a 30-foot tree must be 300 feet away).

THINGS TO AVOID: The site must avoid large 1) industrial heat sources (e.g., rooftops, railways) or any place that produces heat (e.g., asphalt, stone, concrete coverings), 2) steep slopes or sheltered hollows, 3) high vegetation or forests, 4) shaded or irrigated areas, 5) swamps or other large bodies of water (or low places that can hold standing water after rainfall), and 6) areas where snowdrifts can occur.

THIS IS A MUST: Good site locations need to also have a natural plant cover (e.g., grass, weeds, etc.), have uniform and low-growing vegetation (to help avoid either extremely bare soil, fast growing vegetation nearby, or rapid swaps between the two), and be available for visits by technicians, students, and authorities throughout the year.