How NEWA Handles Weather Data

Accurate and reliable weather data are important for good farm management.

Data quality control

Quality control methods are applied to sensor data coming from the weather stations linked with NEWA using a suite of protocols. These methods ensure datasets used by NEWA crop and IPM tools are precise and accurate.

Station outage reports

The NEWA Help Desk notifies weather station owners by email when a data outage occurs. Messages are sent to station owners and maintenance contacts after outage periods of 24 hours, 7 days, and 21 days. The weather station is removed temporarily (status inactive) from the NEWA website after 21 days but is reinstated after the problem is fixed. 

Weather station status reporting

All NEWA State Coordinators receive a daily status summary of all NEWA weather stations in their state. These reports include a list of stations with their respective timestamps of last reported data. The weather stations are grouped into categories of those reporting within the last 24 hours; those with no data reported in the last 24 hours; and those that have not reported for more than 21 days (status inactive). The State Coordinator can then follow up with station owners or make referrals to the NEWA Help Desk if needed. 

Missing weather variables

Temperature and relative humidity data points occasionally are missing in a data record and NEWA attempts to estimate missing values following a two-step process.

1. The data record is examined for non-missing temperature or relative humidity values in the previous hour and the next hour. If both are found, an average of the two is used as an estimate.  
2. If the previous hour and the next hour values are unavailable, temperature or relative humidity data from the National Centers for Environmental Prediction’s Real-Time Mesoscale Analysis (RTMA) and Unrestricted Mesoscale Analysis (URMA) for the nearest location grid are used.

Precipitation and wind direction missing data are sourced from the RTMA and URMA archive.

Solar radiation missing data are estimated based on sky cover data from the RTMA and URMA archive.

Soil temperature and soil moisture measurements are location dependent and are not substituted or estimated in any scenario.

Estimated data are displayed as brown italics in the weather data listings on NEWA. Currently, no other weather variables, other than forecast data, are estimated in the NEWA weather data listings.

 

Data use in NEWA crop & IPM tools

Leaf wetness

Leaf wetness is an important measurement for some NEWA tools, but airport locations and some other weather stations do not have these sensors. For these stations, NEWA records an hour of leaf wetness when the average relative humidity in that hour is greater than 90%. 

In the NEWA tools that use leaf wetness hours, a wet hour is logged when ≥ 1 minute of sensor leaf wetness is recorded.

Relative humidity

Relative humidity (RH) data recorded at airport weather stations and those from NWS RH forecast values are usually not representative of conditions in an agricultural setting. Therefore, these RH values are adjusted using the formula: adjRH = RH / (0.0047*RH + 0.53).