Introduction

In this document I will explore how to create the first part of the evaluation system I proposed. The working title of this is the “Forecast-Hour Evaluation.” The idea here is that we are looking at the performance of the model by looking at how it performed with different start times (using the most recent 00-hr forecast as input).

Read Model and Observation Data

Read WRF Data

For this evaluation system we need to look at three different output folders. Here we use the folders named, forecast_day_minus_0, forecast_day_minus_1, forecast_day_minus_2. The contents of each of these folders will be similar: wrfout files for 86 forecast hours and time-series data for different locations of interest. Here we will first read the forecast data.

Read the OBS Data

Now we will read the observation data from the ASOS stations. The script that downloads the data is in ./obs_station_day_minus_0/dl_ny_asos.py. The lines for the dates to download need to be changed before running it. Once the files are download, the lines below reads the data and adds column names.

## Note: Using an external vector in selections is ambiguous.
## ℹ Use `all_of(select_columns)` instead of `select_columns` to silence this message.
## ℹ See <https://tidyselect.r-lib.org/reference/faq-external-vector.html>.
## This message is displayed once per session.

Unit Conversion

Model and observation data do not share the same units for the same variable. For temperature, WRF is in Kelvin and ASOS is in degreesF. For winds, WRF is in m/s and ASOS is in knots. The formulas used to convert the numbers to a common system is shown here. For temperature I will use Kelvin, and m/s for wind speeds.

Combined Data Frames

Now we have one data frame for all the observations, and three (3) data frames of the WRF data (one data frame per forecast init time). The lines below provide a visual of the data frames.

##             Date.Time year mon day hour min     sec Temperature Mixing.Ratio
## 90 2020-03-02 00:00:05 2020   3   2    0   0  5.0004    278.6126      0.00272
## 2 2020-03-02 00:00:10 2020   3   2    0   0 10.0008    278.6269      0.00272
## 3 2020-03-02 00:00:15 2020   3   2    0   0 15.0012    278.6368      0.00272
## 4 2020-03-02 00:00:20 2020   3   2    0   0 20.0016    278.6466      0.00272
## 5 2020-03-02 00:00:24 2020   3   2    0   0 24.9984    278.6567      0.00273
## 6 2020-03-02 00:00:29 2020   3   2    0   0 29.9988    278.6671      0.00273
##    U_WIND   V_WIND Wind.Speed Wind.Direction Station
## 1 2.20330 -0.56591   2.274815       284.4048     JFK
## 2 2.19619 -0.56805   2.268465       284.5019     JFK
## 3 2.17427 -0.55716   2.244522       284.3729     JFK
## 4 2.15956 -0.55426   2.229552       284.3945     JFK
## 5 2.14220 -0.55204   2.212186       284.4506     JFK
## 6 2.12870 -0.54625   2.197670       284.3922     JFK
##             Date.Time year mon day hour min     sec Temperature Mixing.Ratio
## 1 2020-03-01 00:00:05 2020   3   1    0   0  5.0004    271.9813       0.0017
## 2 2020-03-01 00:00:10 2020   3   1    0   0 10.0008    272.0778       0.0017
## 3 2020-03-01 00:00:15 2020   3   1    0   0 15.0012    272.1663       0.0017
## 4 2020-03-01 00:00:20 2020   3   1    0   0 20.0016    272.2466       0.0017
## 5 2020-03-01 00:00:24 2020   3   1    0   0 24.9984    272.3199       0.0017
## 6 2020-03-01 00:00:29 2020   3   1    0   0 29.9988    272.3868       0.0017
##    U_WIND   V_WIND Wind.Speed Wind.Direction Station
## 1 4.56979 -4.92495   6.718490       317.1422     JFK
## 2 4.45795 -4.72146   6.493497       316.6443     JFK
## 3 4.37077 -4.55255   6.311049       316.1670     JFK
## 4 4.28755 -4.42281   6.159897       315.8897     JFK
## 5 4.21225 -4.31989   6.033614       315.7228     JFK
## 6 4.14124 -4.22575   5.916657       315.5787     JFK
##             Date.Time year mon day hour min     sec Temperature Mixing.Ratio
## 1 2020-02-29 00:00:05 2020   2  29    0   0  5.0004    274.9658      0.00217
## 2 2020-02-29 00:00:10 2020   2  29    0   0 10.0008    275.0897      0.00217
## 3 2020-02-29 00:00:15 2020   2  29    0   0 15.0012    275.1934      0.00217
## 4 2020-02-29 00:00:20 2020   2  29    0   0 20.0016    275.2825      0.00216
## 5 2020-02-29 00:00:24 2020   2  29    0   0 24.9984    275.3604      0.00216
## 6 2020-02-29 00:00:29 2020   2  29    0   0 29.9988    275.4306      0.00216
##     U_WIND   V_WIND Wind.Speed Wind.Direction Station
## 1 10.80950 -0.60489  10.826411       273.2029     JFK
## 2 10.30843 -0.60953  10.326435       273.3839     JFK
## 3  9.95932 -0.60359   9.977594       273.4682     JFK
## 4  9.67320 -0.60363   9.692016       273.5708     JFK
## 5  9.40746 -0.60228   9.426720       273.6632     JFK
## 6  9.17261 -0.59789   9.192075       273.7294     JFK
##   Station           Date.Time Temperature Relative.Humidity Wind.Direction
## 1     JFK 2020-03-01 00:00:00         NaN               NaN            320
## 2     JFK 2020-03-01 00:05:00         NaN               NaN            320
## 3     JFK 2020-03-01 00:10:00         NaN               NaN            320
## 4     JFK 2020-03-01 00:15:00         NaN               NaN            NaN
## 5     JFK 2020-03-01 00:20:00         NaN               NaN            310
## 6     JFK 2020-03-01 00:25:00         NaN               NaN            320
##   Wind.Speed year mon day hour min sec
## 1   9.259259 2020   3   1    0   0   0
## 2   8.230453 2020   3   1    0   5   0
## 3   9.773663 2020   3   1    0  10   0
## 4  10.288066 2020   3   1    0  15   0
## 5   8.230453 2020   3   1    0  20   0
## 6  10.288066 2020   3   1    0  25   0

Locations for Plots

Match Times for Model and Observations

Select Day of Interest

Time-matching is performed using a routine that can be found in Analysis01-Time_Matching_Problem.Rmd. The time matching will be done per variable. For the Forecast-Hour Evaluation product, we will focus on the temperature, wind speed and wind direction variables. Also, now that we have read all the TS data and ASOS data, we need to extract the day of interest, or doi for the time-series.

Note that for this product the “day of interest” will always be the UTC date of the day before.

We now have filtered data frames for the observations and model data for the day of interest.

Next, we will select only the temperature data for comparing the model and observations. This needs to be done on a per station basis. Note that we use the function drop_na() to drop rows which contain NaN or NA data. Since each variable is measured at different intervals, not all variables will have data available at every time step in the ASOS data. The functions may be too sensitive to missing data and thus we take care to remvove it here from the observations, after we have isolated a particular variable.

Temperature Time-Matching

Location: JFK

Location: LGA

Location: NYC

Wind Speed Time-Matching

Location: JFK

Location: LGA

Location: NYC

Wind Direction Time-Matching

Location: JFK

Location: LGA

Location: NYC

Forecast Hour Evaluation for JFK

For the temperature data I will use Bias, RMSE and MAE for the comparison statistics

JFK - WRF 2-m Temperature (K) Performance
Forecast.Init BIAS RMSE MAE
1 WRF D-0 0.325 1.273 0.935
2 WRF D-1 -0.413 0.944 0.783
3 WRF D-2 -7.730 7.958 7.730
JFK - WRF 10-m Wind Speed (m/s) Performance
Forecast.Init BIAS RMSE MAE
1 WRF D-0 -2.869 3.429 2.909
2 WRF D-1 -2.903 3.467 2.986
3 WRF D-2 -2.206 3.944 2.767
JFK - WRF 10-m Wind Direction (degN) Performance
Forecast.Init RMSE MAE
1 WRF D-0 26.299 18.556
2 WRF D-1 61.804 38.299
3 WRF D-2 106.622 103.003

Forecast Hour Evaluation for LGA

LGA - WRF 2-m Temperature (K) Performance
Forecast.Init BIAS RMSE MAE
1 WRF D-0 0.430 1.018 0.822
2 WRF D-1 -0.918 1.398 1.219
3 WRF D-2 -9.322 9.438 9.322
LGA - WRF 10-m Wind Speed (m/s) Performance
Forecast.Init BIAS RMSE MAE
1 WRF D-0 -2.355 2.567 2.379
2 WRF D-1 -2.368 2.612 2.385
3 WRF D-2 -1.774 2.322 1.891
LGA - WRF 10-m Wind Direction (degN) Performance
Forecast.Init RMSE MAE
1 WRF D-0 35.078 28.444
2 WRF D-1 56.790 37.865
3 WRF D-2 112.199 107.557

Forecast Hour Evaluation for NYC

NYC - WRF 2-m Temperature (K) Performance
Forecast.Init BIAS RMSE MAE
1 WRF D-0 0.468 1.209 0.894
2 WRF D-1 -0.675 1.328 1.071
3 WRF D-2 -9.641 9.706 9.641
NYC - WRF 10-m Wind Speed (m/s) Performance
Forecast.Init BIAS RMSE MAE
1 WRF D-0 -1.820 2.272 1.990
2 WRF D-1 -1.809 2.260 1.953
3 WRF D-2 -1.748 2.231 1.970
NYC - WRF 10-m Wind Direction (degN) Performance
Forecast.Init RMSE MAE
1 WRF D-0 66.413 53.435
2 WRF D-1 58.055 49.541
3 WRF D-2 111.906 101.054

uWRF and ASOS Time-Series Visualization

Temperature

## Warning: Removed 41 rows containing missing values (geom_point).
## Warning: Removed 13 rows containing missing values (geom_path).

Wind Speed

Wind Direction