import gradio as gr
import folium
from folium import plugins
import requests
from datetime import datetime, timedelta
from io import BytesIO
from PIL import Image
import base64
import numpy as np
# Domain bounds for different regions
DOMAIN_BOUNDS = {
'conus': [[24.0, -125.0], [50.0, -66.0]],
'alaska': [[51.0, -180.0], [72.0, -130.0]],
'hawaii': [[18.0, -161.0], [23.0, -154.0]],
'full': [[18.0, -180.0], [72.0, -66.0]]
}
# HRRR image bounds (approximate for composite reflectivity images)
HRRR_IMAGE_BOUNDS = {
'conus': [[20.0, -130.0], [52.0, -60.0]],
'alaska': [[48.0, -180.0], [75.0, -125.0]],
'hawaii': [[17.0, -162.0], [24.0, -153.0]]
}
def get_available_runs():
"""Generate list of recent model run times"""
runs = []
now = datetime.utcnow()
current_hour = now.replace(minute=0, second=0, microsecond=0)
for i in range(48): # Last 48 hours
run_time = current_hour - timedelta(hours=i)
runs.append(run_time.strftime("%Y-%m-%d %H:00 UTC"))
return runs
def try_fetch_hrrr_image(run_time_str, forecast_hour, domain='conus'):
"""
Try to fetch HRRR composite reflectivity image from various NOAA sources
Returns:
PIL Image object if found, None otherwise
"""
dt = datetime.strptime(run_time_str, "%Y-%m-%d %H:%M UTC")
run_str = dt.strftime("%Y%m%d%H")
# Map domain to HRRR naming
domain_map = {
'conus': 'conus',
'alaska': 'alaska',
'hawaii': 'hawaii',
'full': 'conus' # Start with conus for full view
}
hrrr_domain = domain_map.get(domain, 'conus')
# Try multiple URL patterns for HRRR composite reflectivity
url_patterns = [
# Pattern 1: Standard for_web structure
f"https://rapidrefresh.noaa.gov/hrrr/HRRR/for_web/hrrr_ncep_jet/{run_str}/{hrrr_domain}/refc_sfc_f{forecast_hour:02d}.png",
# Pattern 2: Alternative structure
f"https://rapidrefresh.noaa.gov/hrrr/HRRR/for_web/hrrr_{hrrr_domain}/{run_str}/refc_sfc_f{forecast_hour:02d}.png",
# Pattern 3: Simplified path
f"https://rapidrefresh.noaa.gov/hrrr/for_web/{run_str}/{hrrr_domain}/refc_sfc_f{forecast_hour:02d}.png",
# Pattern 4: Direct HRRR graphics
f"https://rapidrefresh.noaa.gov/hrrr/HRRR/displayMapLocalDiskDateDomainZipTZModel.cgi?keys=hrrr_ncep_jet:&runtime={run_str}&plot_type=refc&fcst={forecast_hour:02d}",
]
for url in url_patterns:
try:
response = requests.get(url, timeout=10)
if response.status_code == 200 and len(response.content) > 1000: # Valid image
img = Image.open(BytesIO(response.content))
return img, url
except:
continue
return None, None
def apply_hue_shift(image, hue_shift=0.3):
"""
Apply hue shift to image to differentiate from NEXRAD
Args:
image: PIL Image
hue_shift: Hue shift amount (0-1), 0.3 = greenish-blue tint
Returns:
PIL Image with hue shifted
"""
# Convert to RGBA if not already
if image.mode != 'RGBA':
image = image.convert('RGBA')
# Convert to numpy array
img_array = np.array(image)
# Separate RGB and alpha channels
rgb = img_array[:, :, :3].astype(float)
alpha = img_array[:, :, 3]
# Convert RGB to HSV
rgb_normalized = rgb / 255.0
# Simple hue shift by rotating RGB values
# This gives a greenish-blue tint to HRRR data
r, g, b = rgb_normalized[:,:,0], rgb_normalized[:,:,1], rgb_normalized[:,:,2]
# Apply color tint - shift toward cyan/green for HRRR
r_new = r * 0.6 + g * 0.2 + b * 0.2 # Reduce red
g_new = r * 0.1 + g * 0.8 + b * 0.1 # Enhance green
b_new = r * 0.1 + g * 0.3 + b * 0.6 # Moderate blue
# Stack and convert back
rgb_shifted = np.stack([r_new, g_new, b_new], axis=2)
rgb_shifted = np.clip(rgb_shifted * 255, 0, 255).astype(np.uint8)
# Recombine with alpha
img_shifted = np.dstack([rgb_shifted, alpha])
return Image.fromarray(img_shifted, 'RGBA')
def image_to_data_url(image):
"""Convert PIL Image to data URL for folium"""
buffered = BytesIO()
image.save(buffered, format="PNG")
img_str = base64.b64encode(buffered.getvalue()).decode()
return f"data:image/png;base64,{img_str}"
def create_legends():
"""Create HTML legends for both radar types"""
legend_html = '''
Reflectivity (dBZ)
NEXRAD
Real-time
(Standard colors)
HRRR
Forecast
(Green-blue tint)
60+ (Extreme)
50-60 (Severe)
40-50 (Heavy)
30-40 (Moderate)
25-30 (Light)
20-25
10-20 (Weak)
<10 (Trace)
'''
return legend_html
def generate_map(run_time_str, forecast_hour, domain_selection,
show_nexrad, nexrad_opacity, show_hrrr, hrrr_opacity):
"""
Generate Folium map with both NEXRAD and HRRR overlays for comparison
"""
# Set map center and zoom based on domain
domain_configs = {
'full': {'location': [45.0, -100.0], 'zoom': 3},
'conus': {'location': [39.0, -98.0], 'zoom': 4},
'alaska': {'location': [64.0, -152.0], 'zoom': 4},
'hawaii': {'location': [20.5, -157.0], 'zoom': 7}
}
config = domain_configs.get(domain_selection, domain_configs['conus'])
# Create base map
m = folium.Map(
location=config['location'],
zoom_start=config['zoom'],
tiles='CartoDB positron'
)
# Add alternative tile layers
folium.TileLayer('OpenStreetMap', name='Street Map').add_to(m)
folium.TileLayer('CartoDB dark_matter', name='Dark Map').add_to(m)
try:
dt = datetime.strptime(run_time_str, "%Y-%m-%d %H:%M UTC")
valid_time = dt + timedelta(hours=int(forecast_hour))
data_status = []
# Add HRRR forecast overlay if requested
if show_hrrr:
hrrr_img, hrrr_url = try_fetch_hrrr_image(run_time_str, int(forecast_hour), domain_selection)
if hrrr_img:
# Apply hue shift to HRRR data (greenish-blue tint)
hrrr_shifted = apply_hue_shift(hrrr_img)
hrrr_data_url = image_to_data_url(hrrr_shifted)
# Get bounds for this domain
bounds = HRRR_IMAGE_BOUNDS.get(domain_selection, HRRR_IMAGE_BOUNDS['conus'])
folium.raster_layers.ImageOverlay(
image=hrrr_data_url,
bounds=bounds,
opacity=hrrr_opacity,
name='HRRR Forecast (Green-Blue Tint)',
overlay=True,
control=True
).add_to(m)
data_status.append(f"β HRRR F{int(forecast_hour):03d} loaded")
else:
data_status.append(f"β HRRR F{int(forecast_hour):03d} not available")
# Add NEXRAD real-time radar if requested
if show_nexrad:
wms_url = 'https://mapservices.weather.noaa.gov/eventdriven/services/radar/radar_base_reflectivity/MapServer/WMSServer'
folium.raster_layers.WmsTileLayer(
url=wms_url,
layers='0',
name='NEXRAD Real-Time (Standard Colors)',
format='image/png',
transparent=True,
opacity=nexrad_opacity,
attr='NOAA',
overlay=True,
control=True
).add_to(m)
data_status.append("β NEXRAD Real-Time loaded")
# Add comparison info box
comparison_html = f"""
π Data Comparison View
Model Run: {dt.strftime("%Y-%m-%d %H:00 UTC")}
Forecast Hour: F{int(forecast_hour):03d}
Valid Time: {valid_time.strftime("%Y-%m-%d %H:00 UTC")}
Domain: {domain_selection.upper()}
Data Status:
{'
'.join(data_status) if data_status else 'No data layers selected'}
π‘ Comparison Tips:
β’ Red/Purple = NEXRAD standard colors
β’ Green/Cyan = HRRR with color shift
β’ Overlapping areas appear mixed
β’ Perfect alignment = good model performance
β’ Use opacity sliders to adjust visibility
"""
m.get_root().html.add_child(folium.Element(comparison_html))
# Add legend
m.get_root().html.add_child(folium.Element(create_legends()))
# Add domain boundary
if domain_selection in DOMAIN_BOUNDS:
bounds = DOMAIN_BOUNDS[domain_selection]
folium.Rectangle(
bounds=bounds,
color='#3388ff',
fill=False,
weight=2,
popup=f"{domain_selection.upper()} Domain"
).add_to(m)
except Exception as e:
error_html = f"""
Error Loading Data
Error: {str(e)}
"""
m.get_root().html.add_child(folium.Element(error_html))
# Add layer control
folium.LayerControl(position='topright', collapsed=False).add_to(m)
# Add fullscreen and measure controls
plugins.Fullscreen(position='topleft').add_to(m)
plugins.MeasureControl(position='bottomright', primary_length_unit='miles').add_to(m)
return m
def create_interface():
"""Create Gradio interface"""
with gr.Blocks(title="HRRR vs NEXRAD Radar Comparison", theme=gr.themes.Soft()) as demo:
gr.Markdown("""
# π©οΈ HRRR vs NEXRAD Radar Comparison Viewer
Compare NOAA HRRR forecast composite reflectivity with real-time NEXRAD radar data.
**Both layers shown simultaneously with different colors for visual alignment checking.**
**Data Sources:** NOAA NEXRAD Real-Time Radar (standard colors) + HRRR Model Forecast (green-blue tint)
""")
with gr.Row():
with gr.Column(scale=1):
run_time = gr.Dropdown(
choices=get_available_runs(),
value=get_available_runs()[0],
label="π Model Run Time (UTC)",
info="HRRR initialization time"
)
with gr.Column(scale=1):
forecast_hour = gr.Slider(
minimum=0,
maximum=18,
step=1,
value=0,
label="β±οΈ Forecast Hour",
info="F000 = Analysis (best for comparison)"
)
with gr.Column(scale=1):
domain = gr.Radio(
choices=['conus', 'alaska', 'hawaii'],
value='conus',
label="πΊοΈ Domain",
info="Geographic region"
)
gr.Markdown("### π¨ Layer Controls - Adjust to Compare Alignment")
with gr.Row():
with gr.Column(scale=1):
show_nexrad = gr.Checkbox(
value=True,
label="π‘ Show NEXRAD Real-Time",
info="Standard red/purple colors"
)
nexrad_opacity = gr.Slider(
minimum=0.0,
maximum=1.0,
value=0.6,
step=0.1,
label="NEXRAD Opacity",
info="Lower to see HRRR underneath"
)
with gr.Column(scale=1):
show_hrrr = gr.Checkbox(
value=True,
label="π°οΈ Show HRRR Forecast",
info="Green/cyan color tint"
)
hrrr_opacity = gr.Slider(
minimum=0.0,
maximum=1.0,
value=0.5,
step=0.1,
label="HRRR Opacity",
info="Adjust for blending"
)
load_btn = gr.Button("π Load Comparison View", variant="primary", size="lg")
with gr.Row():
map_output = gr.HTML(label="Comparison Map")
def load_map(run_time, forecast_hour, domain, show_nexrad, nexrad_opacity, show_hrrr, hrrr_opacity):
m = generate_map(run_time, int(forecast_hour), domain,
show_nexrad, nexrad_opacity, show_hrrr, hrrr_opacity)
return m._repr_html_()
load_btn.click(
fn=load_map,
inputs=[run_time, forecast_hour, domain, show_nexrad, nexrad_opacity, show_hrrr, hrrr_opacity],
outputs=map_output
)
# Auto-load on startup
demo.load(
fn=load_map,
inputs=[run_time, forecast_hour, domain, show_nexrad, nexrad_opacity, show_hrrr, hrrr_opacity],
outputs=map_output
)
gr.Markdown("""
---
## π How to Use This Comparison Tool
### Visual Alignment Check
1. **Set Forecast Hour to 0** (F000 = HRRR analysis)
2. **Enable both NEXRAD and HRRR** layers
3. **Adjust opacity sliders** to see both layers clearly
4. **Look for alignment:**
- **Perfect overlap** = HRRR correctly assimilated radar data
- **Offset/misalignment** = potential data issues or timing differences
- **Different intensities** = model vs. observation differences
### Color Coding
- **π΄ NEXRAD (Standard Colors):** Red, purple, yellow = Real-time radar observations
- **π’ HRRR (Green-Blue Tint):** Cyan, green = Model forecast with color shift
- **Mixed Areas:** Where both overlap, you'll see blended colors
### Recommended Settings for Comparison
| Purpose | NEXRAD Opacity | HRRR Opacity | Notes |
|---------|---------------|--------------|-------|
| Check alignment | 0.6 | 0.5 | Balanced visibility |
| Focus on NEXRAD | 0.8 | 0.3 | HRRR as reference |
| Focus on HRRR | 0.3 | 0.7 | NEXRAD as reference |
| See differences | 0.5 | 0.5 | Equal blending |
### Understanding Forecast Hours
- **F000**: HRRR analysis - should match NEXRAD closely (uses radar data assimilation)
- **F001-F003**: Very short-term forecast - minor divergence expected
- **F006-F012**: Short-term forecast - moderate divergence
- **F012-F018**: Medium-range forecast - larger divergence from real-time
### Model Coverage
- **CONUS HRRR**: Continental US at 3km resolution, updated hourly
- **Alaska HRRR**: Alaska domain at 3km resolution
- **Hawaii HRRR**: Hawaiian Islands at 3km resolution
### Data Availability
**HRRR Data:**
- Images may not always be available from rapidrefresh.noaa.gov
- Try recent run times (last 6-12 hours) for best availability
- GRIB2 data always available from NOMADS/AWS S3
**NEXRAD Data:**
- Real-time WMS service, always current
- Updates every ~5 minutes
- Covers CONUS, Alaska, Hawaii, Puerto Rico
### π References
- [HRRR Information](https://rapidrefresh.noaa.gov/hrrr/)
- [NEXRAD Documentation](https://www.ncei.noaa.gov/products/radar/next-generation-weather-radar)
- [HRRR on AWS](https://registry.opendata.aws/noaa-hrrr/)
---
Data: NOAA | For research/educational purposes only | Not for operational use
""")
return demo
if __name__ == "__main__":
demo = create_interface()
demo.launch()