import requests, json
def get_advisory(field_id, lat, lon):
forecast = requests.get(f"https://api.weather.gov/points/{lat},{lon}").json()
alerts = []
for period in forecast['properties']['periods'][:5]:
if period['temperature'] > 35:
alerts.append(f"Heat warning on {period['name']}: {period['temperature']}C")
if 'Rain' in period['detailedForecast']:
alerts.append(f"Rain expected {period['name']} - delay fertilizing")
return alerts