Function for filtering weather alerts

weather/tornado_possible.js

@@ -0,0 +1,46 @@
+let alerts = msg.payload
+
+// Filter for Severe Thunderstorm Warnings
+
+let ts = alerts.filter(function(alert) {
+    if (alert.raw.properties &&
+    alert.raw.properties.event === "Severe Thunderstorm Warning") {
+        return true
+    }
+})
+
+// Filter for Severe Thunderstorm Warnings with tornado detection
+// that have a tornado possible parameter
+
+let tstp = alerts.filter(function(alert) {
+    if (alert.raw.properties &&
+    alert.raw.properties.event === "Severe Thunderstorm Warning" &&
+    alert.raw.properties.parameters &&
+    alert.raw.properties.parameters.tornadoDetection &&
+    alert.raw.properties.parameters.tornadoDetection.length > 0) {
+        let tornadoPossible = alert.raw.properties.parameters.tornadoDetection[0]
+        return tornadoPossible === "POSSIBLE"
+    }
+})
+
+// Filter for Flash Flood Warnings
+
+let flash_flood = alerts.filter(function(alert) {
+    if (alert.raw.properties &&
+    alert.raw.properties.event === "Flash Flood Warning") {
+        return true
+    }
+})
+
+// If there are any alerts, return them
+
+msg.ts = ts
+msg.ts_count = ts.length
+
+msg.tstp = tstp
+msg.tstp_count = tstp.length
+
+msg.flash_flood = flash_flood
+msg.flash_flood_count = flash_flood.length
+
+return msg