diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/commondialogs/SCANAlarmThreshDlg.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/commondialogs/SCANAlarmThreshDlg.java
index 51595064c4..17fb90f90a 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/commondialogs/SCANAlarmThreshDlg.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/commondialogs/SCANAlarmThreshDlg.java
@@ -19,6 +19,8 @@
  **/
 package com.raytheon.uf.viz.monitor.scan.commondialogs;
 
+import java.util.Set;
+
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.FocusAdapter;
 import org.eclipse.swt.events.FocusEvent;
@@ -40,8 +42,12 @@ import org.eclipse.swt.widgets.Text;
 import com.raytheon.uf.common.monitor.scan.config.AbsConfigMgr;
 import com.raytheon.uf.common.monitor.scan.config.SCANConfig;
 import com.raytheon.uf.common.monitor.scan.config.SCANConfigEnums.ScanTables;
+import com.raytheon.uf.viz.monitor.scan.ScanMonitor;
+import com.raytheon.uf.viz.monitor.scan.tables.AbstractTableDlg;
 import com.raytheon.uf.viz.monitor.scan.tables.SCANAlarmAlertManager;
+import com.raytheon.uf.viz.monitor.scan.tables.SCANCellTableDlg;
 import com.raytheon.uf.viz.monitor.scan.tables.SCANAlarmAlertManager.AlarmType;
+import com.raytheon.uf.viz.monitor.scan.tables.SCANAlarmAlertManager.AlertedAlarms;
 import com.raytheon.viz.ui.dialogs.CaveSWTDialog;
 
 public class SCANAlarmThreshDlg extends CaveSWTDialog implements
@@ -239,6 +245,16 @@ public class SCANAlarmThreshDlg extends CaveSWTDialog implements
             @Override
             public void widgetSelected(SelectionEvent e) {
                 alarmChoiceChanged();
+                String columnName = attributeCbo.getText();
+                mgr.clearAlertedAlarms(site, scanTable);
+				AbstractTableDlg tableDlg = ScanMonitor.getInstance()
+						.getDialog(scanTable, site);
+				tableDlg.updateThresh(columnName);
+                if (mgr.getAlertedAlarmCount(site, scanTable) == 0) {
+                	tableDlg.turnOffAlarm();
+                } else {
+                	tableDlg.turnOnAlarm();
+                }
                 shell.dispose();
             }
         });
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/resource/ScanResource.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/resource/ScanResource.java
index 0b314f53ec..5d50f74561 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/resource/ScanResource.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/resource/ScanResource.java
@@ -157,7 +157,7 @@ public class ScanResource extends
         VizApp.runAsync(new Runnable() {
             @Override
             public void run() {
-                if (getScanDrawer().font != null) {
+                if (gc != null && getScanDrawer().font != null) {
                     getScanDrawer().font.setMagnification(getCapability(
                             MagnificationCapability.class).getMagnification()
                             .floatValue());
@@ -560,7 +560,7 @@ public class ScanResource extends
      * @return
      */
     public ScanDrawer getScanDrawer() {
-        if (drawer == null) {
+        if (drawer == null && gc != null) {
             if (getTable().equals(ScanTables.CELL)) {
                 drawer = new ScanDrawer(SCANConfig.getInstance()
                         .getStormCellConfig(), gc, getScan()
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/AbstractTableDlg.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/AbstractTableDlg.java
index 87403d054d..2e0e577380 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/AbstractTableDlg.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/AbstractTableDlg.java
@@ -765,4 +765,8 @@ public abstract class AbstractTableDlg extends Dialog implements IMonitor,
     protected abstract void handleRankMenuEvent(SelectionEvent event);
 
     public abstract void updateThresh(String attr);
+
+	public abstract void turnOffAlarm();
+
+	public abstract void turnOnAlarm();
 }
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANAlarmAlertManager.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANAlarmAlertManager.java
index cbd4eaeb10..148ea934d3 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANAlarmAlertManager.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANAlarmAlertManager.java
@@ -21,10 +21,13 @@ package com.raytheon.uf.viz.monitor.scan.tables;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArrayList;
 
@@ -36,6 +39,7 @@ import com.raytheon.uf.common.monitor.scan.config.SCANConfigEnums;
 import com.raytheon.uf.common.monitor.scan.config.SCANConfigEnums.ScanTables;
 import com.raytheon.uf.viz.monitor.scan.ScanMonitor;
 import com.raytheon.uf.viz.monitor.scan.data.ScanDataGenerator;
+import com.raytheon.uf.viz.monitor.scan.tables.SCANAlarmAlertManager.AlarmType;
 
 /**
  * Manager class to hold between scan dialog and alarming capabilities
@@ -74,11 +78,11 @@ public class SCANAlarmAlertManager {
 
     private static SCANAlarmAlertManager instance = null;
 
-    private HashMap<String, HashMap<ScanTables, List<ScheduledAlarms>>> scheduledAlarmsMap;
+    private Map<String, Map<ScanTables, List<ScheduledAlarms>>> scheduledAlarmsMap;
 
-    private HashMap<String, HashMap<ScanTables, Set<AlertedAlarms>>> alertedAlarmsMap;
+    private Map<String, Map<ScanTables, Set<AlertedAlarms>>> alertedAlarmsMap;
 
-    private HashMap<String, HashMap<ScanTables, List<String>>> idents;
+    private Map<String, Map<ScanTables, List<String>>> idents;
 
     private boolean ring = false;
 
@@ -98,7 +102,7 @@ public class SCANAlarmAlertManager {
     public void addSite(String site) {
 
         if (!scheduledAlarmsMap.containsKey(site)) {
-            HashMap<ScanTables, List<ScheduledAlarms>> siteScheduledAlarmsMap = new HashMap<ScanTables, List<ScheduledAlarms>>();
+            Map<ScanTables, List<ScheduledAlarms>> siteScheduledAlarmsMap = Collections.synchronizedMap(new HashMap<ScanTables, List<ScheduledAlarms>>());
             siteScheduledAlarmsMap.put(ScanTables.DMD,
                     new CopyOnWriteArrayList<ScheduledAlarms>());
             siteScheduledAlarmsMap.put(ScanTables.CELL,
@@ -107,7 +111,7 @@ public class SCANAlarmAlertManager {
         }
 
         if (!alertedAlarmsMap.containsKey(site)) {
-            HashMap<ScanTables, Set<AlertedAlarms>> siteAlertedAlarmsSet = new HashMap<ScanTables, Set<AlertedAlarms>>();
+            Map<ScanTables, Set<AlertedAlarms>> siteAlertedAlarmsSet = Collections.synchronizedMap(new HashMap<ScanTables, Set<AlertedAlarms>>());
             siteAlertedAlarmsSet.put(ScanTables.DMD,
                     new HashSet<AlertedAlarms>());
             siteAlertedAlarmsSet.put(ScanTables.CELL,
@@ -116,7 +120,7 @@ public class SCANAlarmAlertManager {
         }
 
         if (!idents.containsKey(site)) {
-            HashMap<ScanTables, List<String>> siteIdents = new HashMap<ScanTables, List<String>>();
+            Map<ScanTables, List<String>> siteIdents = new HashMap<ScanTables, List<String>>();
             siteIdents.put(ScanTables.CELL, new ArrayList<String>());
             siteIdents.put(ScanTables.DMD, new ArrayList<String>());
             idents.put(site, siteIdents);
@@ -126,15 +130,15 @@ public class SCANAlarmAlertManager {
     private SCANAlarmAlertManager() {
 
         if (scheduledAlarmsMap == null) {
-            scheduledAlarmsMap = new HashMap<String, HashMap<ScanTables, List<ScheduledAlarms>>>();
+            scheduledAlarmsMap = Collections.synchronizedMap(new HashMap<String, Map<ScanTables, List<ScheduledAlarms>>>());
         }
 
         if (alertedAlarmsMap == null) {
-            alertedAlarmsMap = new HashMap<String, HashMap<ScanTables, Set<AlertedAlarms>>>();
+            alertedAlarmsMap = Collections.synchronizedMap(new HashMap<String, Map<ScanTables, Set<AlertedAlarms>>>());
         }
 
         if (idents == null) {
-            idents = new HashMap<String, HashMap<ScanTables, List<String>>>();
+            idents = new HashMap<String, Map<ScanTables, List<String>>>();
         }
 
     }
@@ -438,7 +442,7 @@ public class SCANAlarmAlertManager {
         
         return count;
     }
-
+    
     public boolean containsAlarm(String site, ScanTables tableType,
             AlarmType type, String colName, String ident) {
         for (AlertedAlarms alarm : alertedAlarmsMap.get(site).get(tableType)) {
@@ -493,9 +497,10 @@ public class SCANAlarmAlertManager {
             alarm.cleared = true;
         }
     }
-
+    
     public void removeAlertedAlarms(String site, ScanTables tableType) {
         alertedAlarmsMap.get(site).get(tableType).clear();
+        setRing(false);
     }
     
     /**
@@ -603,4 +608,5 @@ public class SCANAlarmAlertManager {
                     + this.row + "\nCol #:" + this.col + "\nCleared: " + cleared + "\n";
         }
     }
+
 }
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANCellTableDlg.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANCellTableDlg.java
index d27cc25325..3f3a10758d 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANCellTableDlg.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANCellTableDlg.java
@@ -475,8 +475,7 @@ public class SCANCellTableDlg extends AbstractTableDlg implements
                 alarmDlg.open();
                 if (!alarmBtn.isDisposed()
                         && (mgr.getAlertedAlarmCount(site, scanTable) == 0)) {
-                    alarmBtn.setVisible(false);
-                    mgr.setRing(false);
+                	turnOffAlarm();
                 }
             }
         });
@@ -488,7 +487,23 @@ public class SCANCellTableDlg extends AbstractTableDlg implements
         timeLbl.setLayoutData(gd);
     }
 
-    // private void resetButtonForegroundColor(Button btn)
+    @Override
+    public void turnOffAlarm() {
+    	if (alarmBtn != null && !alarmBtn.isDisposed()) {
+    		alarmBtn.setVisible(false);
+    	}
+        mgr.setRing(false);
+	}
+
+    @Override
+    public void turnOnAlarm() {
+    	if (alarmBtn != null && !alarmBtn.isDisposed()) {
+    		alarmBtn.setVisible(true);
+    	}
+        mgr.setRing(true);
+	}
+
+	// private void resetButtonForegroundColor(Button btn)
     // {
     // btn.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
     // }
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANDmdTableDlg.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANDmdTableDlg.java
index 833d739c5f..64f217a003 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANDmdTableDlg.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANDmdTableDlg.java
@@ -514,8 +514,7 @@ public class SCANDmdTableDlg extends AbstractTableDlg implements
                 alarmsDlg.open();
                 if (!alarmBtn.isDisposed()
                         && mgr.getAlertedAlarms(site, scanTable).isEmpty()) {
-                    alarmBtn.setVisible(false);
-                    mgr.setRing(false);
+                	turnOffAlarm();
                 }
             }
         });
@@ -1299,4 +1298,19 @@ public class SCANDmdTableDlg extends AbstractTableDlg implements
         dmdTableComp.alarmSelection(ident);
 
     }
+    
+    public void turnOffAlarm() {
+    	if (alarmBtn != null && !alarmBtn.isDisposed()) {
+    		alarmBtn.setVisible(false);
+    	}
+        mgr.setRing(false);
+	}
+
+    public void turnOnAlarm() {
+    	if (alarmBtn != null && !alarmBtn.isDisposed()) {
+    		alarmBtn.setVisible(true);
+    	}
+        mgr.setRing(true);
+	}
+
 }
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANMesoTableDlg.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANMesoTableDlg.java
index 118f85283a..e837e49f45 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANMesoTableDlg.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANMesoTableDlg.java
@@ -647,4 +647,14 @@ public class SCANMesoTableDlg extends AbstractTableDlg implements
         return false;
     }
 
+	@Override
+	public void turnOffAlarm() {
+		mgr.setRing(false);
+	}
+
+	@Override
+	public void turnOnAlarm() {
+		mgr.setRing(true);
+	}
+
 }
diff --git a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANTvsTableDlg.java b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANTvsTableDlg.java
index bc129ffa75..aca8b68deb 100644
--- a/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANTvsTableDlg.java
+++ b/cave/com.raytheon.uf.viz.monitor.scan/src/com/raytheon/uf/viz/monitor/scan/tables/SCANTvsTableDlg.java
@@ -609,4 +609,14 @@ public class SCANTvsTableDlg extends AbstractTableDlg implements
         // Not currently used for TVS
         return false;
     }
+
+	@Override
+	public void turnOffAlarm() {
+		mgr.setRing(false);
+	}
+
+	@Override
+	public void turnOnAlarm() {
+		mgr.setRing(true);
+	}
 }