MPA 12Z 850hPa height 1987 - - - - - - - - - - - 1350.4 1988 1315.1 1415.4 1372.6 1355.3 1363.8 1317.8 1371.1 1321.5 1373.8 1328.3 1300.6 1291.6 1989 1326.2 1365.8 1387.9 1303.4 1358.4 1312.5 1405.9 1391.5 1393.2 1375.1 1336.9 1314.7 1990 - 1425.0 1360.2 1284.4 1344.4 1293.7 1348.6 1287.9 1354.5 1311.8 1271.2 1311.5 1991 1385.9 1367.1 1327.3 1346.2 1273.2 1334.4 1324.0 1384.4 1354.8 1349.5 1313.8 1315.3 1992 1372.4 1338.4 1353.8 1366.4 1293.4 1339.7 1394.0 1373.0 1342.8 1287.9 1395.3 1374.2 1993 1324.2 1391.2 1351.7 1338.0 1326.1 1361.6 1335.3 1329.8 1350.3 1380.0 1349.0 1300.6 1994 1338.8 1329.1 1392.6 1344.3 1301.2 1327.6 1352.0 1346.6 1335.3 1324.4 1343.0 1331.9 1995 1381.4 1392.6 - 1398.6 1340.0 1258.9 1248.0 1300.4 - 1357.4 1357.9 1371.0 1996 1330.9 1350.9 1336.4 1336.8 1328.5 1316.1 1393.9 1329.2 1387.1 1353.0 1304.2 1398.8 1997 1342.5 1354.8 1398.2 1315.3 1401.5 1351.5 1291.8 1336.6 - - - - 1998 1306.8 1394.9 1372.8 1468.1 1420.5 1391.8 1260.3 1293.4 1373.4 1312.7 1343.6 1328.1 1999 1355.8 1335.4 1391.5 1392.0 1342.8 1365.4 1346.4 1339.8 1322.5 1349.2 1388.3 1337.3 2000 1333.0 1383.8 1356.0 1353.1 1399.7 1362.4 1338.6 1307.9 1376.0 1337.3 1316.2 1253.8 2001 1327.7 1300.2 1354.1 1318.0 1380.7 1336.9 1328.7 1359.1 1397.6 1419.1 1333.5 1375.9 2002 1366.3 1389.4 1336.8 1309.5 1314.0 1317.5 1350.5 1386.6 1371.9 1300.8 1313.1 1341.7 2003 1309.2 1348.0 1361.0 1389.4 1365.6 1283.4 1324.4 1379.5 1366.1 1312.7 1292.4 1311.3 2004 1370.1 1444.2 1366.8 1319.0 1416.2 1307.9 1348.3 1375.8 1298.8 1348.5 1426.8 1343.1 2005 1325.0 1422.4 1354.2 1316.6 1289.2 1306.9 1368.5 1372.9 1425.2 1376.5 1332.8 1346.3 2006 1338.2 1403.4 1337.0 1344.6 1392.4 1343.7 1323.2 1337.8 1354.9 1340.6 1323.8 1310.2 2007 1354.4 1333.7 1352.5 1332.0 1384.3 1280.5 1302.4 1359.2 1416.3 1314.9 1314.8 1340.0 2008 1365.7 1387.7 1393.6 1282.8 1354.9 1345.3 1363.3 1316.0 1449.9 1340.8 1339.5 1370.0 2009 - - - - - - - - - - - - 2010 - - - - - - - - - - - - 2011 - - 1394.9 - - - - - - - - - 2012 - - - - - - - - - - - - 2013 - - - - - - - - - - - - 2014 - - - - - - - - - - - - 2015 - - - - - - - - - - - - 2016 - - - - - - - - - - - - 2017 - - - - - - - - - - - - 2018 - - - - - - - - - - - - 2019 - - - - - - - - - - - - 2020 - - - - - - - - - - - - 2021 - - - - - - - - - - - - 2022 - - - - - - - - - - - - 2023 - - - - - - - - - - - - 2024 - - - - - - - - - - - -