MPA 12Z 500hPa height 1987 - - - - - - - - - - - 5424.0 1988 5365.5 5551.1 5499.5 5408.7 5421.7 5324.8 5391.2 5292.5 5400.0 5336.0 5356.9 5362.9 1989 5421.0 5493.9 5494.4 5335.2 5401.9 5333.0 5463.4 5402.9 5400.4 5432.1 5417.8 5403.0 1990 - 5579.0 5457.6 5274.2 5383.8 5324.7 5382.5 5266.8 5374.2 5340.4 5313.0 5379.2 1991 5527.1 5490.0 5428.8 5418.3 5294.2 5316.1 5334.3 5386.2 5374.5 5376.8 5356.4 5368.4 1992 5506.1 5431.1 5454.7 5485.3 5301.2 5306.5 5413.2 5384.1 5359.6 5316.7 5457.0 5470.8 1993 5368.9 5524.8 5460.0 5394.3 5372.1 5393.1 5328.2 5356.8 5367.8 5435.4 5426.8 5360.7 1994 5459.6 5394.7 5498.6 5392.9 5310.6 5337.6 5340.0 5365.2 5324.5 5331.5 5438.6 5422.1 1995 5508.6 5494.8 - 5512.5 5383.0 5222.1 5192.6 5247.4 - 5412.3 5410.5 5475.8 1996 5415.2 5462.4 5434.1 5405.2 5400.7 5315.6 5430.0 5349.7 5424.8 5379.6 5369.2 5483.5 1997 5463.6 5434.6 5536.0 5371.8 5448.9 5353.2 5258.2 5340.0 - - - - 1998 5396.0 5508.9 5471.4 5589.5 5476.4 5422.3 5269.6 5288.3 5365.7 5354.4 5407.9 5392.1 1999 5470.8 5425.0 5485.8 5494.2 5375.5 5362.6 5352.7 5366.0 5313.5 5395.7 5489.2 5413.1 2000 5435.2 5507.6 5455.4 5436.9 5451.2 5365.2 5320.0 5294.6 5332.1 5369.6 5358.4 5286.5 2001 5428.9 5382.9 5440.4 5371.1 5413.1 5332.7 5291.1 5395.9 5415.2 5495.2 5415.8 5483.3 2002 5484.6 5518.3 5391.4 5374.5 5308.5 5287.7 5355.0 5409.3 5381.9 5314.1 5337.9 5434.3 2003 5376.7 5468.8 5463.8 5475.2 5425.2 5277.8 5349.2 5400.7 5379.3 5347.6 5309.6 5373.0 2004 5494.2 5617.7 5498.1 5364.1 5448.1 5333.0 5348.7 5404.8 5302.3 5381.2 5493.2 5438.6 2005 5410.0 5579.6 5444.8 5367.4 5315.2 5306.8 5380.0 5373.8 5468.6 5391.3 5379.7 5400.7 2006 5459.6 5531.2 5445.2 5427.3 5477.3 5355.2 5317.7 5336.0 5342.7 5364.8 5369.3 5395.4 2007 5472.6 5412.7 5430.6 5350.0 5389.2 5272.1 5280.7 5353.3 5462.5 5341.1 5323.4 5425.9 2008 5474.8 5520.4 5523.0 5297.5 5373.7 5362.0 5356.8 5289.6 5493.1 5366.8 5380.4 5469.6 2009 - - - - - - - - - - - - 2010 - - - - - - - - - - - - 2011 - - 5565.0 - - - - - - - - - 2012 - - - - - - - - - - - - 2013 - - - - - - - - - - - - 2014 - - - - - - - - - - - - 2015 - - - - - - - - - - - - 2016 - - - - - - - - - - - - 2017 - - - - - - - - - - - - 2018 - - - - - - - - - - - - 2019 - - - - - - - - - - - - 2020 - - - - - - - - - - - - 2021 - - - - - - - - - - - - 2022 - - - - - - - - - - - - 2023 - - - - - - - - - - - - 2024 - - - - - - - - - - - -