The Pennsylvania Observer May 31, 2012 May 2012 - Pennsylvania Weather Recap By: Paul Knight The majority of the fifth month had temperatures averaging well above seasonal levels with two distinct hot spells, one during the first week and the second centered on the Memorial Day weekend. More importantly, May brought an abundance of rain in the central sections and northeast, where in some places, there was as much rain during this month as there had been from January 1-April 30, 2012. Fortunately, flooding was not an issue as the dry winter and early spring meant the creeks and streams were running low. Rainfall was sparse though in the northwestern third of the state as Atlantic moisture struggled to reach west of the Appalachians. The continued effects of an abnormally warm March were noticed in the state s flora and fauna that matured at rates a few weeks faster than normal. The coolest weather of the month came on the mornings of May 11 th and 18 th when readings dropped into the 30 s across the northern half of the state. Sub-freezing temperatures were common in the northern tier valleys. There were very few severe weather reports for what is typically an active thunderstorm month in Pennsylvania at least until Memorial Day weekend. The first tornado of the year occurred on May 2 nd in Potter County where an EF0 moved through some farmland. The Sunday of Memorial Day weekend brought 52 reports of hail and wind damage mainly in the central part of the state. Record heat and unusually high dew points caused thunderstorms to boil up each afternoon. A cold front finally pushed the tropical air out to sea on May 29 th, but not before triggering another outbreak of severe thunderstorms with 67 reports of hail and wind damage. The month concluded on a tranquil note with seasonably mild, dry weather. Temperatures ranged from +2.5F to more than +7.0F from normal, reversing a cooling trend that had set in during April. Some parts of the central and northeast counties had its top 10 wettest Mays, while portions of northwest Pennsylvania accrued a deficit of more than 1 inch for the month, adding to the drier than usual year so far. In total, 42 reports of hail came in and 102 wind damage claims during May 2012. Other extremes are reported below:
Here are the weather extremes across Pennsylvania (observations taken at 8AM EDT) during May 2012 from the NWS Cooperative & ASOS Networks of which our office receives routine observations. The extremes occurred in the 24-hour period prior to the date listed. Parameter Location Value Date (8 AM EDT) County Highest Temperature Lowest Temperature Greatest Cumulative Liquid Precipitation Least Cumulative Liquid Precipitation York 3 Mi. SSW Pump Stn Oswayo 1 Mi. ENE Lehighton 3.3 Mi. WSW Roseville 6.0 Mi. ENE 97 F May 29 th York 23 F May 12 th Potter 9.84 May 1 st -May 31 st Carbon 2.38 May 1 st -May 31 st Bradford Links to Pennsylvania Weather Stories during May, 2012 Frost takes bite out of PA fruit crops http://www.pennlive.com/midstate/index.ssf/2012/05/frost_took_a_bite_out_of_centr.html http://www.goerie.com/article/20120508/news02/305079919/frost-takes-toll-on-erie-region-fruitcrops Chestnut trees are making a comeback after disease and climate shifts in PA and surrounding states http://somd.com/news/headlines/2012/15476.shtml Pennsylvania requires insurance companies to state how they will prepare for climate change http://www.alternet.org/environment/155164/the_world%27s_insurers_brace_for_climate_change_ --_except in_america Flooding causes lake use problems http://www.wgal.com/news/susquehanna-valley/lancaster/equipment-damage-could-lower-lake- Aldred-water-levels/-/9704306/14164758/-/9tj984/-/index.html
Reports of West Nile Virus - early http://www.wgal.com/news/susquehanna-valley/york-adams/mosquito-tests-positive-in-york-co/- /9704248/13554316/-/cemgop/-/index.html
The Pennsylvania Observer FEATURED CLIMATE HIGHLIGHT By: Paul Knight The outlook for the summer months (Jun-Jul-Aug) based on recent large anomalies of temperature and precipitation in various parts of the nation. It was the third driest winter (Dec- Feb) in the western region (CA/NV) and by far the warmest 6-month period from October-March in the Midwest. It was the fifth wettest Jan-Mar in the South region and ninth driest first quarter to the year in the Southwest.
2012 2.99 2012 34.6 2012 4.41 2012 1.54 1991 2.87 2007 29.3 2009 3.48 2011 1.56 1990 4.35 2006 30.7 2007 3.51 2009 1.71 1989 4.27 2005 29.1 2001 3.74 2002 1.08 1987 4.88 2002 32.2 2000 3.58 1999 1.38 1985 4.01 2000 32.1 1999 3.6 1984 1.67 1977 2.52 1999 30.8 1998 3.72 1977 1.7 1976 3.59 1998 31.3 1990 4.59 1972 0.66 1964 3.03 1995 30.3 1980 4.13 1971 1.38 1961 3.91 1992 29.3 1979 3.8 1967 1.3 1948 3.85 1987 31 1973 6.28 1966 1.56 1947 3.88 1983 30.7 1961 4.06 1964 1.72 1931 4.29 1976 29.6 1957 3.61 1953 1.84 1929 4.79 1964 29.5 1945 4.5 1947 1.4 1928 4.61 1954 30.5 1944 3.65 1934 1.61 1924 3.24 1945 29.1 1927 3.58 1925 1.45 1920 4.79 1942 30.1 1926 4.55 1904 1.65 1912 4.51 1932 30.6 1922 4.92 1902 1.72 1899 4.14 1931 30.9 1905 4 1900 1.2 1898 3.75 1921 31.4 1903 3.54 1896 1.74 When comparing these to previous years, only 1999 and 1964 were common in three of the four regions. The composite for the following summer temps/rain show only a moist signal for western PA.
The Pennsylvania Observer LONG RANGE OUTLOOK By: Kyle Imhoff The following map indicates temperature departures from normal, in degrees Fahrenheit, for the month of May:
Similarly, below is a map of percent of normal precipitation for the month of May:
The anomalous temperature and precipitation regions from the above images were matched with the 9 US climate regions assigned by NCDC with May data for the past 117 years. The following table indicates regions in which the 2012 anomalies fell within the top 20 warmest, coolest, driest, or wettest years as indicated by the table header. The years listed for each region indicate the top 20 extremes from 1895-2011. Years in red are analogous years that match for all 4 regions, orange match 3 of the 4 regions, and yellow match 2 of the 4 regions: Ohio Valley - Warmest Northwest - Coolest South - Driest Upper Midwest - Wettest 1962 69.8 1965 50.1 1998 1.53 1943 4.58 1896 69.4 1974 50 1988 1.9 1991 4.58 1991 68.8 1950 50 1962 1.94 1999 4.6 1987 68 1942 50 1921 2.05 1899 4.62 1965 67.8 1943 49.8 1911 2.16 1944 4.62 1977 67.7 1917 49.8 1996 2.4 1912 4.67 1944 67.7 1911 49.8 1896 2.43 1915 4.75 1911 67.5 1962 49.7 1925 2.49 1902 4.86 1918 67.3 1927 49.4 1945 2.55 1960 4.87 1998 67.2 2011 49.2 1917 2.58 1962 4.87 1982 67.2 1959 49.2 1934 2.61 1973 5.01 1959 67.1 1955 49.2 1963 2.68 2001 5.02 1902 67 1908 49.2 1918 2.73 1896 5.06 2004 66.9 2010 49 2006 2.74 1942 5.14 2007 66.8 1953 49 1927 2.8 1959 5.16 1936 66.5 1977 48.9 1931 2.8 1938 5.29 1934 66.4 1899 48.5 1932 2.82 1905 5.32 1964 66.1 1916 48.3 1942 2.82 1903 5.38 1941 66.1 1933 48.2 2011 2.83 1918 5.4 1975 65.9 1896 47.9 2005 2.89 1908 6.23
When utilizing all the years listed above as analogies for the following June-July, these are the anomalies noted for temperature (left) and precipitation (right):
6/1 6/3 6/5 6/7 6/9 6/11 6/13 6/15 6/17 6/19 6/21 6/23 6/25 6/27 6/29 7/1 7/3 7/5 7/7 7/9 7/11 7/13 7/15 7/17 7/19 7/21 7/23 7/25 7/27 7/29 7/31 Mean Temperature Departure from Normal (deg F) Western Pennsylvania Temperature Forecast June - July 2012 6.0 4.0 2.0 0.0-2.0-4.0-6.0 Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal
6/1 6/3 6/5 6/7 6/9 6/11 6/13 6/15 6/17 6/19 6/21 6/23 6/25 6/27 6/29 7/1 7/3 7/5 7/7 7/9 7/11 7/13 7/15 7/17 7/19 7/21 7/23 7/25 7/27 7/29 7/31 Mean Temperature Departure from Normal (deg F) Central Pennsylvania Temperature Forecast June - July 2012 6.0 4.0 2.0 0.0-2.0-4.0-6.0 Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal
6/1 6/3 6/5 6/7 6/9 6/11 6/13 6/15 6/17 6/19 6/21 6/23 6/25 6/27 6/29 7/1 7/3 7/5 7/7 7/9 7/11 7/13 7/15 7/17 7/19 7/21 7/23 7/25 7/27 7/29 7/31 Mean Temperature Departure from Normal (deg F) Eastern Pennsylvania Temperature Forecast June - July 2012 6.0 4.0 2.0 0.0-2.0-4.0-6.0-8.0 Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal