MONTHLY WEATHER DATA AND OBS - LAVALE MD MAY 2013 OBSERVER SCOTT LOHR DATA COMPILED AND PUBLISHED BY NATE MULLINS Special Observations: F=fog, T=thunder, H=hail, S=sleet, G=glaze, DW=damaging winds Observation time for this station is midnight. Temperature, °F Precipitation, In. Liquid Solid 7am DAY 24-hour Rain Snow/ Snow Special WEATHER Date Max Min Equiv Ice Depth Obs. SUMMARY 1 70 54 Fair/sunny 2 73 41 3 68 45 4 69 42 5 68 42 6 57 43 .14 Late PM rain 7 60 54 1.54 F Record rainfall (old record 1.36" in 1999) 8 68 50 .50 F Overnight rain 9 71 49 10 80 53 .39 T,DW PM severe thunderstorm with scattered wind damage 11 70 58 .25 Rain showers 12 56 47 13 49 34 Record low max 49 F (old record 53 in 1996) 14 59 33 Scattered frost 15 89 46 Dramatic warm-up 16 77 62 .15 T Mild early AM showers with thunder 17 82 50 18 59 56 19 66 57 20 85 61 T PM thunder, no rain 21 88 63 F Dense AM fog 22 86 59 .11 Warm, humid, severe storms east of station 23 77 60 .03 24 66 41 T Much cooler 25 61 40 26 64 39 27 62 40 28 76 53 .02 29 87 60 Very warm 30 90 58 " 31 89 62 " AVG/SUM 71.7 50.1 3.13 0.0 - EXT 90 33 1.54 - - Date 30 14 7 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 60.9°F (+0.1°F) Year precipitation to date: 12.42" (-4.93") May precipitation departure: -1.06" Season snowfall to date: 47.9" (+7.4") Number of days with: Fog 3 Thunder 3 Damaging Winds 1 Note: The high of 49 on the 13th not only set a record low, but was the latest date of highs in the 40s in 65 years of records. MONTHLY SUMMARY May brought near normal temperatures, despite some dramatic temperature swings. Temperature were almost exactly average, just 0.1°F above. Slightly below normal max temperatures offset slightly above normal min temperatures. Following a cold front on the 11th, unseasonably cold readings near freezing occurred the 13th and 14th, with scattered frost. However, the month's low of 33 on the 14th was immediately followed by a dramatic temperature rise to 89 on the 15th, one degree F shy of the month's high of 90 on the 30th. The final week brought unseasonably cool temperatures, again followed by very warm readings at the end of May. In stark constrast to almost every year since 2005, Memorial Day Weekend was cool and dry. In most years from 2006 to 2012, Memorial Day weekend had record or near-record heat and scattered strong to severe thunderstorms. May's precipitation pattern followed suit of all previous months in 2013, in that it was below normal, though not excessively so. The vast majority of the month's rain fell in a six-day period from the 6th to 11th. A cut-off low pressure over the southern Appalachians drifted northeastward into the Mid-Atlantic on the 7th and 8th. An easterly wind flow on the north side of the system brought ample amounts of moisture from the Atlantic Ocean, with local rainfall totals averaging in the 1.5 to 2.5 inch range. Shortly thereafter, the month's most severe thunderstorm brought a brief period of intense rain and wind on the afternoon of the 10th. Showers continued on the 11th, prior to the aforementioned cold frontal passage. The balance of the month was quite dry, with only a few glancing blows from scattered showers and storms.