The Pennsylvania Observer April 2, 2010 March 2010 Pennsylvania Weather Recap Prepared by: Katelyn Johnson March did come in as a lion cub this year. The 1 st proved to be a calm day; however most of Pennsylvania saw snow on the second and third days of March with accumulations of a trace to an inch of snow. Northeastern parts of the state saw greater amounts of snow on the 3 rd due to a deepening low pressure system that inched its way up the coast. These amounts ranged between 1 and 4 inches with Sullivan County receiving the most amount of snow with 3.6 inches. After this snowy start to March, conditions cleared with an upper level ridge and surface high pressure system dominating the region east of the Mississippi River. This caused Pennsylvania to go through a dry spell from March 4 th through March 11 th seeing no precipitation except occasional flurries in some counties. This also allowed for a gentle compaction and melting of the state s deep snow pack. On the 12 th another low pressure system from the Midwest moved south of Pennsylvania causing rain to fall throughout the state. This rain continued through the 13 th with rainfall amounts ranging from a trace to almost two inches in some places. One of those places was Philadelphia which received 1.94 inches in less than 24 hours. Rain continued to fall on the 14 th as the low pushed eastward. The low moved off the coast on the 15 th causing minimal rain amounts to fall. The rain during this period caused rapid snow melting which resulted in river flooding for many counties in Pennsylvania, but major flooding was restricted to the Delaware River and points east. Nice weather persisted until the 21 st when yet another low pressure system moved through the Commonwealth. Philadelphia once again received a significant amount of rain of 1.12 inches in a 24 hour period. The 25 th brought more rain to the region; this time with the most rain falling on the opposite side of the state in the Pittsburgh area. The 28 th -29 th of March was wet for all of the state. The last rain of the month, effecting only eastern parts of the state, came in on the 30 th and 31 st from a low pressure system that curled back inland after moving off the coast. Although it seems like a very rainy month, precipitation totals in the northwestern third of the state were well below average. Temperatures averaged well above normal. The first week of March had below average temperatures with highs in the 30 s and lows in the 20 s, but March quickly warmed up. In mid March, temperatures exceeded 70 degrees in some parts of the state and in some case the low temperature surpassed the average high. At the end of March, temperatures once again dropped a bit below average.
Here are the weather extremes across Pennsylvania (observations taken at 8AM EDT) during March 2010 from the NWS Cooperative & ASOS Networks. The extremes occurred in the 24-hour period prior to the date listed. Parameter Location Value Date (8 AM County EDT) Highest Pottstown 78 F March 21 st Montgomery Temperature Lowest Oswayo -1 F March 6 th Potter Temperature Greatest Sellersville 8.86 - Bucks Cumulative Liquid Precipitation Greatest Monthly Snowfall Laporte 10 - Sullivan Weather Stories Sugar season sours: Producers say early heat sharply cuts 2010's sap run http://www.gazettenet.com/2010/03/27/sugar-season-sours Winter of 2009-10 melts away http://www.timesonline.com/bct_news/news_details/article/1373/2010/march/21/winter-of-2009-10-meltsaway.html Another regional weather record falls http://www.philly.com/philly/health_and_science/89490922.html Massive Nor'easter Rips Through Northeast http://www.cbn.com/cbnnews/us/2010/march/massive-noreaster-rips-through-northeast/ Cleanup continues after record rains http://www.philly.com/philly/news/breaking/87621617.html
The Pennsylvania Observer April Climate Highlight: Prepared By: Wade Paxson The April Climate Highlight predicts what the upcoming hurricane season may feature. Predictions are based upon analog years that also had a waning El Nino in April preceded by a negative Arctic Oscillation (AO) during December, January, and February.
It is well known that the effects of El-Niño, the anomalous warming of the eastern Pacific Ocean, are wide reaching from increased rainfall in California or creating the warm weather that affected the 2010 Winter Olympics in Vancouver, Canada recently. El-Niño also has a noted impact on the Atlantic hurricane season, this month we ll take a look at what the tracks of storms look like under a similar El-Niño condition as we are currently experiencing, a waning El-Niño with an index value between +1 and +1.3. The years that matched up most closely to our current El-Niño were the years of 1998, 1987, 1983 and 1957. We have plotted a composite of all of the storms in the months of June, July, August and September for these years. It is worth noting that in 1957 June, shown here, was a relatively quiet month, 1957 was the only year to see more than one storm which saw two that originated in the Gulf of Mexico. 1987 witnessed no June storms while 1998 and 1983 both featured Pacific storms. Audrey in 1957 reached category 4 status and the name was later retired. July here was quite a bit more active, however there was not a single Atlantic storm in any of the years. 1987 saw 5 storms while 1983 saw 4 and 1998 featured just a single storm while 1957 was stormless. These tracks nearly all start off the coast of Mexico and Central America and work westward.
August, usually a more exciting month for tropical weather than June and July, sees much more activity during these years. Five storms impacted the Gulf of Mexico with varying paths and three storms formed off the coast of Africa to follow similar paths across the Atlantic. The Pacific Ocean saw five storms over these years, each of them following very similar paths. September, usually the busiest month of the hurricane season is no different here. We can see several similar East Pacific storms off the coast of Mexico. A total of four storms formed over these years just near the Cape Verde Islands off the coast of Africa, all but one, Georges in 1998 which eventually impacted the Gulf of Mexico, spun out into the North Atlantic. Four storms also originated in the Gulf during these years as well and were generally the only ones to impact the United States besides Georges and Dean which was in 1983 and formed 1000 miles east of Florida and eventually landed in Virginia. So what can we expect this year? Well from looking at these maps this year might feature a number of Eastern Pacific storms off the coast of Mexico that likely won t find land as well as a high number of storms originating in the Gulf of Mexico and that these storms are the most likely to have any impact on the United States. The third most likely event will be a storm that forms off of the coast of Africa that eventually will spin out into the North Atlantic.
The Pennsylvania Observer Outlook Experimental Long Range Outlook for Pennsylvania: April May 2010 Prepared by: Jordan Dale The basis of this analog prediction scheme uses the notable temperature and precipitation anomaly from the last 30 days (or so) and in a fuzzy way that is setting all anomalies to +/- 0.5 standard deviations from the long-term mean and matches these patterns to the climate division anomalies from 1895- present. The best matched years are selected (using a dozen or less) and these are used to produce the composite anomalies for the next two months and the years are used to create a composite daily anomaly for three regions of Pennsylvania. The Southern United States recorded generally below-average temperatures through the month with Florida experiencing unusually chilly conditions. The Northern United States recorded generally above-average temperatures particularly across the Great Lakes and the Northeast regions.
Below average precipitation was measured throughout portions of the Western United States, the Western Great Lakes region, and the Lower Mississippi Valley. Above average precipitation was measured across the High Plains, Florida, and coastal areas of the Northeastern United States. The following years were matched: 1926, 1999, 2001, 1936, 1959, 1933, 1981, 2004, 1969, 1948 Below are the composite departures for those years for April and May.
4/1 4/3 4/5 4/7 4/9 4/11 4/13 4/15 4/17 4/19 4/21 4/23 4/25 4/27 4/29 5/1 5/3 5/5 5/7 5/9 5/11 5/13 5/15 5/17 5/19 5/21 5/23 5/25 5/27 5/29 Mean Temperature Departure from Normal (deg F) Western Pennsylvania Temperature Forecast April-May 2010 23.0 18.0 13.0 8.0 3.0-2.0-7.0 Date Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal
4/1 4/3 4/5 4/7 4/9 4/11 4/13 4/15 4/17 4/19 4/21 4/23 4/25 4/27 4/29 5/1 5/3 5/5 5/7 5/9 5/11 5/13 5/15 5/17 5/19 5/21 5/23 5/25 5/27 5/29 Mean Temperature Departure from Normal (deg F) Central Pennsylvania Temperature Forecast April-May 2010 15.0 10.0 5.0 0.0-5.0 Date Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal
4/1 4/3 4/5 4/7 4/9 4/11 4/13 4/15 4/17 4/19 4/21 4/23 4/25 4/27 4/29 5/1 5/3 5/5 5/7 5/9 5/11 5/13 5/15 5/17 5/19 5/21 5/23 5/25 5/27 5/29 Mean Temperature Departure from Normal (deg F) Eastern Pennsylvania Temperature Forecast April-May 2010 18.0 13.0 8.0 3.0-2.0-7.0 Date Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal