The Pennsylvania Observer

Transcription

1 The Pennsylvania Observer December 2, 2015 November Pennsylvania Weather Recap By: Anthny Chiavaroli This November was dry with above average temperatures across the state. Western PA saw some very light precipitation on November 1 st, but after that the state dried out through the 5 th as the state remained under the influence of high pressure. A cold front brought with it some showers for PA on the 6 th and exited the region the next day. However, it is important to note that high temperatures for the state were in the 70s from the 4 th to the 7 th, abnormally warm temperatures for this time of year. The weather remained calm until the 10 th when a low and associated warm front moved up the East Coast bringing light precipitation to mostly the southern half of PA. The 12 th brought very strong storm to the region. Precipitation associated with this storm brought a large portion of monthly rainfall for some areas of the state. Temperatures cooled to seasonal levels behind the storm toward the middle of the month. The state remained very dry until the 19 th and 20 th when a frontal passage brought some heavier showers to the region. Another extended period of dry weather ensued through the 27 th with cooler highs in the 30s and 40s from the 23 rd to the 25 th. To end the month, another cold front brought more precipitation to the Keystone State from the 28 th to the 29 th. Overall, the month will be remembered as warm and relatively dry with very little snow to speak of outside of northwestern Pennsylvania where some brief lake-effect snows brought an inch or two in the middle of the month. There were no severe weather reports during the month.

2 Here are the weather extremes across Pennsylvania (observations taken at 8AM EDT) during November 2015 from the NWS Cooperative, ASOS, and CoCoRaHS 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 Philadelphia Int l AP 80 F November 4 th Philadelphia Lowest Temperature Clarence 13 F November 10 th Centre Greatest Cumulative Liquid Precipitation Least Cumulative Liquid Precipitation Greatest Cumulative Snowfall Wellsboro 4 Mi. SW York 2.5 Mi. NNW Chandlers Valley 1 Mi. SE 4.11 November 1 st -30 th Tioga 0.80 November 1 st -30 th York 3.0 November 1 st -30 th Warren Links to Pennsylvania Weather Stories during November 2015 Weather Instrument Lands on Car in Philadelphia New PA town pet law based on weather Western PA prepares for weather emergencies

3 The Pennsylvania Observer FEATURED CLIMATE HIGHLIGHT By: Dominic Ramunni With November being noted among the warmest on record for reporting stations across Pennsylvania, one might ask if this foreshadows a more merciful winter. Perhaps less snow to worry about? To help answer this question, data was analyzed from five stations with a long period of record: State College, West Chester, Ridgway, Uniontown, and Hawley. Seasonal snowfall totals for every year data exists was averaged into a long-term seasonal snowfall mean. Next, the top 25 warmest Novembers for the state were found with their rankings listed below. Top 25 Warmest Novembers for Pennsylvania Year Rank

4 The seasonal snowfall totals during these 25 years were then found and averaged together to compute the mean snowfall following an abnormally warm November. This data is represented in the table below. Station Long-term Mean Snowfall (inches) Warmest Novembers Mean Snowfall (inches) State College West Chester Ridgway Uniontown Hawley Departure from Mean Comparing the long term versus the warm November mean, seasonal snowfall looks to be closer to average than one might expect. Four of the five stations saw less snowfall, albeit, just a bit less. In fact, for each station the average seasonal total following a warm November came within 10% of its

5 long-term average. So while near normal snowfall may appear to be in the cards this winter, Mother Nature, as she always does, will make the final call. The Pennsylvania Observer LONG RANGE OUTLOOK By: Jillian Bohenek The month of November was relatively warm across most of the eastern and central US, with the western third being a bit below average. Much of the Upper Midwest and South were very wet while the Northeast and parts of the West were exceptionally dry for the month. Using these climate anomalies for the month of November 2015, climate records were examined for the aforementioned anomalous regions and the 25 most extreme years are ranked in the table below. After identifying common years in the four anomaly categories, the years with the most categories in common and highest rank are used as analogs. Below is a table containing a list of years in which anomalies in past Novembers matched 2015 s anomalies.

6 Warm Cold Wet Dry Upper Midwest Southwest South Northeast The colors in the table above indicate years in common among all four anomalous regions yellow indicates two of the regions share that specific year, orange indicates three in common, and red indicates all four anomalous regions contain that year. Composite maps for the months of December and January using the analog years in the table above are shown below.

7 The above images show that temperatures will be above normal with plenty of precipitation in Pennsylvania through the end of January. Using the analogous years after 1948, below are forecast temperature anomalies for December and January for western, central and eastern Pennsylvania.

8 11/29 12/1 12/3 12/5 12/7 12/9 12/11 12/13 12/15 12/17 12/19 12/21 12/23 12/25 12/27 12/29 12/31 1/2 1/4 1/6 1/8 1/10 1/12 1/14 1/16 1/18 1/20 1/22 1/24 1/26 1/28 1/30 2/1 Mean Temperature Departure from Normal (deg F) Western Pennsylvania Temperature Forecast December January Date Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal

9 11/29 12/1 12/3 12/5 12/7 12/9 12/11 12/13 12/15 12/17 12/19 12/21 12/23 12/25 12/27 12/29 12/31 1/2 1/4 1/6 1/8 1/10 1/12 1/14 1/16 1/18 1/20 1/22 1/24 1/26 1/28 1/30 2/1 Mean Temperature Departure from Normal (deg F) Central Pennsylvania Temperature Forecast December January Date Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal

10 11/29 12/1 12/3 12/5 12/7 12/9 12/11 12/13 12/15 12/17 12/19 12/21 12/23 12/25 12/27 12/29 12/31 1/2 1/4 1/6 1/8 1/10 1/12 1/14 1/16 1/18 1/20 1/22 1/24 1/26 1/28 1/30 2/1 Mean Temperature Departure from Normal (deg F) Eastern Pennsylvania Temperature Forecast December January Date Forecast 5-Day Mean Forecast Verification 5-Day Mean Verification Normal