The frequency of thunderstorms in Pennsylvania also makes the state vulnerable to hail events. The following synopsis discusses the results for each county within the state of Pennsylvania regarding hail events from 1959-2000.
The following is a map of Pennsylvania with each county outlined. This map is a visual representation of the number of hail events per square mile x 10 ^-3. Along the bottom of the map there is a legend that describes what value each color represents, each color is an increment of 20. From this map we can see that the southeast portions of the state experience a large number of hail events, but the greatest frequency of hail events per square mile is over the western sections.
Figure 1:
The Number of Hail Events Per Square Mile from 1950 - 2002
The first table is a tabulation of the number of hail events that were recorded for each county during the 1959-2000 time period. This data was acquired through The National Climactic Data Center which provides tallied weather events per county ranging from tornadoes, lightning, hail, floods, wind, and the like.
Table 1: A representation of the number of hail events per county
|
County |
# of Hail Events |
|
Adams |
24 |
|
Allegheny |
123 |
|
Armstrong |
11 |
|
Beaver |
62 |
|
Bedford |
18 |
|
Berks |
37 |
|
Blair |
9 |
|
Bradford |
23 |
|
Bucks |
35 |
|
Butler |
53 |
|
Cambria |
20 |
|
Cameron |
8 |
|
Carbon |
19 |
|
Centre |
28 |
|
Chester |
31 |
|
Clarion |
14 |
|
Clearfield |
16 |
|
Clinton |
10 |
|
Columbia |
16 |
|
Crawford |
66 |
|
Cumberland |
16 |
|
Dauphin |
29 |
|
Delaware |
15 |
|
Elk |
12 |
|
Erie |
102 |
|
Fayette |
32 |
|
Forest |
7 |
|
Franklin |
24 |
|
Fulton |
8 |
|
Greene |
17 |
|
Huntington |
21 |
|
Indiana |
10 |
|
Jefferson |
26 |
|
Juniata |
5 |
|
Lackawanna |
19 |
|
Lancaster |
52 |
|
Lawrence |
24 |
|
Lebanon |
15 |
|
Lehigh |
12 |
|
Luzerne |
20 |
|
Lycoming |
49 |
|
McKean |
33 |
|
Mercer |
40 |
|
Mifflin |
8 |
|
Monroe |
27 |
|
Montgomery |
32 |
|
Montour |
1 |
|
Northampton |
18 |
|
Northumberland |
14 |
|
Perry |
11 |
|
Philadelphia |
16 |
|
Pike |
10 |
|
Potter |
20 |
|
Schuylkill |
22 |
|
Snyder |
7 |
|
Somerset |
18 |
|
Sullivan |
9 |
|
Susquehanna |
5 |
|
Tioga |
27 |
|
Union |
6 |
|
Venango |
28 |
|
Warren |
22 |
|
Washington |
35 |
|
Wayne |
12 |
|
Westmoreland |
82 |
|
Wyoming |
3 |
|
York |
45 |
This first chart provides a visual interpretation of the distribution of hail events per county. The x-axis represents the individual counties, the y-axis is the number of hail events with intervals of 20.
The second table is a representation of the Pennsylvania county populations and is included for reference for table 3 and its following chart. These populations are valid as of the 2001 Pennsylvania census.
Table 2: This table consists of the county populations
|
PA Counties |
County Populations |
|
Adams |
92,997 |
|
Allegheny |
1,270,612 |
|
Armstrong |
72,101 |
|
Beaver |
179,871 |
|
Bedford |
49,899 |
|
Berks |
377,679 |
|
Blair |
128,391 |
|
Bradford |
62,859 |
|
Bucks |
605,379 |
|
Butler |
176,593 |
|
Cambria |
150,726 |
|
Cameron |
5,866 |
|
Carbon |
59,506 |
|
Centre |
135,940 |
|
Chester |
443,346 |
|
Clarion |
41,478 |
|
Clearfield |
83,167 |
|
Clinton |
37,753 |
|
Columbia |
64,152 |
|
Crawford |
90,046 |
|
Cumberland |
215,695 |
|
Dauphin |
251,316 |
|
Delaware |
551,158 |
|
Elk |
34,666 |
|
Erie |
279,636 |
|
Fayette |
147,367 |
|
Forest |
4,910 |
|
Franklin |
130,506 |
|
Fulton |
14,314 |
|
Greene |
40,492 |
|
Huntingdon |
45,632 |
|
Indiana |
89,108 |
|
Jefferson |
45,712 |
|
Juniata |
22,877 |
|
Lackawanna |
211,829 |
|
Lancaster |
474,601 |
|
Lawrence |
94,160 |
|
Lebanon |
120,963 |
|
Lehigh |
314,204 |
|
Luzerne |
315,754 |
|
Lycoming |
118,977 |
|
McKean |
45,440 |
|
Mercer |
119,682 |
|
Mifflin |
46,554 |
|
Monroe |
144,676 |
|
Montgomery |
759,953 |
|
Montour |
18,281 |
|
Northampton |
269,779 |
|
Northumberland |
93,662 |
|
Perry |
43,787 |
|
Philadelphia |
1,491,812 |
|
Pike |
48,507 |
|
Potter |
18,154 |
|
Schuylkill |
149,176 |
|
Snyder |
37,720 |
|
Somerset |
79,553 |
|
Sullivan |
6,532 |
|
Susquehanna |
42,165 |
|
Tioga |
41,621 |
|
Union |
41,701 |
|
Venango |
57,098 |
|
Warren |
43,593 |
|
Washington |
203,737 |
|
Wayne |
48,392 |
|
Westmoreland |
368,983 |
|
Wyoming |
28,055 |
|
York |
386,299 |
The third table is the number of hail events per person per county. These numbers were reached by dividing the number of hail events for a particular county by that county’s population. To keep the data uniform, five places after the decimal place were used, which required rounding in some cases.
Philadelphia had the lowest number of hail events per person and Forest County had the highest number of hail events per person. It should be noted that Philadelphia has the greatest population and Forrest County has the least.
Table 3: This table is the number of hail events per person per county
|
County |
Hail Events/Person/County |
|
Adams |
0.00026 |
|
Allegheny |
0.00010 |
|
Armstrong |
0.00015 |
|
Beaver |
0.00034 |
|
Bedford |
0.00036 |
|
Berks |
0.00010 |
|
Blair |
0.00007 |
|
Bradford |
0.00037 |
|
Bucks |
0.00006 |
|
Butler |
0.00030 |
|
Cambria |
0.00013 |
|
Cameron |
0.00136 |
|
Carbon |
0.00032 |
|
Centre |
0.00021 |
|
Chester |
0.00007 |
|
Clarion |
0.00034 |
|
Clearfield |
0.00019 |
|
Clinton |
0.00026 |
|
Columbia |
0.00025 |
|
Crawford |
0.00073 |
|
Cumberland |
0.00007 |
|
Dauphin |
0.00012 |
|
Delaware |
0.00003 |
|
Elk |
0.00035 |
|
Erie |
0.00036 |
|
Fayette |
0.00022 |
|
Forest |
0.00143 |
|
Franklin |
0.00018 |
|
Fulton |
0.00056 |
|
Greene |
0.00042 |
|
Huntington |
0.00046 |
|
Indiana |
0.00011 |
|
Jefferson |
0.00057 |
|
Juniata |
0.00022 |
|
Lackawanna |
0.00009 |
|
Lancaster |
0.00011 |
|
Lawrence |
0.00025 |
|
Lebanon |
0.00012 |
|
Lehigh |
0.00004 |
|
Luzerne |
0.00006 |
|
Lycoming |
0.00041 |
|
McKean |
0.00073 |
|
Mercer |
0.00033 |
|
Mifflin |
0.00017 |
|
Monroe |
0.00019 |
|
Montgomery |
0.00004 |
|
Montour |
0.00005 |
|
Northampton |
0.00007 |
|
Northumberland |
0.00015 |
|
Perry |
0.00025 |
|
Philadelphia |
0.00001 |
|
Pike |
0.00021 |
|
Potter |
0.00110 |
|
Schuylkill |
0.00015 |
|
Snyder |
0.00019 |
|
Somerset |
0.00023 |
|
Sullivan |
0.00138 |
|
Susquehanna |
0.00012 |
|
Tioga |
0.00065 |
|
Union |
0.00014 |
|
Venango |
0.00049 |
|
Warren |
0.00050 |
|
Washington |
0.00017 |
|
Wayne |
0.00025 |
|
Westmoreland |
0.00022 |
| Wyoming | 0.00011 |
|
York |
0.00012 |
This second chart provides a visual interpretation of the distribution of hail events per person per county. The x-axis represents the individual counties, the y-axis is the hail events per person per county with intervals of 0.0002.
This fourth table represents the time of year which is most prone to hail event occurrence in Pennsylvania. This table was made by analyzing the dates of the recorded hail events and tallying them. The month of June has the highest number of hail events with 451, though May and July have a large number as well. This can be confirmed by the fact that these months fall within the time of year where Pennsylvania receives its greatest number of thunderstorms. It should be noted, however, that the numbers are not exact representations as the hail events were originally recorded by county and more than one county can experience the same hail event at one particular time. Therefore, duplicate hail events for one particular day were recorded as a single hail event.
Table 4: This table represents the time of year which is most prone to hail event occurrence in Pennsylvania
|
Months of Hail Events |
# Events |
|
January |
5 |
|
February |
5 |
|
March |
27 |
|
April |
179 |
|
May |
391 |
|
June |
451 |
|
July |
330 |
|
August |
169 |
|
September |
84 |
|
October |
19 |
|
November |
12 |
|
December |
1 |
This third chart provides a visual interpretation of the times of year which are most prone to hail event occurrences in Pennsylvania. The x-axis represents the months, and the y-axis is the number of hail event occurrences.
This fifth table is a representation of the time of day that is most prone to hail events. Differentiation between the times of day, regarding morning, afternoon, and night, were based upon the public’s general understanding of these time brackets. Each hail event is listed below in the table by the time of their occurrence. Times are in 24 hours and the times of occurrence are rounded to the hour.
Table 5: This table represents the time of day that is most prone to hail events
|
PA
Hail Event Frequency by the Hour |
# Events |
|
0: |
5 |
|
|
24 |
|
|
9 |
|
|
11 |
|
|
4 |
|
|
4 |
|
|
3 |
|
|
6 |
|
|
7 |
|
|
12 |
|
|
25 |
|
|
30 |
|
|
66 |
|
|
146 |
|
|
193 |
|
|
241 |
|
|
237 |
|
|
246 |
|
|
164 |
|
|
104 |
|
|
65 |
|
|
40 |
|
|
15 |
|
|
16 |
This fourth chart provides a visual interpretation of the time of day that is most prone to hail events in Pennsylvania. The x-axis represents the times in 24 hours , and the y-axis is the number of hail event occurrences.
The sixth table is documenting the time of day that witnesses the most hail events. Due to gaps in the available data, not all time periods were accurately accounted for. To compensate, the day was broken down into hour intervals and the number of hail events that fell within each hour time period was recorded. This table is based upon data provided in Table 5. Within this table, the day is broken down into early morning, morning, afternoon and evening time periods; these times were based upon the general classification of times within the general public. The time of day that has had the highest number of hail events is afternoon, with 883 hail events.
Table 6: This table represents the time of day that witnesses the most hail events
|
Hail event Frequency by Time of Day |
|
|
Early Morning (0:00:00-6:59:00) |
60 |
|
Morning (7:00:00-11:59:00) |
80 |
|
Afternoon (12:00:0-16:59:00) |
883 |
|
Evening (17:00:00-20:59:00) |
579 |
|
Late Evening (21:00:00-23:59:00) |
71 |