National Weather Service United States Department of Commerce

RECORD COLD TEMPERATURES SATURDAY MAY 9TH

May 9th, 2020 was one of the coldest May days in recorded history as numerous sites set records for coldest low and high temperatures. Please click through the photos as we attempt to contextualize one of the coldest days in May ever observed in Pennsylvania! 

 

Here are the observed temperatures and previous cold temperature records for Saturday. 

Source: https://w2.weather.gov/climate/xmacis.php?wfo=ctp

Lows and Highs on Saturday were some of the lowest ever observed in the entire month of May.

Source: https://w2.weather.gov/climate/xmacis.php?wfo=ctp

Minimum and maximum temperatures on Saturday were highly anomalous with low temperatures greater than 15 degrees below normal and high temperatures greater than 25 degrees below normal in Pennsylvania.

Source: https://www.wpc.ncep.noaa.gov/exper/ndfdmxmn/map.html

Records were set across most of the Eastern US Saturday morning. Here's a depiction of the record cold temperatures. Notice the dark blue circles in PA indicating temperatures that break the monthly record low.

Source: http://coolwx.com/record/usamovie.day.php

If we track where Saturday's air mass originated, it becomes clear why it was so cold. Air from northern Canada sunk into the Mid-Atlantic on Saturday, resulting in temperatures in the 30s in northern PA and 40s in southern PA.

Source: https://ready.noaa.gov/HYSPLIT_traj.php

An expansive area of surface high pressure surged into the eastern US, as shown in this NWS Weather Prediction Center map valid at 8AM Saturday. See surface maps from the record-setting May 9ths of 1947 and 1966 below for comparison.

Source: https://www.wpc.ncep.noaa.gov/index.shtml#page=frt

 

Surface map on May 9th, 1947 when Harrisburg's daily record minimum temperatures were set: 

Source: https://library.noaa.gov/Collections/Digital-Collections/US-Daily-Weather-Maps

 

Surface map on May 9th, 1966 when most of the daily record minimum temperatures were set: 

Source: https://library.noaa.gov/Collections/Digital-Collections/US-Daily-Weather-Maps


000
NOUS41 KCTP 300006
PNSCTP
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-056>059-
063>066-301206-

Public Information Statement
National Weather Service State College PA
806 PM EDT Tue Sep 29 2020

...PRECIPITATION REPORTS...

Location Amount Time/Date Provider

...Pennsylvania...

...Bedford County...
Bedford Airport 0.87 in 0735 PM 09/29 AWOS
Claysburg 0.79 in 0756 PM 09/29 CWOP
2.7 NW Osterburg 0.75 in 0700 PM 09/29 IFLOWS
Everett 0.74 in 0731 PM 09/29 CWOP

...Blair County...
Altoona 1.43 in 0755 PM 09/29 CWOP
Altoona Airport 1.12 in 0753 PM 09/29 ASOS
Blair Helibase 1.09 in 0716 PM 09/29 RAWS
Altoona 1.03 in 0731 PM 09/29 CWOP
Roaring Spring 1.03 in 0800 PM 09/29 AWS
2 NNW Altoona 0.89 in 0800 PM 09/29 AWS
Tyrone 0.76 in 0730 PM 09/29 CWOP

...Cambria County...
Mineral Point 0.91 in 0755 PM 09/29 CWOP
Johnstown Airport 0.64 in 0754 PM 09/29 ASOS
Flinton 0.63 in 0730 PM 09/29 CWOP
Loretto 0.54 in 0725 PM 09/29 AWS

...Centre County...
Garden Hollow 1.32 in 0708 PM 09/29 RAWS
Port Matilda 1.29 in 0759 PM 09/29 CWOP
Aaronsburg 1.18 in 0759 PM 09/29 CWOP
Zion 1.17 in 0758 PM 09/29 CWOP
State College 1.11 in 0758 PM 09/29 CWOP
Stormstown 3NE 1.08 in 0730 PM 09/29 CWOP
State College 1.06 in 0731 PM 09/29 CWOP
Stormstown 1.06 in 0756 PM 09/29 CWOP
Bellefonte 1.04 in 0730 PM 09/29 CWOP
Stormstown 0.99 in 0746 PM 09/29 CWOP
State College 0.92 in 0755 PM 09/29 CWOP
AccuWeather HQ 0.91 in 0755 PM 09/29 CWOP
Port Matilda 0.91 in 0755 PM 09/29 CWOP
State College 0.91 in 0755 PM 09/29 CWOP
Bear Knob 0.88 in 0749 PM 09/29 RAWS
South Philipsburg 0.80 in 0756 PM 09/29 CWOP
State College 0.80 in 0740 PM 09/29 CWOP
3.4 NW Port Matilda 0.52 in 0700 PM 09/29 IFLOWS

...Clearfield County...
3.0 N Brisbin 0.67 in 0700 PM 09/29 IFLOWS
Clearfield Airport 0.54 in 0748 PM 09/29 ASOS

...Clinton County...
Alvin Bush Dam 0.69 in 0700 PM 09/29 COOP
Coffin Rock 0.69 in 0716 PM 09/29 RAWS

...Franklin County...
Mercersburg 1.26 in 0759 PM 09/29 AWS
Upperstrasburg 1.19 in 0755 PM 09/29 CWOP
Greencastle 0.78 in 0731 PM 09/29 CWOP
New Franklin 0.75 in 0745 PM 09/29 CWOP
Chambersburg 0.68 in 0755 PM 09/29 CWOP
Chambersburg 0.56 in 0800 PM 09/29 AWS
Waynesboro 0.56 in 0800 PM 09/29 AWS
Greencastle 0.55 in 0755 PM 09/29 CWOP
Mont Alto 0.55 in 0800 PM 09/29 AWS
Waynesboro 0.50 in 0730 PM 09/29 CWOP

...Fulton County...
Forney Trail 1.12 in 0749 PM 09/29 RAWS

...Juniata County...
Mifflintown 0.65 in 0759 PM 09/29 AWS

...Lycoming County...
Duboistown 1.18 in 0755 PM 09/29 CWOP
Williamsport Airport 1.02 in 0754 PM 09/29 ASOS
Jersey Shore 0.89 in 0730 PM 09/29 CWOP
Montgomery 0.83 in 0757 PM 09/29 CWOP
South Williamsport 0.65 in 0800 PM 09/29 AWS

...Mifflin County...
2 SSW Alfarata 1.06 in 0755 PM 09/29 AWS
Chestnut Springs 0.93 in 0751 PM 09/29 RAWS
Lewistown 0.68 in 0800 PM 09/29 AWS

...Perry County...
Big Knob 0.82 in 0708 PM 09/29 RAWS

...Potter County...
Germania 0.67 in 0730 PM 09/29 CWOP

...Somerset County...
0.9 S Somerset 0.66 in 0730 PM 09/29 HADS
2.8 E Hooversville 0.64 in 0700 PM 09/29 IFLOWS
3.7 S New Baltimore 0.60 in 0700 PM 09/29 IFLOWS
Sipesville 0.52 in 0750 PM 09/29 CWOP

...Tioga County...
Old Mountain 0.90 in 0716 PM 09/29 RAWS
Wellsboro 0.68 in 0755 PM 09/29 CWOP
Liberty 0.67 in 0755 PM 09/29 CWOP
Mansfield 0.64 in 0755 PM 09/29 CWOP
Westfield 0.63 in 0730 PM 09/29 CWOP
Morris 0.62 in 0755 PM 09/29 CWOP
Westfield 0.61 in 0755 PM 09/29 CWOP

...Union County...
1.1 NW Milton 0.52 in 0730 PM 09/29 HADS
&&

**METADATA**
:9/29/2020,1931 PM, PA, Bedford, Everett, , , 40.0142, -78.3645, RAIN_12, 0.74, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1900 PM, PA, Bedford, 2.7 NW Osterburg, , , 40.2167, -78.55, RAIN_12, 0.75, Inch, IFLOWS, 12 hour rainfall,
:9/29/2020,1956 PM, PA, Bedford, Claysburg, , , 40.2599, -78.4924, RAIN_12, 0.79, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1935 PM, PA, Bedford, Bedford Airport, , , 40.0833, -78.5167, RAIN_12, 0.87, Inch, AWOS, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Blair, Tyrone, , , 40.6802, -78.2599, RAIN_12, 0.76, Inch, CWOP, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Blair, 2 NNW Altoona, , , 40.5416, -78.4102, RAIN_12, 0.89, Inch, AWS, 12 hour rainfall,
:9/29/2020,1931 PM, PA, Blair, Altoona, , , 40.5398, -78.3472, RAIN_12, 1.03, Inch, CWOP, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Blair, Roaring Spring, , , 40.3341, -78.3813, RAIN_12, 1.03, Inch, AWS, 12 hour rainfall,
:9/29/2020,1916 PM, PA, Blair, Blair Helibase, , , 40.4417, -78.4197, RAIN_12, 1.09, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1953 PM, PA, Blair, Altoona Airport, , , 40.3, -78.3167, RAIN_12, 1.12, Inch, ASOS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Blair, Altoona, , , 40.4283, -78.3513, RAIN_12, 1.43, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1925 PM, PA, Cambria, Loretto, , , 40.5027, -78.6305, RAIN_12, 0.54, Inch, AWS, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Cambria, Flinton, , , 40.7032, -78.5383, RAIN_12, 0.63, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1954 PM, PA, Cambria, Johnstown Airport, , , 40.3167, -78.8333, RAIN_12, 0.64, Inch, ASOS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Cambria, Mineral Point, , , 40.3988, -78.7963, RAIN_12, 0.91, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1900 PM, PA, Centre, 3.4 NW Port Matilda, , , 40.8333, -78.1, RAIN_12, 0.52, Inch, IFLOWS, 12 hour rainfall,
:9/29/2020,1956 PM, PA, Centre, South Philipsburg, , , 40.8893, -78.2187, RAIN_12, 0.8, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1940 PM, PA, Centre, State College, , , 40.8288, -77.8472, RAIN_12, 0.8, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1949 PM, PA, Centre, Bear Knob, , , 40.9316, -77.9466, RAIN_12, 0.88, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Centre, AccuWeather HQ, , , 40.7816, -77.897, RAIN_12, 0.91, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Centre, Port Matilda, , , 40.8102, -77.9429, RAIN_12, 0.91, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Centre, State College, , , 40.7907, -77.8393, RAIN_12, 0.91, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Centre, State College, , , 40.8006, -77.8707, RAIN_12, 0.92, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1946 PM, PA, Centre, Stormstown, , , 40.791, -78.0158, RAIN_12, 0.99, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Centre, Stormstown, , , 40.7912, -78.0117, RAIN_12, 0.99, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Centre, Bellefonte, , , 40.8727, -77.8542, RAIN_12, 1.04, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1931 PM, PA, Centre, State College, , , 40.8025, -77.9187, RAIN_12, 1.06, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1956 PM, PA, Centre, Stormstown, , , 40.8062, -77.998, RAIN_12, 1.06, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Centre, Stormstown 3NE, , , 40.8213, -77.9662, RAIN_12, 1.08, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1958 PM, PA, Centre, State College, , , 40.7661, -77.8858, RAIN_12, 1.11, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1958 PM, PA, Centre, Zion, , , 40.9108, -77.6845, RAIN_12, 1.17, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1959 PM, PA, Centre, Aaronsburg, , , 40.8993, -77.4592, RAIN_12, 1.18, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1959 PM, PA, Centre, Port Matilda, , , 40.7788, -78.0127, RAIN_12, 1.29, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1908 PM, PA, Centre, Garden Hollow, , , 41.0256, -77.1672, RAIN_12, 1.32, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1948 PM, PA, Clearfield, Clearfield Airport, , , 41.05, -78.4167, RAIN_12, 0.54, Inch, ASOS, 12 hour rainfall,
:9/29/2020,1900 PM, PA, Clearfield, 3.0 N Brisbin, , , 40.8833, -78.35, RAIN_12, 0.67, Inch, IFLOWS, 12 hour rainfall,
:9/29/2020,1900 PM, PA, Clinton, Alvin Bush Dam, , , 41.3579, -77.9264, RAIN_12, 0.69, Inch, COOP, 12 hour rainfall,
:9/29/2020,1916 PM, PA, Clinton, Coffin Rock, , , 41.2378, -77.7517, RAIN_12, 0.69, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Franklin, Waynesboro, , , 39.7445, -77.6297, RAIN_12, 0.5, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Franklin, Greencastle, , , 39.7413, -77.7245, RAIN_12, 0.55, Inch, CWOP, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Franklin, Mont Alto, , , 39.8406, -77.5433, RAIN_12, 0.55, Inch, AWS, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Franklin, Chambersburg, , , 39.9283, -77.6694, RAIN_12, 0.56, Inch, AWS, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Franklin, Waynesboro, , , 39.7494, -77.5702, RAIN_12, 0.56, Inch, AWS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Franklin, Chambersburg, , , 39.9525, -77.5943, RAIN_12, 0.68, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1945 PM, PA, Franklin, New Franklin, , , 39.8663, -77.6068, RAIN_12, 0.75, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1931 PM, PA, Franklin, Greencastle, , , 39.7723, -77.743, RAIN_12, 0.78, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Franklin, Upperstrasburg, , , 40.0823, -77.7405, RAIN_12, 1.19, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1959 PM, PA, Franklin, Mercersburg, , , 39.828, -77.8994, RAIN_12, 1.26, Inch, AWS, 12 hour rainfall,
:9/29/2020,1949 PM, PA, Fulton, Forney Trail, , , 39.9934, -77.9589, RAIN_12, 1.12, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1959 PM, PA, Juniata, Mifflintown, , , 40.5697, -77.3963, RAIN_12, 0.65, Inch, AWS, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Lycoming, South Williamsport, , , 41.2291, -76.9991, RAIN_12, 0.65, Inch, AWS, 12 hour rainfall,
:9/29/2020,1957 PM, PA, Lycoming, Montgomery, , , 41.1733, -76.8815, RAIN_12, 0.83, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Lycoming, Jersey Shore, , , 41.4083, -77.2367, RAIN_12, 0.89, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1954 PM, PA, Lycoming, Williamsport Airport, , , 41.25, -76.9167, RAIN_12, 1.02, Inch, ASOS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Lycoming, Duboistown, , , 41.2197, -77.0463, RAIN_12, 1.18, Inch, CWOP, 12 hour rainfall,
:9/29/2020,2000 PM, PA, Mifflin, Lewistown, , , 40.597, -77.5741, RAIN_12, 0.68, Inch, AWS, 12 hour rainfall,
:9/29/2020,1951 PM, PA, Mifflin, Chestnut Springs, , , 40.6914, -77.7028, RAIN_12, 0.93, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Mifflin, 2 SSW Alfarata, , , 40.6308, -77.4981, RAIN_12, 1.06, Inch, AWS, 12 hour rainfall,
:9/29/2020,1908 PM, PA, Perry, Big Knob, , , 40.3033, -77.5898, RAIN_12, 0.82, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Potter, Germania, , , 41.6578, -77.6733, RAIN_12, 0.67, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1950 PM, PA, Somerset, Sipesville, , , 40.1153, -79.0967, RAIN_12, 0.52, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1900 PM, PA, Somerset, 3.7 S New Baltimore, , , 39.9333, -78.7833, RAIN_12, 0.6, Inch, IFLOWS, 12 hour rainfall,
:9/29/2020,1900 PM, PA, Somerset, 2.8 E Hooversville, , , 40.1333, -78.8667, RAIN_12, 0.64, Inch, IFLOWS, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Somerset, 0.9 S Somerset, , , 39.9917, -79.0808, RAIN_12, 0.66, Inch, HADS, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Tioga, Westfield, , , 41.8365, -77.456, RAIN_12, 0.61, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Tioga, Morris, , , 41.5923, -77.3052, RAIN_12, 0.62, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Tioga, Westfield, , , 41.9128, -77.5468, RAIN_12, 0.63, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Tioga, Mansfield, , , 41.91, -77.011, RAIN_12, 0.64, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Tioga, Liberty, , , 41.6207, -77.137, RAIN_12, 0.67, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1955 PM, PA, Tioga, Wellsboro, , , 41.7395, -77.277, RAIN_12, 0.68, Inch, CWOP, 12 hour rainfall,
:9/29/2020,1916 PM, PA, Tioga, Old Mountain, , , 41.5644, -77.4086, RAIN_12, 0.9, Inch, RAWS, 12 hour rainfall,
:9/29/2020,1930 PM, PA, Union, 1.1 NW Milton, , , 41.0186, -76.8653, RAIN_12, 0.52, Inch, HADS, 12 hour rainfall,

Observations are collected from a variety of sources with varying
equipment and exposures. We thank all volunteer weather observers
for their dedication. Not all data listed are considered official.

$$

 

SNOWFALL: Harrisburg (MDT) also received a trace of snowfall, tying the previous daily record set in 1977.