FORENSIC WEATHER CONSULTANTS, LLC

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1 NOTE: MOST TIMES, LOCATIONS & DATA HAVE BEEN CHANGED FOR THIS SAMPLE REPORT FORENSIC WEATHER CONSULTANTS, LLC Howard Altschule Forensic Meteorologist 1971 Western Avenue, #200 Albany, New York (518) (Phone) (518) (Fax) FORENSIC WEATHER INVESTIGATION OF THE WEATHER AND GROUND CONDITIONS FOR THE PERIOD JANUARY 5-9, 2009 IN THE VICINITY OF BROADWAY IN NEW YORK, NEW YORK September 9, 2011 CASE NAME/FILE NUMBER: DATE AND TIME OF INCIDENT: PREPARED FOR: COMPANY: Plaintiff v. Defendant January 9, 2009 at 5:00 p.m. EST Mr. John Legal, Esquire Law Firm, LLP ASSIGNMENT: This case was assigned to me by Law Firm, LLP. I was asked to perform an in-depth weather analysis and forensic weather investigation in the vicinity of Broadway in New York, New York in order to determine what the weather conditions were leading up to and including the time of this incident. METHODOLOGY: Forensic Weather Consultants, LLC uses only the most trusted and reliable sources of weather information that can be certified by the federal government. In order to accurately determine the weather conditions that existed leading up to and including the time of the incident, a detailed search was performed to find the closest, official weather stations to the location of the incident. Using the computer program Google Earth, weather station locations provided by the National Climatic Data Center were plotted and are indicated by a yellow pushpin. The location of the incident was plotted by our office and is indicated by a red pushpin. This map will help give you 1

2 an approximate location of the weather stations we used in this study and their proximity to the location of the incident. A copy of this Google Earth map can be found below. In order to perform my analysis of the weather conditions that existed, I obtained and reviewed official copies of the following weather records: Hourly surface weather observations / Quality Controlled Local Climatological Data from Central Park Observatory in New York, New York; LaGuardia Airport in Queens, New York; and Newark Airport in Newark, New Jersey in January 2009 Cooperative observer station reports from Bronx, New York in January 2009 The publication Local Climatological Data from Central Park Observatory in New York, New York; LaGuardia Airport in Queens, New York; and Newark Airport in Newark, New Jersey in January 2009 Super-resolution reflectivity Doppler radar images from the Upton, New York radar site zoomed in over the incident location Various National Weather Service (N.W.S.) statements, advisories, bulletins and reports issued by the Upton, New York office. The following is the distance between each weather station location listed above and the incident location: Central Park Observatory: 4 Miles South-Southwest of the incident location Bronx: 7.7 Miles Northeast of the incident location LaGuardia Airport: 6 Miles Southeast of the incident location 2

3 Teterboro Airport: 8.4 Miles Northwest of the incident location The weather data and Climatological records used for this analysis are the official records that Meteorologists rely upon every day during the normal course of business and are either kept in our office or at the National Climatic Data Center. The findings in this report utilize the weather records that were available at the time of data retrieval for this case. Any additional weather records and data that become available at a later date may be incorporated into this report in the future. Super-resolution Doppler radar images and several other types of weather records were used in this study. Doppler radar images are useful for locating precipitation. As the radar unit sends a pulse of energy into the atmosphere and if any precipitation is intercepted by the energy, part of the energy is scattered back to the radar. These return signals, called radar echoes, are assembled to produce radar images. The location of the colored radar echoes indicates where precipitation is falling and the various colors indicate the intensity of the precipitation through the color code key on the right side of the radar image itself. Doppler radar images are received approximately every 6 minutes and can determine if precipitation was falling at the incident location and if so, when it started and stopped. It should be noted that the radar image date and time stamps that are given on the Doppler radar images are given in GMT, which is Greenwich Mean Time. In order to convert GMT to Eastern Standard Time (EST), a subtraction of 5 hours is necessary. ANALYSIS: The following table is a summary of the daily weather and ground conditions day by day at the location of the incident. This summary includes the date, the Maximum temperature for the 24 hour period (in Fahrenheit), the Minimum temperature for the 24 hour period (in Fahrenheit), the Liquid-Equivalent precipitation total for the 24 hour period (in inches), the amount of snow and sleet that fell during the 24 hour period (in inches) and the snow and ice depth that was present on the ground at 7:00 a.m. EST (in inches). It should be noted that any snow and/or ice measurements, including the snow and/or ice depth on the ground, are taken in exposed, untreated and undisturbed areas away from any objects that may act to distort the true measurement. Please note that a Trace in the liquid equivalent precipitation column indicates an amount less than 0.01, or not measurable. The Liquid Equivalent Precipitation/Rain column indicates the total liquid amount of melted snow and ice and/or the amount of rain that accumulated. A Trace in the Snow and Sleet column indicates that less than 0.1 fell, which is also defined as not measurable. A Trace in the Snow/Ice On Ground column indicates a snow and ice depth of less than

4 JANUARY 2009 Date Maximum Air Temperature Minimum Air Temperature Liquid Equivalent Precipitation/Rain Snow/Sleet Snow/Ice On Ground 1/ / / / / Trace Trace 7.0 It should be noted that the table above reflects the snow and ice depth on exposed, untreated and undisturbed surfaces. At 7:00 a.m. on January 5 th, 2009, approximately 9 of snow and ice was present on exposed, undisturbed and untreated surfaces. A weak winter storm moved through the area on January 5 th, 2009 and approximately 4 of snow accumulated. At 7:00 a.m. on January 6 th and 7 th, 2009, approximately 8 of snow and ice was present on exposed, undisturbed and untreated surfaces. On January 6 th, 2009, approximately 0.7 of snow accumulated on exposed, undisturbed and untreated surfaces. On January 7 th, 2009, approximately 1.8 of snow accumulated on exposed, undisturbed and untreated surfaces. As a result of the snow that fell on January 7 th, 2009, approximately 8 of snow and ice was present on exposed, undisturbed and untreated surfaces at 7:00 a.m. on both January 8 th and 9 th, On January 8 th, 2009, there was a snowfall, where approximately 0.6 of snow accumulated on exposed, undisturbed and untreated surfaces. On January 9 th, 2009, A Trace of snow and ice (defined as less than ½ ) was present on exposed, undisturbed and untreated surfaces. Melting and refreezing processes occurred on January 5 th, 7 th and 8 th, 2009 and these processes caused new areas of ice to form in addition to the snow and ice that was already on the ground from the original storm(s). As air temperatures rose into the 20 s, and 30 s, some of the snow and ice that was present melted and caused areas of standing water, puddles, runoff and wet surfaces to accumulate. This was especially the case on any depressions, low lying areas or surfaces adjacent to any snow or ice that was pushed, plowed or shoveled into piles following earlier storms. Direct sunshine and the resultant incoming solar radiation causes melting to occur even when the air temperature is between degrees Fahrenheit. As the air temperature dropped below freezing, or as the sun begins to get lower in the horizon about one hour before sunset (with air temperatures already below freezing), these areas of standing water and runoff refroze to ice on exposed, untreated and undisturbed surfaces. The result is a presence of snow and/or ice from the original storm(s) with additional areas of ice present from the melting and re-freezing processes. JANUARY 8, 2009 (DAY BEFORE THE INCIDENT) On January 8,2009 (day before the incident), Doppler radar images that were zoomed in over the incident location and nearby surface observations indicated that light snow fell from Midnight through approximately 5:05 a.m. Light snow showers fell from approximately 9:11 a.m. through 4

5 10:22 a.m. Approximately 0.6 of snow accumulated on exposed, undisturbed and untreated surfaces. A melting and refreezing process occurred on January 8, 2009 (day before the incident). As air temperatures rose above freezing from approximately 12:51 p.m. through 5:10 p.m., some of the snow and ice that was present melted, and areas of standing water, puddles, runoff and wet surfaces developed in some locations. This was especially the case on any depressions, low lying areas or surfaces adjacent to any snow or ice that was pushed, plowed or shoveled into piles following earlier storms. As the air temperature dropped below freezing at approximately 5:10 p.m., these areas of standing water and runoff refroze to ice on exposed, untreated and undisturbed surfaces. New ice formed between 5:10-7:10 p.m. on January 8, 2009 (day before the incident). TEMPERATURE ANALYSIS FOR JANUARY 8, 2009 On January 8, 2009, the maximum air temperature was 38 degrees Fahrenheit and the minimum air temperature was 20 degrees Fahrenheit. The air temperature was below freezing from Midnight through approximately 12:51 p.m., above freezing from 12:51 p.m. through approximately 5:10 p.m., and at or below freezing from 5:10 p.m. through Midnight. JANUARY 9, 2009 (DAY OF THE INCIDENT) On January 9, 2009 (day of the incident), Doppler radar images that were zoomed in over the incident location and nearby surface observations indicated that light snow fell from approximately 4:29 a.m. through 5:58 a.m. Less than 0.1 (defined as a Trace ) accumulated on exposed, undisturbed and untreated surfaces. This was likely in the form of a coating of snow. At 5:00 p.m. on January 9, 2009 (time and date of incident), light snow was falling, the air temperature was 30 degrees Fahrenheit, and approximately 7 of snow and ice was present on exposed, undisturbed and untreated surfaces, including any ice that was not thoroughly or sufficiently removed or treated after the ice formed the previous evening from melting and refreezing processes. In addition, a new coating of snow accumulated through the time of the incident and this created an even more dangerous condition to be present by concealing the ice that was present underneath the snow. TEMPERATURE ANALYSIS FOR JANUARY 9, 2009 On January 9, 2009, the maximum air temperature was 39 degrees Fahrenheit and the minimum air temperature was 26 degrees Fahrenheit. The air temperature was below freezing from Midnight through approximately 5:12 a.m., and above freezing from approximately 5:12 a.m. through Midnight. CONCLUSIONS In conclusion, it is my opinion that: 5

6 At 7:00 a.m. on January 8, 2009, approximately 7 of snow and ice present on exposed, undisturbed and untreated surfaces. Melting and refreezing processes occurred on January 5th, 7th and 8th, 2009 and these processes caused new areas of ice to form in addition to the snow and ice that was already on the ground from the original storm(s). A period of light snow fell from 4:29 a.m. through 5:58 a.m. on January 9, 2009 and just under 0.1 (defined as a Trace ) of snow accumulated on exposed, untreated and undisturbed surfaces. The coating of snow also accumulated on top of any icy surfaces that formed the night before the incident which were not thoroughly treated or removed, thus creating an even more dangerous situation to be present by concealing and covering up the ice. At 5:00 a.m. on January 9, 2009 (time and date of incident), light snow falling, the air temperature was 30 degrees Fahrenheit and approximately 7 of snow and ice was present on exposed, undisturbed and untreated surfaces, in addition to a new coating of snow that accumulated on top of any pre-existing ice and melt/refreeze that was present since the day before the incident. A melting and refreezing process occurred on January 8, 2009 (day before the incident) and this caused new ice to form between approximately 5:10-7:10 p.m. on January 8, 2009 (10-12 hours before the incident) Any ice that was present at the time of the incident, including any that was concealed by light snow accumulation, had been there for approximately hours before the incident or longer. After studying all of the available weather records and information listed above, I conclude that the findings, opinions and information given in this report are held and supported with a reasonable degree of Meteorological certainty. By: Howard Altschule President, Forensic Meteorologist Forensic Weather Consultants, LLC 6