The Unfathomable Winter Superstorm of March 13, 1993: An Analysis

[Music] the Cyclone of March 13 1993 known as the Storm of the Century was one of the worst and most complex Super Storms to affect the United States in modern day history affecting over 100 million people it barreled through 21 states in just 72 hours spawning a 12-foot storm surge derecho tornado outbreak life-threatening blizzard and crippling ice storm all before transitioning into a devastating New England Nor'easter despite New Age computer models accurately forecasting its approach days in advance over 300 people still lost their lives in the storm's Fury today in the wake of the 30th Anniversary we'll break down the many meteorological components that fell into place the death and destruction that the superstorm ultimately caused and how it represented a major success and significant turning point in modern weather forecasting technology my name is Steve and this is Weatherbox let's dive in a lot of severe weather happened in the early 1990s in the United States in August of 1991 Hurricane Bob veered up the Atlantic coast striking New England as a rare category too one year later Hurricane Andrew tore through southern Florida as a category 5 hurricane causing cataclysmic damage to the City of Homestead in fact so many homes were condemned that the government set up a so-called tent city where residents who no longer had a place to live could seek shelter in hundreds of available tents and be provided basic necessities many people along the coast were left in varying compromising positions going into 1993. and while a slow warming trend of global temperature was observed throughout the late 80s and early 90s which could have certainly fueled intense hurricanes the warming Trend suddenly reversed in June of 1991. [Music] on the 15th of June Mount Pinatubo in the Philippines erupted with cataclysmic Force ejecting one cubic mile of volcanic material into the stratosphere perhaps the scariest part of the eruption was that it occurred as typhoon yunya a category 2 tropical Cyclone made landfall on Luzon passing directly over the erupting volcano as the ash below the troposphere mixed with rain from the typhoon it fell back to Earth as large droplets of mud making driving very difficult for last minute evacuations but the ash that made it into the stratosphere spread throughout the tropics within a few weeks and eventually throughout the globe this effect is measured by something called aerosol Optical depth which is the measure of aerosols like smoke particles desert dust sea salt within the stratosphere and for the next two years after the eruption the global aerosol Optical depth was 10 to 100 times higher which ultimately meant less energy from the Sun was heating the Earth lowering the global temperature by over a full degree Fahrenheit the thing is while globally the surface temperature was lower Winters in the eastern half of the United States are almost always warmer after a major eruption in an examination of the northern hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883 to 1992. it was found that in the two Winters following these major tropical volcanic eruptions North America and Eurasia experienced abnormally warm Winters while the Middle East experienced abnormally cold Winters and wouldn't you know it the winter of January 1992 was the all-time warmest winner on record for much of the U.S the average temperature for the entire winter across the 48 contiguous states was 36.87 degrees Fahrenheit with 93.2 percent of the country reporting warmer than normal temperatures the following winter starting in December of 1992 would likely be warmer as well but less so because it was now 18 months since the Pinatubo eruption the winter forecast issued by NOAA predicted above average temperature in the northern and western regions of the U.S with below average temperatures from Texas to Maine with the highest probability over Western North Carolina one thing's for sure the year started off with much more snow on December 10th a surface low near Virginia moved off the Atlantic coast and became a nor'easter dropping over 40 inches of snow in Western Maryland and four feet of snow in the Berkshires and green mountains of Massachusetts and Vermont the storm surge in heavy rains caused the New York Subway system to flood as 70 mile an hour winds tore through the heart of downtown in early January six days of continuous blinding snowfall buried Salt Lake City in 26 inches of snow one of the highest totals in the city's history on January 20th a powerful Cyclone slammed into the Pacific Northwest causing 75 mile an hour winds in Seattle and bringing widespread destruction to the Pacific northwest coast but much like how Mount Pinatubo had many smaller eruptions before the big one the worst snowstorm of the year was yet to to come by the beginning of March temperatures were fairly mild across the Midwest and Southeast and as the first week progressed an intense Ridge began to build over the Pacific the warm air wasn't limited just to Southern California on March 9th it was 70 in Denver 85 in Dallas 73 in Birmingham and 72 in Raleigh a stationary front slowly sagged south over the course of the few days allowing cooler air to spill further south towards the Gulf of Mexico but the meteorological Operations Division of the National Weather Service was keeping an eye on the weather models for the week ahead and the output was a bit concerning now if you're watching this video you're probably at least somewhat familiar with weather forecasting models they can predict the future if you really want to have fun on a Friday night pull up the latest GFS run go to 350 hours out and see what physics-defying weather system is going to strike your area within 10 days time but in case you don't know a weather forecasting model is quite simply a computer program that contains the mathematical equations that govern physics and thermodynamics in our atmosphere the program is based on a three-dimensional grid of points that represents a different point in space these points are then given initial conditions from weather observations such as wind speed temperature dew point and air pressure the output data from these equations is then assimilated into the computer model at each point on the grid and the equations are stepped forward in time obviously the further out you try to predict the less accurate the model is going to be in the early 1990s the three main models used by the mod for forecasting were the medium range forecast model the United Kingdom meteorology office model and the European Center for medium range forecast model or more passionately known as the Euro now weather prediction isn't just reading the output of models it takes a great deal of knowledge in skilled subjective interpretation of forecast models to accurately predict a weather event and this was much truer in the early 1990s the first sign that a storm could impact the eastern U.S came at the conclusion of the 0z model runs on March 8 1993. you're looking at a forecast map issued by the mod weather forecast Branch based on the 132 108 and 84 hour mrf and UK met models and the 144 120 and 96 hour Euro forecast that's a lot of numbers these numbers that you see on the screen refer to the model name and the forecasted Central pressure of the storm system so for instance m stands for medium range forecast model or mrf and 101 stands for 1001 millibars the low is forecasted to make landfall near Mobile on Saturday March 13th and move up through New England as a nor'easter on Sunday the 14th now five days out was a very far forecast for 1993 and the results were greeted with skepticism by forecasters but over the next 48 hours the models held the line but with slight differences in Cyclone location the zero Z March 10th UK met model now showed the low centered over Northern Georgia on Saturday the 13th but the mrf model had it over Savannah and the Euro headed off the West Coast of Florida it was unclear how far south the low would develop but everything else indicated that a historic winter storm was falling into place the models were in agreement that a major upper level trough would dig down over the eastern half the United States with a jet streak or an area of fast-moving winds in the jet stream centered over the Great Lakes these three pieces of the puzzle appeared to be in place and while the exact position and path of the low was still to be determined it would likely be historic as the day progressed on March 10th mod forecasters decided to issue summary statements at six hour intervals to the weather Community terms were used such as unusually severe and perhaps record-breaking and the 16z statement on Thursday the 11th stated the storm could be of historic proportions along the east coast with potentially record-setting snows over the interior portions now obviously when the National Weather Service uses language like this the media takes notice and by the end of the night the impending blizzard was on on national news throughout the day on the 10th an intense Ridge Aloft was building off the Pacific coast often a precursor to an amplified digging trough to the east one more huge Improvement in weather forecasting came on December 7th 1992 when the mod began using Ensemble forecasts see prior to December 7th a single model run was conducted each day for a 10-day period at the highest resolution possible outputting a single forecast but with an ensemble forecast 14 individual model runs are conducted with very slightly differing initial conditions outputting 14 individual 10-day forecasts this cemented the fundamental ideology that medium range forecasts are stochastic in nature or contain random distributions that cannot be precisely predicted there is no single solution to a forecast rather a range of possible solutions and averaging these Solutions out can help get rid of some of the forecasting errors this is most apparent to the everyday person when looking at forecast tested hurricane tracks on the news there isn't a single precise line that the hurricane is predicted to follow it's an expanding cone that gets larger the further out the hurricane is from landfall The mrf Ensemble product greatly assisted forecasters in predicting the heavy snowfall as well as it likely being an East Coast storm there was also one new parameter called conditional probability of snow or cpos which consistently showed potential for heavy snow accumulation along the spine of the Blue Ridge Mountains but the Ensemble mrf also had some flaws most importantly it failed to predict the rapid strengthening of the low as it moved ashore from the Gulf of Mexico instead it predicted the low intensifying greatly over New England this is significant because the waters in the Gulf of Mexico were a whopping 3 degrees Celsius warmer than normal for that time of year at 8 A.M Eastern on March 11th the surface load that would be the superstorm formed near Monterey Mexico drifting off to the east it was at this time that the winter storm watches started being issued by weather forecast offices offering many areas in the path of the storm nearly 50 hours of lead time within the next 24 hours two individual shortwave troughs are these smaller kinks in the jet stream quickly swung down from the northern Rockies the Southeastern trough reaching the gulf first winds within this jet streak were moving at a blazing 140 knots this greatly increased vorticity to the east or the spin in the atmosphere which was now sitting over the developing Cyclone allowing air to rise the area to the east of the low was a strong Bureau Clinic zone or an area with a tight temperature gradient aided by the abnormally warm Waters near a Southward moving cold air mass east of the Rockies every single parameter was in place for explosive Cyclone growth and by the morning of the 12th cyclogenesis was well underway the central pressure of the low began falling rapidly as it drifted to the East General cloudiness was observed on satellite near the low Center slowly forming a comma head shape a feature typical of extra tropical Cyclones at 4 pm Eastern light snow was falling across Alabama and Mississippi with enough accumulation to cover the spring daffodils in full bloom by the evening of March 12th the Cyclone was off the coast of New Orleans with a Squall line starting to form along the associated cold front southerly winds formed a strong low-level jet ahead of the cold front which pumped tons of warm moist air into the Cyclone causing the rapid development of rain along the warm front as well as near the Cyclone Center these strong stormy extra tropical Cyclones are more often than not found over the Great Plains in the midwest because that's where all the ingredients come together in Spring the one benefit that these land-based Cyclones have is the land that they Traverse over provides friction which actually slows the wind at the surface down quite a lot derechos still impact the Midwest which are fast-moving bands of thunderstorms with destructive winds we're talking like 80 miles an hour August 10 2020 May 12 2022 there have been some historic duratos but all of those were over land this explosive Squall line with embedded supercells was flying to the east over warm ocean waters and would likely strike the West Coast of Florida around midnight in complete darkness while the people at risk were asleep to make matters worse this giratio was not that well forecasted while a tornado watch was issued several hours before the derecho hit the Squall line itself only took a couple hours to form this wasn't like a tropical Cyclone where the Perpetual rain bands exist circulating around the center and you could see it approaching from 500 miles away with mid-latitude Cyclones in unstable atmosphere storm development happens incredibly fast and while severe thunderstorm warnings with 90 mile an hour wind tags were issued in the 10 o'clock hour most people just didn't see those warnings they were in bed on top of this the cold front itself located about 100 miles west of the derecho contained additional 70 mile an hour winds so it would be a long windy night on the west coast of Florida at around this time in the evening the trough in the jet stream Aloft exhibited an extreme negative tilt indicating extremely fast winds Aloft and intense vorticity feeling the explosive cyclogenesis occurring underneath the low continued to deepen as it approached Apalachicola and at 11 PM the fully formed rate show moved ashore in western Florida 95 mile an hour winds battered Clear Water causing a 12-foot storm surge to the north at Pine Island dozens of homes up and down the coast were destroyed by the storm surge the line of storms extended down into Cuba hitting Havana with over 100 mile an hour wind gusts with the reanalysis done by The Institute of meteorology of Cuba estimating 130 mile an hour wind gusts Cuba saw the worst of the damage suffering a billion dollar economic loss from the storm around 40 000 homes were at least partially destroyed back in Florida 11 tornadoes touched down across the state from the embedded supercells with the maximum rating being F2 one of these f2s hit a mobile home park in Chiefland killing 3. another tornado actually went through a tent city where people who lost their homes in Hurricane Andrew were currently living in tents it was a nightmarish scenario in Florida as the Squall line was tearing through the heart of Florida the low Center moved ashore near Apalachicola setting an all-time low pressure record for Tallahassee at just 976 millibars the moisture from the southerly low-level jet was now condensing at an explosive rate to the north causing the first ever thunder snow in Mobile Alabama blizzard warnings were in place for the entirety of the Appalachian Mountains through Pennsylvania and heavy snow warnings were extended into extreme Northwestern Alabama where it became apparent that all-time snowfall records would easily be broken the resulting snowflakes were huge wet clusters piling up quickly at rates over three inches an hour all during 45 mile an hour winds James Spann was on the air throughout the night in Birmingham Alabama keeping residents updated as the temp creatures plummeted into the mid-20s this fantastic moment was caught on camera audible proof of the rare Thunder snowers damage straight line wind damage in Tampa and if you can hear that we've had a tremendous lightning crash outside the station here part of this thunder snow storm we are experiencing one of the camera operators who is out in the blizzard also caught this fantastic moment you tell me that that's Valley Avenue there and I can barely recognize that because the snow is so heavy I'm exactly there there was the flash right there of the lightning and he struck very close to me with power lines falling all throughout the state and very few plows to clear the six inches already on the roads it was clear that the blizzard was an unprecedented life-threatening situation for Alabama by 5 a.m the low Center was over Vidalia Georgia with the central pressure at 971 millibars and falling a pressure on par with a category 2 hurricane the warm moist air from the Atlantic was getting sucked into the low at tremendous speeds meeting the 6 000 foot peaks of the Blue Ridge Mountains in North Carolina and Tennessee then getting forced up the Peaks creating the worst blizzard conditions seen in years somehow dozens of people were hiking along the peaks of Smoky Mountains National Park were just a few days prior the weather had been beautiful and Mild among those hiking was a group of students from Michigan who were practicing survival skills using minimalistic shelters and carrying little to no gear they woke up early on the 13th to collapse 10 buried under three feet of snow stuck for several days they suffered severe frostbite and barely survived requiring hand and foot amputations those that made it back to their cars were luckier as the vehicle became a suitable livable shelter while waiting for the National Guard in Asheville residents woke up to over a foot of snow on the ground and with winds funneling into the French Broad River Valley whiteout conditions May travel Impossible by 9 A.M the low Center was over Rally North Carolina at just 966 millibars State officials in Pennsylvania mobilized the National Guard in closed down interstates across the entire State prior to the Blizzard striking a move only made possible by the 50 hours of lead time given by forecasters for the first time ever New York officials had activated the emergency alert system for a blizzard warning pushing it to all radios and television sets Statewide one thing that was still uncertain for cities on the East Coast was the exact location of the rain snow line the path difference of 20 miles can be the difference between getting an inch of rain or a foot of snow and with many major metropolitan areas on the East Coast being in such close proximity to each other correctly predicting the rain snow line was crucial yet another advancement in weather technology that played a huge role in forecasting this event was the implementation of wsr 88d radar systems which offered a much higher resolution as well as the addition of a velocity product one of the first operational wsr 88d systems in the country was located in Sterling Virginia Which covered the DC metropolitan area individual bands of snow and ice pellets were tracked precisely across Eastern Virginia and now casts were issued every hour to warn those in the heavy bands path not only that but the weather forecasting office was able to take ground-based observations of where that rain snow line was and compare it to the radar imagery that they were receiving at the time the low Center was now approaching the greater DC area and with six inches of snow already on the ground the associated 70 mile an hour wind gusts were grinding the city to a complete stop the mixture of sleet and snow made travel impossible in the nation's capital strong winds blowing out of the East funneled ocean waters into coastal towns in Delaware and New Jersey such as Seabright many of these towns had not yet recovered from the December Nor'easter just three months prior to the west of D.C The Ridges and valleys of Western Virginia Western Maryland and the Appalachian Plateau of West Virginia were getting buried in more snow than they had seen in decades because the path of the low Center stayed west of the Atlantic coast over North Carolina which is not really typical of a nor'easter most of the moisture in cold air flowed over the Appalachian Plateau resulting in record 24-hour snow totals in Pennsylvania even though interstates were closed across the state city officials in Pittsburgh decided not to cancel their St Patrick's Day Parade scheduled for that morning in fact it was the only parade on the entire East Coast that wasn't canceled by new noon the snow was falling at rates of three inches an hour hundreds of vehicles were left stranded on city streets 23.6 inches of snow fell within those 24 hours a record that still stands today to the East and Latrobe three feet of snow fell with drifts as high as 10 feet as Saturday progressed the southeasterly winds ferociously battered the coast of Long Island New York many residents along the coast waited until the blizzard had already begun to consider leaving and that made matters much more difficult in the afternoon with 10 to 20 foot waves already crashing onto the coast officials began transporting tons of sand to coastal areas dumping it via bulldozers in an attempt to stop further erosion while the wind and sleet was pelting New York City unfathomable snow was falling to the North in Upstate New York for cities like Syracuse which had seen over 125 inches of snow that winter already the super storm was just adding insult to injury well actually it was like adding injury to injury the day before Wegmans sold 300 of their daily average sales of merchandise some customers of video king rental service were renting out seven VHS movies at a time to watch during the blizzard which wasn't even enough because for 48 hours the snow on that Northwestern side of the low didn't stop enhanced by moisture from Lake Ontario the greater Syracuse area saw nearly 43 inches of snow by Monday Morning by noon on Sunday the 14th the low Center had passed near Boston holding steady and 962 millibars the entirety of New England proceeded to get 10 to 20 inches of snow within that 24-hour period with higher elevations receiving double that amount all major airports interstates and turnpikes were closed all state highways were impassable by the time the storm had finally moved out of Maine on Sunday evening the entire Eastern third of the United States was completely out of sorts the largest snowfall happened on Mount Lacon in Tennessee a 6600 foot peak in the Smoky Mountains between 50 and 60 inches officially fell at the peak an inescapable amount of snow even for the most experienced hikers Mount Mitchell to the east wasn't too far behind seeing 50 inches which took an entire month to completely melt all-time low record pressure readings were set in Newark Philly D.C Wilmington and Wilkes Barre 60 thousand lightning strikes were observed across the eastern U.S during the storm many occurring within snow squalls an estimated 318 people lost their lives in various ways freezing to death while hiking in the Smokies getting washed out to sea by the duratio-induced storm surge in Florida getting into a car accident while attempting to drive through the freezing rain many people in Florida failed to appreciate the magnitude of the impending storm because it was extra tropical in nature the general feeling was that if it wasn't a hurricane it was no big deal the storm caused over 5 billion dollars in damage across 21 states affecting nearly 30 percent of the entire U.S population but amidst all the chaos the meteorology Operations Division in conjunction with the local forecasting offices absolutely nailed their forecasts retrospective analyzes of the event shows that Medium rage forecast models especially the new Ensemble products were critical in predicting where the greatest snow totals were going to be and Ensemble products are still widely used for weather forecasting today not only that but the usage of the wsr 88d radar in Sterling Virginia showed the forecasters how much more information they could give residents in the forecast area when it came to a snowstorm we're not talking about rotating winds in a supercell thunderstorm visible via velocity products these were primarily convective squalls that produce snow and sleet and still the new radar system provided so much more useful information it will likely be a great while until we see another snowstorm of that magnitude make landfall on the Gulf Coast and then right up the East Coast like the superstorm did in 93 but whenever that happens next we will be able to predict it and there better not be anyone hiking in the Smokies who gets caught off guard by the storm with all our modern technology there's just no excuse for not being weather aware if you guys have any personal stories about the super storm of 93 please share it in the comments below my favorite thing is to read your guys's personal stories about weather events that I've covered and if you want to learn more about weather through past historical events definitely subscribe like and comment that helps me out more than you can imagine and I will see you guys soon thanks

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Keywords: snow, blizzard, weather, The Unfathomable Winter Superstorm of March 13 1993: an analysis, Storm of the Century, march 13 1993, Blizzard 93, worst storm in US history, deadly blizzard, smoky mountains snow, snowstorm, snow in the deep south, alabama snow, cyclone, super storm, storm surge, florida derecho, super derecho 1993, weather models, forecasting models, weatherbox, ryan hall y'all, mount pinatubo eruption, snow hey oh

Id: 3khexyHA-90

Length: 25min 11sec (1511 seconds)

Published: Mon Mar 20 2023