Preparedness & Weather Message Dissemination
While there was a tornado warning for Utica over 20 minutes prior to the tornado striking the town, there were still eight direct fatalities and one indirect fatality. In the past decade, the NWS has worked closely with the entire weather enterprise and its emergency management and broadcast media partners, as well as team with social scientists to better understand response to weather threats and the conveying of that in NWS messages. Much has changed in this realm since 2004, and below is a listing of some of these improvements.
A quote from Patti S. on our Accounts page of this event was "...thinking it was just like any other of the hundred tornado warnings we've seen in our county." While any one area is actually rarely under tornado warnings (sometimes going years without any), it was true that in 2004 all tornado warnings were basically created equal. The entire NWS Central Region (including NWS Chicago) is now issuing Impact Based Warnings. Within these warnings, more information about the threat level and impacts can be conveyed by NWS meteorologists, if the environment, radar, and spotter reports support as such. For instance during the November 17th outbreak, a heightened degree of potential damage was mentioned in multiple warnings given the favored environment and radar signatures for long-lived destructive tornadoes.
Tornadoes on April 20, 2004 passed within two miles of Illinois Valley Community College, Kankakee Community College, and Joliet Junior College, and even directly impacted the IVCC campus. Warnings from NWS Chicago now often mention colleges and universities, as well as other areas where there may be large groups of people, including outdoor venues.
The NWS continues to work closely with emergency managers and expand its reach with community leaders and other public officials toward preparedness for severe weather. The NWS has a program called StormReady to help prepare communities, universities, and other locations to ensure reception and communication of severe weather threats. The NWS Chicago office is very active with this program, having over 60 entities certified. There were only a handful in 2004.
The April 20, 2004 proved an extremely difficult one to forecast at that time. Just a couple hours prior to the tornado and numerous others in the region, it was thought that storms may not even develop, let alone produce significant severe weather.
Meteorologists rely upon high capacity computing systems to run millions of mathematical equations every hour, on massive weather datasets. The computer models provide a visual forecast as to how a particular weather system may evolve in the future. For the most part, Numerical Weather Prediction (NWP) has kept pace with technological advancements, with the National Weather Service (NWS) leveraging these tools extensively when preparing for possible convection. One advancement of NWP that has greatly benefited forecasters has been the ability to perform retrospective analysis of significant events through the Weather Research and Forecasting (WRF) model. By ingesting past data, forecasters can simulate that event in order to gain further insight of the evolution process.
In the early 2000's NWP was limited on resolution capacity; however, this has greatly changed over recent years with newer hi-resolution models coming online and updating on a frequent basis. Forecasters now have tools that analyze mesoscale features which were once very limiting from the 1990's. Below are examples from simulations performed on the Utica Tornado through a retrospective simulation.
In addition to the above images displaying simulated reflectivity, forecasters now have the ability to display the antecedent conditions before seeing the main thunderstorms/supercells develop. Meteorologist scour these environmental parameters, in order to prepare for convective initiation. Below are just a couple parameters forecasters use in solving the meteorological puzzle.
In the past decade there have been several advancements in the computer processing and displaying of radar data. The below image captures the difference in radar resolution that NWS warning forecasters have when interrogating radar data.
In addition, the NWS radars were upgraded to dual-polarization in 2011-2013. This advancement allowed for better detection of precipitation types, including hail. But it also allowed for meteorologists to better detect non-meteorological echoes, including tornadic debris. During the storm pictured above from November 17th, NWS meteorologists could tell there was a destructive tornado based on concentrated debris signatures on radar from Washington to Dana.