The Utility of Non-NWS Upper Air Observations – NC State Soundings Support Severe Weather Operations at NWS Raleigh on May 4th and 5th, 2017

NC State sounding from 0103 UTC 05/05/2017 during a severe weather event.

There are several non-NWS organizations that take upper-air observations and share them with NWS forecasters. These organizations largely consist of universities, military installations or research laboratories. The motivation for taking these observations include research efforts as well as educational and training activities.

One example of such an organization is the “Sounding Club” at NC State University which is lead by students and overseen by professors within the Atmospheric Science department.  Some of the goals of the organization according to their website are to help students obtain hands-on experience in addition to collecting data for projects. In addition to professional development and project support, the soundings have been used by NWS forecasters to support operational needs.

A pair of soundings from the NC State Sounding Club were very helpful during the evening and overnight hours on May 4th and 5th when there was concern for severe convection (SPC reports).  NWS Forecaster Michael Strickler noted the utility of the soundings at approximately 01Z and 03Z on 05 May…

The soundings revealed that the low 70s/low 60s surface temperatures and dew points were already supportive of surface-based convection even prior to the arrival of the mT air mass from the southeast, but with only weak instability and low equilibrium levels. This information provided radar operators confidence of severe wind and tornado potential. The sounding also revealed the character and strength of the low level shear, with a greater degree of confidence relative to that of WSR-derived VWP winds/hodographs that tend to fluctuate/become noisy and are consequently often times less reliable. Pre-QLCS storm motion vectors, as indicated by the soundings, also proved beneficial from a pre-warning situational awareness standpoint.

NWS Chat message from 0525 UTC (0125 AM EDT) 05/05/2017 describing the near term environment.

UNC Asheville sounding from 0300 UTC 01/07/2017 during a winter storm that affected much of the Virginias and Carolinas.

NWS Raleigh forecasters obtain the soundings from the NC State Sounding Club in near real-time either through email, posts to the CSTAR mailing list, or via social media.  In addition to NC State, there are several other organizations that take upper air observations.  UNC Asheville has taken upper air observations during many winter storms in recent years as a part of their Sounding-based Experiment on Mixed Precipitation Events (SEMPE) project. These soundings have been used by the NWS offices in Greenville-Spartanburg, Blacksburg and Raleigh among others.

In the Southeast, we are aware of several organizations taking supplemental observations; some of them are shown in the list below:

  • NC State
  • UNC Asheville
  • UNC Charlotte
  • University of South Carolina
  • University of Alabama Huntsville
  • Mississippi State
  • University of Louisiana-Monroe
  • Simmons AAF Fort Bragg
  • Redstone Arsenal
  • NOAA Lab in Oak Ridge, TN

These observations have a great deal of potential to support NWS warning and forecast operations. Unfortunately, they are often underutilized for a variety of reasons including a lack of awareness and coordination of the sounding operations, limitations in the dissemination and display of the soundings, and an inability to ingest the data into AWIPS.

There is a desire to collect and organize these grass roots observations into a process to improve the awareness, communication, access and display of these observations among NWS forecasters. Collaborators with the NC State CSTAR group will be reaching out to those taking the observations to gauge interest in improve the flow of the data to the NWS and perhaps elsewhere.

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