[Paper Review] Microburst nowcasting applications of GOES

Kenneth L. Pryor|arXiv (Cornell University)|Jun 10, 2011

Meteorological Phenomena and Simulations26 references3 citations

TL;DR

This paper evaluates GOES-based microburst nowcasting products, specifically the Microburst Windspeed Potential Index (MWPI) and a bi-spectral brightness temperature difference (BTD) product, demonstrating their effectiveness in predicting downburst intensity. It shows a statistically significant negative correlation between overshooting top (OT) minimum temperature and MWPI values, confirming that stronger updrafts (indicated by high CAPE) enhance downdraft severity and microburst potential.

ABSTRACT

Recent testing and validation have found that the Geostationary Operational Environmental Satellite (GOES) microburst products are effective in the assessment and short-term forecasting of downburst potential and associated wind gust magnitude. Two products, the GOES sounder Microburst Windspeed Potential Index (MWPI) and a new bi-spectral GOES imager brightness temperature difference (BTD) product have demonstrated capability in downburst potential assessment. In addition, a comparison study between the GOES-R Convective Overshooting Top (OT) Detection and MWPI algorithms has been completed for cases that occurred during the 2007 to 2009 convective seasons over the southern Great Plains. Favorable results of the comparison study include a statistically significant negative correlation between the OT minimum temperature and MWPI values and associated measured downburst wind gust magnitude. The negative functional relationship between the OT parameters and wind gust speed highlights the importance of updraft strength, realized by large CAPE, in the generation of heavy precipitation and subsequent intense convective downdraft generation. This paper provides an updated assessment of the GOES MWPI and GOES BTD algorithms, presents case studies demonstrating effective operational use of the microburst products, and presents results of a cross comparison study of the GOES-R overshooting top (OT) detection algorithm over the United States Great Plains region.

Motivation & Objective

• To assess the operational effectiveness of GOES-derived microburst nowcasting products in predicting downburst potential and wind gust intensity.
• To evaluate the performance of the GOES sounder Microburst Windspeed Potential Index (MWPI) and a new bi-spectral GOES imager brightness temperature difference (BTD) product.
• To compare the GOES-R Convective Overshooting Top (OT) Detection algorithm with the MWPI algorithm over the southern Great Plains during 2007–2009.
• To establish the relationship between updraft strength (via CAPE) and subsequent downdraft intensity in convective systems.
• To provide case studies demonstrating real-time operational utility of these satellite-based microburst detection tools.

Proposed method

• Utilizes the GOES sounder to compute the Microburst Windspeed Potential Index (MWPI), which estimates downdraft wind speed potential based on atmospheric instability and moisture profiles.
• Applies a bi-spectral GOES imager brightness temperature difference (BTD) product to detect overshooting top features indicative of strong updrafts.
• Compares the GOES-R OT detection algorithm with the MWPI algorithm using data from 2007–2009 convective events over the southern Great Plains.
• Analyzes the statistical relationship between OT minimum temperature and MWPI values, as well as observed downburst wind gusts.
• Employs case studies to validate the operational utility of the MWPI and BTD products in real-time microburst forecasting.
• Uses a cross-comparison framework to assess consistency and complementarity between the OT detection and MWPI algorithms.

Experimental results

Research questions

• RQ1 How effective are the GOES sounder MWPI and bi-spectral BTD products in assessing microburst potential?
• RQ2 What is the statistical relationship between GOES-R overshooting top (OT) minimum temperature and observed microburst wind gusts?
• RQ3 To what extent does the OT detection algorithm correlate with the MWPI in identifying systems with high downdraft potential?
• RQ4 How well do these satellite-based products perform in operational nowcasting of microbursts over the southern Great Plains?
• RQ5 What role does updraft strength (as indicated by high CAPE) play in the generation of intense convective downdrafts and microbursts?

Key findings

• The GOES sounder MWPI and bi-spectral BTD products demonstrated strong capability in assessing downburst potential and intensity.
• A statistically significant negative correlation was found between the minimum temperature of overshooting tops (OT) and MWPI values, indicating stronger updrafts are linked to higher microburst wind gusts.
• The negative functional relationship between OT temperature and wind gust speed underscores the importance of updraft strength and high CAPE in generating intense downdrafts.
• The comparison study confirmed that OT detection and MWPI algorithms are complementary, with OT minimum temperature serving as a reliable proxy for updraft intensity.
• Case studies validated the operational utility of these products in real-time microburst nowcasting, particularly in high-impact convective environments.
• The results support the integration of MWPI and OT detection into operational severe weather warning systems for improved lead time and accuracy.