Figure 1.
Conceptual model of a deep convective storm with the potential to generate intense downdrafts and damaging downburst winds. Courtesy of Rob Seigel and Susan C. van den Heever, Global Precipitation Measurement (GPM, available online at
https://gpm.nasa.gov/GPM, accessed on 7 July 2020).
Figure 1.
Conceptual model of a deep convective storm with the potential to generate intense downdrafts and damaging downburst winds. Courtesy of Rob Seigel and Susan C. van den Heever, Global Precipitation Measurement (GPM, available online at
https://gpm.nasa.gov/GPM, accessed on 7 July 2020).
Figure 2.
A summary of observational remote sensing data applied for the study and analysis of the June 2012 North American Derecho. (
a,
c) are examples of vertical sounding profiles generated from IASI and MWRP datasets, respectively, for diagnosing the pre-convective environment, while (
b) is an example of a satellite-derived microwave image product that identifies signatures associated with a derecho-producing convective system (DCS) [
26,
27].
Figure 2.
A summary of observational remote sensing data applied for the study and analysis of the June 2012 North American Derecho. (
a,
c) are examples of vertical sounding profiles generated from IASI and MWRP datasets, respectively, for diagnosing the pre-convective environment, while (
b) is an example of a satellite-derived microwave image product that identifies signatures associated with a derecho-producing convective system (DCS) [
26,
27].
Figure 3.
Summary composite image of the June 2012 North American Derecho displaying the 29 June descending node and 30 June ascending node METOP-A orbit (nadir) tracks, radar reflectivity (dBZ), and significant wind reports (kt) over (a) eastern CONUS and (b) the Mid-Atlantic region; NEXRAD radial velocity (kt) and significant wind reports (kt) over (c) eastern CONUS and (d) the Mid-Atlantic region along the storm track. Black oval outlines the derecho genesis region over the upper Mississippi Valley. Red circle in (a,c) marks the IASI retrieval location over Tipton, Iowa (“RTP”); (b,d) marks the IASI retrieval location near Salisbury, Maryland (“SBY”).
Figure 3.
Summary composite image of the June 2012 North American Derecho displaying the 29 June descending node and 30 June ascending node METOP-A orbit (nadir) tracks, radar reflectivity (dBZ), and significant wind reports (kt) over (a) eastern CONUS and (b) the Mid-Atlantic region; NEXRAD radial velocity (kt) and significant wind reports (kt) over (c) eastern CONUS and (d) the Mid-Atlantic region along the storm track. Black oval outlines the derecho genesis region over the upper Mississippi Valley. Red circle in (a,c) marks the IASI retrieval location over Tipton, Iowa (“RTP”); (b,d) marks the IASI retrieval location near Salisbury, Maryland (“SBY”).
Figure 4.
Hovmӧller diagrams of equivalent potential temperature (θ
e), with overlying plots of θ
e lapse rate (LR), in degrees Kelvin (K), derived from MWRPs at (
a) Cedar Falls, Iowa, (
b) Cleveland, Ohio, (
c) Germantown, Maryland, and (
d) Beltsville, Maryland, for the period 1200 UTC 29 June 2012 to 0400 UTC 30 June 2012. Dashed rectangles in (
a–
c) outline diagram extent in
Section 3.
Figure 4.
Hovmӧller diagrams of equivalent potential temperature (θ
e), with overlying plots of θ
e lapse rate (LR), in degrees Kelvin (K), derived from MWRPs at (
a) Cedar Falls, Iowa, (
b) Cleveland, Ohio, (
c) Germantown, Maryland, and (
d) Beltsville, Maryland, for the period 1200 UTC 29 June 2012 to 0400 UTC 30 June 2012. Dashed rectangles in (
a–
c) outline diagram extent in
Section 3.
Figure 5.
(a) Davenport, Iowa RAOB sounding profile at 1200 UTC, (b) ground-based sounding profile retrieval from the Cedar Falls, Iowa microwave radiometer (MWR) at 1300 UTC, (c) METOP-A IASI sounding profile retrieved near Tipton, Iowa, at 1623 UTC, and (d) sounding profile retrieval from the Cedar Falls MWR at 1623 UTC 29 June 2012. Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), “CI” represents conditional instability, and “PI” represents potential instability. ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 5.
(a) Davenport, Iowa RAOB sounding profile at 1200 UTC, (b) ground-based sounding profile retrieval from the Cedar Falls, Iowa microwave radiometer (MWR) at 1300 UTC, (c) METOP-A IASI sounding profile retrieved near Tipton, Iowa, at 1623 UTC, and (d) sounding profile retrieval from the Cedar Falls MWR at 1623 UTC 29 June 2012. Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), “CI” represents conditional instability, and “PI” represents potential instability. ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 6.
Velocity azimuth display (VAD) wind profile (VWP) in knots (kt) from (
a) Davenport, Iowa NEXRAD between 1145 and 1230 UTC and (
b) Chicago (Romeoville), Illinois NEXRAD between 1545 and 1630 UTC 29 June 2012. Black vertical dashed lines mark the radiosonde observation (RAOB) time at Davenport in (
a) and the METOP-A MHS retrieval time in (
b) as shown in
Figure 5. “UC” represents the undercurrent in (
b).
Figure 6.
Velocity azimuth display (VAD) wind profile (VWP) in knots (kt) from (
a) Davenport, Iowa NEXRAD between 1145 and 1230 UTC and (
b) Chicago (Romeoville), Illinois NEXRAD between 1545 and 1630 UTC 29 June 2012. Black vertical dashed lines mark the radiosonde observation (RAOB) time at Davenport in (
a) and the METOP-A MHS retrieval time in (
b) as shown in
Figure 5. “UC” represents the undercurrent in (
b).
Figure 7.
NEXRAD reflectivity (dBZ) map-view images at 1400 UTC 29 June 2012 from (a) Des Moines and (b) Davenport, Iowa; 1300 to 1430 UTC 29 June 2012 Hovmӧller diagrams of (c) liquid density (g m−3) and (d) equivalent potential temperature (θe in degrees Kelvin (K)) as derived from Cedar Falls, Iowa MWRP. Des Moines NEXRAD DVIL is plotted over the diagrams at corresponding MWRP retrieval times.
Figure 7.
NEXRAD reflectivity (dBZ) map-view images at 1400 UTC 29 June 2012 from (a) Des Moines and (b) Davenport, Iowa; 1300 to 1430 UTC 29 June 2012 Hovmӧller diagrams of (c) liquid density (g m−3) and (d) equivalent potential temperature (θe in degrees Kelvin (K)) as derived from Cedar Falls, Iowa MWRP. Des Moines NEXRAD DVIL is plotted over the diagrams at corresponding MWRP retrieval times.
Figure 8.
METOP-A MHS (a) 89 GHz channel brightness temperature (TB, degrees Kelvin (K)) image and (b) 157 GHz scattering index (SI157) at 1623 UTC 29 June 2012. (c,d) as in (a,b) with overlying Davenport, Iowa (DVN) NEXRAD reflectivity (dBZ) measurements. “CF” marks the location of the Cedar Falls, Iowa MWRP, “RTP”is the location of the IASI retrieval over Tipton, Iowa, and “53” is the location of the first severe wind report of the event (27 m s−1 (53 kt)) recorded at Burns Harbor, Indiana. White lines mark the 29 June descending node METOP-A orbit (nadir) tracks.
Figure 8.
METOP-A MHS (a) 89 GHz channel brightness temperature (TB, degrees Kelvin (K)) image and (b) 157 GHz scattering index (SI157) at 1623 UTC 29 June 2012. (c,d) as in (a,b) with overlying Davenport, Iowa (DVN) NEXRAD reflectivity (dBZ) measurements. “CF” marks the location of the Cedar Falls, Iowa MWRP, “RTP”is the location of the IASI retrieval over Tipton, Iowa, and “53” is the location of the first severe wind report of the event (27 m s−1 (53 kt)) recorded at Burns Harbor, Indiana. White lines mark the 29 June descending node METOP-A orbit (nadir) tracks.
Figure 9.
Ground-based sounding profile retrievals from the Cleveland, Ohio, microwave radiometer (MWR) on 29 June 2012: (a) zenith at 2100 UTC, (b) south scan at 2100 UTC, (c) zenith at 2200 UTC, and (d) south scan at 2200 UTC. Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “EML” represents the elevated mixed layer. ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 9.
Ground-based sounding profile retrievals from the Cleveland, Ohio, microwave radiometer (MWR) on 29 June 2012: (a) zenith at 2100 UTC, (b) south scan at 2100 UTC, (c) zenith at 2200 UTC, and (d) south scan at 2200 UTC. Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “EML” represents the elevated mixed layer. ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 10.
NEXRAD reflectivity map-view images from (a) Cleveland, Ohio (CLE), at 2232 UTC, (b) Detroit, Michigan (DTX), at 2230 UTC, and (c) Pittsburgh, Pennsylvania (PBZ), at 2230 UTC 29 June 2012.
Figure 10.
NEXRAD reflectivity map-view images from (a) Cleveland, Ohio (CLE), at 2232 UTC, (b) Detroit, Michigan (DTX), at 2230 UTC, and (c) Pittsburgh, Pennsylvania (PBZ), at 2230 UTC 29 June 2012.
Figure 11.
F-17 SSMIS (a) polarization corrected temperature (PCT) and (b) 150 GHz scattering index (SI150), in degrees Kelvin (K), at 2207 UTC 29 June 2012. (c,d) display the product imagery with overlying Pittsburgh, Pennsylvania NEXRAD reflectivity (dBZ). White circle marks the location of the Cleveland, Ohio MWRP. “DTX” and “PBZ” mark the location of the Detroit, Michigan, and Pittsburgh NEXRAD stations, respectively.
Figure 11.
F-17 SSMIS (a) polarization corrected temperature (PCT) and (b) 150 GHz scattering index (SI150), in degrees Kelvin (K), at 2207 UTC 29 June 2012. (c,d) display the product imagery with overlying Pittsburgh, Pennsylvania NEXRAD reflectivity (dBZ). White circle marks the location of the Cleveland, Ohio MWRP. “DTX” and “PBZ” mark the location of the Detroit, Michigan, and Pittsburgh NEXRAD stations, respectively.
Figure 12.
2000 to 2315 UTC 29 June 2012 Hovmӧller diagrams of (a) liquid density (g m−3), (b) equivalent potential temperature (θe in degrees Kelvin (K)), and (d) vertical gradient of potential temperature (Del θ) as derived from Cleveland, Ohio MWRP. (c) Del θ Hovmӧller diagram (c) from 1200 UTC 29 June to 0400 UTC 30 June 2012 and (d) from 2000 to 2315 UTC 29 June 2012. Detroit, Michigan NEXRAD DVIL is plotted over (a) and (b) at corresponding MWRP retrieval times.
Figure 12.
2000 to 2315 UTC 29 June 2012 Hovmӧller diagrams of (a) liquid density (g m−3), (b) equivalent potential temperature (θe in degrees Kelvin (K)), and (d) vertical gradient of potential temperature (Del θ) as derived from Cleveland, Ohio MWRP. (c) Del θ Hovmӧller diagram (c) from 1200 UTC 29 June to 0400 UTC 30 June 2012 and (d) from 2000 to 2315 UTC 29 June 2012. Detroit, Michigan NEXRAD DVIL is plotted over (a) and (b) at corresponding MWRP retrieval times.
Figure 13.
METOP-A IASI retrievals near Salisbury, Maryland, during the evening of 29 June 2012 (0203 UTC 30 June): (a) IR+MW sounding profile; (b) IR+MW sounding profile modified by observed surface temperature and dew point at Salisbury Regional Airport; (c) modified IR+MW sounding profile plotted with virtual temperature. Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “TPW” represents total precipitable water in inches (in). ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 13.
METOP-A IASI retrievals near Salisbury, Maryland, during the evening of 29 June 2012 (0203 UTC 30 June): (a) IR+MW sounding profile; (b) IR+MW sounding profile modified by observed surface temperature and dew point at Salisbury Regional Airport; (c) modified IR+MW sounding profile plotted with virtual temperature. Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “TPW” represents total precipitable water in inches (in). ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 14.
(a) Modified METOP-A IASI IR+MW sounding profile retrieved near Salisbury, Maryland, at 0203 UTC 30 June 2012 as compared to (b) a ground-based sounding profile retrieval from the Germantown, Maryland, microwave radiometer (MWR). Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “TPW” represents total precipitable water in inches (in). ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 14.
(a) Modified METOP-A IASI IR+MW sounding profile retrieved near Salisbury, Maryland, at 0203 UTC 30 June 2012 as compared to (b) a ground-based sounding profile retrieval from the Germantown, Maryland, microwave radiometer (MWR). Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “TPW” represents total precipitable water in inches (in). ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 15.
(a) Modified METOP-A IASI IR+MW sounding profile retrieved near Salisbury, Maryland, at 0203 UTC 30 June 2012 as compared to (b) a ground-based sounding profile retrieval from the Howard University, Beltsville, Maryland (HUBC), microwave radiometer (MWR). Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “TPW” represents total precipitable water in inches (in). ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 15.
(a) Modified METOP-A IASI IR+MW sounding profile retrieved near Salisbury, Maryland, at 0203 UTC 30 June 2012 as compared to (b) a ground-based sounding profile retrieval from the Howard University, Beltsville, Maryland (HUBC), microwave radiometer (MWR). Red curves and green curves represent the temperature and dewpoint soundings in degrees Celsius (°C), respectively. “MUCAPE” is most unstable parcel CAPE in J kg−1, “MWPI” represents the Microburst Windspeed Potential Index (Pryor 2015), “WGP” represents wind gust potential derived from the MWPI in knots (kt), and “TPW” represents total precipitable water in inches (in). ΓT and Γw represent dry-bulb temperature and wet-bulb temperature lapse rates, respectively.
Figure 16.
METOP-A MHS 89 GHz brightness temperature (TB, K) image at 0200 UTC 30 June 2012 with (a) overlying Sterling, Virginia (LWX) NEXRAD radial velocity (kt) and (b) reflectivity (dBZ) measurements. (c,d) as in (a,b) with overlying Sterling, Virginia (LWX) NEXRAD reflectivity (dBZ) measurements. “GER” and “BLT” mark the location of the Germantown and Beltsville, Maryland MWRPs, respectively. The white circle marks the location of the IASI retrieval over Salisbury, Maryland, and “62” is the location of the first severe wind report in the Washington, DC, metropolitan area (31.7 m s−1 (62 kt)) recorded at Dulles International Airport, Virginia. White lines mark the 30 June ascending node METOP-A orbit (nadir) tracks.
Figure 16.
METOP-A MHS 89 GHz brightness temperature (TB, K) image at 0200 UTC 30 June 2012 with (a) overlying Sterling, Virginia (LWX) NEXRAD radial velocity (kt) and (b) reflectivity (dBZ) measurements. (c,d) as in (a,b) with overlying Sterling, Virginia (LWX) NEXRAD reflectivity (dBZ) measurements. “GER” and “BLT” mark the location of the Germantown and Beltsville, Maryland MWRPs, respectively. The white circle marks the location of the IASI retrieval over Salisbury, Maryland, and “62” is the location of the first severe wind report in the Washington, DC, metropolitan area (31.7 m s−1 (62 kt)) recorded at Dulles International Airport, Virginia. White lines mark the 30 June ascending node METOP-A orbit (nadir) tracks.
Figure 17.
(a,b) Sterling, Virginia NEXRAD Constant Altitude—Plan Position Indicator (CAPPI) reflectivity (dBZ) at 300 and 2500 m altitude, respectively, at 0235 UTC 30 June 2012; (c) 0144 to 0244 UTC 30 June 2012 Hovmӧller diagram of the deviation of equivalent potential temperature (in degrees Kelvin (K)) as derived from Germantown, Maryland MWRP.
Figure 17.
(a,b) Sterling, Virginia NEXRAD Constant Altitude—Plan Position Indicator (CAPPI) reflectivity (dBZ) at 300 and 2500 m altitude, respectively, at 0235 UTC 30 June 2012; (c) 0144 to 0244 UTC 30 June 2012 Hovmӧller diagram of the deviation of equivalent potential temperature (in degrees Kelvin (K)) as derived from Germantown, Maryland MWRP.
Figure 18.
0200 to 0400 UTC 30 June 2012 Hovmӧller diagrams of (a) liquid density (g m−3) and (b) equivalent potential temperature (θe in degrees Kelvin (K)) as derived from Germantown, Maryland MWRP. Sterling, Virginia NEXRAD DVIL is plotted over the diagrams at corresponding MWRP retrieval times.
Figure 18.
0200 to 0400 UTC 30 June 2012 Hovmӧller diagrams of (a) liquid density (g m−3) and (b) equivalent potential temperature (θe in degrees Kelvin (K)) as derived from Germantown, Maryland MWRP. Sterling, Virginia NEXRAD DVIL is plotted over the diagrams at corresponding MWRP retrieval times.
Figure 19.
Velocity azimuth display (VAD) wind profile (VWP) in knots (kt) from Sterling, Virginia NEXRAD between 0200 and 0300 UTC 30 June 2012.
Figure 19.
Velocity azimuth display (VAD) wind profile (VWP) in knots (kt) from Sterling, Virginia NEXRAD between 0200 and 0300 UTC 30 June 2012.
Figure 20.
(a) TERRA MODIS split window IR brightness temperature difference product image at 0305 UTC 30 June 2012 compared to VAD wind profiles, in knots (kt), from (b) Sterling, Virginia, (c) Philadelphia, Pennsylvania (Manchester Township, New Jersey), and (d) Norfolk-Richmond, Virginia (Wakefield, Virginia) NEXRAD stations, surrounding the retrieval time of the MODIS image.
Figure 20.
(a) TERRA MODIS split window IR brightness temperature difference product image at 0305 UTC 30 June 2012 compared to VAD wind profiles, in knots (kt), from (b) Sterling, Virginia, (c) Philadelphia, Pennsylvania (Manchester Township, New Jersey), and (d) Norfolk-Richmond, Virginia (Wakefield, Virginia) NEXRAD stations, surrounding the retrieval time of the MODIS image.
Table 1.
Derecho peak wind measurements (m s−1) compared to gust factors (G), surface peak temperature departures (ΔT), and MWR and IASI-derived MWPI values and associated wind gust potential (kt). Time is in UTC, ΔT in K, and wind gust potential (WGP) is in m s−1. “NA” denotes that an IASI retrieval not available at the event time.
Table 1.
Derecho peak wind measurements (m s−1) compared to gust factors (G), surface peak temperature departures (ΔT), and MWR and IASI-derived MWPI values and associated wind gust potential (kt). Time is in UTC, ΔT in K, and wind gust potential (WGP) is in m s−1. “NA” denotes that an IASI retrieval not available at the event time.
METAR Station | Date/ Time | Peak Wind | G | ΔT | MWR MWPI | MWR WGP | IASI MWPI | IASI WGP | Ret Time |
---|
DPA | 29/1602 | 23.7 | 2.42 | −5 | 4.8 | 24.7 | 3.8 | 22.6 | 1623 |
MFD | 29/2136 | 19 | 1.85 | −8 | 1.9 | 19.5 | NA | NA | 2100 |
IAD | 30/0235 | 30.4 | 2.27 | −9 | 6.8 | 30.4 | 6.4 | 29.3 | 0200 |
DCA | 30/0252 | 31.4 | 2.54 | −10 | 6.8 | 30.4 | 6.4 | 29.3 | 0200 |
BWI | 30/0305 | 29.3 | 1.78 | −10 | 6 | 28.3 | 6.4 | 29.3 | 0200 |
Table 2.
Correlation of peak wind and ΔT to MWR-derived MWPI values, and peak wind to ΔT.
Table 2.
Correlation of peak wind and ΔT to MWR-derived MWPI values, and peak wind to ΔT.
| Peak Wind to MWPI | ΔT to MWPI | Peak Wind to ΔT |
---|
R | 0.98 | 0.52 | 0.68 |
R2 | 0.96 | 0.27 | 0.46 |