Mission Summary
20190831H2 Aircraft 42RF
TDR into Dorian

Aircraft Crew (42RF)
Aircraft CommanderJustin Kibbey
Co-pilotJohn Rossi
Co-pilotAdam Abittol
Flight Engineer
NavigatorSam Urato
Flight DirectorJack Parrish
System Engineer
Data Technician

Science crew (42RF)
LPSAndrew HazeltonHRD
DropsondeKathryn SellwoodHRD
RadarRob RogersHRD
ObserverZorana JelenakNESDIS
ObserverJoe SappNESDIS
GuestMarcus Garzaunk

Science crew (Ground)
RadarJohn GamacheHRD

Figure 1. Flight plan for 20190831H2 mission for Dorian

Figure 2. Actual flight track for 20190831H2 mission for Dorian

Mission Plan :

his was an EMC-tasked NOAA42 Tail Doppler Radar (TDR) mission with a proposed butterfly pattern (Figure 1), as well as a NESDIS Ocean Winds add-on. The pattern was executed well.

Mission Summary :

Take off Landing
Linder_Lakeland, FL 21:06 UTC Linder_Lakeland, FL 03:39 UTC
Expendables 30 sondes

Figure 2: Infrared satellite image of Hurricane Dorian valid
at 0146 UTC 01 September 2019.

Figure 3: Hurricane Analysis and Forecast System (HAFS) analysis of 850-hPa vorticity and
200-hPa wind valid at 00 UTC 01 September 2019.

Dorian had strengthened from the previous day, and was a strong Category 4 hurricane with 130-knot winds during the flight. Figure 2 shows an infrared satellite image of Dorian during the time of the flight. The storm had grown in size (in terms of the CDO) and the core was more symmetric, although there was still some hint of asymmetry due to shear from the NW. Analzyed 200-hPa winds at this time showed that Dorian was embedded in an area of light upper-level flow, with a well-established outflow channel to the east and south of the TC.

Figure 4: 2-km TDR reflectivity/wind for the 20190831H2 mission (image from Paul Reasor).

Figure 5: TDR radial velocity for the second pass across
the center during the 20190831H2 mission (image from Paul Reasor).
The radar data collected once again provided complete coverage of the inner-core region as well as outer bands (Figure 4). Radar data was collected on all 3 passes across the TC, as well as on an ocean winds pattern completed at the end of the mission. This pattern involved flying back into the center from the WNW (303 degrees) and then out to the NNW (346 degrees). The merged radar analysis showed a small, symmetric inner core, with an RMW of only 9 n mi. There were also some strong outer bands evident on the reflectivity, but there was no evidence of an eyewall replacement cycle with a prominent secondary wind maximum. The radial velocity derived from the TDR revealed a very symmetric structure, with strong inflow in the lowest 0.5-1 km and strong outflow above 13 km. There was little hint of shear-relative inflow asymmetry, indicative of the overall lack of shear impact on the TC inner-core region during the flight.
Prepared by the Hurricane Research Division
Aug. 28, 2019 12:15 PM EDT
Aircraft: N42RF
Proposed takeoff: 31/2100Z
deg min deg min deg nm hr:min
1S25 3376 02 90/2401:06
2S27 0373 09 90/0601:52
3S27 4874 36 90/3602:15
4S24 4874 36 90/1803:01
5S25 3373 10 90/1203:24
6S27 0376 03 90/3004:10

Mission Evaluation / Problems :

Figure 6: SFMR wind speed (colors) and dropsonde locations (brown squares)
along the flight track during the 20190831H2 mission
(Image from Heather Holbach).

The mission was successful in gathering and delivering TDR data. 3 successful passes across the center were made, and two NESDIS ocean-winds passes through the eyewall were also accomplished (Figure 6). There were no major problems with the flight. 31 sondes were dropped and the data was good on 30 of the 31. No AXBTs were dropped on this mission. The data gathered throughout the flight showed a storm that had continued to intensify to the threshold of Category 5 status, with flight level winds of ~145 kt and SFMR winds of ~150 kt (Figure 7). These values were supported by dropsonde winds, including one sonde with 151 kt mean winds in the lowest 150 m of the sounding (Figure 8).

Figure 7: Flight level, SFMR, and dropsonde-adjusted wind speeds
along the flight track for 20190831H2, along with the extrapolated pressure and altitude
(Image from Heather Holbach).

Figure 8: Dropsonde winds from a dropsonde launched in the
NW eyewall during the 20190831H2 mission.

Mission Data :

Flight level wind along track

Flight level wind along track in storm

SFMR wind along flight track

SFMR wind along flight track in storm

Altitude, Pressure, Rain Rate, and Wind

LPS log | Radar log | Drop log Flight Director's log | Flight Director's manifest | NetCDF data |

Page last updated Nov 22, 2019
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