Multi-Scale Analysis of the Kinematic and Thermodynamic Structure of TS Humberto Using

Dropsonde and Satellite Data

Jeffrey B. Halverson, UMBCAlex Martin, UMBC

Research Objectives• Multi-scale analyses: Satellite, environmental, in situ

dropsonde structure• Study warm core, vortex symmetry, shear interactions, SAL

interactions – in context of a “dud” TC season with hostile synoptic environment (i.e. dry air, subsidence)

• Develop 3D structural visualizations utilizing a GIS framework• Hurricane Humberto (2013)• Hurricane Gabrielle (2013)• Upcoming 2014 cases• 17-year TC dropsonde climatology

Humberto Case Study• Developed on September 7th, 2013• Became TS strength on September 9th

• Reached peak intensity on September 14th at 80 knots

• Sampled by AV-6 on Sept 16-17 using racetrack pattern

• Developed deep convection in north portion

• Highly asymmetric, disjointed storm structure

Snapshot of Humberto at peak intensity

4 Hours before first drop 21 minutes after first drop

7 minutes after last drop55 minutes before last drop

IR

37 GHz 85 GHz

85 GHz

0145 UTC IR imagery

White arrow represents shear vector; black arrow is storm motion

0437 UTC 85 GHz Microwave Imagery

Wavenumber 1 Asymmetry

Mature DMC

InitiationOf DMC

SubsidenceRegion

- Strong, unidirectional deep shear interacting

with storm- Magnitude of shear vector = 23 m/s- Strong asymmetry /wrt/ vortex and deep convective region - Suggestive of a wave-number one structure

GIS ArcScene Analysis – 3D visualization

x

x

x

x

x Deep Layer Shear 270° 23 m/s

vortex center

Storm Motion

Examine thermodynamic and kinematic structure using framework of downshear and upshear quadrants (RAOB software)

Composite Dropsonde Structure

Deep Shear

0015 UTC

0305 UTC

0408 UTC

Humberto Case Study Summary• Highly asymmetric, struggling TC• Low level vortex center exposed • Deep moist convection (DMC) displaced to north of center• Vortex wind maxima in NE quadrant /wrt/ deep shear vector• DMC triggered in NE quad, within low level speed convergence zone • Overall structure may be linked to strong wave number one

asymmetry• Shallow, weak warm core on southern edge of DMC mass (likely

subsidence induced)• Need to better understand if there is any SAL interaction• Need to develop understanding of large-scale environmental

(hostile) context for the storm’s mesoscale structure

NCAR Dropsonde Re-Analysis

• 1996 to 2012 NOAA dropsonde dataset• Build composite vertical profiles inside Atlantic basin

TC eye, eyewall, rainbands, surrounding environment• Composites as a function of radial distance, quadrant

/wrt/ motion vector, storm intensity• PBL wind structure, • 120 tropical cyclones included• 13,681 quality controlled soundings• Article by J. Wang et al. submitted to BAMS

Composite Wind Profiles By Intensity Category

Questions?