29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

Hurricane outflow structures observed during HS3 2012-13 from AV-6 dropsondes and

CIMSS Atmospheric Motion Vectors

Peter G. Black1, James D. Doyle2, Jon Moskaitis2, Scott Braun3 and Chris Velden4

1SAIC, Inc./ Naval Research Laboratory, Monterey, CA2Naval Research Laboratory, Monterey, CA

3NASA Goddard Spaceflight Center, Greenbelt, MD4Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin,

Madison, WI

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

ObjectiveEstablish the pattern of outflow layer jet features with which hurricane structure and intensity change may be associated.

Utilize in-situ, new-generation atmospheric profiling dropsondes (AVAPS minisonde, HDSS/XDD-2014) and state-of-the-art remote sensors flown on Global Hawk UAVs and reconditioned WB-57 aircraft, in concert with satellite-derived Atmospheric Motion Vectors (AMVs), to directly observe hurricane outflow layer features.

Approach

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

HYPOTHESIS

I. TC development- Single Equatorward-directed JetII. Intensification and RI: Dual Equatorward and Poleward JetsIII. Mature & decay: Primarily, single Poleward-directed Jet

TC Life Cycle, including Rapid Intensification (RI),is associated with environmentally-forced

outflow jet evolution:

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

Leslie, 2012

Storm Intensity

Nadine, 2012

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

Leslie

Leslie Outflow Jet

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

LeslieCloud Physics Lidar

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

Nadine

Nadine

Nadine Outflow Jet

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

200 mb

925 mb

• Single environmental, poleward-directed outflow jet develops during GH legs 3-hr after center passage.• Thick outflow jet typical

of inner-core develops with multiple constant-wind shear layers• Intense convective

development south of P.R., 100 km east of surface, after GH sampling- from WC-130J, NWS 88D Radar.

Pre-Gabrielle (30 kt), 2013

04/ 1930Z – 05/ 1017Z4 Sept 18Z, 14L

5 Sept 06Z, 02L

5 Sept 00Z, 20L

0240-0435Z,2240-0035L

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

Convective DevelopmentACHA vs SJU Radar

Pre-Gabrielle 2013

05/0000Z

05/0000Z 05/0600Z

05/0600Z

05/0330Z

05/0330Z

05/0600Z 05/0900Z 05/1200Z 05/1500Z

04/2130Z

04/2130Z

04/1730L

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

5 Sept 00Z, 4/20L

AMV DiurnalOutflow Pattern

4 Sept 18Z, 14L

Pre- Gabrielle2013

5 Sept 06Z, 02L

4 Sept 21Z, 17L

5 Sept 03Z, 4/23L 5 Sept 09Z, 05L

5 Sept 12Z, 08L 5 Sept 15Z, 11L 5 Sept 18Z, 14L

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

Key Features from Major Hurricanes TCs have a clear diurnal cycle in IR Brightness Temperature (TB) The TC diurnal cycle has the form of a pulse with coldest TB originating near

the inner core at midnight, propagating outward to the 600 km radius by evening (1800-2100 LST)

Upper outflow jets appear to exhibit a strong diurnal pulse.

TC Diurnal Cycle(2001-2010: 31 Major Hurricanes)

Courtesy: Jason Dunion

29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA

13

Outflow Layer Analysis

Achievements and Key Findings

Three TC outflow layers sampled 2012-13: Leslie, Nadine, Pre-Gabrielle.

Outflow layer jets appear to precede intense inner core convection

— Thin peripheral outflow jets are forced by environmental features: Leslie

Subtropical jets Upper cold lows Tropical Upper Tropospheric Troughs (TUTTs)

— Thick inner-core outflow jets associated with convective bursts: Nadine and Pre-Gabriel

Here-to-for unknown outflow jet fine-structure may lead to instabilities which enhance outflow layer mixing not yet adequately modelled.

Outflow jets appear to have diurnal modulation.