Paper on the rapid intensification of Hurricane Earl in 2010 released online in Monthly Weather Review

The paper discusses changes to the structure of Hurricane Earl (2010) as it rapidly intensified.   It found

  • Earl tilted with height before it intensified, but was upright during the intensification.
  • Strong thunderstorms played a significant role in the rapid intensification of Hurricane Earl.
  • Thunderstorms located on the inside of the eyewall are a condition favorable for intensification.
  • It is important to learn why thunderstorms form where they do to improve forecasts.
  • It is also important to observe the structure of the hurricane to better represent where these thunderstorms may occur in forecast models and improve hurricane forecasts.

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The paper can be accessed at http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-14-00175.1.

Paper on a dataset of dropwindsonde observations in tropical cyclones released online by the Bulletin of the American Meteorological Society

A long-term (1996–2012), high-quality, high vertical resolution (∼5–15 m) GPS dropsonde dataset is created from NOAA Hurricane flights and consists of 13,681 atmospheric profiles for 120 tropical cyclones.

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The paper can be accessed at http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-13-00203.1.

Doppler radar quick-looks from 11:00 AM P-3 flight into Hurricane Simon, 5 October 2014

As Simon continued its northwestward motion southwest of Baja a NOAA P-3 collected airborne Doppler radar data to use in initializing and evaluating the HWRF model. Included here you see images of the horizontal winds within 360 km of Simon sampled from the tail Doppler radar on the P-3 aircraft during the early afternoon of 5 October 2014. These images are at three altitudes (1 km, 3 km, and 6 km) and are a composite of winds from the P-3 Doppler patterns around Simon. Also plotted on each analysis are the locations of dropsondes deployed by the P-3 (plotted using standard station symbols). These analyses show that Simon had an asymmetric distribution of precipitation around the storm center at all altitudes with the majority of the precipitation in the northeast semicircle. A vertical cross-section of the radar reflectivity on the leg to the northwest from the center showed that the radar echo tops in the eyewall dropped significantly in 24 h with echo tops only reaching up to 8-11 km altitude, with a distinct “bright band” extending radially outward from the center denoting the altitude of the 0° isotherm. There is clear indication of a circulation center at all altitudes, with a very broad area of stronger winds 30-40 km east-northeast of the circulation center at all altitudes. There is also a slight indication of a secondary wind maximum 130-140 km northeast of the circulation center at 1- and 3-km altitudes, and in the vertical cross-section. From 1-6 km altitude there is a 10-15 km tilt of the circulation center toward the east with height suggesting increasing westerly shear of the horizontal wind over Simon at this time.

All the Simon radar composites at 0.5-km height resolution are available at http://www.aoml.noaa.gov/hrd/Storm_pages/simon2014/radar.html

Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Doppler radar quick-looks from 11:00 AM P-3 flight into Hurricane Simon, 4 October 2014

As Simon continued its northwestward motion southwest of Baja a NOAA P-3 collected airborne Doppler radar data to use in initializing and evaluating the HWRF model. Included here you see images of the horizontal winds within 360 km of Simon sampled from the tail Doppler radar on the P-3 aircraft during the early afternoon of 4 October 2014. These images are at three altitudes (1 km, 3 km, and 6 km) and are a composite of winds from the P-3 Doppler patterns around Simon. Also plotted on each analysis are the locations of dropsondes deployed by the P-3 (plotted using standard station symbols). These analyses show that Simon had a symmetric distribution of precipitation around the storm center at all altitudes. A vertical cross-section of the radar reflectivity on the leg to the northwest from the center showed that the radar echo tops in the eyewall were as high as 15-km altitude, and a distinct “bright band” extending radially outward from the center denoting the altitude of the 0° isotherm. There is clear indication of a circulation center at all altitudes, with stronger winds only 5-10 km northeast of the circulation center at all altitudes. There is also an indication of a secondary wind maximum 110-120 km in the northern semicircle around the circulation center at all altitudes, and in the vertical cross-section. From 1-6 km altitude there is very little tilt of the circulation center with height suggesting very little vertical shear of the horizontal wind over Simon at this time.

All the Simon radar composites at 0.5-km height resolution are available at http://www.aoml.noaa.gov/hrd/Storm_pages/simon2014/radar.html

Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Doppler radar quick-looks from 5:00 AM P-3 flight into Hurricane Gonzalo, 17 October 2014

As Gonzalo continued its northeastward motion toward Bermuda a NOAA P-3 collected airborne Doppler radar data to use in initializing and evaluating the HWRF model, and as part of an Ocean Winds and Rain experiment. Included here you see images of the horizontal winds within 300 km of Gonzalo sampled from the tail Doppler radar on the P-3 aircraft during the early morning of 17 October 2014. These images are at three altitudes (1 km, 3 km, and 6 km) and are a composite of winds from the P-3 Doppler patterns around Gonzalo. Also plotted on each analysis are the locations of dropsondes deployed by the P-3 (plotted using standard station symbols). These analyses show that Gonzalo still had a symmetric distribution of precipitation around the storm center at all altitudes. A vertical cross-section of the radar reflectivity on the leg to the northwest from the center showed that the radar echo tops in the eyewall were as high as 15-km altitude, and a distinct “bright band” extending radially outward from the center denoting the altitude of the 0° isotherm. There is a clear indication of a circulation center at all altitudes, with stronger winds 30-35 km east of the circulation center at 1-km altitude, rotating upwind (clockwise) with increasing height, indicative of increasing westerly flow with altitude. There is also an indication of a secondary wind maximum 75-80 km in the eastern semicircle around the circulation center at all altitudes. From 1-6 km altitude there is 5-10 tilt of the circulation center with height toward the east-southeast indicative of increasing westerly shear of the horizontal wind.

All the Gonzalo radar composites at 0.5-km height resolution are available at http://www.aoml.noaa.gov/hrd/Storm_pages/gonzalo2014/radar.html

Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Doppler radar quick-looks from 5:00 AM P-3 flight into Hurricane Gonzalo, 16 October 2014

As Gonzalo continued its northward motion southwest of Bermuda a NOAA P-3 collected airborne Doppler radar data to use in initializing and evaluating the HWRF model, and as part of an Ocean Winds and Rain experiment. Included here you see images of the horizontal winds within 300 km of Gonzalo sampled from the tail Doppler radar on the P-3 aircraft during the early morning of 16 October 2014. These images are at three altitudes (1 km, 3 km, and 6 km) and are a composite of winds from the P-3 Doppler patterns around Gonzalo. Also plotted on each analysis are the locations of dropsondes deployed by the P-3 (plotted using standard station symbols). These analyses show that Gonzalo still had a symmetric distribution of precipitation around the storm center at all altitudes. A vertical cross-section of the radar reflectivity on the leg to the northwest from the center showed that the radar echo tops in the eyewall were as high as 16-km altitude, and a distinct “bright band” extending radially outward from the center denoting the altitude of the 0° isotherm. There is a clear indication of a circulation center at all altitudes, with stronger winds 15-20 km east-northeast of the circulation center at 1-km altitude, rotating upwind (clockwise) with increasing height, indicative of increasing southwesterly flow with altitude. From 1-6 km altitude there is very little tilt of the circulation center with height.

All the Gonzalo radar composites at 0.5-km height resolution are available at http://www.aoml.noaa.gov/hrd/Storm_pages/gonzalo2014/radar.html

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Radius-altitude reflectivity cross-section to the northwest of the center of Gonzalo. Aircraft altitude is denoted by the white line near 3-km altitude.

Hurricane Field Program Update – Friday, October 17, 2014 11AM Eastern

OPERATIONS

Friday, 17 October 2014

G-IV: Is tasked for another synoptic surveillance mission around Tropical Storm Ana. The aircraft will depart Honolulu, HI at 1730 UTC and recover in Long Beach, CA about 8 h later.

NOAA43: Is tasked for the 1130 UTC reconnaissance center fix for Hurricane Gonzalo. The aircraft will depart St. Croix at 0830 UTC and recover in MacDill AFB about 8 h later.

Drifter buoy deployment:  A series of 10 drifting buoys will be deployed from an Air Force C-130 aircraft southeast of the Big Island of Hawaii, ahead of Tropical Storm Ana’s track. The launch is scheduled for the time between 1200 and 1600 UTC.

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For the latest information about tropical cyclones and other weather systems, please visit the NOAA/NWS/National Hurricane Center web site at http://www.nhc.noaa.gov

To access updates on IFEX and other HRD activities via Facebook, Twitter, or RSS feed, check out the HRD home page at: http://www.aoml.noaa.gov/hrd

To directly access updates on IFEX HFP Operations via our WordPress blog on the web, check the site https://noaahrd.wordpress.com/category/ifex-hurricane-field-program/

DISCLAIMER: The above discussion is intended to provide a brief summary of recent and future HRD Hurricane Field Program Operations. Any use of this material beyond its original intent is prohibited without permission of the HRD Director. Media inquiries should be directed to Erica Rule (305-361-4541) or Erica.Rule@noaa.gov, Evan Forde (305-361-4327) or Evan.Forde@noaa.gov, Monica Allen (301-734-1123) or Monica.Allen@noaa.gov.

Doppler radar quick-looks from 10:00 AM P-3 flights into Hurricane Edouard, 17 September 2014

As Edouard continued its northeastward motion east-northeast of Bermuda a NOAA P-3 collected airborne Doppler radar data to use in initializing and evaluating the HWRF model. Included here you see images of the horizontal winds within 300 km of Edouard sampled from the tail Doppler radar on the P-3 aircraft during midday of 17 September 2014. These images are at three altitudes (1 km, 3 km, and 6 km) and are a composite of winds from the P-3 Doppler patterns around Edouard. Also plotted on each analysis are the locations of dropsondes deployed by the P-3 (plotted using standard station symbols). These analyses show that Edouard still had a relatively symmetric distribution of precipitation around the storm center at all altitudes. There is indication of a circulation center at all altitudes, with stronger winds 35-40 km southeast of the circulation center at 1-km altitude, rotating upwind (clockwise) with increasing height, indicative of increasing westerly flow with altitude. There is also indication of a secondary wind maximum 75-80 km south-southeast of the circulation center at all altitudes. From 1-6 km altitude there is  10-15 km tilt to the east of the circulation center with height from 1- to 6-km altitude indicative of increasing westerly shear of the horizontal wind with height over the storm.

All the Edouard radar composites at 0.5-km height resolution are available at http://www.aoml.noaa.gov/hrd/Storm_pages/edouard2014/radar.html