A small taste of how the NHC uses Hurricane Hunter aircraft data (5 of 6)

If you have been following along on my articles on Hurricane Hunting aircraft then you know that Hurricane Hunters are flown by NOAA and those flown by the USAF Reserve 53rd Weather Reconnaissance Squadron.  In the course of doing background research for these articles, I got interested in how the National Hurricane Center (NHC) uses the reconnaissance data gathered by the NOAA and the USAF Hurricane Hunter aircraft when they fly into tropical depressions, tropical storms and hurricanes. 

Before beginning, my focus in this article continues to be on Hurricane Hunting aircraft. If you are interested in learning more about what the work of the National Hurricane Center (NHC) you might want to check out NHC's virtual tour in eight parts. You might also want to look at the NHC’s 2015 Hurricane Preparedness Week presentations. If you are arriving at this article first and want a good overview about what NOAA's Hurricane Hunters do and to learn about the dropsonde instrument that is dropped from the belly of the plane into the hurricane to measure some weather perimeters go and watch this five and a half minute video produced by the City of Tampa (FL).

Knowing that the NHC has an entry page for archives of past hurricanes, I scrolled to the section of the page for “Tropical Cyclone Advisory Archives.” I am using Sandy (2012) here. So I selected 2012 in the drop down box which lead me to the 2012 Tropical Cyclone Advisory Archive page. From the column reading “Atlantic”, I clicked on Hurricane Sandy. This leads me to a page with a full listing of all of NHC products for Hurricane Sandy: forecast advisories, public advisories, discussions and wind speed probabilities as well as a link to a graphics archive. The products that I am referring to here are found under “discussions” with a couple being "public advisory updates.”

What follows is a listing from some of the NHC discussions and a couple of public advisory updates referencing Hurricane Hunter aircraft observations (with links). I picked out NHC products that interested me because of the reference to the Hurricane Hunters. Some of the points that I was interested in were: a change in strength, a change in direction, land strike, etc. Sandy was not the strongest Hurricane that the Hurricane Hunters flew into, at her height she was a category two and that was bad enough. Sandy interested me because she made landfall in New Jersey (as a post-tropical cyclone) causing severe impacts region-wide. Certain aircraft observations from each NHC discussion or public advisory update referenced are indicated in red.

• Hurricane Sandy discussion #2 Mon Oct 22 2012, 5:00 PM EDT: "THE AIR FORCE HURRICANE HUNTERS FOUND A BAND OF SURFACE WINDS NEAR 35 KT OVER THE SOUTHEASTERN QUADRANT OF THE CYCLONE...SO THE SYSTEM IS BEING NAMED AT THIS TIME."
• Hurricane Sandy discussion #7 Tues Oct 23 2012, 11:00 PM EDT:  "REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SHOW THAT SANDY IS STRENGTHENING.  THE AIRCRAFT REPORTED 850-MB FLIGHT-LEVEL WINDS OF 65 KT AND SFMR SURFACE WIND ESTIMATES NEAR 50 KT.  THE MINIMUM CENTRAL PRESSURE WAS 989 MB.  BASED ON THESE DATA...THE INITIAL INTENSITY IS RAISED TO 50 KT.  THE AIRCRAFT ALSO REPORTED THAT A RAGGED EYE WAS FORMING."
• Hurricane Sandy discussion #9 Wed. Oct 24 2012, 11:00 AM EDT:  "DATA FROM THE HURRICANE HUNTER AIRCRAFT INDICATE THAT SANDY HAS REACHED HURRICANE STRENGTH. THE AIRCRAFT JUST MEASURED A PEAK 700-MB FLIGHT-LEVEL WIND OF 86 KT...AND BLENDING THAT WITH THE PEAK SFMR WINDS YIELDS AN INITIAL INTENSITY OF 70 KT. THE CENTRAL PRESSURE HAS ALSO FALLEN TO 973 MB BASED ON DATA FROM THE PLANE."
• Hurricane Sandy discussion #11 Wed Oct 24 2012, 11:00 PM EDT: "CUBAN RADAR DATA AND REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT SANDY IS BECOMING BETTER ORGANIZED THIS EVENING.  THE CENTRAL PRESSURE HAS FALLEN RAPIDLY TO 954 MB... AND A 20-25 N MI WIDE EYE HAS DEVELOPED."
• Hurricane Sandy public advisory update Thurs. Oct 25 2012, 12:30 AM EDT EDT: "RECENT REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INDICATE HURRICANE SANDY HAS RAPIDLY STRENGTHENED...AND MAXIMUM SUSTAINED WINDS ARE NOW ESTIMATED TO BE 110 MPH...175 KM/H. THIS MAKE SANDY A STRONG CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON HURRICANE WIND SCALE."
• Hurricane Sandy discussion #12 Thurs. Oct. 25 2012, 5:00 AM EDT: "EARLIER THIS MORNING...SANDY MADE LANDFALL JUST WEST OF SANTIAGO DE CUBA AS A STRONG CATEGORY TWO HURRICANE. CUBAN RADAR DATA AND REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INDICATED THAT SANDY HAD A WELL-DEFINED 20-24 N MI DIAMETER EYE WHEN IT MADE LANDFALL. THE AIRCRAFT REPORTED MAXIMUM 700-MB FLIGHT-LEVEL WINDS OF 117 KT AND BIAS-CORRECTED SFMR SURFACE ESTIMATES OF 91-92 KT."
• Hurricane Sandy discussion #15 Thurs. Oct. 25 2012, 11:00 PM EDT: "REPORTS FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT SANDY HAS WEAKENED A LITTLE THIS EVENING.  THE MAXIMUM FLIGHT-LEVEL WINDS AT 8000 FT WERE 90 KT...AND DROPSONDES IN WHAT REMAINED OF THE EYEWALL SUGGESTED 70 KT SURFACE WINDS.  THE CENTRAL PRESSURE HAD RISEN TO 968 MB."
• Hurricane Sandy discussion #27 Sun. Oct 28, 2012, 11:00 PM EDT: "THE CONVECTION NEAR THE CENTER OF SANDY HAS BECOME A LITTLE BETTER ORGANIZED THIS EVENING...WITH A NOAA HURRICANE HUNTER AIRCRAFT REPORTING A 25-35 MILE WIDE EYE WITH AN OPEN EYEWALL.  HOWEVER...THE STRONGEST WINDS IN THE STORM ARE NOT OCCURRING IN THE EYEWALL...AS THE NOAA AND AIR FORCE RESERVE AIRCRAFT FOUND A LARGE AREA OF AT LEAST 60 KT SURFACE WINDS ABOUT 100-120 N MI SOUTHWEST OF THE CENTER.  IN ADDITION...THE AIR FORCE PLANE REPORTED 700-MB FLIGHT-LEVEL WINDS OF 102 KT. BASED ON THESE DATA...THE INITIAL INTENSITY IS REDUCED TO 80 KT...AND THIS COULD BE A LITTLE GENEROUS."
• Hurricane Sandy discussion #29 Mon Oct. 29 2012, 11:00 AM EDT: "SANDY IS MAINTAINING A SMALL AREA OF DEEP CONVECTION NEAR THE CENTER...WITH BOTH AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT DATA AND VARIOUS MICROWAVE SATELLITE DATA INDICATING A 20 N MI DIAMETER EYE HAS DEVELOPED SINCE THE PREVIOUS ADVISORY. … SANDY HAS BEGUN ITS ANTICIPATED LEFT TURN AND THE INITIAL MOTION IS NOW 335/11.  THE HURRICANE SHOULD CONTINUE A GENERAL NORTH-NORTHWESTWARD MOTION FOR THE NEXT 24 HOURS OR SO AS IT INTERACTS WITH A MID/UPPER-LEVEL LOW OVER THE FLORIDA STRAITS.  AFTER THAT...A DEEP-LAYER LONGWAVE TROUGH MOVING INTO THE EASTERN UNITED STATES SHOULD CAUSE SANDY TO TURN NORTHWARD AND NORTHEASTWARD. "
• Hurricane Sandy public advisory update Oct 29 2012, 8:00 PM EDT: "SURFACE...RADAR...AND AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT DATA INDICATE THAT POST-TROPICAL CYCLONE SANDY MADE LANDFALL NEAR ATLANTIC CITY NEW JERSEY AROUND 800 PM EDT...0000 UTC...WITH MAXIMUM SUSTAINED WINDS OF 80 MPH...130 KM/H. NATIONAL OCEAN SERVICE TIDE GAUGES HAVE RECENTLY REPORTED STORM SURGE HEIGHTS OF 11.9 FEET AT KINGS POINT NEW YORK...8.4 FEET AT THE BATTERY NEW YORK...AND 8.6 FEET AT SANDY HOOK NEW JERSEY. WITHIN THE PAST HOUR OR SO...A SUSTAINED WIND OF 49 MPH WITH A GUST TO 73 MPH WAS REPORTED AT JFK INTERNATIONAL AIRPORT IN NEW YORK. A WIND GUST TO 71 MPH WAS RECENTLY OBSERVED AT FARMINGDALE NEW YORK. "

The Hurricane Hunters fed their data to the NHC. My local NWS office, the US National Weather Service at Mt. Holly got data (all of which is public data) on Sandy from the NHC and were in telephone contact with National Hurricane Center (NHC) as needed. Emergency managers heeded the warnings issued by the National Weather Service at Mt. Holly and issued evacuation orders for the barrier islands off the New Jersey Coast with roads to and from the barrier islands being closed well in advance of Sandy's landfall. Most businesses and schools in New Jersey and adjoining areas of New York were closed on the 29th. The New York City subway system was shut down on 7 PM on October 28, 2012. In New Jersey, Gov. Christie declared a State of Emergency in New Jersey on Oct. 27, 2012

I was well inland. I knew from the NHC advisories and forecasts from the NWS Mt. Holly that Sandy was a large storm with high winds (in excess of 58 mph) that would reach inland to where I was in the northwestern section of NJ. So on the 26th and the 27th I prepared and was glad that I did. We hunkered down and eleven days later we had our electrical power back (our power went out at 8:30 PM on the 29th). As most of you know, New Jersey and adjoining areas of New York were hit extremely hard by Sandy. It would have been a whole lot worse without the hurricane advisories and forecast discussions from the NHC as well as the forecasts and warnings from the NWS Mt. Holly. A lot of lives were saved because of the work of the Hurricane Hunters, the NHC, and the US National Weather Service at Mt. Holly.

Thank-you Hurricane Hunters!

Thank-you National Hurricane Center!

Thank-you US National Weather Service at Mt. Holly!

For those who are interested: The US National Weather Service at Mt. Holly has some archived data on Sandy:

• Summary and records (rainfall, peak wind, minimum pressure, storm surge)
• Radar images, storm summary, etc (includes links to still more information on Sandy)
• Link to Mt Holly Event Archive Page, click on 2012 under the graphic, then the link for Oct 29 - Super Storm Sandy (includes some of the information linked to above)

Septebmer 10, 2016: outdated links removed, other outdated links have been updated

Other articles in this series:
Part 1 (June 1): Hurricane Hunters: Introduction
Part 2 (June 3): From NOAA about the WP-3D, dropsondes, and the G-IV
Part 3 (June 5): A little more about the WP-3D Hurricane Hunter mission
Part 4 (June 8): more pictures and videos of NOAA’s Hurricane Hunters
Part 6 (June 12): NOAA's WP-3Ds undergoing major overhaul