The east coast and NE does see some hurricane action, although its rare for one to have a considerable impact on the larger cities in the northeast.
Vortex Data Message
Aircraft recon missions have a vital and important part in forecasting tropical cyclones. Data is transmitted to the National Hurricane Center through coded messages. These coded messages are known as Vortex Data Messages. Data includes latitude and longitude of the storm center as well as its maximum winds, maximum temperature, and minimum sea level pressure.
One key piece of data I would like to focus on is line P, the flight meteorologists remarks. These are flight level winds in the eastern side of the storm.
Vortex Data Message
000
URNT12 KNHC 280635
VORTEX DATA MESSAGE AL092011
A. 28/05:49:30Z
B. 38 deg 10 min N
074 deg 57 min W
C. 700 mb 2716 m
D. 65 kt
E. 045 deg 8 nm
F. 140 deg 51 kt
G. 042 deg 18 nm
H. 959 mb
I. 10 C / 3048 m
J. 13 C / 3046 m
K. 13 C / NA
L. NA
M. NA
N. 1345 / 7
O. 0.02 / 1 nm
P. AF304 3409A IRENE OB 35
MAX FL WIND 94 KT E QUAD 03:57:40Z
MAX OUTBOUND FL WIND 59 KT SW QUAD 06:06:20Z
;
Now here’s a more detailed list of what that data means:
| 000 URNT12 KNHC 280635 VORTEX DATA MESSAGE AL092011 |
|
| A. 28/05:49:30z |
Date and center or “fix” is located. Local EDT is 1:49am Aug 28 2011 |
| B. 38 deg 10min N 074 deg 57 min W |
Latitude and Longitude of the fix location |
| C. 700mb 2716m | Flight level pressure and height (of flight) |
| D. 65 KT | Estimated maximum surface wind speed. MPH |
| E. 045 deg 8 nm |
Bearing of max est surface wind from center of storm |
| F. 140 deg 51kt | Max flight level wind on last flight in the eye |
| G. 042 deg 18 nm | Bearing of max flight level wind from center of storm |
| H. 959 mb |
Minimum Sea Level Pressure (measured or extrapolated) |
| I. 10 C / 3048 m |
Max flight level temp and pressure altitude outside eye |
| J. 13 C / 3046 m |
Max flight level temp and pressure altitude inside eye |
| K. 13 C/ NA | |
| L. NA | Flight meteorologist’s notes about the eyewall |
| M. NA |
|
| N. 1345 /7 |
|
| P. AF304 3409A IRENE OB 35 MAX FL WIND 94 KT E QUAD 03:57:40Z MAX OUTBOUND FL WIND 59 KT SW QUAD 06:06:20Z |
Flight meteorologist’s comments: max flight level winds during recon were 94 kt (mph) in the East Quadrant |
Multiplatform Satellite Surface Wind Analysis
The multiplatform wind analysis was calculated with four different data sources. They are AMSU (Advanced Microwave Sounding Unit), Cloud Drift Wind Imagery, Infrared Imagery, and Scatterometry (ASCAT). Since scatterometry has attenuation problems where there are areas of heavy rain, the other three data sources where valuable in creating an analysis. There was a lot of moisture and heavy rain bands with Irene and so there is no extensive data near or around the center of the storm from the scatterometry.
Multiplatform Satellite Surface Wind Analysis
The wind speed observed is 65 knots in its VMAX, this is also matching data from line D in the vortex data message that was transmitted around the same time.
HRD Wind Analysis
The HRD wind analysis comes from several different data sources including aircraft reconnaissance, GPS dropsondes, ASCAT, a moored buoy, CMAN and ASOS.
HRD Wind Analysis
This wind analysis was created approximately one hour prior to the other data sources used in this assignment. Observed maximum surface winds at this time were 57 kts which indicate it had a trend in strengthening.
Conclusion
Data sources yielded agreeing results with surface winds 65 kts (75MPH) on the vortex data message and multiplatform wind analysis. The HRD analysis was also within range at 57 kts (65mph)
