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Public Information Statement

NOUS41 KNHC 241611

Public Information Statement
NWS National Hurricane Center Miami FL
1210 PM EDT Mon Apr 24 2017

To:      Subscribers:
         -NOAA Weather Wire Service
         -Emergency Managers Weather Information Network
         Other NWS Partners, Users and Employees

From:    James Franklin
         Branch Chief, Hurricane Specialist Unit
         NCEP/National Hurricane Center

Subject: Soliciting Public Comments through
         May 26, 2017 on Changing the
         Reconnaissance Vortex Data Message Format

The Office of the Federal Coordinator for Meteorology Working Group
for Hurricane and Winter Storm Operations and Research (WG/HWSOR),
at the 2017 Interdepartmental Hurricane Conference, has proposed to
change the reconnaissance Vortex Data Message format for the 2018
hurricane season.  This product is transmitted from NOAA and Air
Force hurricane hunter aircraft and issued under AWIPS header
MIAREPNT2 and WMO header URNT12 KNHC. The format changes below will
enhance the utility of the Vortex Message by including important
parameters previously not provided, or provided only optionally in
the comment section, and by improving the organization of the
message.  The NWS is seeking comments on these proposed changes
through May 26, 2017.

The primary changes and rationales are listed below, along with
examples of the current and proposed message format:

1.  The current format (see example) has a formal entry only for
inbound wind maxima, with any outbound wind maxima appearing in the
comment section.  In the proposed format, Items L through O comprise
a new outbound wind maxima section to simplify data decoding and to
ensure that no data are missed.  The new outbound wind maxima
section appears in a similar format to the inbound maxima data
(Items H through K).

2.  The latitude and longitude will be listed in decimal degrees
instead of degrees and minutes to better accommodate NHC and other
users' needs.

3.  The proposed message includes a new tropical cyclone center data
block section (Items C through G).  The surface wind reported by
dropsonde at the system's center is now given in Item E.  Center/eye
shape and size characteristic lines are moved up to Items F and G
from Items L and M.

4.  The current message lacks most wind observation times; the
proposed format appends the observation times to the bearing and
range location Items.

5.  To better collect similar data together, the inbound maximum
surface and flight-level wind block (Items E through G in the
current format) is shifted downward to Items H through K.

NWS and the WG/HWSOR will evaluate all comments to determine whether
to proceed with this change.

Send comments on this proposal to:

Jessica Schauer
NWS Marine, Tropical and Tsunami Services Branch
National Hurricane Center
Miami, FL  33165


James Franklin
Hurricane Specialist Unit
National Hurricane Center
Miami, FL  33165

National Public Information Statements are online at:

Current format example:

URNT12 KNHC 241133
A. 24/11:12:50Z
B. 10 deg 58 min N
  082 deg 46 min W
C. 700 mb 2927 m
D. 90 kt
E. 144 deg 5 nm
F. 253 deg 78 kt
G. 158 deg 8 nm
H. 977 mb
I. 10 C / 3042 m
J. 18 C / 3045 m
K. NA / NA
M. C20
N. 12345 / 7
O. 0.02 / 1 nm
P. AF301 0616A OTTO               OB 13
MAX OUTBOUND AND MAX FL WIND 108 KT 349 / 14 NM 11:17:00Z

An explanation of the current format can be found at:
(see Figure 5-3, page 5-6).

Proposed format example:

URNT12 KNHC 241133
A. 24/11:12:50Z
B. 10.97 deg N 082.77 deg W
C. 700 mb 2927 m
D. 977 mb
E. 210 deg 11 kt
G. C20
H. 90 kt
I. 144 deg 5 nm 11:07:00Z
J. 253 deg 78 kt
K. 158 deg 8 nm 11:07:30Z
L. 95 kt
M. 314 deg 5 nm 11:17:00Z
N. 033 deg 108 kt
O. 349 deg 14 nm 11:17:30Z
P. 10 C / 3042 m
Q. 18 C / 3045 m
R. NA / NA
S. 12345 / 7
T. 0.02 / 1 nm
U. AF301 0616A OTTO OB 13
MAX FL WIND 108 KT 349 / 14 NM 11:17:00Z

The individual items in the proposed format are defined as follows:

A. Date and time of fix
B. Latitude and longitude of vortex center fix
C. Minimum height at standard atmospheric level
D. Minimum sea-level pressure from dropsonde or extrapolation
E. Dropsonde center wind speed and direction
F. Eye character
G. Eye shape/orientation/diameter
H. Estimate of maximum inbound surface wind observed
I. Bearing, range and time of wind observed in Item H
J. Maximum inbound flight-level wind
K. Bearing, range and time of wind observed in item J
L. Estimate of maximum outbound surface wind observed
M. Bearing, range and time of wind observed in item L
N. Maximum outbound flight-level wind
O. Bearing, range and time of wind observed in item N
P. Maximum flight-level temp/pressure altitude outside eye
Q. Maximum flight-level temp/pressure altitude inside eye
R. Dew point temperature/sea surface temperature inside eye
S. Fix determined by (codes for observation type)
T. Navigation fix accuracy/meteorological accuracy
U. Aircraft id, mission number, cyclone name, and observation number
End remarks include maximum flight-level wind, bearing, range and
time during mission