Download Hurricane Hazard Depiction for Standardized Air Force Weather

Hurricane Hazard Depiction for
Standardized Air Force
Weather Forecast Charts
Capt Kevin LaCroix
1LT Christopher Wireman
28th Operational Weather Squadron
Overview
• 28th Operational Weather Squadron SE
CONUS mission
• Hurricane Hazards
– Turbulence
– Icing
– Lightning/Thunderstorms
 Weather
SE CONUS Operations
support to 90
units at 70+
locations (AF,
Army, Guard,
and Reserve)
 22 TAF sites
 Flight weather
briefings
 1500+ aircraft
supported
 Flight hazards
graphics
 Tropical
Cyclone Threat
Assessment
Advisory/Warning Locations
TAF Locations
Air Force Weather Research
• Air Force Weather Technical Library (AFWTL) located in
Asheville, NC houses nearly 250,000 volumes; serves the
information needs of meteorologists, climatologists, space
scientists, computer scientists and experts in all other
disciplines of interest to military meteorology.
• Holdings include foreign language documents, that they
translate if needed.
• Requested they search all holdings for Tropical storms,
turbulence, icing and severe weather.
• 88 documents were found in this search including several
not held by the AFWTL.
• All references were either peer-reviewed, or major
meteorological publications by AMS, Royal Met. Soc. etc.
Hurricane Horizontal Structure
Left Front
Quadrant
Right Front
Quadrant
Eye -> 5-30km
Diameter
Storm
Motion
Eyewall -> 540km
Inner
Rainbands ->
Eyewall - 100km
Outer
Rainbands ->
~150km - 300km
Left Rear
Quadrant
Right Rear
Quadrant
Hurricane Vertical Structure
Eye/Eyewall
Outer
Rainbands
Outer
Rainbands
Radius of Eyewall is ~1015km wider at top than at the
surface
18
km
Outer rainband
Updrafts < 10 m/s
16
km
Eyewall Updrafts
< 8 m/s
Outer rainbands can sometimes include
thunderstorms with high CB’s called “Hot
Towers” these reach more than 10 miles
high, and result in very heavy precipitation
Dry, warm
subsiding
air
Updrafts
Hurricane Turbulence
Light
500
Moderate
CONT
SFC
Severe
Extreme
Percent
Encounter
99.4%
0.5%
0.0015%
0.0000033%
Moderate
Turbulence
only in the
strongest
convection
Only
encounter
severe or
extreme
turbulence
in lowest
1km of
eyewall
Hurricane Turbulence Cont.
Turbulence
not
prevalent
because of
lack of
shear, both
horizontal
and vertical
Vertical Cross Section of Hurricane
200
400
M 500
b
L
e
v
e 850
l
Cross
section
location
975
Sea
Level
20
10
0
10
25
100
Distance from Storm Center
300
Area of
Shear
Hurricane Icing
Eye/Eyewall
Outer
Rainbands *
Outer
Rainbands
- 40˚
200
-10˚
Mixed
-15˚
Area of
possible
Icing
- 4˚
160
Clear
> FL 130
0˚
Average
Freezing level
Supercooled
Droplets only in
strongest updrafts
* Different Vertical Scale
Icing mostly clear due to large drop size and
lack of supercooled droplets. Weak updrafts
also limit icing. Severe Clear icing in eyewall,
typically well above research aircraft
penetration level.
Updrafts
Hurricane Icing Forecast
Icing in
hurricanes is all
inside
thunderstorms.
How it could be
depicted is
shown here.
Temperature
guidance for
more accurate
height
representation is
given on
previous page.
500
200
200
160
Severe Clear
Severe Mixed
Icing Potential Area
Hurricane Lightning
• Eyewall Flash
Rate: < 60 flashes
per 100 sq km/day
• Inner Rainband:
< 20 flashes per
100 sq km/day
Greatest Flash
Density in
Right Front
Quadrant
• Outer Rainband:
> 300 flashes per
100 sq km/day
• Typical
Thunderstorm: >
36,000 flashes per
100 sq km/day
Storm
Motion
• Equates to 4-6
times more chance
for lightning in
outerband than
eyewall
Hurricane
Flashes: ~ 4400
per day
Hurricane Thunderstorm Forecast
600
Thunderstorm
Coverage for
FITL Chart
NMRS
520
600
FEW
SCT
350
NSW
Max Tops
550
NMRS
Coverage
ISOLD
Aviation Hazards on Buttons
Tropical Cyclone Forecast
Representation
•OWS worldwide have standardized map backgrounds, colors, and
symbology so that a forecaster will be familiar with any products on a
OWS webpage no matter what theater they are in, or what OWS they
are at
• Following slides show designated process for depicting Tropical
Cyclones on OWS Charts
• Process uses 150-300km radius from storm center as area of major
outer ring convection.
• Limitations to depicting features:
• Forecaster experience – want same “rules” for drawing storms to
be worldwide
• Map Scale – eyewall process to small to accurately draw on our
scale
• Technical limitations to graphics program at OWS, Leading
Environmental Analysis and Display System (LEADS)
Low Level Turbulence
Icing
Thunderstorms
Questions?
Contact Information:
Capt Kevin LaCroix
28th Operational Weather Sq.
905 Patrol Rd.
Shaw AFB, SC 29152
(803)895-0654
[email protected]