Moving Geostationary Satellite retrievals
from
Observations to Forecasts
Using GOES Sounder Products to Improve Regional
Hazardous Weather Forecasts
Ralph A. Petersen : University of Wisconsin – Madison
Robert M Aune : NOAA/NESDIS/STAR - Advanced Satellite Products Branch - Madison, WI
Specific Objective:
Expand the value of moisture Information contained in
Geostationary Sounder Derived Product Images (DPIs)
Build upon GOES’ Strengths:
+ Derived Product Images (DPI) of soundings
speeds comprehension of information
+ Data improves upon model-based first guess
TPW NWP Guess Error Reduction using GOES-12
90%
Improvement
of GOES DPI over NWP guess
% Reduction with GOES-12
GOES Sounder products images already are
available to forecasters. Products currently
available include:
- Total column Precipitable Water (TPW)
- Stability Indices (LI, CAPE)
- 3-layers Precipitable Water (PW) . . .
80%
70%
60%
50%
900-700 hPa
40%
700-300 hPa
30%
20%
10%
0%
BIAS(mm)
SD(mm)
Vertical Layer
HOWEVER, some operational roadblocks:
- DPIs used primarily as observations
- No predictive component
- 3-layer DPIs not used in current NWP models
- Cloud development/expansion often obscures
IR observations when needed most
Need to add a DPI prediction capability
to close these information gaps
10 Feb 2009, 1700 UTC 900-700
hPa GOES PW 6-Hr NearCast
What is an Objective NearCasting System
A NearCasting model should:
Focus on the next 1-6 hours – Fill the Gap between Nowcasts and NWP
Fill the Gap
Between Nowcasting & NWP
Update/enhance NWP guidance:
- Be Fast and updated very frequently
- Enhance information during ‘spin-up” period
Use ALL available data - quickly:
- “Draw closely” to good data
- Avoid analysis smoothing / superobing
(Issues of longer-range NWP)
- Retain Maxima / Minima
Anticipate rapidly developing weather events:
- “Perishable” products need rapid delivery
- Detect the “pre-storm environment”
- Increase lead time and
Probability of Detection (POD)
- Reduce False Alarm Rate (FAR)
Run locally if needed:
- Few resources needed
- Improve Forecaster’s Situational Awareness
0
1
5
6 hours
What is an Objective NearCasting System
A NearCasting model should:
Focus on the next 1-6 hours – Fill the Gap between Nowcasts and NWP
Fill the Gap
Between Nowcasting & NWP
Update/enhance NWP guidance:
- Be Fast and updated very frequently
- Enhance information during ‘spin-up” period
Use ALL available data - quickly:
- “Draw closely” to good data
- Avoid analysis smoothing / superobing
(Issues of longer-range NWP)
- Retain Maxima / Minima
Anticipate rapidly developing weather events:
0
1
5
6 hours
- “Perishable” products need rapid delivery
- Detect the “pre-storm environment”
Increase Satellite Product Usefulness
- Increase lead time and earlier
Project earlier stability information into areas of concern
Probability of Detection (POD)
even after cirrus from initial convection ‘blocks’ IR data
- Reduce False Alarm Rate (FAR)
Run locally if needed:
- Few resources needed
- Improve Forecaster’s Situational Awareness
How the Lagrangian NearCasts work:
13 April 2006 – 2100 UTC
900-700 hPa GOES PW
0 Hour Ob Locations
Objectives:
♦Preserve Data Maxima/Minima/Large Gradients
♦Use Geostationary satellite data at Full
Resolution
♦Be Fast
Methodology:
The Lagrangian approach first interpolates wind
data to locations of full resolution GOES multilayer moisture & temperature observations
Updated Hourly - Full-resolution 10 km data - 10 minute time steps
How the Lagrangian NearCasts work:
13 April 2006 – 2100 UTC
900-700 hPa GOES PW
0 Hour Ob Locations
Objectives:
♦Preserve Data Maxima/Minima/Large Gradients
♦Use Geostationary satellite data at Full
Resolution
♦Be Fast
Methodology:
13 April 2006 – 2100 UTC
900-700 hPa GOES PW
3 Hour NearCast Image
The Lagrangian approach first interpolates wind
data to locations of full resolution GOES multilayer moisture & temperature observations
Next, these high-definition data are moved to
future locations, using dynamically changing
winds with ‘long’ (10 min.) time steps.
.
Updated Hourly - Full-resolution 10 km data - 10 minute time steps
How the Lagrangian NearCasts work:
13 April 2006 – 2100 UTC
900-700 hPa GOES PW
0 Hour Ob Locations
Objectives:
♦Preserve Data Maxima/Minima/Large Gradients
♦Use Geostationary satellite data at Full
Resolution
♦Be Fast
Methodology:
13 April 2006 – 2100 UTC
900-700 hPa GOES PW
3 Hour NearCast Image
The Lagrangian approach first interpolates wind
data to locations of full resolution GOES multilayer moisture & temperature observations
Next, these high-definition data are moved to
future locations, using dynamically changing
winds with ‘long’ (10 min.) time steps.
.
Vertical Moisture Gradient (indicating Convective Instability)
(900-700 hPa GOES PW -700-500 hPa GOES PW)
3 Hour NearCast : Valid 0000UTC
Verification
Updated Hourly - Full-resolution 10 km data - 10 minute time steps
Finally, the moved ‘obs’ values from
each layer are then both:
1) Transferred back to an ‘image’
for display of ‘predicted DPIs’,
2) Several parameters are combined to
produce derived parameters and
3) Results between layers are compared
to obtain various “Stability Indices”
that are combined with ‘conventional
tools’ to identify mesoscale areas where
severe convective will develop even after convective clouds appear.
Progress since the last meeting . . .
• Example many new cases where NearCasts of GOES vertical
moisture gradients (a necessary condition for Convective
Instability) helped isolate areas of Hazardous Weather
Potential
– Useful in many seasons/regions of US
• Severe Convection
• Emphasis on rapid development of isolated storm
– Heavy Precipitation
– Output in GRIB-II and NWS Graphics formats
– ...
• Expanded analyses of Convective Environment
• Diagnose case using SEVIRI data
• Note: This approach only detects where convection
will form rapidly if a sufficient lifting/trigger mechanism is also
present at that location/time
Vertical Moisture Difference
Moving GOES data from Observations to Forecasts
Vertical Moisture Gradient
(900-700 hPa GOES PW 700-500 hPa GOES PW)
6 Hour NearCast from 1500UTC
From 24 October 2008
Formation
of
Pre-Frontal
Convection
Event: Fall Tornado
Begin Date: 24 Oct 2008,
17:55:00 PM EST
Begin Location:
Tarboro, FL
(31°01'N / 81°48'W)
End Date: 24 Oct 2008,
17:55:00 PM EST
End Location: Not Known
Magnitude: F0
Moving GOES data from Observations to Forecasts
Mid-layer Moisture
(900-700 hPa GOES PW )
7 Analyses plus 6-Hour NearCast from 1100UTC
10 February, 2009
Formation
of
Strong PreFrontal
Convection
Event: Winter Tornado
Begin Date: 10 Feb 2009,
14:52:00 PM CST
Begin Location: Edmond,
Oklahoma
Path: 6.5 miles
End Date: 10 Feb 2009,
15:05:00 PM CST
End Location: Not Known
Magnitude: EF2
Moving GOES data from Observations to Forecasts
Vertical Moisture Gradient
(900-700 hPa GOES PW 700-500 hPa GOES PW)
7 Analyses Plus 6-Hour NearCast from 1100UTC
10 February 2009
Formation
of
Strong PreFrontal
Convection
Verification: Radar/Reports
Using Equivalent Potential Temperature ( Theta-E or Θe ) instead of TPW to
diagnose Total Thermal Energy and true Convective Instability
Fundament Question:
Do GOES temperature profiles add information
regarding the potential for the timing and location of convection development
to that already present in the DPI moisture products already being used?
A case when
Severe Thunderstorm Warnings
were issued for
all of western Iowa
Rapid Development of Convection over NE IA
between 2000 and 2100 UTC 9 July 2009
Using Equivalent Potential Temperature ( Theta-E or Θe ) instead of TPW to
diagnose Total Thermal Energy and true Convective Instability
A case when Severe Thunderstorm Warnings were issued for all of western Iowa
Theta-E measures TOTAL moist energy,
not only latent heat potential
6 hr NearCast for 2100 UTC
Low Layer Theta-E
 Lower-Layer Θe NearCasts shows warm / moist air band
moving into far NW Iowa, where deep convection formed rapidly
by 2100 UTC.
 Warm temperatures expand area of highest
values of Θe across more of
South West Iowa than TPW alone.
6 hr NearCast for 2100 UTC
Low to Mid level PW Difference
Rapid Development of Convection over NE IA
between 2000 and 2100 UTC 9 July 2009
Using Equivalent Potential Temperature ( Theta-E or Θe ) instead of TPW
to diagnose Total Thermal Energy and true Convective Instability
A case when Severe Thunderstorm Warnings were issued for all of western Iowa
6 hr NearCast for 2100 UTC
Low Layer Theta-E
Theta-E measures TOTAL moist energy,
not only latent heat potential
 Lower-Layer Theta-E NearCasts shows warm / moist air band
moving into far NW Iowa, where deep convection formed rapidly
by 2100 UTC.
 Vertical Θe Differences shows full
Convective Instability - at the correct time and place
- GOES temperature data in Θe do enhance the
vertical moisture gradient fields used previously.
Negative ∂Θe/∂Z (blue to
red areas) indicates
Convective Instability
6 hr NearCast for 2100 UTC
Low to Mid Layer Theta-E Differences
Rapid Development of Convection over NE IA
between 2000 and 2100 UTC 9 July 2009
How well can the NearCasting approach
be applied to SEVIRI data?
•
Tests were conducted with 2 time periods of retrievals obtained 8
and 6 hours prior to development of the F2/T4 tornado that occurred
in Częstochowa, Poland near 16UTC - 20 July 2007.
–
–
Full description in Pajek, Iwanski, König and Struzik from last meeting
Results using only 09UTC retrievals (provided by König) shown here
•
•
•
•
NearCast results valid from 09UTC to 15UTC
Initial Wind and Geopotential data from NCEP GFS @ 0.5o resolution
Results displayed on 0.25o output grid
NearCasts were made or a wider variety of variable than in previous US
tests
– Multi-Layer and Total Precipitable Water
– Lower- and Mid-tropospheric parameters:
•
•
•
•
•
Temperature
Mixing Ratio
Temperature at LCL
Equivalent Potential Temperature
Several Stability Indices were derived from NearCasts of these
primary variables
How well can the NearCasting approach
be applied to SEVIRI data?
•
Tests were conducted with 2 time periods of retrievals obtained 8
and 6 hours prior to development of the F2/T4 tornado that occurred
in Częstochowa, Poland near 16UTC - 20 July 2007.
–
–
Full description in Pajek, Iwanski, König and Struzik from last meeting
Results using only 09UTC retrievals (provided by Konig) shown here
•
•
•
•
NearCast results valid from 09UTC to 15UTC
Initial Wind and Geopotential data from NCEP GFS @ 0.5o resolution
Results displayed on 0.25o output grid
NearCasts were made for more variable than in previous US tests
–
–
Multi-Layer and Total Precipitable Water
Lower- and Mid-tropospheric parameters:
•
•
•
•
Temperature
Mixing Ratio
Temperature at LCL
Equivalent Potential Temperature
•
Several Stability Indices were derived from NearCasts of these primary
variables
•
Advance apologies for “quality” of graphics - but they get the point across
– See summary slides
Lowest-Layer Precipitable Water – 09Z – F00:Valid 09Z
Slide Orientation
NearCast Length
and
Valid Time indicated by
F00:Valid 09Z
Display area:
11o to 27o E
and 47o to 60o N
Location of
F2/T4
Tornado indicated by
Cross
Lowest-Layer Precipitable Water – 09Z – F00:Valid 09Z
Lowest-Layer
Precipitable Water
Observations show:
- Minima in areas of
high terrain
- Possible postprocessing issue
“Mid”-Layer Precipitable Water – 09Z – F00:Valid 09Z
“Mid”-Layer Precipitable Water – 09Z – F00:Valid 09Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F01:Valid 10Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F02:Valid 11Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F03:Valid 12Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F04:Valid 13Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F05:Valid 14Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F06:Valid 15Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
“Mid”-Layer Precipitable Water – 09Z – F06:Valid 15Z
Middle-Layer
Precipitable Water
Observations show:
- No terrain effects
------------------------------
Maximum of
Middle-Layer PW
- Only one observed
maximum in area
-Initially West of
tornado location
- Also moves to
region North-West
of Tornado at time of
development
Temperature – 840 hPa – 09Z – F00:Valid 09Z
Temperature – 840 hPa – 09Z – F00:Valid 09Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F00:Valid 09Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F01:Valid 10Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F02:Valid 12Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F03:Valid 12Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F04:Valid 13Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperature
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F05:Valid 14Z
Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperature
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F06:Valid 15Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Temperature – 840 hPa – 09Z – F06:Valid 15Z
Lower-Tropospheric
Temperature
Observations show:
- Temperature front
North of area of
tornado formation
- Highest
Temperatures were
well south of tornado
----------------------------- Front strengthens
and temperatures
increase near and
west of tornadic area
during NearCast
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F00:Valid 09Z
Equivalent Potential
Temperature (Өe)
------------------------------- Combines impacts
of temperature and
moisture
- Measures Total
Thermal Potential
- Clearly defines:
-
Fronts
- Areas of
Warm/Moist air
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F00:Valid 09Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F00:Valid 09Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F01:Valid 10Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F02:Valid 11Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F03:Valid 12Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F04:Valid 13Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
-Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F05:Valid 14Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F06:Valid 15Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F06:Valid 15Z
Lower-Tropospheric
Equivalent Potential
Temperature (Өe)
Observations show:
- Significant front
immediately North of
area where tornado
formed (a potential
lifting mechanism)
- Area of Warm/Moist
air South-West of
tornado development
-Warm/Moist air
moved to area where
severe convection
was forming rapidly
by 15UTC
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F00:Valid 09Z
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F00:Valid 09Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F00:Valid 09Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F01:Valid 10Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F02:Valid 11Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F03:Valid 12Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F04:Valid 13Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F05:Valid 14Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F06:Valid 15Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Lapse Rate (∂T/∂p) – 840-480 hPa – 09Z – F06:Valid 15Z
Lower-to-Middle
Tropospheric
Lapse Rate
Observations show:
- Weakest Lapse
rates initial well south
of convective area
----------------------------- NearCasts show
combined effects of
differential advection
between lower- and
mid-levels
- Movement of warm
pockets aloft first
increases and then
decreases stability in
vicinity of tornado
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F00:Valid 09Z
Convective Instability
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F00:Valid 09Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F00:Valid 09Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F01:Valid 10Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F02:Valid 11Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F03:Valid 12Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of weakest
strengthens as it
move to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F04:Valid 13Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F05:Valid 14Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F06:Valid 15Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F06:Valid 15Z
Convective Instability
Convective
Instability
Observations show:
- Weakest Stability
South-West of
tornado development--------------------------- NearCasts show
combined effects of
differential advection
between Warm/Moist
air at low levels and
Dry/Cool air aloft
- Area of greatest
Convective Instability
moves to tornado site
at same time as rapid
lapse rate change
Lifted Index – 840-480 hPa – 09Z – F00:Valid 09Z
Lifted Index – 840-480 hPa – 09Z – F00:Valid 09Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F00:Valid 09Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F01:Valid 10Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F02:Valid 11Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F03:Valid 12Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F04:Valid 13Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F05:Valid 14Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F06:Valid 15Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Lifted Index – 840-480 hPa – 09Z – F06:Valid 15Z
Lifted Index
Difference between
TLCL840 and T480
Observations show:
- Weakest Stability
South-West of
tornado development…but…
- NearCasts show:
- Initial Instability
weakens and moves
East
- Second area of
Instability forms to
west and moves to
tornado site by 15Z
Summary
• Additional tests show utility of GOES DPI NearCasts in detecting the
pre-convective environment for hazardous weather in many US cases
• Effective for detecting isolated convection and reducing warning area sizes
• Important for predicting various type of Hazardous Convection
• Useful in adding detail to Heavy Precipitation Forecasts
• GOES Temperature Soundings provide additional information enhancing
moisture signal for detecting Convective Potential when using ӨE
•Tests with SEVIRI retrieval were positive
• Useful in diagnosing the pre-convective
environment evolution
• Information contained in multiple
forecasting indicators
• Additional tests being conducted to
determine amount of information added by
satellite vs. ‘first guess’
FUTURE
• Beta-test version available by mid-October, including time-lag ensembles
• Major US testing at SPC/NSSL in 2010
• Improve graphics using McIDAS-V, Ensembles , Consistency measures, . . .