Upload
cameron-cannon
View
225
Download
0
Tags:
Embed Size (px)
Citation preview
Extending Geostationary Satellite Retrievals from
Observations into Forecasts
Using GOES Sounder Products to Improve Regional Using GOES Sounder Products to Improve Regional Hazardous Weather ForecastsHazardous Weather Forecasts
Ralph A. Petersen : University of Wisconsin – MadisonRobert M Aune : NOAA/NESDIS/STAR - Advanced Satellite Products Branch - Madison, WI
Focus on the next 1-6 hours – Fill the Gap between Nowcasts and NWP
Update/enhance NWP guidance:- Be Fast and updated very frequently
Use ALL available data - quickly:- “Draw closely” to good data- Avoid analysis smoothing / superobing
(Issues of longer-range NWP) Anticipate rapidly developing weather events:
- “Perishable” guidance products need rapid delivery
- Detect the “pre-storm environment”- Increase lead time Probability ofDetection (POD)- Reduce False Alarm Rate (FAR)
Run locally if needed:- Few resources needed
- Improve Forecaster’s Situational Awareness
What is an Objective NearCasting System
0 1 5 6 hours
Fill the GapBetween Nowcasting & NWP
A NearCasting model should:
13 April 2006 – 2100 UTC900-700 hPa GOES PW
0 Hour Ob Locations
Updated Hourly - Full-resolution 10 km data - 10 minute time steps
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 multi-layer moisture & temperature observations
How the Lagrangian NearCasts work:
13 April 2006 – 2100 UTC900-700 hPa GOES PW
0 Hour Ob Locations
13 April 2006 – 2100 UTC900-700 hPa GOES PW3 Hour NearCast Image
Updated Hourly - Full-resolution 10 km data - 10 minute time steps
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 multi-layer moisture & temperature observations
Next, these high-definition data are moved to future locations, using dynamically changing winds with ‘long’ (10 min.) time steps.
.
How the Lagrangian NearCasts work:
13 April 2006 – 2100 UTC900-700 hPa GOES PW
0 Hour Ob Locations
13 April 2006 – 2100 UTC900-700 hPa GOES PW3 Hour NearCast Image
Updated Hourly - Full-resolution 10 km data - 10 minute time steps
Vertical Moisture Gradient (indicating Convective Instability)(900-700 hPa GOES PW -700-500 hPa GOES PW)
3 Hour NearCast : Valid 0000UTC
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 multi-layer moisture & temperature observations
Next, these high-definition data are moved to future locations, using dynamically changing winds with ‘long’ (10 min.) 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.
Verification
How the Lagrangian NearCasts work:
Recent Progress
• 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
Mid-layer Moisture(900-700 hPa GOES PW )
7 Analyses plus 6-Hour NearCast from 1100UTC10 February, 2009
Formationof
Strong Pre-Frontal
Convection
Moving GOES data from Observations to Forecasts
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
Vertical Moisture Gradient(900-700 hPa GOES PW - 700-500 hPa GOES PW)
7 Analyses Plus 6-Hour NearCast from 1100UTC10 February 2009
Moving GOES data from Observations to Forecasts
Formationof
Strong Pre-Frontal
ConvectionVerification: Radar/ReportsPsuedo-Convective Stability
Using true Equivalent Potential Temperature ( Theta-E or Θe ) instead of TPW, to diagnose Total Thermal Energy and
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
Lower-Layer Θe 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.
Neg
ativ
e ∂Θ
e/∂
Z (b
lue
to
red
area
s) in
dica
tes
Con
vect
ive
Inst
abili
ty
Rapid Development of Convection over NE IA between 2000 and 2100 UTC 9 July 2009
6 hr NearCast for 2100 UTCLow to Mid Layer Theta-E Differences
6 hr NearCast for 2100 UTCLow Layer Theta-E
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 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
• 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
• Note: Apologies for “quality” of graphics - but they get the point across– Currently integrating NearCasts into McIdas-V
How well can the NearCasting approach be applied to SEVIRI
data?
900-700 hPa Precipitable Water – 09Z – F00:Valid 09Z
Slide Orientation
NearCast Length and
Valid Time indicated by F00:Valid 09Z
Display area:
Centered on Poland11o to 27o E
and 47o to 60o N
Location ofF2/T4
Tornado indicated by Cross
900-700 hPa Precipitable Water – 09Z – F06:Valid 15Z Middle-Layer Precipitable Water
Observations show:
- No terrain effects
------------------------------ Maximum of Middle-Layer PW
- Only one observedmaximum in area
-Initially West of tornado location
- Moves to region North-West of Tornado at time of development
Lower-Tropospheric Temperature
Observations show:
- Temperature front North of area of tornado formation
- Highest Temperatures were well south of tornado
-----------------------------
Temperature – 840 hPa – 09Z – F00:Valid 09Z
Temperature – 840 hPa – 09Z – F06:Valid 15ZLower-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
- Low-level Lifting ?
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F00:Valid 09ZLower-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
Equivalent Potential Temperature (Өe) – 840 hPa – 09Z – F06:Valid 15ZLower-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
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 09ZConvective Instability
Vertical Equiv. Pot. Temp. Difference (∂Өe/∂p) – 840-480 hPa – 09Z – F00:Valid 09ZConvective 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 10ZConvective 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 11ZConvective 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 12ZConvective 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 13ZConvective 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 14ZConvective 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 15ZConvective 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 15ZConvective 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
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 – 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
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
• Effect 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 beyond TPW in defining Convective Potential when using Өe
•Tests using SEVIRI retrieval positive
• Useful in diagnosing the pre-convective environment evolution
• Applicable to many forecasting Indices
FUTURE• Beta-test version available for distribution by mid-October
• Major US testing at SPC/NSSL in 2010
• Plans for improved graphics using McIDAS-V Ensembles , Consistency, . . .