PERTURBATION VS' ERROR CORRELATION ANALYSIS PECA

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NOAA THORPEX PERSPECTIVE ON T-PARC / IPY
Zoltan Toth
      
Environmental Modeling Center NOAA/NWS/NCEP
USA Acknowledgements John Gaynor, Yucheng
Song, Sharan Majumdar, Rolf Langland, Mel
Shapiro, Mark Moran http//wwwt.emc.ncep.noaa.go
v/gmb/ens/index.html
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OUTLINE / SUMMARY

• LINKS BETWEEN THORPEX IPY
• Both global programs
• THORPEX is weather component of IPY
• Joint field program during IPY
• SCIENTIFIC HYPOTHESES FOR THORPEX-IPY
• Main sources of observational uncertainty over NH
• Main factors supporting / limiting predictability
  over two hemispheres
• NOAAS INTERESTS IN THORPEX-IPY
• Short-Term Arctic Predictability (STAP)
• 3-90 days forecast of high impact weather, sea
  ice, ocean wave, land surface
• PACIFIC PREDICTABILITY EXPERIMENT
• THORPEX-IPY theme
• Complemented by meso-scale studies
• NORTH AMERICAN ENSEMBLE FORECAST SYSTEM

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LINKS BETWEEN IPY THORPEX
International Polar Year (IPY) Multi- and
interdisciplinary international research
experiment 03/2007-02/2009 Study areas of
strongest climate change impact Comprehensive
research in both polar regions Strong links to
the rest of the globe - Theme 3 (of 6) Advance
our understanding of polar - global interactions
by studying teleconnections on all
scales. THORPEX A World Weather Research
Program (WWRP) Accelerate improvements in
skill/utility of 1-14 day weather
forecasts Long-term (10-yrs) global research
program in areas of Observing system, data
assimilation, numerical modeling/ensemble,
socioec. appl. Strong link with operational
Numerical Weather Prediction (NWP)
centers International program under
WMO Planning initiated with discussions about
North Pacific experiment gt Opportunities for IPY
- THORPEX Collaboration Joint THORPEX-IPY
Observing period Major opportunity for
accelerating observing system design
work Improved weather forecasts for polar
regions IPY activities Scientific
investigations Link between weather and
climate processes Mid-latitude Polar
interactions THORPEX IS THE WEATHER COMPONENT OF
IPY
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SCIENTIFIC HYPOTHESES FOR THORPEX-IPY RESEARCH

• HYPOTHESIS A Initial conditions
• Main sources of forecast uncertainty /
  impediments to extending forecasts to day 14
• Tropical excitation of waves from the Pacific
  ocean, especially from Maritime Continent
• The mid-latitude flow regime over the Pacific
  Ocean
• The polar circulation with episodes of cross
  polar flow
• Assess relative importance of three sources of
  uncertainty their interaction
• What is optimal mix of observations to reduce
  forecast uncertainty?
• What is best way of assimilating relevant data?
• HYPOTHESIS B Numerical modeling
• The level of predictability forecast skill over
  the NH vs. SH are influenced by
• Nature of flow regimes in polar regions
• More symmetric circumpolar vortex with little to
  no cross polar flow over the Antarctic
• Less symmetric vortex with major episodes of
  cross polar flow over the Arctic
• Difference in distribution of continents and
  oceans over two hemispheres
• Much larger contrast between land and ocean
  masses over NH
• Nature of wave guides for tropical to
  extratropical energy transfer
• Better defined / spatially locked wave guide
  (PNA) over NH
• Assess relative role of three factors their
  relationship in
• Supporting and limiting atmospheric
  predictability for

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NOAAS POTENTIAL INVOLVEMENT IN T-PARC / IPY
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NOAAS INTEREST IN THORPEX-IPY

• SHORT-TERM ARCTIC PREDICTABILITY (STAP, IPY
  Proposal 798)
• Study variability predictability of Arctic high
  impact
• Atmospheric, ice, ocean, and land surface events
• Their interaction with global processes
• On 3-90 days time scale
• Program elements
• Observing System
• Study effect of supplemental Arctic IPY data on
  NWP skill, including ocean wave sea ice
• Test new satellite in situ platforms/instrument
  s
• Collect adaptive obs. along N-Pacific storm track
  its source region in tropics to improve IPY
  fcsts
• Data Assimilation
• Develop targeting methods for improved high
  impact Arctic events
• Improve assimilation of current future atmos.
  (over ice/snow), sea ice, ocean/land surface
  data
• Contribute to design of new global observing
  system over 2 polar regions in framework of GEOSS
• Numerical Modeling
• Identify diagnose model weaknesses critical for
  polar regions polar-extrapolar interactions
• Improve atmospheric, sea ice, n land surface
  model formulation
• Accelerate testing implementation of Hybrid
  Coordinate Ocean Model (HYCOM) for storm surges

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SHORT-TERM ARCTIC PREDICTABILITY (STAP, 798)

• Principal Investigators
• Satellite data / assimilation
• Jeff Key (NOAA), Chris Velden (SIMSS), John
  LeMarshall (JCSDA)
• Coupled Atmosphere-ice-ocean-land surface
  diagnosis and modeling
• Robert Grumbine, Julian Wang, Mel Shapiro (NOAA)
• Socio-Economic Applications
• James Partain (NOAA), Rebecca Morss (NCAR), Arun
  Kumar (NOAA)
• Connections with other IPY activities
• Cluster 2
• Terrestrial cryosphere, NH (392 - Grumbine)
• Arctic Sea Ice (185, Grumbine)
• Cross-cutting (Shapiro, Toth)
• Cluster 4
• Weather-Climate link (Kumar, Wang)
• THORPEX (Toth, Shapiro)
• Observing Systems (129, 138, 699, 732, Key,
  Velden, LeMarshall)
• Teleconnections (Shapiro, Toth)
• Cluster 5

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SHORT-TERM ARCTIC PREDICTABILITY (STAP, 798)

• NOAA IPY Connections
• IPY activities coordinated by John Calder
• STAP is one of 10 NOAA IPY proposals, linked in
  particular with
• Causes impacts of recent changes in Pacific
  Arctic (157, Calder K. Crane)
• Data Management/Arctic Change Detection (879,
  Florence Fetterer)
• Decision support in Alaska the Arctic (215,
  Juniper Neill)
• Arctic climate modelling (337, Tony Beesley)
• Arctic system reanalysis (179, John Calder)
• Satellite products (600, Jeff Key)
• US Connections
• US participation in THORPEX Pacific-Asian
  Regional Campaign (T-PARC)
• USTSSC in charge Led by Jim Hansen
• Need for agency (NASA, ONR, NSF) wider
  community (univ./private) coordination
• Need a formal WG for planning and execution
• Mesos-cale activities may leverage off /
  complement THORPEX-IPY work
• North American Connections
• North American Ensemble Forecast System (NAEFS)

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PACIFIC PREDICTABILITY EXPERIMENT T-PARC

• Main interest?
• Build around THORPEX goals of
• Extending predictability linked with large scale
  processes
• Link up with IPY
• Unique opportunity, excellent leveraging
• Complement it with meso-scale aspects if there is
  interest
• Field OR laboratory experiment?
• BOTH
• Lab work (Improve DA, NWP modeling, targeting
  Use OSSEs)
• Design field phase
• Generalize field results
• Field work
• Real time test demonstration
• Support IPY activities (lab work cannot achieve
  all on ground)
• Timing?
• Must be driven by IPY, March 2007 February 2009
• G-lV available from 1 Dec 2008 Could ET work be
  scheduled for same period?

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PACIFIC PREDICTABILITY EXPERIMENT T-PARC

• PROPOSE STUDYING LIFECYCLE OF WAVES ON PAC. STORM
  TRACK
• Western Tropical Pacific (ONR, Canada, Asian
  nations?)
• Energy transfer from tropics to extra-tropics
• Extra-tropical transition of tropical cyclones
• Convection linked with Madden Julian or other
  waves
• Western Extra-tropical Pacific (NOAA, NASA?)
• Initial phase of extra-tropical lows
• Targeted observations with 3-5 day lead time
• Adaptive collection of data
• In situ observations (dropsondes, aerosondes?)
• Complement Winter Storm Reconnaissance (WSR)
  program over Eastern Pacific
• Adaptive processing of data
• Satellite observations (dynamically controlled
  thinning etc)
• Arctic Region (IPY)
• Forecast applications (NAEFS)
• Effect of data on extra-tropical forecasts
• Continental US (NOAA)
• Assess effect of IPY data on forecasts for cold
  air outbreaks etc
• Southern Hemisphere (SH THORPEX partners)

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PACIFIC PREDICTABILITY EXPERIMENT T-PARC

• STUDY LIFECYCLE OF WAVES ON PACIFIC STORM TRACK
• Tropical wave in ensemble forecasts (13-16 May)
• Connection between NH SH (NCEP PQPF)
• How well predicted? (ECMWF NCEP MSLP ensemble
  mean)
• Midlatitude low, influenced by tropical wave,
  affects polar region (17-23 May)
• ECMWF NCEP MSLP ensemble mean forecast
  verifying analysis
• Connection
• Can targeting with in situ observations
  (dropsondes) help?
• Results from Winter Storm Reconnessaince over
  NE-Pacific
• T-PARC can complement WSR data over NW-Pacific
• Is West Coast of US more exposed to data void
  than rest of US? (Myth)
• Beyond 24-36 hrs, all areas equally exposed to
  data void
• Predictability over West Coast may be higher
• First generation storms hitting coast at end of
  well organized storm track
• Rest of continent affected by 2nd generation
  storms
• ECMWF
• Targeting to improve longer range / second
  generation storms?
• Beyond

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Energy propagates from tropical wave to
extratropics around 125E, 0N, 00UTC 16 May
Courtesy of Y. Zhu Majumdar
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How well the effect of tropical wave is captured
in NWP forecast of subtropical low? 96-72-48-24
hr forecasts verifying On May 16
Courtesy of Marchok Majumdar
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Extratropical life cycle of storm 00UTC 17 May
00UTC 23 May Subtropical low traverses high
pressure area Develops into deep storm in Gulf
of Alaska
Verifying analyses
Ensemble mean forecast
Courtesy of Marchok Majumdar
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SUMMARY OF WINTER STORM RECONNAISSANCE RESULTS
NORPEX-98 WSR 1999-2005 WSR operational since
2001

• 60-80 of forecasts improved because of targeted
  observations
• 12-hour gain in forecast lead time
• RMS forecast errors reduced by 10-20
• Local improvement similar to that achieved over
  20 yrs (1975-95) due to advances in data
  coverage/quality

Toth et al. (2000)
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WESTERN VS. EASTERN US PREDICTABILITY Winter of
2002/03
There are seasons when predictability is higher
over western US
WSR00
West
East
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Individual Case Comparison
1 denotes positive effect 0 denotes
neutral effect -1 denotes negative effect
VR OBSDATE P T V OVERALL REGION
FHOUR E 20050120 1 1 1 1 82W
,37N 72 W 20050128 1 1 1 1
123W ,40N 24 C 20050205 1 1 1 1
97W ,31N 36 H 20050206 1 1 1 1
155W ,19.5N 24 C 20050206 1 1 1
1 90W ,43N 72 C 20050207 1 1 1
1 90W ,42N 60 C 20050208 1 -1
1 1 90W ,42N 36 AK 20050208 -1 -1
-1 -1 150W ,61N 48 E 20050208 1
0 -1 0 74W ,43N 48 C 20050209 -1
1 1 1 93W ,35N 96 AK 20050210
-1 -1 1 -1 135W ,55N 24 E
20050212 1 1 1 1 88W ,46N 48
W 20050213 1 1 1 1 123W ,38N
48 W 20050213 1 1 -1 1 123W ,38N
60 W 20050213 1 1 -1 1 123W
,38N 72 AK 20050219 1 1 1 1
150W ,61N 48 W 20050220 -1 1 1 1
118W ,34N 48 W 20050221 1 1 1 1
118W ,34N 24 AK 20050222 -1 -1 -1
-1 138W ,58N 24 AK 20050223 -1 1 1
1 140W ,60N 24 AK 20050225 1 1
1 1 140W ,60N 48 W 20050225 1 1
-1 1 123W ,40N 72 E 20050225 1
1 -1 1 75W ,40N 96 E 20050303 -1
1 1 1 86W ,41N 48 AK 20050309
-1 1 -1 -1 130W ,57N 36 H
20050312 1 -1 -1 -1 157W ,21N 24
E 20050313 0 1 1 1 81W ,32N
96 E 20050314 1 -1 -1 -1 79W ,32N
72 E 20050316 -1 -1 -1 -1 78W
,37N 48 W 20050317 1 1 1 1
122W ,38N 48
22 OVERALL POSITIVE
1 OVERALL NEUTRAL 7 OVERALL NEGATIVE
73 improved 23 degraded
OVERALL EFFECT
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Winds
WSR05
Temperature
Humidity
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Precipitation verification

• Precipitation verification is still in a testing
  stage due to the lack of station observation data
  in some regions.

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Impact of WSR data (00 UTC 20 Jan. 2005) on 1st,
2nd, 3rd generation storms
84 hrs
168 hrs
Initial time
Courtesy of Dan Hodyss, S. Majumdar, Y. Song
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NORTH AMERICAN ENSEMBLEFORECAST SYSTEM (NAEFS)

• Zoltan Toth, EMC/NCEP/NWS/NOAA, USA
• Jean-Guy Desmarais, MSC/CMC, Canada

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INAUGURATIONCEREMONY
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NORTH AMERICAN ENSEMBLE FORECAST SYSTEM -NAEFS

• Combines global ensemble forecasts from Canada
  USA
• 60 members per day from MSC NWS
• Generates products for
• Intermediate users
• E.g., weather forecasters at NCEP Service Centers
  (US NWS)
• Specialized users
• E.g., hydrologic applications in all three
  countries
• End users
• E.g., forecasts for public distribution in Canada
  (MSC) and Mexico (NMSM)
• Requires moderate additional investment for
• New telecommunication arrangements
• Extra coordination in research/development
  implementations
• Operational implementation March 2006
• Ready to serve IPY and PAPEX community in
  2007-2009

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NAEFS THORPEX

• Expands national/international collaboration
• Mexico joined in November 2004
• UK Met Office, FNMOC, AFWA to join in 2006
• Provides framework for transitioning research
  into operations
• Prototype for ensemble component of THORPEX
  legacy forecast system
• Global Ensemble Prediction System (GEPS), part
  of
• Global Interactive Forecast System (GIFS)

RESEARCH
THORPEX Interactive Grand Global Ensemble (TIGGE)
THORPEX
RESEARCH
Articulates operational needs
Transfers New methods
North American Ensemble Forecast System (NAEFS)
OPERATIONAL
LEGACY (GIFS)
OPERATIONS
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OUTLINE / SUMMARY

• LINKS BETWEEN THORPEX IPY
• Both global programs
• THORPEX is weather component of IPY
• Joint field program during IPY
• SCIENTIFIC HYPOTHESES FOR THORPEX-IPY
• Main sources of observational uncertainty over NH
• Main factors supporting / limiting predictability
  over two hemispheres
• NOAAS INTERESTS IN THORPEX-IPY
• Short-Term Arctic Predictability (STAP)
• 3-90 days forecast of high impact weather, sea
  ice, ocean wave, land surface
• PACIFIC PREDICTABILITY EXPERIMENT
• THORPEX-IPY theme
• Complemented by meso-scale studies
• NORTH AMERICAN ENSEMBLE FORECAST SYSTEM

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Composite summary maps
139.6W 59.8N 36hrs (7)
92W 38.6N 60hrs (5)
122W 37.5N 49.5hrs (8)
80W 38.6N 63.5hrs (8)
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Courtesy of Marchok Majumdar
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Courtesy of Marchok Majumdar
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PROPOSED NORTH PACIFIC THORPEX REGIONAL CAMPAIGN
(NP-TREC)
2-MONTH FIELD PROGRAM DURING IPY Joint THORPEX
IPY Observing Period, Winter of 2007/08
1) Utilize enhanced IPY polar observing system
in NWP (2 yrs) Advantages for THORPEX Ensure
real-time accessibility of data (for NWP centers,
through GTS transmission) Explore targeted use
of IPY polar data on forecasts over NA (cold air
outbreaks, etc) Consider special enhancement of
IPY data if needed 2) Enhance atmospheric
observations in NW Pacific (2 mos) Contributing
to IPY activities Manned and unmanned aircraft,
driftsonde, satellite, etc Extension of
operational NWS Winter Storm Recon coverage
(northeast Pacific) Targeted to improve Alaskan
(and Northern Canadian) forecasts Study
mid-latitude polar interaction on daily time
scale 3) Evaluate effect of enhanced observing
system on forecasts (2 mos) Mutual
benefits Study combined effect of North Pacific
(NP-TREC) polar region (IPY) observations 2-3
days Polar regions of NA 3-14 days NA, NH,
Global domains PLANNING a) Interface with IPY -
International THORPEX coordination b) Develop
detailed US plan Coordinate within NA c)
Start scientific work (eg, OSSE) as soon as
possible d) NP-TOST for testing new components
of observing system (2006)
Opportunities for THORPEX Assessment of major
observational enhancements over polar
regions Scientific collaboration on time scales
of weather/climate interface
Benefits for IPY Link to mid-latitude weather
processes (science and organizational) Improved
targeted weather forecasts Improved sea ice air
quality forecasts
Ample time for planning coordinated field program
- Possible joint funding opportunities
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Winter Storm Reconnaissance Program
Greatest Impact 1 2 Day Forecast on West
Coast and Alaska 2 4 Day Forecast in Central
U.S. and East Coast
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Results from Winter Storm Reconnaissance (WSR)
2005 programs

• Yucheng Song IMSG at EMC/NCEP
• Zoltan Toth EMC/NCEP/NWS
  
• Sharan Majumdar Univ. of Miami
• Craig H. Bishop
  NRL
• Roy Smith NCO/NCEP/NWS

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Acknowledgments

• NWS field offices, HPC/NCEP and SDMs
• NOAA G-IV and the USAFR C-130 flight crews
• CARCAH (John Pavone)
• Jack Woollen - EMC
• Russ Treadon - EMC
• Mark Iredell - EMC
• Istvan Szunyogh Univ. of Maryland
• others who have contributed!

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About the Winter Storm Reconnaissance (WSR)
Program

• Took place 20 Jan 17 March 2005
• Dropwinsonde observations taken over the NE
  Pacific by aircraft operated by NOAAs Aircraft
  Operations Center (G-IV) and the US Air Force
  Reserve (C-130s).
• Observations are adaptive
• collected only prior to significant winter
  weather events of interest
• in areas that might influence forecast the most.
• Operational since January 2001
• 31 flights, around 500 dropsondes this winter
  which is reduced from 720 drops last year

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NOAA G-IV and US Air Force Reserve (C-130s)
C-130
G-IV
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Evaluation methodology

• Compare two parallel runs from NCEP GFS analysis
  and forecast cycles (T126L28 resolution)
• Operational including all operationally
  available data (includes dropsondes)
• Control excluding only dropsonde data in the
  targeted area
• Verify against observations over the pre-selected
  area of interest (verification region)
• Rawinsonde observations for surface pressure,
  1000-250mb temperature, wind speed and moisture
• Rain gauge data for precipitation

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Blizzard of 2005(Jan 22-23,2005)
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Blizzard of 2005(Jan 22-23,2005)
The ETKF spotted the target area
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Forecast verification(Jan 22-23,2005)
SLP
250mb Height
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Forecast Impact(Jan 22-23,2005)
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Results for Surface Pressure
Of the cases 20 improved 1 neutral 9 degraded
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Results for Temperature
Of the cases 22 improved 1 neutral 7 degraded
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Results for Vector Wind
Of all cases 19 improved 0 neutral 11 degraded
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Results for Specific humidity
Of all cases 19 improved 0 neutral 11
degraded
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Breakdown for cases
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Individual Case Comparison
1 denotes positive effect 0 denotes
neutral effect -1 denotes negative effect
VR OBSDATE P T V OVERALL REGION
FHOUR E 20050120 1 1 1 1 82W
,37N 72 W 20050128 1 1 1 1
123W ,40N 24 C 20050205 1 1 1 1
97W ,31N 36 H 20050206 1 1 1 1
155W ,19.5N 24 C 20050206 1 1 1
1 90W ,43N 72 C 20050207 1 1 1
1 90W ,42N 60 C 20050208 1 -1
1 1 90W ,42N 36 AK 20050208 -1 -1
-1 -1 150W ,61N 48 E 20050208 1
0 -1 0 74W ,43N 48 C 20050209 -1
1 1 1 93W ,35N 96 AK 20050210
-1 -1 1 -1 135W ,55N 24 E
20050212 1 1 1 1 88W ,46N 48
W 20050213 1 1 1 1 123W ,38N
48 W 20050213 1 1 -1 1 123W ,38N
60 W 20050213 1 1 -1 1 123W
,38N 72 AK 20050219 1 1 1 1
150W ,61N 48 W 20050220 -1 1 1 1
118W ,34N 48 W 20050221 1 1 1 1
118W ,34N 24 AK 20050222 -1 -1 -1
-1 138W ,58N 24 AK 20050223 -1 1 1
1 140W ,60N 24 AK 20050225 1 1
1 1 140W ,60N 48 W 20050225 1 1
-1 1 123W ,40N 72 E 20050225 1
1 -1 1 75W ,40N 96 E 20050303 -1
1 1 1 86W ,41N 48 AK 20050309
-1 1 -1 -1 130W ,57N 36 H
20050312 1 -1 -1 -1 157W ,21N 24
E 20050313 0 1 1 1 81W ,32N
96 E 20050314 1 -1 -1 -1 79W ,32N
72 E 20050316 -1 -1 -1 -1 78W
,37N 48 W 20050317 1 1 1 1
122W ,38N 48
22 OVERALL POSITIVE
1 OVERALL NEUTRAL 7 OVERALL NEGATIVE
73 improved 23 degraded
OVERALL EFFECT
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BACKGROUND
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Winter Storm Reconnaissance Program

• Objective Improve Forecasts of
  Significant Winter Weather
  Events Through Targeted
  Observations in Data Sparse
  Northeast Pacific Ocean
• Approach 1) Collected Only Prior to Significant
  Winter Weather Events of Interest
• 2) Collected in Areas that Influence the
  Forecast the Most
• Results 60 80 of Targeted Numerical Weather
  Predictions Improve Significantly Due to
  Winter Storm Reconnaissance Program (Became
  Operational in January 2001)

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A Typical Winter Storm
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ETKF-based targeting strategy