FORECASTING%20EASTERN%20US%20WINTER%20STORMS%20Are%20We%20Getting%20Better%20and%20Why?

1
FORECASTING EASTERN US WINTER STORMSAre We
Getting Better and Why?

• Jeff S. Waldstreicher
• NOAA/NWS Eastern Region
• Scientific Services Division Bohemia, NY
• Northeast Regional Operational Workshop (NROW)
• November 4, 2004

2
OUTLINE

• Winter Storm Warning Program
• Verification Review
• Key Activities and Developments
• Relationship Between Event Totals and Warning
  Performance
• Summary

3
MOTIVATION

• Winter of 2003-2004 Performance
• EASTERN REGION WIDE
• POD - .921
• FAR - .321
• Lead Time 18.5 hours
• NORTHEAST
• POD - .920
• FAR - .321
• Lead Time 20.3 hours
• Is this indicative of a positive performance
  trend?
• If yes, what are the contributing factors?

4
(No Transcript)
5
(No Transcript)
6
WINTER STORM WARNINGVERIFICATION RESULTS

• 1993-94 to 2003-04

7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
NORTHEASTPOD
12
NORTHEASTFAR
13
NORTHEASTLEAD TIME
14
KEY ACTIVITIES AND DEVELOPMENTS RELATED TO
FORECASTING WINTER STORMS

• 1993-2004

15
NWP ADVANCES

• Global Model
• 1993 AVN/MRF at T126/L28
• 2/day AVN to 126h and 1/day MRF to 240h
• 2004 GFS at T256/L64 to 84 h
• 4/day to 384h (T170/L42 84-180h T126/L28 to
  386h)
• Numerous improvements to physics, data
  assimilation etc
• Medium Range Ensemble Forecast System (MREF)
• 1997 1/day 12 member system
• 2004 4/day 48 member system including lag
  members
• NGM Static Since 1993

16
NWP ADVANCES

• Eta (NAM)
• 1993 Early Eta 80 km / 38 levels / 00 and 12Z /
  48h
• 1995 Meso Eta 32 km / 50 levels / 03 and 15Z /
  33h
• 2004 MesoEta 12 km / 60 levels / 4 x day / 84
  hr
• Numerous improvements to physics, data
  assimilation etc
• Local Area Modeling - Workstation Eta
• Short Range Ensemble Forecast System (SREF)
• 1999 10 members (5 48 km Eta / 5 RSM)
• 2004 15 members (10- 32 km Eta / 5- 40 km RSM)
• Rapid Update Cycle (RUC)
• 1994 RUC1 60 km / 25 levels
• 1998 RUC2 40 km / 40 levels
• 2004 RUC2 20 km / 50 levels

17
1994-1997

• WSR-88D Network Installation Completed
• PCGRIDDS/NAWIPS/GARP
• Gridded Model Data into Field Offices
• NWS Lake Effect Snow Study
• BUFKIT
• Expansions of Snow Spotter Networks
• Expansion of Collaborative Research Projects
  (COMET)
• First Real-time local model in NWS ER field
  office (MM5 at BUF and BGM)

18
1998-2000

• AWIPS Installations Completed
• Advanced Workstations w/ Integrated Data Sets
• Public Forecast Program Transfers
• 1998-99 BGM/CTP start Winter Warning Program
• 1999-00 AKQ/BTV/CAR/RNK start Winter Warning
  Program
• Pros New ideas/techniques, Smaller Forecast
  Areas
• Cons Less experience
• Active Teletraining Program Established
• Web based training modules

19
1998-2000

• Regional Workshops/Conferences
• Northeast Regional Operational Workshop
• Southern New England Workshop
• Great Lakes Operational Meteorology Workshop
• Northeast Storm Conference
• Continued Expansion of COMET Projects
• CSTAR Collaborative Research Projects Funded
• North Carolina State Univ. WFO Raleigh (early
  2000)
• State Univ. of New York at Albany WFO Albany
  (late 2000)

20
2001-2004

• Eastern Region Winter Weather Best Practices Team
  (2001)
• IFPS
• Collaborative Forecast Process
• HPC Winter Weather Experiment (WWE)
• 2001-02 4 WFOs (AKQ/LWX/PHI/CTP)
• 2002-03 All Eastern Region
• 2003-04 75 of CONUS
• 2004-05 Integrated into routine HPC Operations
• Test new collaborative forecast process among HPC
  and WFOs for winter storm events
• Evaluate new products from SREF

21
2001-2004

• Implementation of CSTAR Research Results
• U. at Albany Project
• Mesoscale Banding in Winter Storms
• Precipitation Microphysics
• Cold Season Closed Lows
• Terrain-Forced Snow Storms
• Impacts of Climate Regimes (ENSO, NAO, etc)
• N.C. State Project
• Cold Air Damming
• Coastal Fronts
• Precipitation Type Forecasting Methodologies
• Regional COMET Projects
• BTV/McGill Univ.
• OKX/Stony Brook Univ.

22
2001-2004

• Weather Event Simulator (WES) 2001
• Training Workstation that can simulate real-time
  data flow and forecast processes
• AWIPS Archive Server - 2002
• Local Capability to archive full AWIPS data sets
  for WES playback
• Expansion of local office training activities and
  workshops

23
2001-2004

• Coming together of several activities and
  developments
• Applied Research and Technique Development
• Technologies
• Training
• Operational Application and Procedures

24
Mesoscale Band Project Timeline
25
RELATIONSHIP BETWEEN EVENT COUNTS AND WARNING
PERFORMANCE

• IMPACTS OF CLIMATE REGIMES?

26
ACTIVE SEASONS IN NORTHEAST gt1200 Events
Season of Events POD FAR Lead Time
93-94 1416 .923 .230 11.8
95-96 1713 .842 .246 14.6
00-01 1220 .913 .296 18.0
02-03 1383 .916 .277 16.2
Mean .899 .262 15.2
27
MODERATE SEASONS IN NORTHEAST800-1200 Events
Season of Events POD FAR Lead Time
98-99 1050 .890 .314 13.6
99-00 1016 .902 .201 12.7
03-04 1069 .920 .321 20.3
Mean .904 .279 15.5
28
LAME SEASONS IN NORTHEAST lt800 Events
Season of Events POD FAR Lead Time
94-95 561 .772 .467 13.6
96-97 654 .855 .538 11.3
97-98 788 .803 .489 12.8
01-02 470 .840 .402 11.7
Mean .818 .474 12.3
29
MONTHLY NAO/PNA vs. Events

• Cumulative Winter (Dec-Jan-Feb-Mar) Monthly Mean
  NAO shows some correlation to number of winter
  storm events
• Cumulative Winter Monthly Mean PNA shows little
  or no correlation
• Shorter term (daily/weekly) index values likely
  more important

30
SUMMARY

• Winter storm warning performance appears to be
  improving across the Northeast
• Greatest improvements in Lead Time
• Lead Time improvements are not a result of
  improved POD
• No increase in false alarms noted
• Event totals impact warning performance
• More events better performance
• Most impact on False Alarms and Lead Time

31
SUMMARY

• Performance improvements appear to be related to
  an evolving end-to-end collaborative process
  of
• Discovery and Sharing
• Demonstration of Added Value (Operational
  Utility)
• Operational Implementation
• Training Activities
• Periodic Review and Refinement