patterns of historic river flood events in the mid-atlantic region richard h. grumm noaa/nws weather...
TRANSCRIPT
![Page 1: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/1.jpg)
Patterns of Historic River Flood Events in the Mid-Atlantic Region
Richard H. GrummNOAA/NWS Weather Forecast Office, State College, Pennsylvania
and Charles Chillag
NOAA/NWS Middle Atlantic River Forecast Center, State College, Pennsylvania
Contributions byAlaina MacFarlane and Ron Holmes
![Page 2: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/2.jpg)
Motivation
• Ability to compare and rank flood events– For impacts and Federal disasters– Learning from the past to gain knowledge
• Understand flood events– Patterns and conditions for flooding– Education forecasters, users, students
• Knowledge and data should be F U N
![Page 3: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/3.jpg)
![Page 4: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/4.jpg)
Methods and Data
• Mid-Atlantic River Forecast Center Flood data– From archive (points/stages) and research– Extensive dataset with pre-20th Century examples– Based on points over flood and ranked
• Climate data rainfall observations– Where how much when.
• Re-analysis data – Reconstruct the cases 20th Century, NCEP/NCAR, CFSR
![Page 5: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/5.jpg)
20th Century Re-analysis• Used for cases prior to 1949
• 24 pressure levels including 10 hPa
• 6-hourly data
• netCDF or plot-4-U
![Page 6: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/6.jpg)
20th Century Re-analysis site
![Page 7: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/7.jpg)
MARFC Flood Power RankingsIs a arbitrary value weighted according to flood severity
• Simple Method to rate flood based on– Number of points raw number bias
• Power Ranking based on severity/Type of Flood:– minor (1) – moderate(5) – major (10)– unknown (1)
Points Minor Moderate Major Unknown Ranking Event17 5 5 5 2 82 Example
140 34 47 58 1 850 Jan 1996120 20 19 81 0 925 Agnes 1972109 34 43 32 0 569 Lee32 10 11 11 0 175 May 194617 2 7 8 0 117 May 1924
![Page 8: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/8.jpg)
Flood Data Display and Access main access site
• Extensive database with pre-20th Century cases
• Top floods of all time and Month– Sortable by number, categories, and rankings
• Event summaries
![Page 9: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/9.jpg)
Top 20Flood Events
Ranked by points over flood stage
![Page 10: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/10.jpg)
January record
by Events
andthen
Power ranking
![Page 11: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/11.jpg)
May Rankings
1946 event is shown
later
![Page 12: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/12.jpg)
June Events
![Page 13: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/13.jpg)
September Events
![Page 14: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/14.jpg)
Case Example
• Flooding Event of 26 May 1946– 20th Century Re-analysis Example
• Wet month with several day wet period
• Sunbury, PA wet May
![Page 15: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/15.jpg)
May 1946provides summary of event type and flood data
Flood StatisticsYear Count Month Count Total Minor Moderate Major Missing Power
Ranking4 of 8 2 of 2 32 10 11 11 0 175
Weather Summary
See May 21, 1946 flood. The ridge retrograded about 24 May and a surge of high PW air came up the coast. It was a textbook case with a quasi east-west boundary and easterly
flow setting up over the Mid-Atlantic region with a deep southerly jet into it. Heavy rainfall was with strong easterly flow along the boundary and a surge of high PW up the
coast. The low was a southern stream low. Similar to the pattern for the March 2010 Boston/RI flood event in many respects. Probably a Frontal to synoptic transition. – (Rich
Grumm National Weather Service State College, PA)
Additional InformationMARFC Power Ranking is (Minor = 1 - Moderate = 5 - Major = 10 - Missing = 1)
NOAA Daily Weather Maps LinkNOAA Northeast Regional Climate Center Link
![Page 16: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/16.jpg)
NAME TYPE Total Precipitation SUNBURY COOP 11.80SELINSGROVE 2 S COOP 11.32LANSFORD COOP 11.15TAMAQUA 4 N DAM COOP 10.96WATROUS 9 S LEE FIRE COOP 10.88
QUAKERTOWN COOP 10.64LANSFORD FOREMANS SH COOP 10.58
TAMAQUA COOP 10.53JIM THORPE COOP 10.29MONROETON 2 S COOP 10.23TOWER CITY 5 SW COOP 10.19FREELAND COOP 10.19SUNBURY AP WBAN 10.14BERWICK COOP 10.11GREENWOOD RSVR COOP 10.09GRANTVILLE 2 SW COOP 10.04NEW CASTLE 1 N COOP 9.96RETREAT 1 SW COOP 9.90KANE 1 NNE COOP 9.89ALBION COOP 9.88RENOVO COOP 9.82GOULDSBORO COOP 9.70PLEASANT MT 1 W COOP 9.61LEHIGHTON COOP 9.60CANTON 1 NW COOP 9.59NEW BLOOMFIELD COOP 9.52WILKES BARRE COOP 9.51BEAR GAP COOP 9.50EAGLES MERE COOP 9.46Williamsport Area ThreadEx 9.45WILLIAMSPORT WBAN 9.45NEWBURG 3 W COOP 9.45
May 1946Rainfall
For Month
over Pennsylvania
![Page 17: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/17.jpg)
Sunbury Rainfall May 1946
• A wet period
• Wettest May at Sunbury
• Several days of rainfall
• Antecedent conditions played a role. – Some flooding 21 May in NY 1 point!
Date Rainfall1946-05-01 0.001946-05-02 0.001946-05-03 0.001946-05-04 T1946-05-05 0.091946-05-06 0.001946-05-07 0.021946-05-08 0.661946-05-09 0.001946-05-10 0.001946-05-11 0.021946-05-12 0.161946-05-13 0.921946-05-14 0.001946-05-15 0.671946-05-16 0.001946-05-17 0.231946-05-18 0.341946-05-19 0.451946-05-20 0.001946-05-21 1.541946-05-22 0.291946-05-23 0.001946-05-24 0.001946-05-25 0.001946-05-26 1.441946-05-27 1.531946-05-28 3.221946-05-29 0.221946-05-30 0.001946-05-31 0.00Sum 11.80Average -Normal 3.72
![Page 18: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/18.jpg)
The Pattern for the Event
• 20th Century re-analysis data– 250 hPa heights and anomalies sharp wave– 500 hPa heights and anomalies cut-off– High PW East-west then more north-south– LLJ• Easterly flow north of frontal boundary• Southerly flow in warm sector (+5s)
• Textbook P A T T E R N
![Page 19: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/19.jpg)
![Page 20: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/20.jpg)
![Page 21: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/21.jpg)
![Page 22: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/22.jpg)
![Page 23: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/23.jpg)
![Page 24: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/24.jpg)
End of May Pattern
• Large ridge 20-26 May over northwestern Atlantic
• The East Coast and Mid-Atlantic had wet period– Some location had wettest May on record– Sunbury showed wet period
• Persistent pattern then big rain Flood
![Page 25: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/25.jpg)
![Page 26: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/26.jpg)
Event Types Emerge
• Strong south-north PW surges– With strong LLJ– Maddox Synoptic Pattern– Ridge to EAST often critical
• Strong Frontal Systems with easterly flow
• Tropical Systems– With Maddox-Frontal often record events
• Lesser seen cut-off low events
![Page 27: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/27.jpg)
![Page 28: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/28.jpg)
Cut-off Events
• Lack the high PW air
• Slow moving
• Cold core
• Instability driven? There are fewer of these and typically not many points and low power rankings.
![Page 29: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/29.jpg)
![Page 30: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/30.jpg)
Patterns with CFSR Cases
![Page 31: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/31.jpg)
![Page 32: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/32.jpg)
Key Issues and follow-ons
• Data base exists to rank and sort floods
• Not all the floods have been characterized– The data exist to accomplish this back into the 19th
Century– Good learning and teaching tool– Good basic student research Project
• Could be semi-automated?
![Page 33: Patterns of Historic River Flood Events in the Mid-Atlantic Region Richard H. Grumm NOAA/NWS Weather Forecast Office, State College, Pennsylvania and Charles](https://reader038.vdocuments.us/reader038/viewer/2022103023/56649dd15503460f94ac7a2f/html5/thumbnails/33.jpg)
Summary
• Ability to compare and rank flood events– For impacts and Federal disasters– Learning from the past to gain knowledge– Power rankings are helpful
• Understand flood events– Patterns and conditions for flooding– Education forecasters, users, students– Use our knowledge to improve pattern recognition and
perhaps better identify Extreme Weather Events (EWE)