Pittsburgh Urban Flash Flood May 18, 1999. AMBER Time Display Interval 5-minute ABR: Used to compute ABR Rate and to display 2-hour accumulated ABR.5-minute

Pittsburgh Urban Flash FloodPittsburgh Urban Flash Flood

May 18, 1999May 18, 1999

AVERAGE BASIN RAINFALL (ABR)TURTLE CREEK WATERSHED 147mi2

01-02JUL1997

01/2200-

02/0015 UTC

X.XX = ABR (in)

MONONGAHELARIVER

ALLEGHENYCOUNTY

WESTMORELANDCOUNTY

N

PITCAIRN

0 5km

1108 2303 2306

2307

2304 2305

1.21 1.73 0.740.12

0.41 0.16

1108 = TURTLE CREEK(1)2303 = TURTLE CREEK(2)2304 = BRUSH CREEK(1)

2305 = BRUSH CREEK(2)2306 = TURTLE CREEK(3)

2307 = TURTLE CREEK(4)

0.76

24.0mi2

10.2mi228.2mi2

22.4mi2 34.8mi2

26.9mi2

AVERAGE BASIN RAINFALL (ABR)TURTLE CREEK WATERSHED 147mi2

18-19May1999

18/2100-

19/0200 UTC

X.XX = ABR (in)

MONONGAHELARIVER

ALLEGHENYCOUNTY

WESTMORELANDCOUNTY

N

PITCAIRN

0 5km

1108 2303 2306

2307

2304 2305

3.03 2.03 1.661.33

2.04 1.13

1108 = TURTLE CREEK(1)2303 = TURTLE CREEK(2)2304 = BRUSH CREEK(1)

2305 = BRUSH CREEK(2)2306 = TURTLE CREEK(3)

2307 = TURTLE CREEK(4)

1.86

24.0mi2

10.2mi228.2mi2

22.4mi2 34.8mi2

26.9mi2

1hr FFG 1.83hr FFG 2.6

AMBER Time Display IntervalAMBER Time Display Interval

• 5-minute ABR5-minute ABR: Used to compute ABR Rate : Used to compute ABR Rate and to display 2-hour accumulated ABR.and to display 2-hour accumulated ABR.

• 15-minute ABR15-minute ABR: Used for comparison with : Used for comparison with IFLOWS rain gage data and to display IFLOWS rain gage data and to display 6-hour accumulated ABR.6-hour accumulated ABR.

• 1-hour ABR1-hour ABR: Used for history of ABR in a : Used for history of ABR in a watershed and to display 24-hour watershed and to display 24-hour accumulated ABR.accumulated ABR.

0

0.5

1

1.5

2

2.501

00

0500

0900

1300

1700

2100

ABR Rate

ABR

Turtle Creek (1) ABR #1108Turtle Creek (1) ABR #110818May, 1999 1-hour data18May, 1999 1-hour data

0

0.5

1

1.5

2

2.5

3

3.520

00

2100

2200

2300

0000

0100

0200

ABR Rate

ABR

Turtle Creek (1) ABR #1108Turtle Creek (1) ABR #110818-19May, 1999 15-minute data18-19May, 1999 15-minute data

Turtle Creek(1)#1108

Turtle Creek

MonongahelaRiver

BraddockLock

Kenmore Ave.

Electric St.

53215322

6334

6598

63366597

6335

6599 6309

63106605

6596

Pitcairn

5.09

4.404.28

3.76

3.72

3.22

3.09

3.09

1.81

2.12

2.46

1.75

X.XX = ABR18MAY1999 2000 UTC-19MAY1999 0200 UTC

3.03

(inches)

2.42.3

3.8

3.12.8

1.8

2.7

0.70.5

1.4

0.2

0.9

x.x = Area(square miles)

00.5

11.5

22.5

33.5

44.5

520

00

2100

2200

2300

0000

0100

0200

ABR Rate

ABR

Forest Hills Run ABR #5321Forest Hills Run ABR #532118-19May1999 15 min. data18-19May1999 15 min. data

0

0.5

1

1.5

2

2.5

3

3.521

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Forest Hills Run ABR #5321Forest Hills Run ABR #532118May1999 5 min. data18May1999 5 min. data

PA Route 30Ardmore Blvd

TurtleCreek

1.0 mi2

0.6 mi2

1.1 mi2

0 4000ft

Forest Hills Run#5321

17,200ft Stream Length

6,000ft above ground

11,200ft below ground

Vincent'sPizza

Taco Bell

KenmoreAve

ElectricAve

Park

Forest Hills Run in Parklooking downstream.

Forest Hills Run exits the parkunder Route 30.

Forrest Hills Run underground.Notice new cement in storm drain.

KenmoreAvenue

Natural creek channel between Taco Bell and house.

Dumpster at Vincent’sPizza washed 1 miledownstream along ElectricAve. Water and mud damage in building.

Electric Ave.

Road is built on Forrest HillsRun creek bed, buried underground.

Forest Hills EMA ReportsForest Hills EMA Reports

• 2215 UTC - First reports of water in 2215 UTC - First reports of water in basements. basements.

• 2300 - 0100 UTC many cars stranded along 2300 - 0100 UTC many cars stranded along Ardmore Boulevard.Ardmore Boulevard.

• 0056 UTC - 10/homes/20 people evacuated 0056 UTC - 10/homes/20 people evacuated on Kenmore Avenue.on Kenmore Avenue.

MonongahelaRiver

YoughioghenyRiver

Braddock Lock12191218

63986399

1725

5333

5332

1226

4030

4032

41344031

4058

4117

4028

4059

4029

4028 Braddock 4029 Clairton4030 McKeesport4031 Glassport4032 Portvue4058 Dravosburg4059 Wilson4117 Duquesne4134 Liberty

(4332)

Urban Areas:

4.38

3.86

3.99

3.74

3.58

3.90

3.673.28

4.213.49 3.01

3.18

2.32

2.93

2.90

3.273.18

5.26 (4.44)Rain Gage

0.9

3.0

2.21.4

1.3

1.2

0.4

2.0

0.4

x.xx = ABR18May1999 2000 UTC-19May1999 0200 UTC

x.x = Area in(square miles)

1.6

3.2

1.8 2.3

3.1

1.5

0.9

1.5

6398 Thomson Run(1)6399 Thompson Run(2)

1218 West Run1219 Homestead Run

1226 Crooked Run

1725 Curry HollowRoad Run

5332 Coal Valley Run5333 New EnglandRoad Run

Mon Valley Urban AreasMon Valley Urban AreasTotal population 86,565Total population 86,565

• Rankin/Braddock 8,256 3.0miRankin/Braddock 8,256 3.0mi22

• Clairton 12,188 1.3miClairton 12,188 1.3mi22

• McKeesport 31,012 2.0miMcKeesport 31,012 2.0mi22

• Glassport 6,242 1.2miGlassport 6,242 1.2mi22

• Port Vue 5,316 0.9miPort Vue 5,316 0.9mi22

• Wilson/Dravosburg 11,075 0.8miWilson/Dravosburg 11,075 0.8mi22

• Duquesne 10,094 1.4miDuquesne 10,094 1.4mi22

• Liberty 3,112 2.2miLiberty 3,112 2.2mi22

00.5

11.5

22.5

33.5

44.5

520

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Port Vue #4032 0.9miPort Vue #4032 0.9mi22

18-19May1999 15 min. data18-19May1999 15 min. data

0

0.5

1

1.5

2

2.5

3

3.5

4

4.521

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Port Vue #4032 0.9miPort Vue #4032 0.9mi22

18May1999 5 min. data18May1999 5 min. data

0

0.5

1

1.5

2

2.5

3

3.5

4

4.520

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Rankin/Braddock #4028 3.0miRankin/Braddock #4028 3.0mi22


0

0.5

1

1.5

2

2.5

321

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Rankin/Braddock #4028 3.0miRankin/Braddock #4028 3.0mi22


0

0.5

1

1.5

2

2.5

3

3.5

4

4.520

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Liberty #4134 2.2miLiberty #4134 2.2mi22


0

0.5

1

1.5

2

2.5

3

3.5

4

4.521

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Liberty #4028 2.2miLiberty #4028 2.2mi22


0

0.5

1

1.5

2

2.5

3

3.5

420

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Duquesne #4117 1.4miDuquesne #4117 1.4mi22


0

0.5

1

1.5

2

2.5

3

3.521

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Duquesne #4117 1.4miDuquesne #4117 1.4mi22


0

0.5

1

1.5

2

2.5

3

3.5

420

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Clairton #4029 1.3miClairton #4029 1.3mi22


0

0.5

1

1.5

2

2.5

3

3.5

421

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR



AMBER’sAMBER’s SlidingSliding Time WindowTime Window

• AMBER gives the forecaster the option of AMBER gives the forecaster the option of examining rainfall in any time duration.examining rainfall in any time duration.

• The capability of examining rainfall in a The capability of examining rainfall in a moving time window is a very powerful moving time window is a very powerful feature for the flash flood forecaster.feature for the flash flood forecaster.

• One inch of rain falling in 15 minutes One inch of rain falling in 15 minutes produces a much large stream response than produces a much large stream response than one inch of rain distributed through 1 hour.one inch of rain distributed through 1 hour.

0

0.5

1

1.5

2

2.5

3

3.5

420

26

2036

2046

2056

2106

2116

2126

2136

ABR Rate

ABR



0

0.5

1

1.5

2

2.5

3

3.521

51

2206

2221

2236

2251

2306

2321

2336

2351

ABR Rate

ABR



24 Hour ABR-Rainfall History24 Hour ABR-Rainfall History

• The history of previous rainfall in a The history of previous rainfall in a watershed is invaluable in determing flash watershed is invaluable in determing flash flood potential.flood potential.

• The AMBER 24 hour rainfall product can The AMBER 24 hour rainfall product can be used to quickly determine the rainfall be used to quickly determine the rainfall distribution in any watershed for the past 24 distribution in any watershed for the past 24 hours. hours.

• ABR is displayed in one hour increments.ABR is displayed in one hour increments.

0

0.5

1

1.5

2

2.5

3

3.501

00

0500

0900

1300

1700

2100

ABR Rate

ABR


18May1999 1 hour data18May1999 1 hour data

0

0.5

1

1.5

2

2.5

3

3.5

4

4.520

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Glassport #4031 1.2miGlassport #4031 1.2mi22


0

0.5

1

1.5

2

2.5

3

3.5

4

4.521

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Glassport #4031 1.2miGlassport #4031 1.2mi22


0

0.5

1

1.5

2

2.5

3

3.5

4

4.520

00

2100

2200

2300

0000

0100

0200

ABR RateABR

Thompson Run(1) #6398 1.6miThompson Run(1) #6398 1.6mi22


0

0.5

1

1.5

2

2.5

3

3.5

421

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR



0

0.5

1

1.5

2

2.5

3

3.5

420

00

2100

2200

2300

0000

0100

0200

ABR RateABR



0

0.5

1

1.5

2

2.5

3

3.5

421

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR



0

1

2

3

4

5

620

00

2100

2200

2300

0000

0100

0200

ABR Rate

ABR

Braddock Lock 2 ABR #4332Braddock Lock 2 ABR #433218-19May1999 15 min. data18-19May1999 15 min. data

0

0.5

1

1.5

2

2.5

3

3.5

4

4.521

06

2121

2136

2151

2206

2221

2236

2251

2306

ABR Rate

ABR

Braddock Lock 2 ABR #4332Braddock Lock 2 ABR #433218May1999 5 min. data18May1999 5 min. data

ConclusionsConclusions

• Small watersheds definition is the key to Small watersheds definition is the key to detection of flash flooding.detection of flash flooding.

• ABR Rate gives early warning for flash ABR Rate gives early warning for flash flood potential. flood potential.

• Time duration of rainfall display impacts Time duration of rainfall display impacts forecaster perception of flash flood threat.forecaster perception of flash flood threat.

• User selectable time window needed.User selectable time window needed.

Documents

Pittsburgh Urban Flash Flood May 18, 1999. AMBER Time Display Interval 5-minute ABR: Used to compute ABR Rate and to display 2-hour accumulated ABR.5-minute