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AMBER/FFMP Overview. COMET Basin Customization 02-03 06 August 2002 Robert S. Davis, Pittsburgh NWSWFO. AWIPS Flash Flood Monitoring and Prediction (FFMP). AWIPS build 5.1.2 (Early 2002) the AMBER implementation of FFMP using DHR.
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AMBER/FFMPOverview COMET Basin Customization 02-03 06 August 2002 Robert S. Davis, Pittsburgh NWSWFO
AWIPS Flash Flood Monitoring and Prediction (FFMP) • AWIPS build 5.1.2 (Early 2002) the AMBER implementation of FFMP using DHR. • Requires NSSL CD of ArcView defined watersheds and WSR-88D bin assignments. • Provides graphic display of ABR and ABR–FFG for time periods of 30,60,90,120,180,360 minutes. • Provides line graph of ABR,ABR Rate, and FFG for the same time periods. • 1 level of streams supported • FFMP small subset of AMBERGIS functionality.
FFMP Graphics • County display of CWA-maximum ABR for any stream in county displayed. Left click on Fips code to get “stream display”. • Stream display for a county- ABR for time period selected displayed for each basin. right click on stream ID to get “line graph”. • Line graph of ABR + ABR Rate + FFG
Worthville, PA Flash Flood 05 June 2002 Jefferson County, PA
FFMP Text Data on AWIPS /data/fxa/radar/k@@@/ffmp Where @@@ is your WSR-88D ID
FFMP file archiving • ABR file is archived to hard disk on AWIPS for current GMT day and previous day only. • /data/fxa/radar/k@@@/ffmp/yyyymmdd + yyyymmdd.index for a GMT day • Index file holds the time for each volume scan. • Date file holds the ABR data for each stream (integer*2 data with a record length equal to 2 times the number of FFMP watersheds).
FFMP Basin Attributes • /data/fxa/radar/k@@@/ffmp/basinList.dat • /basinToCounty.dat • /binToBasin.dat • Radar bins are numbered consecutively from 0 to 82799 starting with radial 0.5 degrees. Bin 0 = 0.5 degrees at 0.5 km, bin 230 = 1.5 degrees at 0.5km, etc.
basinList.dat • First line in file is number of basins (5609) • Basin ID number in FFMP display is position in this file basin id =0 (2nd line), 1 (3rd line), 2 (4th line), 3 (5th line), etc. • Pfafstetter ID • Latitude/longitude of basin centroid • Name of creek
binToBasin.dat • First line is number of basins • Second line is data for watershed id=0 • 1st element (number of bins assigned) • Bin number for each assigned bin follows, if 3 bins assigned to this stream, 3 bin numbers will be listed. • Last element: area of bin summation (km2)
basinToCounty.dat • Number of counties on first line • Two letter state • County name • County Fips code • Number of streams assigned to this county • List of Basin Ids assigned to this county • County assigned by MDL lat/lon of centroid
National Basin Delineation • 30Sep1999 – NWS agrees to fund the AMBER National Basin Delineation project by NSSL for all of the continental United States. • ArcInfo used to define the watershed boundaries. • USGS 1 arc second (30 m) DEM data supplied by EROS Data Center. • www.nssl.noaa.gov/teams/western/basins • Continental U.S. completed June 2002.
NSSL Basins 18,488 Aggregated 12,784 229.5 km Range ring Aggregate: Clip all basins beyond 230 km Eliminate all segments < 2 mi2
FFMP Basins 5,608 NSSL CD FFMP
Purpose of the Basin Customization Course • To describe the content of the NSSL dataset (ArcView shapefiles and data attributes). • To provide tools that allow the local forecast office to modify, correct, or enhance the NSSL set of defined basins. • To demonstrate why modifications or additions may enhance the application of FFMP to the flash flood warning process.
Choices: Customization Options • No Customization (used delivered cd) • Minor Customization (add stream names, make minor adjustments to basins to correct errors) Must still run localization. • Major Customization (add new streams, divided existing streams) • Paul’s procedure for hydrologic connectivity, allows use of Paul’s tools.
Choices: Display options at WFO • Display FFMP graphics as delivered • Run Paul Jendrowski’s AMBER for more stream layers, 7 AWIPS radar graphic products including ABR rate + 6 user selected time periods, AMBER browser, and line graph of past 6 hours. • Use ArcView as display for geographic information.
Areal Mean Basin Estimated Rainfall ( AMBER) 1990-2002 • All watersheds in county warning area are defined to a Minimum Basin Area (MBA) of 2 mi2 to show spatial rainfall distribution. • The WSR-88D polar grid (1o by 1 km) is mapped to the defined watersheds. • Average Basin Rainfall (ABR) is computed for each watershed every volume scan. • An hourly ABR rate is determined from the single volume scan (5-6 min.) of ABR.
AMBERGIS (2000 – 2002) • Paul Jendrowski creation using ArcView. • ABR data computed and archived (5 min). • AWIPS ABR Rate display of radar umbrella. • AWIPS ABR graphic display of radar umbrella for 6 user selected time periods. • Line graph of ABR, ABR Rate, and FFG for each defined stream and rain gage. • Nine layers of streams or rain gages supported. • Alert for 3 user selected levels of ABR - FFG.
Graphical Radar Rainfall OHP – One hour rainfall STP – Storm total rainfall THP – Three hour rainfall
Storm Total Rainfall 19 May1999 Grid 1o x 2km
AMBER/FFMP Digital Rainfall AMBER/FFMP computes 5 minute rainfall using WSR-88D precipitation algorithm with Digital Hybrid Scan Reflectivity (DHR) product as input.
Digital Hybrid Scan Reflectivity (DHR) • Time interval (5-6 minutes) • Grid size (1 degree x 1 km) • Reflectivity to the nearest 0.5 dBZ
DHR Digital Rainfall Estimate 2130 – 2135 UTC Rainfall (in) .16 .30 .38 .29 .14 .24 .39 .41 .37 .20 Grid size 1o x 1km
DHR Digital Rainfall Estimate 2130 – 2135 UTC Rainfall (mm) .16 .30 .38 .29 .14 .24 .39 .41 .37 .20 Watershed Boundary…compute ABR
Average Basin Rainfall = 0.29 2130 – 2135 UTC ABR (in) .29 .29 .29 .29 .29 .29 .29 .29 .29 .29 Copy ABR back into DHR grid for FFMP or AMBERGIS graphics
Average Basin Rainfall = 0.29 2130 – 2135 UTC ABR (in) .16 .30 .38 .29 .14 .24 .39 .41 .37 .20 Divide watershed into segments??
Average Basin Rainfall = .29 in 2130 – 2135 UTC ABR (in) .20 .37 .37 .25 .25 .20 .37 .37 .25 .25 Large variation of ABR in short distances!!
Flash Flood Index (FF)FF = ABR - FFG Determining the Flash Flood Threat
Flash Flood Guidance (FFG) • ABR in a specific time period (1, 3 hours) to initiate flooding on streams. • Assumes stream at low flow level. • Assumes no rainfall since data cutoff • FFG is the amount of ABR needed to produce threshold runoff (climatic average runoff needed to start flooding of streams)
Flash Flood Guidance (FFG) • FFG = TR + SM, where TR is the threshold runoff and SM is the amount of ABR needed to initiate runoff based on soil moisture content. • Threshold runoff is constant for all watersheds 1.00” in three hours for most of eastern U.S (0.75” for western PA + WV). Ask your servicing RFC for your TR!!!
FF Index = ABR - FFGABR and FFG in inches • FF0 ABR = FFG • FF1 ABR = FFG + 1.00 inches • FF2 ABR = FFG + 2.00 inches • FF3 ABR = FFG + 3.00 inches • FF4 ABR = FFG + 4.00 inches • FF5 ABR = FFG + 5.00 inches, etc
Noble County, OH Almost a flash flood.ABR-FFG = 0.40 12 June 2002 2235-2327 UTC 1-Hour FFG = 1.70
FFMP FFG
AMBER 90-min ABR AMBER ABR-Rate AMBER 120-min ABR