Uses Digital Hybrid Reflectivity Scan from WSR-88D on 1deg x 1 km to compute radar rainfall estimates for small scale drainage basins. Average Basin Rainfall (ABR) is computed for individual range bins and averaged every volume scan. ABR is summed to produce running accumulations for 6 alert periods (30 min, 45 min, 1 hr, 2 hr, 3 hr, and 6 hr) Basin Rate of Accumulation (BRA) is the volume scan ABR divided by time between scans. Comparisons area made between ABR and FFG for each time period to give an Alert Status. Three display methods used at the TUS WFO. Areal Mean Basin Estimated Rainfall
An Assessment of the Use of AMBER in a Semi-Arid Desert Region
Melissa A. Goering NOAA/NWS/Tucson, AZ Paul Jendrowski
NOAA/NWS/Honolulu, HI AMBER Background and Display Methods Flash
Flood event: Douglas, Arizona on July 24, 2001 AMBER Limitations
General Conclusions TUS WFO verification for 2001 Monsoon season
Future work Introduction Uses Digital Hybrid Reflectivity Scan from
WSR-88D on 1deg x 1 km to compute radar rainfall estimates for
small scale drainage basins. Average Basin Rainfall (ABR) is
computed for individual range bins and averaged every volume scan.
ABR is summed to produce running accumulations for 6 alert periods
(30 min, 45 min, 1 hr, 2 hr, 3 hr, and 6 hr) Basin Rate of
Accumulation (BRA) is the volume scan ABR divided by time between
scans. Comparisons area made between ABR and FFG for each time
period to give an Alert Status. Three display methods used at the
TUS WFO. Areal Mean Basin Estimated Rainfall Shows ABR for the six
alert time periods and BRA Gives forecasters quick display method
of area and values AMBER in AWIPS D2D BRA at 1634 MST Douglas, AZ
Browser allows users to view computed BR A and ABR values for each
basin Color coded Alert Status: Green (< 60% of FFG) Yellow
(60-90% of FFG) Red (90-150% of FFG) Purple (>150% of FFG) Alert
Window Provides GIS capabilities and allows wide range of features:
Streets Washes/Rivers Towns/Cities Flow Direction Terrain AMBER
ArcView Flash Flood: July 24, 2001 Douglas AZ Population of 19,500
Thunderstorms developed over the Perilla Mountains and moved
southwest towards Douglas Heaviest precipitation fell between 1630
and 1700 MST NO warning issued Alert Status Flash Flood: July 24,
2001 Douglas AZ 1634 MST 30 minute ABR Basin Rate of Accumulation
Alert Status Flash Flood: July 24, 2001 Douglas AZ 1654 MST 30
minute ABR Basin Rate of Accumulation Alert Status Flash Flood:
July 24, 2001 Douglas AZ 1714 MST 30 minute ABR Basin Rate of
Accumulation Flash Flood Aftermath: Douglas, AZ Estimated 100,000
to 200,000 dollars in damage. Some homes on northwest side of
Douglas had 10 inches of standing water and few evacuations. Levy
on east side of town broke and retention pond undersized. Four
swift water rescues on northwest side of city. Basin 7276 graph at
1709 MST Seveal residents rain gages received 4.0 inches of
precipitation during 30 to 45 minute event. Port Authority closed
for 75 minutes and entry had 2 inches of standing water. Severe
winds caused windows to break and lifted a small utility shed from
a backyard and onto a neighbors fence AMBER Limitations AMBER will
be not be able to detect flash flood events in far western and
northeastern portions of Tucsons county warning area. AMBER
coverage is only from a single radar, thus will have the same
limitations as the radar. Verification from 2001 Monsoon Season FAR
POD CSI Lead time (minutes) Improvement in POD and lead time.
Athough AMBER is not the entirely the reason for improvement on
verification scores and lead time, it does have some effect. Total
Warnings:44 Verified:20 Missed:2 Future Work Work on FFG values for
each basin (steepness of terrain, antecedent moisture, soil, etc)
Comparisons between : 1.AMBER and NSSLs QIWI 2.AMBER and FFMPs
AMBER version Statistical significance of AMBERs effect on the
verification scores Flash Flood: August 14, 2001 Tucson AZ AMBER
was useful in the decision making process of issuing a flash flood
warning. 45 minute lead time Silverbell Road between Ina and Camino
del Cerro closed. Heaviest precipitation fell between 1700 and 1800
MST. Flash Flood: August 14, 2001 Tucson AZ 1728 MST Alert Status
Basin Rate of Accumulation Flash Flood: August 14, 2001 Tucson AZ
1733 MST Alert Status Basin Rate of Accumulation Flash Flood:
August 14, 2001 Tucson AZ 1758 MST Alert Status Basin Rate of
Accumulation Flash Flood: July 5, 2001 Green Valley AZ 15 minute
lead time could have been increased by 10 or 12 minutes Flash
Flood: July 5, 2001 Green Valley AZ 1827 MST Alert Status Basin
Rate of Accumulation Flash Flood: July 5, 2001 Green Valley AZ 1833
MST Alert Status Basin Rate of Accumulation Flash Flood: July 5,
2001 Green Valley AZ 1850 MST Alert Status Basin Rate of
Accumulation
