# Presentation: 263347

## Integration of Multiple Precipitation Estimates for Flash Flood Forecasting

***Reggina Cabrera***
***NOAA/National Weather Service***

## In this presentation

- Multisensor Precipitation Estimates (MPE) and Flash Flood Monitoring and Prediction (FFMP)
- Data sources
- Generation and usage of MPE and FFMP
- Limitations
- Work in progress

## Ideal for Flash Flood Warning

**TOOL **that would provide a **GOOD**
- estimate of precipitation to improve
**lead-time for Flash Flood**
**warning**

## National Weather Service Structure for Issuing Flash Flood Warning

**River Forecast Centers (RFC)**
- 	Issues Flash Flood Guidance (FFG). Amount of rainfall needed in a given period to initiate flooding in small streams.
**Weather Forecast Office (WFO)**
-         Uses FFG to issue Flash Flood Warnings.

## MPE and FFMP

- MPE is used to feed Hydrologic models and create Flash Flood Guidance (FFG)
- FFMP is fed with the FFG and used to issue Flash Flood warnings

## MPE

**Allows**
- 		 evaluation of precipitation estimates from individual sensors as well as combined fields. It can be used also to fill areas with missing data.
- 	                   and...
-                  it is used** **in** real-time**

## FFMP

**Allows**
- 		 continuous monitoring of rainfall rate and accumulation with comparison to flash flood guidance for high resolution small basins
- 		            and...
-                  it is also used** **in** real-time**

## Current Data Sources for MPE

**Rain Gauges** can provide good point value representations of precipitation at a small area at the surface.
**Radar** is excellent for delineating intensity and spatial distribution of precipitation.  Represents precipitation above the ground.
**Satellite** provides nearly continuous geographical coverage but high cirrus often obscures details of precipitation.

##  Multi-scale requirements

-  Multi-scale requirements

**MPE** at the River Forecast Center can display only **hourly** multi-sensor estimates at a 4x4 Km
**FFMP** at the Weather Forecast Office can display the rainfall rate at every **volume scan** and rainfall accumulations for pre-defined small basins.

## Satellite Data for Precipitation Estimates

- MPE can only display the **hourly**
- Hydro-Estimator products from
- NESDIS
- Local bias correction using gauge data
- is being evaluated

## Satellite Estimates of Precipitation

## Radar Data for Precipitation Estimates

**MPE** at the River Forecast Center can display only **hourly** multi-sensor estimates.
**FFMP** at the Weather Forecast Office can display the rainfall rate at every **volume scan** and accumulations
**Radar bias** corrections using gauge data is available

## Comparison of MPE for Radar and Satellite

## MPE and Radar

- Radar Coverage and
- Umbrellas in the
- Southeast USA
- Limitations of radar
- precipitation estimates:
- Bright band and Hail contamination
- Inaccurate Z/R relationship

## RFC generates FFG1-, 3-, and 6-hour in HRAP

- RFC generates FFG1-, 3-, and 6-hour in HRAP

**ZCZC ATLFFGFFC CES**
**FOUS62 KALR 060115**
**COUNTY FLASH FLOOD GUIDANCE...ATLANTA CWA                               **
**NATIONAL WEATHER SERVICE                                                **
**SOUTHEAST RIVER FORECAST CENTER...ATLANTA GA                  **
**815 PM EST SUN MAR 5 2006**
**                                                              **
**                                                              **
**INCHES OF RAINFALL FOR SPECIFIED DURATIONS REQUIRED TO PRODUCE**
**FLASH FLOODING IN FORECAST ZONES.  LOWER AMOUNTS MAY CAUSE    **
**FLASH FLOODING IN URBAN OR MOUNTAINOUS AREAS.                 **
**                                                              **
**.B ATR 20060306 Z DH00/DC200603060115 /DUE/PPHCF/PPTCF/PPQCF **
**:IDENTIFIERS ARE 2-LETTER STATE, Z FOR ZONE, 3-DIGIT ZONE NUMB**
**:                                                             **
**:IDENT    1HR   3HR   6HR  ZONE NAME             **
**:======= ====  ====  ====  ====================  **
**GAZ004    2.0/  2.6/  3.3 :WHITFIELD**
**GAZ005    2.0/  2.5/  3.1 :MURRAY**
**GAZ007    2.2/  2.5/  3.1 :GILMER**
**GAZ011    1.8/  2.2/  2.6 :CHATTOOGA**
**.END**
- $$

## In the past...

-  **ZCZC ATLFFGFFC CES****FOUS62 KALR 060115****COUNTY FLASH FLOOD GUIDANCE...ATLANTA CWA                               ****NATIONAL WEATHER SERVICE                                                ****SOUTHEAST RIVER FORECAST CENTER...ATLANTA GA                  ****815 PM EST SUN MAR 5 2006****                                                              ****                                                              ****INCHES OF RAINFALL FOR SPECIFIED DURATIONS REQUIRED TO PRODUCE****FLASH FLOODING IN FORECAST ZONES.  LOWER AMOUNTS MAY CAUSE    ****FLASH FLOODING IN URBAN OR MOUNTAINOUS AREAS.                 ****                                                              ****.B ATR 20060306 Z DH00/DC200603060115 /DUE/PPHCF/PPTCF/PPQCF ****:IDENTIFIERS ARE 2-LETTER STATE, Z FOR ZONE, 3-DIGIT ZONE NUMB****:                                                             ****:IDENT    1HR   3HR   6HR  ZONE NAME             ****:======= ====  ====  ====  ====================  ****GAZ031    2.3/  2.7/  2.9 :PAULDING****GAZ032    2.2/  2.5/  2.7 :COBB****GAZ033    2.1/  2.4/  2.6 :FULTON-NORTH****GAZ034    2.5/  2.9/  3.1 :GWINNETT****GAZ112    2.5/  3.1/  3.5 :MONTGOMERY****GAZ113    2.6/  3.2/  3.5 :TOOMBS****.END****$$**

## Now....FFMP

- B ATR 20060306 Z DH00/DC200603060115 /DUE/PPHCF/PPTCF/PPQCF :IDENTIFIERS ARE 2-LETTER STATE, Z FOR ZONE, 3-DIGIT ZONE NUMB:                                                             :IDENT    1HR   3HR   6HR  ZONE NAME             :======= ====  ====  ====  ====================  GAZ031    2.3/  2.7/  2.9 :PAULDINGGAZ032    2.2/  2.5/  2.7 :COBBGAZ033    2.1/  2.4/  2.6 :FULTON-NORTHGAZ034    2.5/  2.9/  3.1 :GWINNETTGAZ112    2.5/  3.1/  3.5 :MONTGOMERYGAZ113    2.6/  3.2/  3.5 :TOOMBS.END

## Use other tools with FFMP

- Looping Radar Images
- MPE
- Satellite estimates
- Lightning

_**Modifying FFG**_
**Urbanization**
**Deforestation**
**Fire Scars**

## FFMP Output

**Map and Table of**:
- Basin rainfall accumulation
- Ratio of basin accumulations to FFG
- Difference between accumulations and FFG
- For time periods from 30 minutes to 6 hours
- Line graph of basin rainfall, basin rainfall rate, and FFG for the same time periods

**Notes:**
That’s not all! FFMP provides all of this in graphic displays.

## FFMP Limitations

**FFMP Limitations**

- Radar estimates of rainfall accumulations may be inaccurate.
- FFMP displays may mask problems.
**Flash Flood Guidance is not always representative of basins.**
- Does not account for rainfall since data cutoff
- Does not always represent special cases... urban centers, deforestation, fire scars.

## Improvements for Flash Flood Warning

- Precipitation on the ground... QPE
**Forecast Precipitation..... QPF**
** **
**FFG generated at a smaller**
**resolution**

## NOWCAST of precipitation

- Extrapolation of radar rates field forward in time using local pattern matching technique

## Gridded FFG at smaller resolution???

**Gridded FFG at smaller resolution???**

## Questions

- ?

## 164 DOPPLER RADARS 
	-good spatial and temporal coverage
	-problems in mountains

3 GEOSTATIONARY  SATELLITES 
-could provide 15 minute  1 km imagery 
-cloud top temperatures based precipitation estimation algorithms

991 NWS ASOS STATIONS WITH HEATED TIPPING BUCKETS
	-good for point value estimates of precipitation

OTHER SOURCES OF AUTOMATED GAGE OBS
	-timeliness and data quality problems.

- 	-good spatial and temporal coverage
- 	-problems in mountains
**3 GEOSTATIONARY  SATELLITES**
- -could provide 15 minute  1 km imagery
- -cloud top temperatures based precipitation estimation algorithms
**991 NWS ASOS STATIONS WITH HEATED TIPPING BUCKETS**
**	****-**good for point value estimates of precipitation
**OTHER SOURCES OF AUTOMATED GAGE OBS**
- 	-timeliness and data quality problems.