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					 Hydrologic Application
          of the
    Tropical Cyclone
Precipitation Climatology
   PAMS Mini-Technical Conference
          March 15, 2005

          Jason Caldwell, HAS Forecaster
       Lower Mississippi River Forecast Center
                     Slidell, LA

       Gloria Forthun, Regional Climatologist
        Southeast Regional Climate Center
                   Columbia, SC
     National Weather Service
Hydrologic Services Program Mission

   Provide river and flood forecasts and warnings
    for the protection of lives and property.


   Provide basic hydrologic forecast information for
    the nation’s environmental and economic well
    being.
          Hydrologic Services Program

   RIVER FORECAST CENTERS (RFCs)
      Strong Technical Support/Focus
      Calibrates/Maintains/Executes Hydrologic Forecast Models
      Works directly with some sophisticated water users
       (e.g., USACE, USGS, DWR, etc.)



   WEATHER FORECAST OFFICES (WFOs)
     Uses/Tailors RFC Forecasts/Services to Local Users
     River/Flood Forecast Watch/Warning Program
     Delivers Products/Services to the Local Media/Public
Two Main RFC Functions
   Operations
     Flood/River Forecasting

     Dam Break Support

     Flash Flood Support

     Snowmelt Forecasting

     Water Supply Forecasting

     Precipitation Forecasting

     Data QC


   Procedure Development
      Model Calibration

      Model Maintenance/Support

      Special Studies
    Operational Flood Forecasting

                     Hydrologist

           hydrologic
                              model
           expertise &
                             guidance
            judgment

H                         River                     Flood Forecast
A      forecast          Forecast       bulletins
     precip / temp                      graphics       Guidance
S                        System

                 data               parameters

         Observing               Calibration
         Systems
        LMRFC AREA OF RESPONSIBILITY
                 • 2900+ River/Precipitation Gage Network
                 • 220 Forecast Points (189 Daily, 31 Flood-only)
                 • Weekly 28-day Forecasts at 10 Locations




  Servicing
  18 WFOs
RNK      GSP
FFC      MRX
BNA      HUN
MEM      PAH
LSX      SGF
LIT      JAN
TSA      SHV
LIX     MOB
FWD      LCH
WEB-BASED PRODUCTS OF THE RFC


  PRECIPITATION



      FLOODING

                http://www.srh.noaa.gov/lmrfc
          EXPANSION OF THE TROPICAL
        CYCLONE-INDUCED PRECIPITATION
                CLIMATOLOGY
-ALL tropical cyclone landfalls from
 TX/Mexico border to Chincoteague, VA
 (TX,LA,AR,MS,AL,TN,NC,SC,VA,FL)

-Period of record from 1971-2000

-Storm characteristics include:
   State(s) affected, direction of motion,
   speed of motion, storm intensity, and,
   potentially, synoptic interaction

-Potential application to QPF and RVF at
 NWS WFOs and RFCs

-WAAAYYY in the future……..a web-
 based application to develop the plots
 dynamically from the database
 DATA COLLECTION AND CLIMO QPF
 CLIMATOLOGICAL                         CAVEATS
PRECIPITATION DATA           -USED DAILY DATA TO COMPUTE
                             STORM TOTAL PRECIPITATION

INTERPOLATE TO GRIDDED       -ONLY USED STATIONS WITH
     DATA USING GIS          100%; VARY BY STORM
                             -ASSUMED T-DISTRIBUTION USING
                             FEW HOURLY SITES
       GRID STATISTICS TO
      PRODUCE BASIN MAP      -PRECIPITATION TIMING BASED ON
                             FORECASTS W/ ERRORS

         TIME DISTRIBUTE THE DATA
             INTO 6HR VALUES


                  USE HPC AND NHC
                   FORECASTS TO
                DETERMINE START TIME
HURRICANE KATRINA CASE STUDY




0000UTC 29 AUGUST 2005




1200UTC 30 AUGUST 2005
MISSISSIPPI MAJOR HURRICANES 1971-2000




                Andrew     August 26-28, 1992
                Carmen     September 7-9, 1974
                Opal       October 4-5, 1995
                Frederic   September 12-14, 1979
                Eloise     September 22-24, 1975
                Elena      September 2-4, 1985
SITE SELECTION

                                  AVAILABLE SITES BY STORM

                 160
                       142          140
                 140                           136
                                                             130                 128
                                                                       126
                 120

                 100                                                                         94




         COUNT
                 80

                 60

                 40

                 20

                  0




                                                                                 Opal95
                                                            Elena85
                                   Eloise75


                                              Frederic79




                                                                                          Katrina05
                       Carmen74




                                                                      Andrew92
                                                           STORM




        •361 Observation Sites Available
        •Approximately 40% with 100% data
BIG BLACK FORECAST GROUP
                       MODELED BASINS
             Kilmichael         S        Big Black
             West               F        Big Black
             Goodman            S        Big Black
             Way St/Hwy 16      S        Big Black
             Bentonia           F        Big Black
             Bovina             F        Big Black
             Willows            H        Bayou Pierre
             Eddiceton          S        Homochitto
             Rosetta            F        Homochitto
             Woodville          H        Buffalo


             F          Forecast Point
             S          Support Point
             H          Headwater
PERFORMING A CONTINGENCY FORECAST

                  MAXIMUM PRECIPITATION PLOT
                  INDICATED 2-6” ACROSS BIG
                  BLACK FORECAST GROUP


                  USED 72 QPF FROM HPC/LMRFC
                  AND CLIMO MAX IN HYDROLOGIC
                  MODELS


                  USED 8/27 12UTC AS A STARTING
                  POINT FOR FORECAST TO
                  INCREASE LEAD TIME OF
                  POTENTIAL RIVER FLOODING


                  FIRST MUST TIME DISTRIBUTE THE
                  MAX CLIMO PRECIPITATION FOR
                  USE IN THE MODELS
                          HOURLY PRECIPITATION CLIMATOLOGY
                               FOR MAJOR HURRICANES
                                   AT JACKSON, MS

                 1
               0.95
                0.9
               0.85
                0.8
               0.75
                0.7
               0.65
                0.6
PRECIP (IN.)




               0.55
                0.5
               0.45
                0.4
               0.35
                0.3
               0.25
                0.2
               0.15
                0.1
               0.05
                 0
                      1   13       25               37                   49           61
                                                   HOUR

                                 carmen   andrew    eloise   frederick        Total
                                     TIME-DISTRIBUTED PRECIPITATION
                                             AT JACKSON, MS
                         45%
                                                 41%
                         40%


                         35%
PERCENT OF STORM TOTAL




                         30%


                         25%


                         20%               18%
                               15%
                         15%

                                                       10%
                         10%
                                     7%
                                                                5%
                         5%
                                                                       1%    1%    1%    1%
                         0%
                               F06   F12   F18   F24   F30      F36    F42   F48   F54   F60
                                                       FORECAST HOUR
                                                            THE TIMING ISSUE
                                                    NHC Forecast placed Katrina approx. 250NM
                                                    from Big Black Forecast Group by 2AM 8/29


                                                                  TIME-DISTRIBUTION OF FMAP
                                                            BIG BLACK FORECAST POINTS 8/27@12UTC
                                         3




                                        2.5




                                         2
                                                                                                         WSTM6-OP
                                                                                                         BTAM6-OP
HPC/LMRFC QPF
                         PRECIP (IN.)




                                                                                                         BOVM6-OP
                                                                                                         RSAM6-OP
began at F42 from                       1.5
                                                                                                         WSTM6-MAX
                                                                                                         BTAM6-MAX
8/27 12UTC grids                                                                                         BOVM6-MAX
                                                                                                         RSAM6-MAX
                                         1
Correlated to first 6-
hour period ending
                                        0.5
1AM 8/29
                                         0
                                              F42     F48         F54         F60         F66      F72
                                                                   FORECAST HOUR
                                                FMAP VS. OBSERVATIONS
                                              BIG BLACK FORECAST GROUP


               7




               6




               5
PRECIP (IN.)




               4                                                                                   8/27 QPF
                                                                                                   8/28 QPF
                                                                                                   MAXQPF
               3                                                                                   KATRINA




               2




               1




               0
                   KILM6   WSTM6   GOOM6   BBWM6   BTAM6   BOVM6   WBPM6   EDDM6   RSAM6   WOOM6
                                                      BASINS
WHAT TO EXPECT FROM THE FORECASTS?
                 MAX UNDER-PREDICTED ACROSS
                 UPPER BIG BLACK FORECAST
                 GROUP; OVER-PREDICTED LOWER
                 HPC/LMRFC QPF PERFORMED WELL
                 UPPER BIG BLACK; UNDER IN
                 LOWER
                 MAX PRODUCED HIGHEST QPF
                 EARLIER THAN HPC/LMRFC WITH
                 LESS SPREAD


                 SO……WHAT DOES THIS MEAN?
                 EXPECT BEST PERFORMANCE BY
                 HPC/LMRFC IN BIG BLACK, BETTER
                 PERFORMANCE ACROSS
                 HOMOCHITTO BY MAX
            MAX27                        OP27




           CREST*=14.7                      *
                                      CREST=16.6
           7am 9/1                    7am 9/1




WEST,
MS
                         CREST=17.0             *Still rising, not
FORECAST                 noon 9/1               actual crest
FROM                                            OBS=16.8 at
8/27 @                                          7am 9/1
12UTC                    OBS
           MAX27                      OP27




         CREST=13.5                CREST=16.0*
         7pm 8/30                  7am 9/1




BENTONIA,
MS
                      CREST=19.5             *Still rising, not
FORECAST              7pm 8/31               actual crest
FROM                                         OBS=19.4 at
8/27 @ 12UTC                                 7am 9/1
                      OBS
            MAX27                        OP27




           CREST*=13.5                CREST*=13.0
           7am 9/1                    7am 9/1




BOVINA,
MS
                         CREST=25.0             *Still rising, not
FORECAST                 7pm 8/30               actual crest
FROM                                            OBS=22.8 at
8/27 @                                          7am 9/1
12UTC                    OBS
           MAX27                    OP27




                                 CREST=5.4
                                  CREST=5.6
         CREST=8.2               7am 8/30
                                  7am 8/31
         7am 8/30




ROSETTA,
MS                   CREST=8.2
                     7pm 8/30
FORECAST
FROM
8/27 @ 12UTC
                     OBS
                                          BIG BLACK FORECAST CREST* VS. OBS

           30.0




           25.0




           20.0


                                                                              MAX                 MAX27
                                                                            Performed
HG (FT.)




                                                                                                  MAX28
           15.0                                                                                   OP27
                                                                            Well Lower
                                                                                                  OP28
                                                                             Forecast             OBSV

           10.0
                                                                              Group
                    MAX Under-Estimated
                       Gage Heights
            5.0




            0.0
                  KILM6   WSTM6   GOOM6   BBWM6   BTAM6   BOVM6   WBPM6   EDDM6   RSAM6   WOOM6
                                                     BASIN
                     CONCLUSIONS
• MAX under-predicted precipitation in Big Black, over-
       predicted in Homochitto
• HPC/LMRFC did good job in Big Black, under-predicted in
       Homochitto
• As a result, HPC/LMRFC river forecasts better across Big Black
        with best results from MAX in Homochitto
• Need to expand climatology to include similar track and speed
       storms regardless of intensity
• For contingency purposes in Katrina, climatology would have
       been safe bet for using 72 hours of QPF in forecast models
       without exceeding observed crests
                              HOWEVER…..
A contingency forecast should give a “worst-case” scenario given
         the current hydrometeorological conditions……

 MAX FAILED AT THIS TASK ACROSS THE BIG BLACK
          ACKNOWLEDGMENTS
     Southeast Regional Climate Center
Gloria Forthun, Justin Glenn, Andy Brandenburg, and Michael Johnson

   South Carolina State Climatology Office
           National Climatic Data Center
                Dave Brandon, CBRFC
                   Dave Reed, LMRFC
END OF SLIDE SHOW,
 ADDITIONAL SLIDES
      FOLLOW
MAX27         MAX28




OP27          OP28




        OBS




WBPM6
MAX27         MAX28




OP27          OP28




        OBS




RSAM6
MAX27         MAX28




OP27          OP28




        OBS




EDDM6
MAX27         MAX28




OP27          OP28




        OBS




WOOM6
                                            QPF 8/27/06 VS. MAX CLIMO
                       2



                     1.5



                       1



                     0.5
PRECIP ERROR (IN.)




                       0
                            KILM6   WSTM6   BTAM6   BOVM6    WBPM6      EDDM6   RSAM6   WOOM6   8/27 12z
                                                                                                MAX
                     -0.5



                      -1



                     -1.5



                      -2



                     -2.5
                                                       FORECAST BASIN
MAX27         MAX28




OP27          OP28




        OBS




WSTM6
MAX27         MAX28




OP27          OP28




        OBS




BTAM6
MAX27         MAX28




OP27          OP28




        OBS




BOVM6

				
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