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Forecasting Oceanic Cyclones at the NOAA
Ocean Prediction CenterJoseph M. Sienkiewicz, D. Scott Prosise, and Anthony Crutch
NOAA/NWS/NCEP/Ocean Prediction CenterCamp Springs, MD
TimelineSanders and Gyakum, 1980 – Defined the meteorological oceanic “BOMB”
Anthes et al., 1983 – QE-II Storm – “…major improvements…through…improved initial conditions, improved horizontal and vertical resolution and changes in the physical
parameterization of surface fluxes and latent heating.”
1986-Genesis of Atlantic Lows Experiment (GALE)
Sanders, 1986 – “LFM is able to capture essentials of the baroclinic process, and that the amount of response
to baroclinic forcing remains intractable.”
1988-89 Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA)
Sanders (1992) – “the state of the art in prediction of marine cyclones has advanced substantially over the last 15 years”
Uccellini et al., 1999 – “…the occurrence and position of intense, fast moving oceanic storms can be forecast in the day-4 time range.”
OPC Graphical Forecast Verification
48 Hour Surface Forecast VT 1200 UTC 18 Mar 2004
96 Hour Surface Forecast VT 1200 UTC 18 Mar 2004
Verifying Surface Analysis1200 UTC 18 Mar 2004
MethodologyFor all observed cyclones
Compare forecast & analyzed Position
Central pressure Wind warning category
OOCL AmericaPacific - Jan 2000
350 containers lost overboard 217 crushed or bent out of usable condition.
Vessel lost power for a short periodand took several severe rolls.
OPC Extratropical Cyclone Track Error for 48 and 96 hour Forecasts (All Cyclones)
45
81
116
150
225
282
374
143
240157
295
0
50
100
150
200
250
300
350
400
12 24 36 48 72 96 120
Forecast Hour
Erro
r (N
M)
TPC ATLC TC TrackError (1993-2002)ATLC (2003-2004)
PAC (2003-2004)
OPC Extratropical Cyclone Track Error for 48 and 96 hour Forecasts (cyclones 980 hPa or less)
45
81
116
150
225
282
374
103
208
136
260
0
50
100
150
200
250
300
350
400
12 24 36 48 72 96 120
Forecast Hour
Erro
r (N
M) TPC ATLC TC Track
Error (1993-2002)ATLC (2003-2004)
PAC (2003-2004)
OPC Extratropical Cyclone Track Error for 48 and 96 hour Forecasts (965 hPa or less)
45
81
116
150
225
282
374
84
185132
209
0
50
100
150
200
250
300
350
400
12 24 36 48 72 96 120
Forecast Hour
Erro
r (N
M)
TPC ATLC TC TrackError (1993-2002)ATLC (2003-2004)
PAC (2003-2004)
OPC Extratropical Cyclone Track Error for 48 and 96 hour Forecasts (Hurricane Force Cyclones)
45
81
116
150
282
374
64
242
123
279
225
0
50
100
150
200
250
300
350
400
12 24 36 48 72 96 120
Forecast Hour
Erro
r (N
M)
TPC ATLC TC TrackError (1993-2002)ATLC (2003-2004)
PAC (2003-2004)
October 2003 through March 2004
P-228
A-170
A-350
P-279
- Sanders, 1988-89(A-AtlanticP-Pacific)
Categorical Position ErrorsOPC Cyclone Forecast Position Errors (Categorical)
0
50
100
150
200
250
300
350
ALL 980 or less 965 or less Hurcn ForceCyclone Category
Erro
r (N
M) 48 HR ATLC
48 HR PAC96 HR ATLC96 HR PAC
P48-228
A48-170
A96-350
P96-279 P96-284P96-284
P96-248P96-248
P96- Uccellini et alP96- Uccellini et al1993-941993-94
A,P;48,96 – Sanders 88-89A,P;48,96 – Sanders 88-89
Categorical MSLP ErrorsOPC Cyclone MSLP Errors (Bias)
(Categorical)
-1
0
1
2
3
4
5
6
7
8
9
ALL 980 orless
965 orless
HurcnForce
Storm Gale
Cyclone Category
Avg
. Err
or (h
Pa)
48 HR ATLC48 HR PAC96 HR ATLC96 HR PAC
Warning Verification (% Correct)
01020304050607080
Percent Correct (%)
48 hrATLC
48 HRPAC
96 HRATLC
96 HRPAC
Forecasts
Warning Forecasts (Categorical) (Percent Correct)
HURCN FORCE
STORM
GALE
Warning Verification
0
10
20
30
40
50
60
70
80
Percent (%)
HURCN FORCE STORM GALE
Warning Category
48 HOUR PACIFIC
Overforecast
CorrectUnderforecast
0
10
20
30
40
50
60
70
Percent (%)
HURCN FORCE STORM GALE
Warning Category
96 HOUR PACIFIC
Overforecast
CorrectUnderforecast
0
10
20
30
40
50
60
70
80
Percent (%)
HURCN FORCE STORM GALE
Warning Category
48 HOUR ATLANTIC
Overforecast
CorrectUnderforecast
0
10
20
30
40
50
60
70
Percent (%)
HURCN FORCE STORM GALE
Warning Category
96 HOUR ATLANTIC
Overforecast
Correct
Underforecast
ConclusionsRemarkable progress in 25 years!!!
48 and 96 hour extratropical cyclone forecasts comparable or exceed 10 year average track errors for Atlantic Tropical Cyclones
Track error less for Atlantic than Pacific for all categories of cyclonesHurricane Force – track error significantly higher than other
categories of strong cyclones for 96 hour forecasts
Mean pressure errors - tendency to underforecast highest for extreme stormserror larger for Atlantic than Pacific (96 hours, 965 hPa or less)
Warnings – Difficulty forecasting intensity of the hurricane force eventtend to underforecast by one warning category
NWP Forecast windsNWP Pressure errorsShort lived events (24 hours or less)
Future WorkImprove day 4 forecasts of Hurricane Force Cyclones
Climatology of extreme eventsReanalysis data, cyclone phase diagrams
Are we missing something?SST, small scale structure
Ensembles - Improve deterministic forecasts
- Develop a suite of ensemble based probabilistic forecastsMust educate the customer
Forecasts for 6 to 10 day period