Major Upgrades Planned in 2011 for Major Upgrades Planned in 2011 for GFDL/GFDN Hurricane Prediction SystemsGFDL/GFDN Hurricane Prediction Systems

Morris A. Bender (NOAA/GFDL) Isaac Ginis, Biju Thomas, and Richard Yablonsky

University of Rhode Island

65th Interdepartmenal Hurricane ConferenceMiami, FL (Tuesday, March 1st)

Need to Address Degraded Track Skill in the GFDL model in the 4-5 day range

Major Upgrades Planned in GFDL/GFDN for the 2011 Hurricane/Typhoon Season

• Upgrade of the Simplified Arakawa-Schubert (SAS) Deep Convection

• Implementation of Shallow Convection• Upgrade of GFS PBL Scheme will be tested

in parallel for 2012 implementation• Modified enthalpy (ch) exchange coefficient• Numerous bug fixes• Modified Dissipative Heating• Expansion of Ocean Coupling region in

Eastern Atlantic3

EVALUATION OF TRACK ERROR WITH 2011 UPGRADED GFDL SYSTEM

Significantly Reduced Track Error in Atlantic Basin (All results with new GFDL are also with upgraded GFS)

5

Normalized Track ErrorTrack Error in Nautical Miles

Total number of runs: 290

Reduction in Track Error Averaged 20% at most Forecast time levels for the 4 Long-Lived Intense

Hurricanes(Danielle, Earl, Igor, Julia - 143 cases)

6

Track Error in Nautical Miles Normalized Track Error

Total number of runs: 140

Hurricane Danielle

7

OLD GFDL

OLD GFDLNEW GFDL

August 22nd, 12z August 23rd, 00z

August 23rd, 12z August 24th, 12z

NEW GFDL

NEW GFDLOLD GFDL

OLD GFDL

NEW GFDL

Hurricane Earl

8

NEW GFDL

OLD GFDL

ddAugust 29th, 0z August 29th, 12z

August 30th, 0z

August 30th, 6z

OLD GFDL

NEW GFDL

NEW GFDL

OLD GFDL

OLD GFDL

NEW GFDL

Hurricane Igor

9

OLD GFDL

OLD GFDL

NEW GFDL

NEW GFDL

NEW GFDL

OLD GFDL

OLD GFDL

September 9th, 12z September 10th, 0z

OLD GFDL

September 12th, 18z September 13th, 6z

Hurricane Julia

10

September 12th, 18z

OLD GFDLNEW GFDL

September 13th, 06z

OLD GFDL

September 13th, 18z

OLD GFDL

September 14th, 06z

NEW GFDL

Hurricane Alex

11

June 26th, 0z June 26th, 18z

June 28th, 06zJune 27th, 12z

OLD GFDL

OLD GFDLNEW GFDL

NEW GFDL

New model had better tracks but fast speed bias.)

Hurricane Richard

12

NEW GFDL with NEW GFS

NEW GFDL with NEW GFS

OLD GFDL

OLD GFDL

OLD GFDL

OLD GFDL

October 21st, 0z October 21st, 6z

October 21st, 12z October 21st, 18z

OLD GFDL with NEW GFS

OLD GFDL with NEW GFS

NEW GFDL with NEW GFS

OLD GFDL NEW GFS

Hurricane Tomas

13

NEW GFDL

October 30th, 18z

November 2nd 12z November 3rd 12z

November 1st, 12z

NEW GFDL

OLD GFDL

TRACK DEGRADATION IN EASTERN PACIFIC IN LONGER TIME

(Limited Cases, primarily impact of Celia:northward bias with straight moving storm)

14

Track Error in Nautical Miles Normalized Track Error

Total number of runs: 103

Hurricane Celia was the only long lived storm (where most of the skill was lost)

15

June 20th, 0Z June 21st , 0Z

June 22nd , 0Z June 24th , 0Z

NEW GFDL

NEW GFDL

OLD GFDL

OLD GFDL

New model ableto forecast subtlelooping

Hurricane Darby

16

June 23rd , 0Z June 23rd, 6Z

June 23rd, 12Z June 23rd, 18Z

NEW GFDL

OLD GFDLOLD GFDL

OLD GFDLOLD GFDL

NEW GFDL

Hurricane Estelle

17

August 6th, 0ZOLD GFDL

NEW GFDL

August 6th, 6ZOLD GFDL

August 6th, 12Z

OLD GFDL

NEW GFDL

NEW GFDL

Hurricane Frank

18

August 22nd , 12Z August 23rd, 0Z

August 23rd , 12Z August 24th, 0Z

NEW GFDL

NEW GFDL

OLD GFDL

OLD GFDL

NEW GFDL

EVALUATION OF INTENSITY SKILLWITH 2011 UPGRADED GFDL SYSTEM

ATLANTIC INTENSITY ERRORS

20

TOMAS REMOVED

Total number of runs: 290 Total number of runs: 259

Current Operational Model Also Had Degraded Intensity Error in Atlantic with New GFS

Analysis

21

TOMAS REMOVED

EAST PACIFIC INTENSITY ERRORS

22

INTENSITY BIAS IN KNOTS 12 24 36 48 72 96 120 OLD -4.2 -55 -5.2 -7.7 -11.8 -16.0 -18.3 NEW -3.7 -4.6 -3.2 -3.8 0.4 0.7 -1.7

LARGE NEGATIVE BIAS REDUCED

Jun 20th , 12Z

Hurricane CeliaMaximum Winds (kts)

NEW GFDL

OLD GFDL

1.UPGRADED GFDL FORECAST SYSTEM DEMONSTRATES SIGNFICIANTLY REDUCED ATLANTIC TRACK ERRORS PARTICULARLY IN THE 4-5 DAY FORECAST PERIOD.

2.DEGRADED TRACK SKILL IN EASTERN PACIFIC BUT VERY LIMITED SAMPLE SIZE.

3. INTENSITY SKILL WAS IMPROVED IN THE EASTERN PACIFIC BUT DEGRADED IN THE ATLANTIC IN THE 3-4 DAY FORECAST PERIOD PRIMARILY DUE TO OVER PREDICTION OF TOMAS.