# Presentation: 060025

-                 Naomi Surgi
-                          and  HWRF Team

- NCEP/Environmental Modeling Center

**WHERE  AMERICA’S  CLIMATE  AND  WEATHER  SERVICES  BEGIN**

- Advanced Hurricane Modeling
- at EMC:   The HWRF

**TM**

**Notes:**
Some of the season highlights include
 12 tropical storms of which 8 became hurricanes
 5 major hurricanes, all Category 4...an all-time record
 5 year total of 41 hurricanes...an all-time record
 3 hurricanes (Bret, Floyd, Irene) and 2 tropical storms (Dennis and Harvey) made landfall in the mainland U.S.

## HWRF TEAM

**Bob T., Qingfu L.,  Vijay T.,  Young K.,   Janna O’C,   Zack Z.  **
**A****lso, Many thanks to Isaac G. & URI    **
**Morris B......**

## Overview

**HWRF ’07 implementation strategy, initial HWRF config,  T&E requirements **
**2007 HWRF  **
**2008 implementation **
**       ****Advancement of HWRF**
**       ****GFS, Waves   **

##    HWRF  Development

**CONDUCTED 27  EXPERIMENTS since 2002 ,  ie: 27 versions of the HWRF  **
**Tested each upgrade (numerics, physics, coupling) for clean comparisons  -  ****comprehensive testing (>200 runs)**
**FINALIZED HWRF FOR ‘07**
**PERFORMED EXTENSIVE COMPARISONS BETWEEN GFDL AND HWRF FOR MULTIPLE SEASONS AND STORMS  - ****THREE**** ****SEASONS****   ****(‘04, ’05, ’06) for both ATL and EPAC basins        **
**     ****Note:  ****HWRF, 1745 runs****;  GFDL 900 runs;  ****HWRF ran 4X/day****, GFDL 2X/day.  Ran homogeneous comparison between HWRF and GFDL for 0Z and 12Z runs  **
**NO TUNING OF HWRF  (tuning has a lot of impact on track and intensity skill) **
**NO OCEAN COUPLING IN EPAC**

## Hurricane Forecast System Requirements Document for T20

**          ****Requirements document co-written between EMC and TPC  for transition to NCEP operations of a new candidate hurricane model...or for annual or periodic upgrades to an existing operational hurricane model for transition to NCEP operations.  **
**   **

**Sets standards for:   **
**        ****Performance testing – case load, eval criteria**
**        ****System functionality – initialization, coupling **
**        ****Computational performance **

## THE  HWRF SYSTEM    (Initial Operating Capability) 

_**THE  HWRF SYSTEM**__**    (Initial Operating Capability) **_
_**2007**_
**  ****Movable, 2- way nested grid   (9km; 27km/42L;  ~75X75)**
**  ****Advanced Physics    (GFS&GFDL)**
** ****Advanced vortex initialization – made use of prototype  GSI 3D var    (advancement over bogus) **
** ****POM  ocean (w/loop current init – same as GFDL) **

## 2007 HURRICANE SEASON 

## Slide 8

## Slide 9

## HWRF

**HWRF**

**GFDL**

**Hurricane Dean**
**August 11–22, 2007**

## Hurricane Dean 5 day forecasts of maximum winds starting from 8/19/06Z  

**Tropical Storm**
**08/16 00Z**

**Cat. 1**

**Cat. 2**

**Cat. 3**
**08/17 12Z**

**08/18 00Z**
**Cat. 4**

**Cat. 5**

**Cat. 4**

**Cat. 5**
**08/20 18Z**

**08/21 06Z**
**Cat. 5**

**Cat. 1**

**08/22 18Z**
**Cat. 2**

**08/20 18Z**

**08/22 18Z**

**90 kts**
**Cat. 2**

**139 kts**

**Cat. 5**

**     ****TS     Cat 1      Cat 2      Cat 3       Cat 4       Cat 5**

- Hurricane Dean 5 day forecasts of maximum winds starting from 8/19/06Z

**08/19 06Z**

## HWRF

**HWRF**

**GFDL**

**Hurricane Felix**
**Aug. 28–Sep. 05, 2007**

## HWRF

**HWRF**

**GFDL**

**Hurricane Humberto**
**September 12-13, 2007**

## HWRF

**HWRF**

**GFDL**

**Hurricane Noel**
**October 25-November 02, 2007**

## EPAC

**EPAC**

## HWRF Track

**HWRF Track**

**HWRF Track  **

## Tropical Storm Kiko

**Tropical Storm Kiko**
**July 14 – 24, 2007**

**GFDL**

**HWRF**

**GFDL**

## TS KIKO

**TS KIKO**

## TS  BARBARA

**TS  BARBARA**

**HWRF**

**         ****HWRF**

## Hurricane Henriette

**Hurricane Henriette**

**GFDL**
**Nearly a perfect forecast..... **

## 2008 IMPLEMENTATION 

**  ****UPGRADE PHYSICS  **
**     ****T&E – rerun ‘05 and Aug/Sept. 07**** **
** ****To run In parallel:   **
**     ****Vortex initialization w/assimilation of airborne doppler     radar obs **
**    ****HWRF + HYCOM + WAVEWATCH    **

**2008 IMPLEMENTATION**** **

## WAVEWATCH III

**Coupled HWRF-HYCOM-WAVEWATCH model system****.**
**HWRF-HYCOM parallel runs 2008 hurricane season, test with adding WAVEWATCH late FY2008.**
**WAVEWATCH w/ relocating inner HWRF nest only.**
**Coupling based on Hara’s stress parameterization.**
**Developing two-way nested WAVEWATCH with relocatable nest for expanded coupling (2008-2009).**
**Expand (shallow water) physics (2009 and**** beyond).**

- 5

## WAVEWATCH III

- 2

- Resolution in minutes of the 8 grids making up the multi-grid model

## WAVEWATCH III

- 3

- old WNA model

- new multi-grid model      including surf zone physics

- Katrina

## GFS/Proposed data assimilation and model changes

**FOTO (First-Order Time-extrapolation to Observations- simplified 4-D var), **
**Situation dependent variances**
**Improvements in physics, treatment of clouds **
**Mountain blocking, gravity waves   **
**Improved analyses in global tropics**
**Improved GFS track skill **

**Notes:**
Pretty safe implementation for the fall       craig   hua-lu             put on prev?  & separate imp talk?

## 2008-2012 HURRICANE UPGRADE PLAN

**  ****Data assimilation:  **
**Continuous upgrades to HWRF  hurricane core initialization through advanced ****4-D data assimilation****  for winds and reflectivity (requires nearly continuous obs for hurricane structure from storm top to surface beginning in depression stages through evolution of storm lifecycle).  Augment doppler data with GPS sondes.  Also, explore use of satellite microwave data.   UAV’s?**
**  ****Model upgrades:  **
**  ****Increase resolution**** – 4-6km/64-100L.  **
**   ****Hurricane Ensembles for structure/intensity:****  Hi-res hurricane multi-model ensembles,      e.g.  HWRF, GFDL, NAM, GFDN, COAMPS?     Work underway   **

##    Model Physics:  Continuous upgrades to atm/ocean boundary layer,   microphysics/deep convection (cloud resolving scales?), radiation  

**   ****Advance Wave Model (WAVEWATCH III) to forecast waves up to the beach, ie:  improve non-linear interactions, surf zone shallow water physics, wave interactions with currents **
**  ****Coupling to land surface model w/ adv. Sfc. Physics for improved rainfall forecasts at landfall.   Important input to hydrology and streamflow  models to address inland flooding.   **
**ALL hurricane model  physics upgrades dependent on allowable resolution, e.g. affordable complexity of microphysics, sea spray, explicit representation of all clouds.     **

## Radial velocities  Advance reflectivity  - 4DVAR     

**    ****08                  09**                **10                 11                     12**

**Radial velocities  Advance reflectivity  - ****4DVAR     **
**  **

**Mesoscale Data Assimilation for Hurricane Core**

**  **

** **

**  **

**          ****Advancing  HURRICANE WRF System**

**Atm. Model  physics and resolution upgrades (continuous) **

**   ****Atm/ocean boundary layer:  wave drag,   enthalpy fluxes       **
**                                   ****Microphysics, radiation  **

**        ****Incr. Res:  4-6km/100L?    **

** **

**                                                          ****Land surface Coupling**** **
**Waves****:          multi-grid/surf-zone physics**
**Ocean:****  4km.    - continuous upgrades in  Ocean Data Assimilation **

- .

**           ****HWRF Ensembles**

**  ****SS**

## HWRF SYSTEM 

**High resolution **
**Coastal, Bay & **
**Estuarine **
**hydrodynamic model**

**Atmosphere/oceanic Boundary Layer**

**HYCOM**
**3D ocean circulation**
**model**

**WAVEWATCH III**
**Spectral wave model**

**NOAH LSM**

**NOS**
**land and coastal waters**

**NCEP/****Environmental Modeling Center**
**Atmosphere- Ocean-Wave-Land**

**runoff**

**fluxes**

- wave fluxes

-                    wave
-                  spectra

- winds
- air temp.

- SST
- currents

- elevations
-        currents
- 3D   salinities
-         temperatures

- other fluxes

**surge**
**inundation**

- radiative
- fluxes

**HWRF SYSTEM **

**NMM hurricane atmosphere**

**HWRF/multi-model hi-res ensembles (2013) for adv. storm surge model**

## HWRF and the community

**HWRF code available to community w/op imp**
**1****st****  DTC  HWRF tutorial – 2009?  (resources permitting)**
**HWRF team establishing many working collaborations, e.g. URI, FSU, CSU, Univ. of Hawaii,  PSU, NRL, UKMO, JMA **

## NOAA’s Aircraft in Hurricanes

**Working on flight strategies for GIV and P-3’s**
**Operational requirement for core data at 0Z, 12Z to  initialize HWRF core circulation  (06,18Z ?)**
**Two mission profiles:     Environment ****& CORE**
**Observations:                  GPS, ****Radar, AXBT’s**** **
** **
**THANKS TO AOC AND HRD**

## THANK  YOU 

**FOR  YOUR**
**ATTENTION... **

## Research model forecasts of storm intensity for Hurricane Katrina showing benefit of high (1.6 km) resolution

**Notes:**
An example of such a research model experiment was carried out during Hurricane Katrina. One key feature of the new computer model is finer mesh (or high grid resolution) to better resolve the fine scale features in hurricanes. This figure shows observed storm intensity (the best track in black), the NHC official forecast made ~70 hr before landfall (dashed black line), and forecast made by computer models with various grid resolutions. Current operational global models has no skill, the best current operational hurricane model by the GFDL (magenta) did not capture the rapid intensification, and two high-resolution research model at 1.6 km grids) made the best forecast.

These forecasts were made during RAINEX in real-time using high-resolution MM5 and WRF with various large-scale operational model forecast fields (GFS, NOGAPS, CMC, GFDL) as initial and lateral boundary conditions (referred to as high-resolution mini ensemble). Both MM5 and WRF are configured as triple-nested domains with 15, 5, and 1.6km resolutions, respectively. The two inner nests (5 and 1.6km) are vortex-following moving grids. 
MM5-gfdl 1.6km (MM5 model, three domain nest – 15, 5, and 1.67km)
WRF-gfdl 1.6km (WRF model, three domain nest – 15, 5, and 1.67km)
gfdl = GFDL model forecast fields as initial and lateral boundary conditions for the MM5 and WRF forecasts.

Research to operation challenges: we have a small sample size with a limited number of hurricane forecasts in research mode. It will need to be tested and improved for operational use.  

## Intensity Forecast of Hurricane

_**Research model forecasts of storm intensity for Hurricane Katrina showing benefit of high (1.6km)  resolution (S. Chen)**_

**Intensity Forecast of Hurricane**

**Katrina 0000 UTC 27 August 2005**

## IN FACT:  

From 114 hrs to 60 hrs before landfall, seven HWRF forecasts predicted rapid intensification of Hurricane Katrina, predicting Category 5 Hurricane
Three HWRF forecasts predicted Category 3 landfall for Hurricane Katrina
Three HWRF forecasts of max. intensity coincided with observed maximum intensity

**From 114 hrs to 60 hrs before landfall, seven HWRF forecasts predicted rapid intensification of Hurricane Katrina, predicting Category 5 Hurricane**
**Three HWRF forecasts predicted Category 3 landfall for Hurricane Katrina**
**Three HWRF forecasts of max. intensity coincided with observed maximum intensity**

## Katrina Landfall

**Katrina Landfall**

**HWRF Max. Intensity: 147 kts**

**Obs Max. Intensity: 150 kts**

## Katrina Landfall

**HWRF Max. Intensity: 144 kts**

**Katrina Landfall**

**Obs Max. Intensity: 150 kts**

## Katrina Landfall

**HWRF Max. Intensity: 138 kts**

**Katrina Landfall**

**Obs Max. Intensity: 150 kts**

## Katrina Landfall

**HWRF Max. Intensity: 140 kts**

**Katrina Landfall**

**Obs Max. Intensity: 150 kts**

## Katrina Landfall

**HWRF Max. Intensity: 156 kts**

**Katrina Landfall**

**Obs Max. Intensity: 150 kts**

## Katrina Landfall

**HWRF Max. Intensity: 150 kts**

**Katrina Landfall**

**Obs Max. Intensity: 150 kts**

## Katrina Landfall

**HWRF Max. Intensity: 154 kts**

**Katrina Landfall**

**Obs Max. Intensity: 150 kts**

## Hurricane Initialization in HWRF model

- Regional GSI analysis cycle (3D VAR)

- 9 hours forecast at time t-3, t, t+3

- GSI analysis at time t-6

- Relocate the modified hurricane vortex

- GSI analysis at time t

- 3 or more days forecast

- t   t+6

## Hurricane vortex modification
Intensity correction
Better balanced wind, temperature and pressure fields
Storm depth correction
Moisture and hydrometeor correction
GSI analysis
Airborne radar data (parallel run)

- Intensity correction
- Better balanced wind, temperature and pressure fields
- Storm depth correction
- Moisture and hydrometeor correction
- GSI analysis
- Airborne radar data (parallel run)

## FOTO

- (formerly called Simplified 4d-Var)
- At no additional cost includes:
- Includes time extrapolation to observation using slow modes
- Improves fit to obs
- Some slowing of convergence

**Notes:**
Now the foto

## 3D-VAR 

- Obs - Background

- Analysis

**3D-VAR **

**Notes:**
Steve had me modify some charts

## FOTO

- Obs - Background

- Analysis

**FOTO**

**Notes:**
In the 1st order system we have             mark

## Situation dependent background variances

- Variances modified based on 9hr-3hr differences
- Increased in rapidly changing locations
- Decreased in others (global mean preserved)
- No additional cost

**Notes:**
Situation dep bg variances

## NOAA’s Aircraft in Hurricanes

**Working on flight strategies for GIV and P-3’s**
**Working to obtain resources for flight hrs/add’l crews**
**Operational requirement for core data at 0Z, 12Z to  initialize HWRF core circulation  (06,18Z ?)**
**Operational requirement for AXBT’s **
**Two mission profiles:     Environment ****& CORE**
**Observations:                  GPS, ****Radar, AXBT’s**** **
**New operational status of P-3’s **

## operational

- parallel

- parallel