Current and Potential Thesis Topics:

- Forecasting of tropical cyclone formation and intensity

- Predictability associated with the extratropical transition of tropical cyclones

- General predictability characteristics associated with increased spread in ensemble forecasts

• Application to operational products that are derived from NWP output

• Quantifying the utility in a probabilistic forecast based on ensemble characteristics.

- Analysis of the variability in global-scale, slowly-varying circulations with respect tovarious forcing mechanisms and the impact on synoptic-scale circulations.

• circulation regimes• teleconnections

- Definition of a model to define an optimal decision process for preparing for tropical cyclone impacts using imperfect forecasts.

Operational Interface:Based on MySQL database run in a LINUX environment

Database queries defined with a PHP interface via web-based inputTwo components:

1: Model output for daily monitoring of forecasts of current tropical vortices2: Calculate and examine overall model error statistics

Tropical Cyclone Formation and Intensity

Hurricane Dennis: NOGAPS 850-500 vorticity

Statistical examinations of operational forecasts of tropical cyclone formation and life cycle

•Multivariate approaches to post-processing model output•Discriminant Analysis for identification of developers and non-developers•Logistic regression approach•Basin dependencies

•Consensus forecasting of tropical cyclone formation•Consensus forecasting of tropical cyclone intensity

Data: Several years of WPAC and ATL tropical cyclone forecasts

Areas of Concentration: Tropical, Weather Analysis and Forecasting, General Meteorology

DoD Relevance: Increased accuracy of tropical cyclone forecasts.

Ex-TY David

GMS IR 1232 UTC 970920

Extratropical Transition: Results in a fast-moving, rapidly- developing,extratropical Cyclone that often results in cold-season-like Conditions throughout the midlatitudes during the normally “quiet” warm season.

Issues:Timing of the interactionsbetween the decayingtropical cyclone and themidlatitude circulation intowhich it is moving.

Downstream impact

The timing is related to predictability associated with ET events. Reduced predictability is not just an issue near the ET event, but extends far downstream.

The Downstream Influences of the Extratropical Transition of Tropical Cyclones

Patrick HarrNaval Postgraduate School

GFS 500 hPa Ensembles +108 h VT 1200 UTC 20 Sep 03

0000 UTC 16 Sep 2003 GFS Ensembles +00

Hurricane Isabel

Acknowledgment: Office of NavalResearch, Marine Meteorology Program

TY Nabi TY Saola

Impacts on Numerical Model Performance

Goals:

• Examine the relationships between ET and the decrease in downstream predictability

• Examine the variability associated with the impacts of a poleward-moving tropical cyclone on the midlatitude circulation

• Timing• Midlatitude basic state• Tropical cyclone characteristics

• convection• frontogenesis

•Tools• Model output• Satellite data

Areas of Concentration: Weather Analysis and Forecasting, Tropical, General Meteorology, NWP

Large-scale circulations and intraseasonal variability:Interannual changes and their impact on the synoptic scale

There are large-scale,slowly varying circulations that Have pronounced impacts onseasonal, and synoptic-scalecirculations.

These circulations also vary byseason,year,ENSO mode,others?

TCs?

monsoon breaks

Activemonsoons

Wheeler (2000)

Goals:Examine some of the mechanisms that might influence the interannual variability andIts impact on the synoptic scale.

ENSO has been examined somewhat, others?Prime candidates are the Antarctic Oscillation (AAO) and Arctic Oscillation (AO).

The AO has been linked to global-scale variationsin various circulations (jet streams, storm tracks),And extreme weather episodes.

The AAO has not been examined as extensively As the AO. Since the AAO signal is largest duringNorthern Summer, it might have the most Impact on the summer MJO

DATA: AO,AAO indices, NCEP Reanalysis dataTechniques: statistical techniques such as Regression of intraseasonal fields on the AAO Index.

Areas of Concentration: Climatology, Tropical, Weather Analysis and Forecasting, General Meteorology

Wallace and Thompson 2002

Requirements for Assessing Forecast Value as Related Requirements for Assessing Forecast Value as Related to to Tropical Cyclone ForecastingTropical Cyclone Forecasting with Eva Regnier, DRMI, NPS.with Eva Regnier, DRMI, NPS.

Costs ($)

pro

bab

ility

Costs ($)

pro

bab

ility

C1 C2C1 > C2

Greater forecast uncertainty: Higher Costs

Smaller forecast uncertainty:Lower Costs

GOALS:Devise a framework in which the process that leads to a “protect” vs “no protect”decision must be made when there is uncertainty in the variables upon whichthe decision must be based.

-define uncertainty in tropical cyclone track forecasts-define the value of tropical cyclone track forecasts

-related to a climatological probability of a tropical cyclone strike

-define the utility of a forecast to the decision maker- utility will be based on the relative value of the assets to be protected vs being lost.

-link the framework to a financial model that defines impacts to baseassets (storing aircraft, sorting ships, changing personnelschedules)

-apply to a “conceptual” strike at a DoD installation on the east coastof North America

Data: Climatological tropical cyclone data base (HURDAT), forecast tracks from several operational models, financial data regarding base impacts due to severe weather.Areas of Concentration: Weather Analysis and Forecasting, Tropical, GeneralMeteorology.DoD Relevance: Force protection, optimal use of resources.