oman nwp forecast during phet tropicaal cyclone

IOTCCC-2012, 14-17 Feb 2012, New Delhi, India

Introduction (Tropical Cyclone Phet ) NWP Models at DGMAN DGMAN’s NWP forecast during Phet:

Intensity Tracks Rainfall

How was DGMAN’s NWP forecast compared to others

Remarks


31/5/2010 2:30 UTC 1/6/2010 19:30 UTC

2/6/2010 8:00 UTC 3/6/2010 0:00 UTC

3/6/2010 15:00 UTC 4/6/2010 11:30 UTC

Date:time (UTC) 1:18 2:2 3:00 3:12 4:00 4:4 4:18

classification TC (phet) TC TC TC TC TC TS

Wind speed 75 90 120 90 90 80 55

Note CAT2 CAT3 CAT2 Landfall CAT1


Characterized by: Followed a rare track in Arabian Sea

(1877-2009) Longest tracks in recent years Long life period Two landfall and affected three countries


Total precipitation and maximum wind speed recorded during 1-5 June 2010IOTCCC-2012, 14-17 Feb 2012, New Delhi, India

Prognostic variablesSurface pressure ps

Temperature TWater vapour qv

Cloud water qc

Cloud ice qi

Horizontal wind u, vSeveral surface/soil

parameters

Diagnostic variables

Vertical velocity Geopotential Cloud cover clcDiffusion coefficients

tkvm/h

Operational Forecasting Model


Prognostic variablespressure perturbation p‘Temperature Tspecific humidity qvCloud water qcCloud ice qiHorizontal/virtical wind

u, v,w

Diagnostic variables

Total air densityprecipitation fluxes of

rain and snow.

Operational Forecasting Model


Vertical Layers: 40

FCT Hours:78-120

FCT times: 00,12 UTC

7 – 35.25 N

30 – 78 E

Initial/LBC: GME


Min. surface pressure forecast (hpa) (02-Jun)

Min. surface pressure forecast (hpa) (03-Jun)Max. wind Speed forecast (kt) (03-Jun)

Max. wind Speed forecast (kt) (02-Jun)

Max. wind Speed forecast (kt) (01-Jun) Min. surface pressure forecast (hpa) (01-Jun)


Even though HRM/COSMO are not TC specialized models, both have given the signal for Phet.

All model underestimated the intensity of the tropical cyclone

Both 14_07 and COSMO_07 have signaled 48h rainfall of more than 400mm with reasonable spatial and good amount agreement with the satellite estimated precipitation.

2.8km resolution clearly indicated landfall in Oman 24h prior to the landfall while other model resolution did not forecast the landfall correctly

The intensity underestimation is believed due to the initialization problem

There is a need for detailed investigate to understand why all models failed to forecast Phet??


oman nwp forecast during phet tropicaal cyclone

Education

new delhi

wind speed forecast

surface pressure forecast

dgman dgmans nwp forecast

model resolution

maximum wind speed

time utc

intensity tracks rainfall