Using the NWC SAF products over South Africa and

southern Africa to enhance nowcasting capabilities in data

sparse regionsE de Coning, Morne Gijben, Louis van Hemert,

Bathobile Maseko

South African Weather Service

Content

• Background

• CRR examples for SA and SADC

• CRR vs Hydroestimator vs rain gauge data for Oct-Dec 2014

• RDT examples for SA and SADC

• RDT validated against lightning data for Dec ’14 and Jan ‘15

• Conclusions and future work

Background• Nowcasting is needed to warn the public of severe weather

events

• Data sparse regions – very few lightning/radar networks

• Satellite and NWP blended products (WMO SWFDP)

• In SA: using local version of UKMO Unified Model (12km)

• NWCSAF v2012 tested with case studies over SA/SADC

• NWCSAF v2013 installed operationally in SA during 2014

• Southern African domain since Oct 2014.

• CRR and RDT, no other products yet

CRR example: Daily rainfall CRR vs Hydroe vs raingauges for 23 Feb 2010 (using v2012)

HydroestimatorUsing 1 MSG channel

CRR using 3 MSG channels

Rain gauges

4

CRR example: Daily rainfall CRR and Hydroe vs TRMM for 2 Jan 2014 (using v2012)

HydroestimatorUsing 1 MSG channel

CRR using 3 MSG channels

CRR validation against daily rainfall totals over South Africa (using v2013)

• International Preciptiation Working Group (IPWG)

• Different rainfall algorithms (NWP and satellite)

• 0.25° resolution

• Daily rain gauges (24 hour) totals

• Hydroestimator (1 MSG channel) and CRR (3 MSG channels) added to this suite of products

RMSE and Correlation Coefficient (v2013)

CRR validation thus far…

• Encouraging

• Better than Hydroestimator in Oct-Dec 2014

• Will continue monitoring…

1130 UTC 1130 UTC

RDT example 9 Nov 2012 (v2012)

RDT example 28 Dec 2013 at 1200 UTC Zimbabwe (v2012)

RDT example 20 September 2014 – Afternoon thunderstorms and hail in JhB (v2013)

Operational! v2013

RDT validation against lightning data over South Africa (v2012)

– No lighting data input– Bufr to hdf5– Growing and mature phases used for validation– Validated against SALDN – CG lightning only. 10 min before

and after each RDT time step– Object-oriented methodology (R, SpativalVx)

9 Oct 2012 v2012Graphs supplied by Morne Gijben

R statistical software used with SpatialVx package for O-O validation developed at NCAR

RDT validation against lightning data over South Africa (v2013)

– No lighting data input– No OT detection input– Bufr3 output since Dec 2013 – Growing, mature and decaying phases used for validation– Validated against SALDN – CG lightning only. 10 min before

and after each RDT time step– Between 1100 and 1800 UTC (13:00 and 20:00 SA local time)– Object-oriented methodology (R, SpativalVx)

23 Dec 2014 v2013

Validation for Dec 2014 and Jan 2015 (v2013)

Conclusions and Future work

• Encouraging results especially for data sparse regions!

• Submission to national journal accepted for publication

• Add lightning (and OT?) as input data (this year)

• Validate against radar (where available) over SA

• New HPC, latest upgrades of UM (this year) – 4km, 1.5km

• Funded research project 2015-2017

• NWCSAF V2015?