NCAS Weather Work:

1
NCAS Weather Work current and 2009 Ralph Burton
(Leeds)
2
T-REX statistical analyses of severe windstorms
and rotors
With Stephen Mobbs, Simon Vosper and Peter
Sheridan (Met Office)
3
T-REX statistical analyses of severe windstorms
and rotors
Diurnal cycle of extreme events
Flow associated with rotor-type events
Linking to upstream flow parameters
4
COPS
With Alan Gadian, Victoria Smith, Sarah-Jane
Lock, Stephen Mobbs, Alan Blyth, Lindsay Bennet
(Leeds) Collaboration with Chris Collier, Jenny
Davis, Fay Davies (Salford)
Dual-Doppler Radar comparison with Lindsay
5
15th July COPS case changing the surface layer RH
6
15th July COPS case changing the surface layer RH
ECMWF analysis
7
15th July COPS case changing the surface layer RH
ECMWF analysis Surface RH x 1.3
8
15th July COPS case changing the surface layer RH
ECMWF analysis Surface RH x 1.5
9
Response of WRF to boundary layer forcing

• To be shown (hopefully) at ICAM2009
• Sensitivity of WRF to boundary layer scheme
• Comparison with observations
• Idealised tests
• Recommendations for usage

1156m
1000m
669m
962m
842m
798m
T2
928m
667m
507m
Time of day
Burton, Gadian, Mobbs, Smith
Problems with boundary layer in WRF? (data from
Innsbruck AWS, COPS)
10
25th October storm in Lake District can WRF cope?
With Stephen Mobbs
11
25th October storm in Lake District can WRF cope?
MIDAS OBS
WRF (GFS)
1
2
3
1
2
3
hourly precip (mm)
5
6
5
6
4
4
Hours after 0Z 25/10/08
3
1
2
3
2
4
6
1
5
6
4
5
12
African Monsoon Multidisciplinary Analyses
Near surface convergence in Sahel seen in UM and
WRF with Doug Parker, Gerard Devine (Leeds)
Courtesy Gerard Devine, Leeds
13
VOCALS modelling
Altitude of lowest cloud in preliminary WRF
run Initialised with ECMWF With Alan Gadian, ...
14
Summary
T-REX modelling and analysis of flows. Huge
dataset for model evaluation steep terrain,
hazardous to aviation COPS test cases
etc. Lake District Storm Model evaluation
predicting severe and hazardous weather how well
does WRF deal with this? AMMA are models
introducing a spurious dynamical effect
here? Very important to get forecasts correct in
this part of the world VOCALS test cases, etc.
Ingesting climate data?
15
Summary
T-REX modelling and analysis of flows. Huge
dataset for model evaluation steep terrain,
hazardous to aviation COPS test cases
etc. Lake District Storm Model evaluation
predicting severe and hazardous weather how well
does WRF deal with this? AMMA are models
introducing a spurious dynamical effect
here? Very important to get forecasts correct in
this part of the world VOCALS test cases, etc.
Ingesting climate data?
WRF is used almost routinely now. But how good is
it??