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First Results of Thunderstorm Forecast Verification in Terminal Aerodrome Forecasts in Croatia
Jadran Jurković and Igor KosCroatia control Ltd, MET Division
Croatian-USA Workshop on Mesometeorology 18-20 June 2012
Croatia Control Ltd.
2
Introduction
Part of Quality management system (ICAO Annex 3)
Forecasts Improvement Understand correct, miss, false alarm events Verification of special problems
• Convection (TS)
• Fog (reduced visibility)
• Wind (especially bora events)
Thunderstorm (TS) Mesoscale phenomenon (deep and moist convection) Month with max. frequency of days with TS has 12-25% Impact on aviation
First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
Croatia Control Ltd.
04/11/23
o METAR Surface wind
• Direction• Speed• Gusts
Visibility Runway visual range (RVR) Present weather Cloud
• Amount• Height of cloud base • [TCU/CB]
T i Td Atmospheric pressure Recent weather Wind shear State of the runway Trend forecast
o METAR ( 30min)∀ Surface wind
• Direction• Speed• Gusts
Visibility Runway visual range (RVR) Present weather Cloud
• Amount• Height of cloud base • [TCU/CB]
T i Td Atmospheric pressure Recent weather Wind shear State of the runway Trend forecast
o TAF (T=9/24 3/6h)∀ Surface wind
• Direction• Speed• Gusts
Visibility Present weather Cloud
• Amount• Height of cloud base• [TCU/CB]
Change groups-BECMG-FROM-TEMPO-PROBABILITY 30/40
o TAF Surface wind
• Direction• Speed• Gusts
Visibility Present weather Cloud
• Amount• Height of cloud base• [TCU/CB]
Change groups-BECMG-FROM-TEMPO-PROBABILITY 30/40
04/11/23First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
3
Verification- a larger view
InputForecaster skill, experience, education Available tools and materialsModels quality, interpretation, availabilityObservation systemClimatologyTechnical details Criteria for weather elements, formatSystem supervisionEducation systemCustomer requirements
FORECASTER’S PICTURE
WEATHER FORECAST
OBSERVED WEATHER
REAL STATE OF
ATMOSPHERE
VERIFICATION
= ≠
Croatia Control Ltd.
METAR
TAF
04/11/234
Approach Method similar to Austrocrontrol’s
Mahringer (2008) TAF, two basic principles
forecast for time periods contains a range of forecast conditions
Each hour Example for TS
TAF LDSP 230500Z 2306/2406 11010KT 9999 FEW050
TEMPO 2308/2320 RA
PROB30 TEMPO 2310/2406 TSRA FEW030CB BKN040
BECMG 2311/2313 18012KT
BECMG 2316/2318 VRB02KT=
UTC
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
00
01
02
03
04
05
00 30
METAR
+TS RA
TS RA
TS
+TS RA
-RA
RA
-TS RA
-TS RA
First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
Croatia Control Ltd.
04/11/235
Data Forecasts for 6 airport in Croatia
Inland: Zagreb (LDZA), Osijek (LDOS) Onshore: Pula (LDPL), Zadar (LDZD), Split (LDSP), Dubrovnik (LDDU)
Period 2009-2011 ~500,000 forecasted hours Contingency tables for each airport
aForecast Yes No Total b Fa lse a larm
Yes a b a+b cNo c d c+d d
Total a+c b+d n=a+b+c+d
Hit
Miss
Correct rejection
Observation
First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
Croatia Control Ltd.
04/11/236
Results Proportion correct (PC)
First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
Bias
Croatia Control Ltd.
First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
04/11/237
Results
PC - better for inland airports and LDPL Climatology
Bias similar results LDPL smallest bias-local characteristics
Season contribution of TS events and Daily distribution through seasonLDZAWinter Spring Summer Autumn
LDDUWinter Spring Summer Autumn
64,8%20,1% 13,6%1,4%
20,7% 18,0% 24,6% 36,7%
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Conclusions
Verification has been initiated Frequency of hours with TS ~1-1.5% Better scores when forecast TS period is shorter Less bias at inland airports due to pronounced daily and
yearly maxima Local features
Future work (in progress): Details for every miss and false alarm event Synoptic situations Lead time and duration
Croatia Control Ltd.
THANK YOU
First Results of Thunderstorms Forecast Verification in TAF in CroatiaCroatian-USA Workshop on Mesometeorology 18-20 June 2012
Acknowledgement to Ms. Laurette Rako for helping with translation
