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Bihać, 28 April 2014

WEATHER ANALYSIS OF EXTREME FOREST FIRE ON ISLAND BRAČ FROM 14 TO 17 JULY 2011 Boris Mifka Višnja Vučetić Meteorological and Hydrological Service Maja Telišman Prtenjak Geophysical Departement "Andrija Mohorovičić" of the Faculty of Science, University of Zagreb. Bihać, 28 April 2014.

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Bihać, 28 April 2014

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  1. WEATHER ANALYSIS OF EXTREME FOREST FIRE ON ISLAND BRAČ FROM 14 TO 17 JULY 2011 Boris Mifka Višnja VučetićMeteorological and Hydrological ServiceMaja Telišman PrtenjakGeophysical Departement "Andrija Mohorovičić" of the Faculty of Science, University of Zagreb Bihać, 28 April 2014 Photo: Siniša Miličić 14.7.2011 14:57

  2. INTRODUCTION • WILDLAND FIRE  POTENTIAL DANGER IN LONG LASTING DRY AND HOT PERIODS • EXTREME FOREST FIRE BEHAVIORHIGH SPEED OF FIRE SPREAD, OCCURENCE OF MULTIPLE FIRE FRONTS • OBJECTIVE TO ANALYZE WEATHER CONDITIONS DURING WILDLAND FIRE AT THE ISLAND BRAČ FROM 14 TO 17 JULY 2011  TO EXPLAIN DYNAMIC ATMOSPHERIC PROCESSES WHICH INFLUENCED EXTREME WILDLAND FIRE BEHAVIOUR • AREA LOST IN FIRE WAS ABOUT 5600 ha (average annual burnt area is about 9000 ha )

  3. Island of Brač14 July 2011. Source: Vuko, 2011

  4. (Photo by:Siniša Miličić http://https://plus.google.com/110700915204596022370/posts/85atoEBhe5K (Photos by:Predrag Mandić i Pero Dragičević, http://www.braconline.com.hr)

  5. DATA Zagreb Synoptic and automatic stations Climatological stations Radio-sounding station Automatic station Zadar-airport METEOROLOGICAL ELEMENTS: WIND SPEED AND DIRECTION, RELATIVE HUMIDITY, AIR TEMPERATURE AND PRESSURE METEOROLOGICAL STATIONS AND DATA: • 10-min DATA FROM AUTOMATIC STATIONS  HOURLY DATA FROM SYNOPTIC STATIONS • DATA AT 7,14 I 21 H CET FROM CLIMATOLOGICAL STATIONS • RADIO-SOUNDING DATA AND VERTICAL PROFILES Split-Marjan Sutivan Bol-airport Bol Jelsa Hvar

  6. CANADIAN FWI METHOD Precipitation Relative humidity Wind speed Air temperature Precipitation Relative humidity Air temperature Precipitation Air temperature FFMC DMC DC Wind speed ISI BUI FWI

  7. RESULTSFWI METHOD • MID-ADRIATIC, JUNE AND JULY 2011  DRY AND HOT WEATHER

  8. SYNOPTIC SITUATION TFP ADVECTION 14 July 2011

  9. DIURNAL CYCLES OF WIND SPEED AND DIRECTION wind speed (m/s) FIRE START CET wind direction ( °) FIRE START CET

  10. DIURNAL CYCLES DATE AIR TEMPERATURE AND REL. HUMIDITY air pressure ( hPa) air temperature ( °C) relative humidity (%) FIRE START CET FIRE START AIR PRESSURE CET

  11. SURFACE METEOROLOGICAL FIELDS SIMULATIONS OF ALADIN/HR MODEL RELATIVE HUMIDITY AIR PRESSURE 14. 7.2011.– WEAK ANTICYCLONE ON MESOSCALE (MA) OVER BOSNIA, SHALLOW CYCLONE OVER ADRIATIC SEA ( 1010 hPa ISOBARE IS OVER BRAČ AND HVAR) • Vmaks8–10.8 m/s NEAR BRAČ BOTTOM SIDE OF MA : SE SE–E WIND INCOMING DRY AND HOT AIR FROM THE DALMATIAN HINTERLAND (RH < 40 % & Tmaks = 35 °C) 14.7.2011. WIND

  12. ZADAR-AIRPORT 14–17 July 2011. 00 and 12 UTC -INVERSION TOP 994 m -LOW LEVEL JET 12. 9 m/s at 379 m

  13. BOL ALADIN: 14 July 2011. 8-15 UTC WIND SPEED MAX <12m/s

  14. VERTICAL CROSSECTIONS, 14 July 2011 at 12 UTC WARM ADVECTION BUOYANCY SPEED (source: http://satreponline.org)

  15. WARM ADVECTION TEMPERATURE INVERSION? • LOADED GUN THEROY – TEMPERATURE INVERSION AS A CAP ON A STEAM POT • CIN = -417.83 J/kg AT ZADAR-A & CAPE 463.01 J/kg • MECHANISM OF CONVECTION TRIGGERING – VISINSKA CIKLONA CUT OFF, WITH CONVECTIVE CLOUDINESS AT WATER WAPOR SATELITE IMAGES  THOUGH IT WAS TO DRY FOR CONVECTIVE CLOUDINESS DEVELOPEMENT • VCS  INCREASED VERTICAL SPEED VERTICAL SPEED (-2 DO -4 hPa/h 0.5–1 cm/s od 950–700 hPa) 14 to15 July 2011 Max. at 700 hPa

  16. CONCLUSION • GREAT AREA AFFECTED BY FIRE (ROUND 5200 ha) • DRY AND HOT CONDITIONS BEFORE THE FIRE START  HIGH FWI INDEX • MODERATE TO STRONG SE WIND PRECEDED THE FIRE START • MESOSCALE: SHALOW CYCLONE ABOVE ADRIATIC SEA AND WEAK ANTIYCYCLONE OVER BOSNIA DURING THE PASAGE OF DRY FRONT • SOUNDINGS STABILE LAYER AT 994 m, LOW LEVEL JET BELOW, INCOMING COLD FRONT EXTREME WILDLAND FIRE BEHAVIOUR • IMPACT OF THE WARM ADVECTION ON STABILE LAYER – DISTORTION (LOADED GUN THERY) ? • IN THE MORNING OF 15 July 2011, WEATHER CHANGE ETESIA WINDS+SEA BREZE MAESTRAL

  17. THANK YOU !

  18. ALADIN/HR • HYDROSTATIC MODEL WITH 8 KM HORIZONTAL RESOLUTION AND 37 VERTICAL LEVELS (LOWEST AT 17 M) • SPECTRAL MODEL WITH TERAIN FOLOWING VERTICAL COORDINATE • PRIMITIVE EQUATION SYSTEM AND PHYSICAL PARAMETRIZATION INCLUDED OPERATIVE MODE INITIAL AND BOUNDARY CONDITIONS (APPROVED BY RCLACE DATA ASSIMILATION CYCLE - ARPEGE(Meteo France) ) DYNAMICAL ADAPTATION  downscaling from 8 km to 2 km resolution on a 450 X 450 point grid

  19. PRILOG 1 14.7.2011 U 12 UTC  USPOREDBA RADIOSONDAŽNIH MJERENJA I PROCJENE MODELA ALADIN/HR

  20. PRILOG 2 Prognostički vertikalni vremenski presjek atmosfere za Bol od 14. do 16. srpnja 2011. prema modelu ALADIN/HR.

  21. PRILOG 3

  22. PRILOG 4

  23. VERTIKLANA STRUKTURA ATMOSFERE I USPOREDBA S NUMERIČKIM SIMULACIJAMA • U POČETKU ŠUMSKOG POŽARA OKO 2000 ha IZGORENOG RASLINJA U VREMENU OD 2 SATA NAKON POČETKA, UZ POPRATNE ZANIMLJIVE METEOROLOŠKE POJAVE • MET- VELIČINE IZ RADIOSOANDAŽE I PSEUDOTEMPOVI (ALADIN/HR): BRZINA I SMJER VJETRA, TEMPERATURA I POT. TEMPERATURA ZRAKA I UZGONSKA FREKVENCIJA SONDAZA: • VJETAR : 14.7.2011. U 12 UTC MAKS. BRZINA OD 12.9 m/s NA 379 m MLAZNA STRUJA PREMA 1. KRITERIJU (BLACKADAR, 1957), IDUĆEG DANA SLABI SMJER VJETRA ZAKREĆE IZ SE U S I SW (1512 m ) • TEMPERATURNA INVERZIJA - OD 955-994 m NAD TLOM UZ OPADANJE TEMPERATURE U TOM SLOJU 3.6 °C/100 m • PSEUDOTEMP:– MODELIRANE PROCJENE VISINSKIH PROFILA POMOĆU MODELA ALADIN

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