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AVIATION METEOROLOGY. Initial Forecasters Course. AVIATION WEATHER SUMMARY. Importance Climatology of a station. Average weather for the station
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AVIATION METEOROLOGY Initial Forecasters Course
AVIATION WEATHER SUMMARY IFC:AvWx Smry
Importance Climatology of a station. Average weather for the station Guide to a forecaster in respect of behaviour of each element of weather phenomena not only in terms of frequency of occurrence but also about time. Major input for a forecaster in his decision tree steps. Essential input for nowcasting. AVIATION WEATHER SUMMARY IFC:AvWx Smry
AVIATION WEATHER SUMMARY(Refer: IAP 3202,Ch – XI) General Information Exist for all IAF flying stations. Updated every fifth year. Compiled under the following headings: - Preface. & Contents, List of graphs, tables and diagrams/charts. Geographical and Topographical Information. Seasonal Features as a separate chapter for each season. Monthly Statistical Data as a separate chapter for each month of that season. Climatological Information, consisting statistical averages & monthly weather statistics and extremes. Reference IFC:AvWx Smry
GEO & TOPOGRAPHICAL INFO Detailed information on geography & topography of station is mentioned. Emphasis on location of sources of pollution like townships, railway yards, industries & significant water bodies in and around airfield which can lead to atmospheric obscurity or low clouds. Significant topographicaldetails such as hillocks which can influencesurface wind/weatheris specifically highlighted. IFC:AvWx Smry
Season wise pattern of weather for:- Winter (Dec-Mar) Pre-Monsoon (Apr-May) Monsoon (Jun-Sep) and Post-Monsoon (Oct-Nov) Frequency of adverse weather spells:- Pptn, T'stom, Low Clds. Vis <3000 m & <1000 m. Seasonal T’ storm characteristics:- Peak period of occurrence, Location of synoptic feature , local parameters and forecasting hints Bar graph for each month. Wx state for the months of respective season. Detailed Aviation Wx Hazards SEASONAL FEATURES IFC:AvWx Smry
Broad description of month wise wx features. Monthly statistical data including tables. Detailed Aviation Wx Hazards month wise with Frqs, Extremes & SD. Summary of main aviation wx hazards - month wise. Monthly wx graphs ( last 10 yrs) Description of chief adverse weather features (most sig wx hazard) of month. Selection based on Frq & longest mean duration. Abnormally prolonged spells of adverse wx. Simultaneity of adverse wx at base and diversion. PB means (1000’, 2000’, 3000’ 5000’ and 10000’) and monthly wind roses (surface) Comfort index Forecasting hints MONTHLY FEATURES IFC:AvWx Smry
CLIMATOLOGICAL INFORMATION Climatological tables are prepared using data sets of 30 years or more. Means & extremes of:- QFF, Dry & Wet Bulb Temp RH (0300 UTC and 1200 UTC) Max & Min Temp. 24 h rainfall & monthly averages Temporal Variations:- Synoptic hour QFE, Dry & Wet bulb Temperature RH diagram with Isopleths at suitable interval Pentad Normals : Max & Min Temperatures (along with SD) and QFF of 03 and 12 UTC IFC:AvWx Smry
MONTHLY WEATHER GRAPH Gives at a glance time distribution of various hazardous wx phenomena & other met info at station as a composite picture. Comparative study of such graphs highlights important features of the weather over the area such as :- Intensity, Persistence, Susceptibility of incidence, Preferred hours of occurrence, Variations – diurnal, spatial and seasonal, Local peculiarities, Relationship between weather & synoptic situations Simultaneity of occurrence amongst neighbouring airfields. Provide a much better picture of the overall weather at station than climatological tables and descriptions, and would prove a valuable aid for the realistic planning of terminal operations. IFC:AvWx Smry
WIND ROSES IFC:AvWx Smry
PLOTTING OF WIND ROSES Wind roses are prepared for synoptic hours viz: 0230, 0530, 0830, 1130, 1430, 1730, 2030 and 2330 IST Percentage frequencies reduced to eight point of compass along with total frequency and frequencies of individual speed group for a period of time are to be plotted. Frequency of calm wind is to be plotted in the centre of circle against total frequency. IFC:AvWx Smry
WIND ROSE Station: lat/long Month: Jan Ht: (m) Time:0530 IST N Most Prevalent Wind 335 025 10 A-05 B-05 Speed in knot A – 1-5 B – 6-15 C – 16-30 D – 31-45 E - >45 NW NE 08 A-05 B-03 03 A-01 B-02 295 065 102/142 04 A-03 B-01 07 A-05 B-02 W E Directions N – 335-025 NE – 026-064 E – 065-115 SE – 116-154 S – 155-205 SW – 206-244 W – 245-295 NW – 296-334 245 05 A-02 B-03 0 115 CALM 03 A-02 B-01 SW SE 205 2nd Most Prevalent Wind 155 S IFC:AvWx Smry
WIND ROSE Station: lat/long Month: Jan Ht: (m) Time:0530 IST N Most Prevalent Wind 335 025 7.04% NW NE 5.63% 2.11% 295 065 71.83% W E 2.81% 4.92% 245 0% 115 3.52% 2.11% SW SE 205 2nd Most Prevalent Wind 155 S In Jan morning hour winds are calm otherwise Nly prevails IFC:AvWx Smry
CRITERIA FOR WEATHER SUITABILITY CLASSIFICATION(MSI NO. 01/02) IFC:AvWx Smry
INTRODUCTION Statistics of weather state are valuable for operational planning. Since fighter and transport operators are governed by different set of weather criteria , it is necessary , that these statistics provide meaningful information for planning both types of operations. Distinction between rated and unrated weather is of fundamental value for flying activity. Weather minima for pilots , are with reference to surface visibility and cloud ceiling. IFC:AvWx Smry
TIME BLOCKS Six blocks of 2 hr duration each, starting from 0600 hr to 1800 hr (0600-0800 hr, 0801-1000 hr. etc) will be considered individually for classification into Good, Marginal and Bad weather days. Similarly six blocks starting from 1800 hr will be classified for night. Classification of period 2200-0600 hr is optional. IFC:AvWx Smry
TIME BLOCKS • Day and Night are divided into six hr each. • Day 0600-1200 h & 1200-1800 h • Night 1800-2400 h & 0000-0600 h. IFC:AvWx Smry
PARTS OF THE DAY IFC:AvWx Smry
CRITERIA FOR WEATHER Bad Weather (B) • Prevalence of or Warning Issued for any of the following will be termed as Bad Weather :- Visibility <1km Ceiling (> 4 Oktas) 300 m or less Weather TS/DS/Heavy Rainfall/ Showers/ Snow/Squall/Gale Optional Surface Winds > 30kt Surface Temp >400 C IFC:AvWx Smry
CRITERIA FOR WEATHER Marginal Weather (M) • Prevalence of or warning or CMR issued for anyone or more of following will be termed as marginal weather: Visibility 1km≤V≤3km Cloud Base 300m<Base <450m Weather Light Rain/Drizzle/ Mist/Haze Optional Gusty SW- speed conditions & Temp criterion 400 C or Sub-Zero Temp to be defined locally. Good Weather (G) None of the above. IFC:AvWx Smry
CLASSIFICATION OF WEATHER When any of the following criteria has occurred in 2 time blocks out of 3 blocks (each 2 hr duration), it will be classified as :- IFC:AvWx Smry
CLASSIFICATION OF WEATHER If each block is different it will be classified as marginal. IFC:AvWx Smry