Meteorology in Aeronautics Part 8 - Analysis and Forecasting Products PDF

Lecture Meteorology in Aeronautics Part 8 Analysis and forecasting products Part 8 Analysis and forecasting products 8.1 Weather maps 8.2 METAR 8.3 TAF 8.4 Weather radar Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics...

Lecture Meteorology in Aeronautics Part 8 Analysis and forecasting products Part 8 Analysis and forecasting products 8.1 Weather maps 8.2 METAR 8.3 TAF 8.4 Weather radar Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 330 Thomas Hain Part 8 Analysis and forecasting products Low-Level-SWC Satellite image Source: DWD RADAR image Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 331 Thomas Hain 8.1 Weather maps Surface weather chart 26 May 2024, 12 UTC Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 332 Thomas Hain Surface weather chart What should you know about surface weather charts? ▪ A variety of weather data, determined according to the same criteria worldwide, is entered in these maps in coded graphic form. ▪ The MSL level is the reference level for the pressure visualisation. ▪ These maps provide an overview of the current (but also the forecast) weather situation at a specific point in time over a very large area (Germany map 1:5 million, Europe 1:15 million). Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 333 Thomas Hain Surface weather chart What should you know about surface weather charts? ▪ Around a high (in the northern hemisphere), the air masses flow out of it clockwise at a ‘small’ angle to the isobars. ▪ Around a low (in the northern hemisphere), the air masses flow into it in counter clockwise direction at a ‘small’ angle to the isobars. ▪ A large distance between the isobars indicates low wind. ▪ A small distance between the isobars indicates strong wind. Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 334 Thomas Hain Surface weather chart Area with strong wind Occlusion Low Cold front Convergence Warm front High Area with low wind Surface weather chart 31 May 2019, 06 UTC Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 335 Thomas Hain Symbols in weather charts Cloud cover (total coverage) 5 eighths 8 eighths 0/8 1/8 2/8 3/8 4/8 7 eighths 2 eighths 5/8 6/8 7/8 8/8 Sky not recognisable 0 eighths The indication is given in eighths! Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 336 Thomas Hain Symbols in weather charts Fronts Note: The fronts move in the direction in Warm front which the symbols point! Cold front Occlusion Stationary front Direction of movement of fronts Convergence line Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 337 Thomas Hain Symbols in weather charts Weather phenomenon Notes: The symbols shown here represent the basic symbols. Depending on the intensity and type of weather phenomena, these can be Thunderstorm Fog Gewitter Nebel displayed in different combinations. The symbols shown here are not only used Hail Hagel Rain Regen in surface weather maps, but also in other analysis and forecasting products. , Sprühregen Drizzle Trockener Dry haze Dunst Rain shower (moderate) Rain Feuchter Schauer Mist Shower Dunst Thunderstorm (light) Rain Gefrierender Freezing Regen rain Snow Schnee (moderate) Drizzle Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 338 Thomas Hain Symbols in weather charts Wind ▪ Wind shaft indicates which direction the wind is blowing from ▪ Barbs indication of wind force always drawn on the cyclonic (low pressure) side short barb 5 knots long barb 10 knots pennant 50 knots Note: Also used in upper air charts! Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 339 Thomas Hain Symbols in weather charts Wind Knots: abbreviation kn or kt Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 340 Thomas Hain Upper air charts Note: The upper air chart shown here serves only as an example. Upper air charts can be created for almost any altitude range within the troposphere, with various combined weather elements (pressure, temperature, humidity, wind, etc.). Upper air chart FL180 (500 hPa) 22 June 2024, 18 UTC Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 341 Thomas Hain Upper air charts What should you know about upper air weather charts? ▪ Instead of isobars there are isohypses (lines connecting places of equal height on a pressure level). ▪ Around a high (in the northern hemisphere), the air masses flow clockwise parallel to the isohypses. ▪ Around a low (in the northern hemisphere), the air masses flow anti-clockwise parallel to the isohypses. ▪ A large distance between the isohyses indicates low wind. ▪ A small distance between the isohypses indicates strong wind. Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 342 Thomas Hain Upper air charts Isohypses Area with Upper air Low strong wind Area with Upper air High low wind Upper air chart FL180 (500 hPa) 22 June 2024, 18 UTC Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 343 Thomas Hain 8.2 METAR METeorological Aviation Routine Weather Report (METAR) These are routinely issued weather reports. The issue (observation) times are: h + 20 and h + 50. It always contains (additional information are possible) the current weather conditions at an airport: ▪ Wind ▪ Visibility ▪ Weather phenomenon ▪ Clouds ▪ Temperatures ▪ QNH ▪ Trend The attached weather forecast (TREND) is valid for 2 hours from the time of issue (observation). Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 344 Thomas Hain Decoding METAR Please see attached dececoding table! Note: You can use it in your exam! Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 345 Thomas Hain Decoding METAR METAR: Decoding table Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 346 Thomas Hain Decoding METAR METAR: Decoding table Only if needed No longer distributed Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 347 Thomas Hain  1 2 Source: DWD Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 348 Thomas Hain  3 Source: DWD Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 349 Thomas Hain  4 Source: DWD Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 350 Thomas Hain Decoding METAR BECMG / TEMPO / NOSIG ▪ Only the parameters that change significantly according to defined criteria are specified BECMG = transition to new weather phenomena / wind / visibility / clouds (old basic state changes to a new one) => Change begins and ends within 2 hours from time of observation. TEMPO = TEMPOary change in weather phenomena / wind / visibility / clouds (despite interim changes, the old basic status is restored) => Change begins and ends within 2 hours from time of observation. NOSIG = NO SIGnificant change Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 351 Thomas Hain Decoding METAR Example 1 METAR EDDL 201920z 18015G25KT 2000 BR SCT030 12/09 Q1017 BECMG 1000 RA BKN003= ▪ METAR for Düsseldorf Airport ▪ issued on the 20th day of the month at 19:20 UTC ▪ The wind blows from 180 degrees at an average of 15 knots. The gusts reach 25 knots. ▪ Visibility is 2000 metres due to mist. ▪ There are 3 to 4 eighths cloud cover and a cloud base at 3000 feet above ground. ▪ The air temperature is 12°C, the dew point is 9°C. ▪ The QNH is 1017 hPa ▪ Over the next 2 hours are expected: visibility drops to 1000 metres, moderate rain, 5 to 7 eighths cloud cover and cloud base at 300 feet above ground Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 352 Thomas Hain Decoding METAR Example 2 METAR EDDP 151550z 32010KT 2500 SN BKN010 M01/M03 Q1001 BECMG 24020G30KT 7000 SHRA OVC020CB= ▪ METAR for Leipzig / Halle Airport ▪ Observation time 15th day of a month at 15:50 Uhr UTC ▪ Wind from 320 degrees at 10 KT average ▪ Visibility 2500 m ▪ Weather phenomena moderate snowfall ▪ Clouds 5 bis 7 eighths at 1000 FT/Ground ▪ Temperature minus 1 degrees C ▪ Dew point minus 3 degrees C ▪ QNH 1001 hPa ▪ Weather phenomena at 17:50 UTC moderate rain shower ▪ Clouds at 17:50 UTC 8 eighths Cumulonimbus at 2000 FT/Ground ▪ Wind at 17:50 UTC from 240 degrees at 20 KT average and gusts 30 KT Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 353 Thomas Hain 8.3 TAF Teminal Aerodrome Forecast These are routinely issued forecast products for international commercial airports and regional airports. They serve as a planning document for a future period. There are long-term and short-term TAFs. ▪ Long-term TAF every 6 h (4 x daily) validity 24 h or 30 h ▪ Short-term TAF usually every 3 h (during operating time) validity 9 h Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 354 Thomas Hain 8.3 TAF Teminal Aerodrome Forecast They included the precisely predicted values for: ▪ Wind ▪ Visibility ▪ Weather phenomena ▪ Clouds ▪ Sometimes (not in Germany) Maximum and Minimum temperatures Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 355 Thomas Hain Decoding TAF Please see attached dececoding table! Note: You can use it in your exam! Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 356 Thomas Hain Decoding TAF TAF: Decoding table Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 357 Thomas Hain Decoding TAF BECMG / TEMPO ▪ Only the parameters that change significantly according to defined criteria are specified. ▪ A weather phenomenon (e.g. -RA, -SN) is only coded as a substantiating element for a deterioration in visibility. ▪ NOSIG is not used in TAF Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 358 Thomas Hain Decoding TAF BECMG / TEMPO BECMG 0917/0920 = transition to new weather phenomena / wind / visibility / clouds (old basic state changes to a new one) TEMPO 0917/0920 = TEMPOary change in weather phenomena / wind / visibility / clouds (despite interim changes, the old basic status is restored) => Change starts earliest on 09th at 17 UTC, => Change ends latest on 09th at 20 UTC not: The weather change lasts from 17 - 20 UTC Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 359 Thomas Hain Decoding TAF FM Complete description of the weather with at least wind, visibility, clouds, weather phenomenon if applicable. Only significant weather phenomena are coded. FM 0917 From 09th at 17 UTC the weather changes => The end of the significant change can be described with TL (till) if necessary. Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 360 Thomas Hain Decoding TAF Example 1 For a flight you need at least 3 km visibility and a ceiling (at least 5 eighths cloud cover in one layer = BKN) of 1200 feet/GND. When can you take off guaranteed in Dresden? TAF EDDC 120500z 1206/1306 34010KT 2000 BR SCT010 BKN015 TEMPO 1210/1212 3000 BECMG 1214/1216 04005KT 9999 BKN014 PROB40 TEMPO 1217/1306 4000 SHRA SCT008 BKN010CB= On the 12th of the month between 16 and 17 UTC ! Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 361 Thomas Hain Decoding TAF Example 2 The following TAF of Erfurt Airport is available: TAF EDDE 091100z 0912/1012 24010KT 9999 SCT040 TEMPO 0916/0919 29020G35KT 1200 +SHSN BKN004 BKN009CB= What is predicted for the 09th of the month at the following times? 14 UTC Wind from 240 degrees at 10 KT Clouds 3 bis 4 eighths at 4000 FT/Ground (no CB/TCU) Visibility at least 10 km 17 UTC Wind from 240 degrees at 10 KT, tempoary from 290 degrees, at 20 KT avg., gusts 35 KT Weather mostly no significant weather phenomena, but tempoary heavy snow showers Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 362 Thomas Hain 8.4 Weather radar Source: DWD Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 363 Thomas Hain Weather radar - Locations Dresden Radius 150 km This is the range in which meaningful measurements are possible from the individual locations Source: DWD Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 364 Thomas Hain Weather radar - Functional principle The emitted wave is reflected by the precipitation. The distance of the precipitation can be determined from the difference in propagation time. The intensity of the precipitation can be determined from the strength of the reflected signal. Radiation of pulses with a fixed wavelength (DWD uses C-band with wavelength 4 to 7.5 cm). Parts of the radiation: - passes through the precipitation or is absorbed - is scattered by the precipitation - is reflected, reaches the radar unit again and is displayed. Intensity of reflection depends on type, size and distance of obstacle. Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 365 Thomas Hain Weather radar - Functional principle Distance Impulse Ground Distance measurement Distance measurement Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 366 Thomas Hain Weather radar - Functional principle The strength of the reflection depends on the diameter (D) of the droplet (directly proportional to D6.) ▪ => small drops (cloud droplets) are not recognized ▪ the larger the reflecting particle, the stronger the reflection ▪ A few large droplets produce a stronger echo than many small ones. Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 367 Thomas Hain  Weather radar - Interpretation Shower and thunderstorms ▪ Showers and thunderstorms are associated with Cumulonimbus clouds. ▪ Precipitation is limited in time and location. ▪ Showers / thunderstorms appear in the radar image as narrowly defined echoes that vary greatly in colour. Note: If it is not clear whether it is a shower or a thunderstorm, a lightning map should be used for comparison. Shower and Thunderstorms in Source: DWD RADAR image Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 368 Thomas Hain Weather radar - Interpretation Continuos rainfall ▪ Continous rain and snow fall from Nimbostratus clouds in a stable stratified atmosphere. ▪ Precipitation falls in a large area for a long time. ▪ => Continuous precipitation appears in the radar image as an extended echo that varies only slightly in colour. Source: DWD Continous rain in Radar image Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 369 Thomas Hain  Thank you very much for your attention ! Meteorology in Aeronautics Part 8 Chair of Air Transport and Logistics 370 Thomas Hain