WEATHER CHARTS
T L O
Enabling Learning Objective (ELO) A Action: The student will interpret the information contained in a surface analysis chart. Condition: Given pertinent information about surface analysis charts. Standard: IAW AC 00-45G
SURFACE ANALYSIS CHART PURPOSE.... TO PROVIDE THE PILOT WITH A GENERAL PICTURE OF THE WEATHER AT A SPECIFIC TIME
SURFACE ANALYSIS CHART Chart is issued every 3 hours Information taken from METAR reports
CONDITIONS DETERMINED FROM CHART 1. SURFACE WINDS 2. FRONTAL SYSTEMS 3. PRESSURE SYSTEMS 4. SKY COVERAGE 5. TEMPERATURE AND DEW POINT PRECIPITATION AND OBSCURATIONS STATION PRESSURE (corrected for sea level)
, METAR KATL 151450Z 28025KT 4SM DZFG SCT014 BKN120 OVC300 15/13 315 METAR KATL 151450Z 28025KT 4SM DZFG SCT014 BKN120 OVC300 15/13 A3049 RMK SLP315
OVERCAST (8 octas) CLEAR FEW (1-2 octas) OBSCURED SCATTERED SKY COVER MISSING BROKEN (5-7 octas) REF: AC 00-45G
WIND DIRECTION
CALM 05 KNOTS 10 KNOTS WIND SPEED 15 KNOTS 20 KNOTS 50 KNOTS 65 KNOTS
TEMPERATURE 15 13 , 315
WEATHER & OBSCURATION , 315 15 13
RAIN
RAIN HAIL SHOWER DRIZZLE RAIN SHOWER SNOW ICE PELLETS SNOW SHOWER
T/STORM FOG SMOKE FREEZING DRIZZLE FREEZING RAIN HAZE
15 13 , 315 DEWPOINT
STATION PRESSURE 15 13 , 315
1. STATION PRESSURE CORRECTED TO SEA LEVEL 2. SHOWN IN HECTOPASCALS / MILLIBARS 1013.2 = 132 986.6 = 866
, PRESSURE TENDENCY (3 HOUR) 1031.5 - .6 1030.9 3 hours ago 315 15 13 - .6 1030.9 3 hours ago PRESSURE TENDENCY (3 HOUR)
, = 1009.3 CURRENT STATION PRESSURE = 1010.1 INCREASING 15 13 , 8 101 CURRENT STATION PRESSURE = 1010.1 INCREASING PRESSURE TREND = PRESSURE 3 HOURS AGO 1010.1 - 0.8 = 1009.3
, CURRENT STATION PRESSURE = 1010.0 DECREASING PRESSURE TREND = 1010.0 100 15 13 12 CURRENT STATION PRESSURE = 1010.0 DECREASING PRESSURE TREND = 1010.0 + 1.2 = 1011.2 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 998.2 INCREASE THEN PRESSURE TREND = 15 13 , 3 982 CURRENT STATION PRESSURE = 998.2 INCREASE THEN STEADY PRESSURE TREND = 998.2 - 0.3 = 997.9 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 1016.0 DECREASE THEN PRESSURE TREND = 160 15 13 24 CURRENT STATION PRESSURE = 1016.0 DECREASE THEN STEADY PRESSURE TREND = 1016.0 +2.4 =1018.4 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 1017.4 DECREASE THEN PRESSURE TREND = 174 15 13 15 CURRENT STATION PRESSURE = 1017.4 DECREASE THEN INCREASE PRESSURE TREND = 1017.4 +1.5 =1018.9 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 1014.2 INCREASE THEN PRESSURE TREND = 142 15 13 15 CURRENT STATION PRESSURE = 1014.2 INCREASE THEN DECREASE PRESSURE TREND = 1014.2 -1.5 =1012.7 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 1014.2 STEADY PRESSURE TREND = 1014.2 142 15 13 CURRENT STATION PRESSURE = 1014.2 STEADY PRESSURE TREND = 1014.2 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 1014.2 INCREASE THEN PRESSURE TREND = 142 15 13 CURRENT STATION PRESSURE = 1014.2 INCREASE THEN DECREASE PRESSURE TREND = 1014.2 PRESSURE 3 HOURS AGO
, CURRENT STATION PRESSURE = 1014.2 DECREASE THEN PRESSURE TREND = 142 15 13 CURRENT STATION PRESSURE = 1014.2 DECREASE THEN INCREASE PRESSURE TREND = 1014.2 PRESSURE 3 HOURS AGO
L H t o L Indicated True H
L H IND TRUE H L L H
Break Time Countdown
Enabling Learning Objective (ELO) B Action: The student will interpret data contained in a weather depiction chart. Condition: Given pertinent information about weather depiction charts. Standard: IAW AC 00-45G
WEATHER DEPICTION CHART
WEATHER DEPICTION CHART PURPOSE - To portray areas of IFR, VFR and MVFR FREQUENCY - Issued every 3 hours
OVERCAST (8 octas) CLEAR FEW (1-2 octas) OBSCURED SCATTERED SKY COVER MISSING OR PARTIAL OBSCURATION BROKEN (5-7 octas) BREAKS IN OVERCAST REF: AC 00-45F
SKY CLEAR OVC FEW BINOVC SCT OBSCURATION MISSING DATA BKN
SKY CLEAR OVC FEW BINOVC SCT OBSCURATION MISSING DATA BKN
ONLY SHOWN WHEN 5 SM OR LESS VISIBILITY ONLY SHOWN WHEN 5 SM OR LESS ‚ 4
NO VISIBILITY SHOWN MEANS VISIBILITY IS GREATER THAN 5 SM
WEATHER AND OBSTRUCTIONS ‚ 4
The altitude below the station will show the ceiling. Sky cover symbols shown on the weather depiction chart are the worst sky conditions (summation method) for that station. The altitude below the station will show the ceiling.
‚ CLOUD BASE 4 No altitude will be given if FEW or SCT. If BKN or OVC, height is ceiling. ‚ 4
‚ CLOUD BASE 4 5 No altitude will be given if FEW or SCT. If BKN or OVC, height is ceiling. ‚ 4 5
Using the summation method W.D. S.A. Using the summation method 020 SCT010 BKN020 OVC030
W.D. S.A. FEW010 FEW020 SCT030
AREAS DEPICTED VFR MVFR IFR CEILING AND VISIBILITY GREATER THAN 3000 -- 5 VFR 3000 -- 5 To 1000 -- 3 MVFR CEILING AND / OR VISIBILITY LESS THAN 1000 -- 3 IFR
SHADED AREAS … IFR WITH CIG LESS THAN 1000 FT AND/OR VSBY LESS THAN 3 MI CONTOURED WITHOUT SHADING…MVFR AREAS WITH CIG GREATER THAN OR EQUAL TO 1000 TO LESS THAN OR EQUAL TO 3000 FT AND/OR VSBY GREATER THAN OR EQUAL TO 3 TO LESS THAN OR EQUAL TO 5 MI NO CONTOURS… VFR AREAS WITH CIG GREATER THAN 3000 FT AND VSBY GREATER THAN 5 MI
, , W.D. S.A. METAR KATL 151450Z 28025KT 4SM DZFG 315 15 4 13 120 METAR KATL 151450Z 28025KT 4SM DZFG SCT014 BKN120 OVC300 15/13 A3049 RMK SLP315
Enabling Learning Objective (ELO) C Action: The student will interpret the information contained on a Radar Summary Chart. Condition: Given pertinent information about radar summary charts. Standard: Technical Information Notice 13-11 NWS (Effective 11 June 3012)
RADAR SUMMARY
Radar Summary Chart Shows intensity, coverage, tops, and movement of precipitation Creates gives a three-dimensional viewpoint of precipitation
(15 and 45 minutes of the hour) Radar Summary Chart Issued twice per hour (15 and 45 minutes of the hour)
Intensity measured in decibels (dBZ) light green to purple dBZ Nondimensional "unit" of radar reflectivity which represents a logarithmic power ratio (in decibels, or dB) with respect to radar reflectivity factor, Z.
Wind barbs show direction the cell is moving FROM “FROM the NE at 15 kts”
Tops of echoes are labeled in hundreds of feet in bold black numbers “Tops at 57,000 ft”
End of SU5: Weather Charts
CONTOURS AT LEVELS 1, 2, AND 3. 3 Extreme 2 Heavy 1 Light to Moderate
Maximum echo top does not equal maximum cloud top TOPS OF ECHO Maximum echo top does not equal maximum cloud top 450
CELL MOVEMENT 30 Area/Line Movement
Symbol Meaning R Rain RW Rain Shower S Snow SW Snow Shower T Thunderstorm NE No Echoes NA Not Available OM Out for Maintenance
Line of Echoes – Solid (SLD) WS999 Severe Thunderstorm WT999 Tornado Watch HOOK Hook Echo Severe weather watch area
They’re worse! Thunderstorms are not as bad Safety First… Thunderstorms are not as bad as they look on the outside…. They’re worse!
FM 1-230 References for today Surface Analysis Chart 18-4 Weather Depiction Chart 18-5 Radar Summary 18-8
FM 1-230 References for tomorrow… TAF App B-11 Winds Aloft Chart 18-10
That’s All Folks!