Station report
San Juan, in 6 sheets Drawn from its report of Oct 11, 2026, 1:56 AM local time, in the manner of the Field Book, and opened beside the plates that explain each part of it.
1 The sky2 The air3 The wind4 The column5 The sun6 The instrumentA few clouds at 2,700 ft, a few clouds at 7,000 ft; visibility 10 mi or more.
Section of the sky over San Juan, height above the station to scale: a few clouds cloud with its base at 2,700 feet, a few clouds cloud with its base at 7,000 feet, and visibility of 10 mi or more. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 A A B B C C D D E E © 2026 STORM STATION 247 THE FIELD BOOK STATION REPORT TJSJ FIG. A THE SKY OVER SAN JUAN SECTION, HEIGHT ABOVE THE STATION TO SCALE, EACH LAYER AT THE HEIGHT OF ITS BASE AS REPORTED; COVER IN EIGHTHS OF THE SKY; TOPS NOT MEASURED FT ABOVE THE STATION 0 2,500 5,000 7,500 10,000 12,500 ETAGES LOW MIDDLE THE STATION THE CEILOMETER READS TO 12,000 FT FEW 7,000 FT A FEW CLOUDS, 1 TO 2 EIGHTHS OF THE SKY FEW 2,700 FT A FEW CLOUDS, 1 TO 2 EIGHTHS OF THE SKY VISIBILITY, MILES: 10 MI OR MORE 0 5 10 TITLE San Juan, the sky STATION REPORT · ASOS TJSJ TYPE SECTION SCALE HEIGHT TO SCALE REV AS REPORTED SHEET 1 of 6 DATE 2026-10-11 ID SR-TJSJ-1 DRAWN AS linework on paper SOURCES FB-SKY-001, FB-SKY-017, FB-SKY-016, FB-SKY-018, FB-SKY-013, FB-SKY-014 From the Field Book FB-SKY-001, Fig. A Cloud classification The ten cloud genera by height: the etages these layers fall in.
FB-SKY-017, Fig. A Stratus A cloud with its base at 2,700 ft is in the low etage, where stratus forms.
FB-SKY-016, Fig. A Stratocumulus A cloud with its base at 2,700 ft is in the low etage, where stratocumulus forms.
FB-SKY-018, Fig. A Cumulus A cloud with its base at 2,700 ft is in the low etage, where cumulus forms.
FB-SKY-013, Fig. A Altocumulus A cloud with its base at 7,000 ft is in the middle etage, where altocumulus forms.
FB-SKY-014, Fig. A Altostratus A cloud with its base at 7,000 ft is in the middle etage, where altostratus forms.
78.0 F with a dew point of 73.0 F, 85 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 1,200 ft up; the lowest cloud reported is at 2,700 ft.
Chart of the air at San Juan: temperature 78.0 degrees Fahrenheit and dew point 73.0, 85 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 1,200 feet above the station, against the lowest cloud reported at 2,700 feet; height to scale. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 A A B B C C D D E E © 2026 STORM STATION 247 THE FIELD BOOK STATION REPORT TJSJ FIG. B THE AIR AT SAN JUAN THE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALE FT ABOVE THE STATION 0 1,000 2,000 3,000 4,000 60 F 70 F 80 F 90 F SATURATES 1,200 FT ABOVE THE STATION, AT 71.8 F LOWEST CLOUD REPORTED, FEW 2,700 FT TEMPERATURE 78.0 F DEW POINT 73.0 F SPREAD 5.0 F RELATIVE HUMIDITY 85 PER CENT THE AIR COOLS ABOUT 5.4 F EACH 1,000 FT IT RISES, AND ITS DEW POINT ABOUT 1 F SOLID: THE LIFTED AIR'S TEMPERATURE; DASHED: ITS DEW POINT TITLE San Juan, the air STATION REPORT · ASOS TJSJ TYPE CHART SCALE HEIGHT TO SCALE REV AS REPORTED SHEET 2 of 6 DATE 2026-10-11 ID SR-TJSJ-2 DRAWN AS linework on paper SOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005 Calm.
Plan of the wind at San Juan, north up: calm; beside it the Beaufort scale from calm to hurricane force, force 0, calm, marked. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 A A B B C C D D E E © 2026 STORM STATION 247 THE FIELD BOOK STATION REPORT TJSJ FIG. C THE WIND AT SAN JUAN PLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALE N E S W THE STATION CALM BEAUFORT FORCE LEAST WIND, MPH 0 CALM 0 NOW, 0 MPH 1 LIGHT AIR 1 2 LIGHT BREEZE 4 3 GENTLE BREEZE 8 4 MODERATE BREEZE 13 5 FRESH BREEZE 19 6 STRONG BREEZE 25 7 NEAR GALE 32 8 GALE 39 9 STRONG GALE 47 10 STORM 55 11 VIOLENT STORM 64 12 HURRICANE FORCE 73 TITLE San Juan, the wind STATION REPORT · ASOS TJSJ TYPE PLAN north up SCALE NOT TO SCALE REV AS REPORTED SHEET 3 of 6 DATE 2026-10-11 ID SR-TJSJ-3 DRAWN AS linework on paper SOURCES FB-EVT-150, FB-ENG-008, FB-INS-002 At 9 ft above sea level, 0 per cent of the atmosphere's air lies below the station. The standard atmosphere puts the pressure there at 29.91 inHg and the temperature at 59.0 F; the station's altimeter setting of 30.00 inHg means its barometer reads 29.99 inHg; it reports 78.0 F, 19.0 F warmer than standard.
Section from sea level of where San Juan stands in the atmosphere, height to scale: the station 9 feet above sea level with 0 per cent of the air below it; the standard atmosphere's pressure there, 29.91 inches of mercury, and temperature, 59.0 degrees Fahrenheit; the altimeter setting of 30.00 and the station pressure it means, 29.99. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 A A B B C C D D E E © 2026 STORM STATION 247 THE FIELD BOOK STATION REPORT TJSJ FIG. D WHERE SAN JUAN STANDS IN THE ATMOSPHERE SECTION FROM SEA LEVEL, HEIGHT TO SCALE, THE STATION IN THE STANDARD ATMOSPHERE FT ABOVE SEA LEVEL 0 5,000 10,000 15,000 SEA LEVEL, 29.92 inHg IN THE STANDARD ATMOSPHERE SAN JUAN 0 PER CENT OF THE AIR BELOW IT 9 FT 10 PER CENT OF THE AIR BELOW, 2,890 FT 20 PER CENT OF THE AIR BELOW, 6,050 FT 30 PER CENT OF THE AIR BELOW, 9,540 FT 40 PER CENT OF THE AIR BELOW, 13,470 FT STANDARD PRESSURE HERE 29.91 inHg STANDARD TEMPERATURE HERE 59.0 F ALTIMETER SETTING, REPORTED 30.00 inHg ITS BAROMETER READS 29.99 inHg TEMPERATURE, REPORTED 78.0 F TITLE San Juan, the column STATION REPORT · ASOS TJSJ TYPE SECTION SCALE HEIGHT TO SCALE REV AS REPORTED SHEET 4 of 6 DATE 2026-10-11 ID SR-TJSJ-4 DRAWN AS linework on paper SOURCES FB-ENG-001, FB-ENG-003 On Oct 11 the noon sun stands 64 degrees above the horizon at 18.43 N, and the day is 11 h 41 min long. Level ground there takes 90 per cent of the noon sunlight a surface facing the sun would.
Elevation of the noon sun at San Juan, angles true: on Oct 11 it stands 64 degrees above the horizon, against 85 at the June solstice, 72 at the equinoxes and 48 at the December solstice; the day is 11 h 41 min long. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 A A B B C C D D E E © 2026 STORM STATION 247 THE FIELD BOOK STATION REPORT TJSJ FIG. E THE SUN AT SAN JUAN ELEVATION LOOKING WEST, SOUTH TO THE LEFT: THE NOON SUN ON THE DAY OF THE REPORT, AND AT THE SOLSTICES AND EQUINOXES; ANGLES TRUE THE STATION JUNE SOLSTICE 85° EQUINOXES 72° DECEMBER SOLSTICE 48° OCT 11, 64° SOUTH ANGLES TRUE; THE RAYS ARE OF ONE LENGTH AND DRAW DIRECTION ONLY DAY LENGTH 11 H 41 MIN LEVEL GROUND TAKES 90 PER CENT OF THE NOON SUN A FACING SURFACE WOULD LATITUDE 18.43 N; THE SUN'S DECLINATION -7.2° TITLE San Juan, the sun STATION REPORT · ASOS TJSJ TYPE ELEVATION SCALE ANGLES TRUE REV AS REPORTED SHEET 5 of 6 DATE 2026-10-11 ID SR-TJSJ-5 DRAWN AS linework on paper SOURCES FB-ENG-007 An airport station, 9 ft above sea level. Its report of Oct 11, 2026, 1:56 AM local time is written on the sensors that made it.
Elevation of an airport station, San Juan, each sensor drawn and labelled with what it read: barometers, in the shelter, altimeter 30.00 inhg; visibility sensor, 7 ft, 10 mi or more; ceilometer, looking up, few 2,700 ft; temperature in its shield, 5 ft, 78.0 f, dew point 73.0 f; wind, 33 ft, calm. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 A A B B C C D D E E © 2026 STORM STATION 247 THE FIELD BOOK STATION REPORT TJSJ FIG. F THE INSTRUMENT ELEVATION OF AN AIRPORT STATION, EACH SENSOR WITH WHAT IT READ, OCT 11, 2026, 1:56 AM LOCAL TIME BAROMETERS, IN THE SHELTER ALTIMETER 30.00 inHg HEATED RAIN GAUGE - VISIBILITY SENSOR, 7 FT 10 MI OR MORE BEAM CEILOMETER, LOOKING UP FEW 2,700 FT TEMPERATURE IN ITS SHIELD, 5 FT 78.0 F, DEW POINT 73.0 F WIND, 33 FT CALM 33 FT 5 FT HEIGHTS TO SCALE; THE SPACING BETWEEN SENSORS IS NOT TITLE San Juan, the instrument STATION REPORT · ASOS TJSJ TYPE ELEVATION SCALE PARTLY TO SCALE REV AS REPORTED SHEET 6 of 6 DATE 2026-10-11 ID SR-TJSJ-6 DRAWN AS linework on paper SOURCES FB-INS-002, FB-INS-001, FB-INS-009 
FB-SKY-001, Fig. ACloud classification
FB-SKY-017, Fig. AStratus
FB-SKY-016, Fig. AStratocumulus
FB-SKY-018, Fig. ACumulus
FB-SKY-013, Fig. AAltocumulus
FB-SKY-014, Fig. AAltostratus
