410 Synoptic Reports

What is the purpose of synoptic reports

They’re the basis of the synoptic picture that is necessary in the production of forecasts and the elaboration of climatological data to satisfy the needs of aviation, agriculture, industry, and the public

When is group 7wwW₁W₂ included

If present weather of significance is observed during the previous synoptic period

When is group 8N_hC_LC_MC_H included

If clouds are observed

When is group 9S_pS_ps_ps_p included

If there are special phenomena to report

When is group 7wwW₁W₂ omitted

When weather of no significance is observed, ww may be coded as 00, 01, 02, 03, W₁W₂ as 0, 1, 2

When may W₁W₂ be reported as XX

There has been a break in the weather watch exceeding 30 min which in the considered opinion of the observer makes a reasonable assessment of past weather impossible

How long must a break in precipitation be to be considered a new period

15 min

When shall 8N_hC_LC_MC_H be omitted

When sky is clear or totally obstructed with no clouds below

What is the one cloud type considered to be a different etage for the purpose of synoptics

Nimbostratus is considered to be mid etage

When shall group 4E’sss be included

When solid precipitation is on the ground and precipitation has occurred since the previous main synoptic observation