Chase-day briefing

Goal: a concise field briefing for a target point today — what's expected, is the environment loaded and trending up, is anything already happening, and a clear go / hold / no-go with the window of greatest concern.

Reminder: SHEARLINE is decision support. Official NWS watches/warnings drive life-safety decisions; say so in the briefing.

Inputs you need

• Target — lat, lon (CONUS). For a region, pick the centroid or run the

sequence for two or three candidate points.

Procedure (run in this order; the later steps refine the earlier)

1. The forecast frame. get_spc_outlook(lat, lon, day=1)

• Note data.categorical.label (MRGL→HIGH) and the tornado/hail/wind

probabilities. If you're planning ahead, also day=2.

1. The environment now. get_point_environment(lat, lon)

• Read the interpretation — it names the regime (pulse / cool-season high-shear /

classic supercell). Note MLCAPE, 0–6 km shear, 0–1 km SRH, SCP, effective STP, and whether instability is capped (large negative MLCIN matters — storms may not fire until the cap erodes).

1. The trajectory. get_environment_trend(lat, lon)

• This is the chase-critical step: is STP/CAPE rising into the afternoon, or

stabilizing? Read the trend interpretation ("intensifying" vs "weakening").

1. What's already up. get_active_warnings(lat, lon, radius_km=80) and

get_mrms_severe(lat, lon, radius_km=80)

• Any active warnings, and any MESH / rotation-track signatures already in range

(storms upstream that will move toward the target).

1. Synthesize. Optionally run get_threat_brief(lat, lon) for the composite level,

then write the call.

Output template

Chase briefing — (<lat>, <lon>), <date>
Outlook: SPC <category>; tornado <x>% / hail <y>% / wind <z>%
Environment: <regime in one phrase>; MLCAPE <..> J/kg, 0-6km shear <..> kt,
             0-1km SRH <..>, eff-STP <..>, SCP <..>; cap: <none/weak/strong>
Trend (f00→f06): <intensifying | steady | weakening> — <one line>
Already active: <warnings / MESH / rotation in range, or "nothing yet">
CALL: <GO | HOLD | NO-GO>
Target window: <e.g. 21–01Z as heating maximizes / cap erodes>
Watch for: <the single signal that would change the call, e.g.
            "rotation track appearing within 60 km to the SW">
Safety: follow live NWS warnings; this is planning support only.