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Exam 02
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Mock Exam 02 — Image Based
10 image-only questions · Dark navy SVG diagrams · All Nationals-level content with full answer key
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Exam 03
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Mock Exam 03 — Full Length
68 questions · Full 100-point Nationals exam · All sections including free response
Exam 04
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Mock Exam 04 — Nationals Special
Heavy Skew-T and space weather focus · Highest-difficulty section
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📋 Topic Checklist
75+ topics with checkboxes, star mastery ratings, search and filter. Progress saves automatically.
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⏱ Calculation Drills
9 timed drills — LCL, CME travel time, X-ray arrival, HDD/CDD, wind chill and more.
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Key Numbers — Memorize Cold
24 mb / 24 hr
Bombogenesis threshold
5,400 m (540 dm)
1000-500 mb rain/snow boundary
35 mph + ¼ mi + 3 hr
NWS blizzard criteria (all 3)
8.3 minutes
X-ray travel time Sun → Earth
~11 years
Sunspot cycle length (Schwabe)
−12 to −16°C
Dendrite snow crystal formation
Kp ≥ 5
G1 geomagnetic storm threshold
CAPE > 3,000 J/kg
Extreme instability classification
LI < −6
Extreme instability — Lifted Index
125 × (T − Td)
LCL height in meters AGL
10:1 ratio
NWS standard snow-to-liquid
4°C
Temperature of max water density
23.5°
Earth axial tilt — drives seasons
149.6 million km
Mean Earth-Sun distance
400-800 km/s
Typical solar wind speed
f = 2Ω sin(φ)
Coriolis parameter formula