import { FlightRules, Metar, MetarFlightRuleColor, MetarColorCode } from './metar.types.js';
/**
 * Creates a Metar object from a raw METAR string.
 *
 * @param raw The raw METAR string
 * @returns A Metar object
 */
export declare function createMetarFromString(raw: string): Metar;
/**
 * Calculates the ceiling from METAR data.
 * The ceiling is defined as the height of the lowest cloud layer that is 'BKN' (broken) or 'OVC' (overcast).
 *
 * @param {Metar} metar - The METAR data.
 * @returns {number | undefined} The ceiling height in feet, or undefined if no ceiling exists.
 */
export declare function metarCeiling(metar: Metar): number | undefined;
/**
 * Determines the flight rules category based on METAR data.
 *
 * @param {Metar} metar - The METAR data.
 * @returns {FlightRules} The flight rules category (LIFR, IFR, MVFR, VFR).
 */
export declare function metarFlightRule(metar: Metar): FlightRules;
/**
 * Checks if a METAR report has expired.
 *
 * By default, it uses standard expiration rules: 60 minutes for regular METARs,
 * and 30 minutes for SPECI reports.
 * A custom expiration time in minutes can also be provided.
 *
 * @param {Metar} metar - The METAR data.
 * @param {object} [options] - Options for expiration checking.
 * @param {number} [options.customMinutes] - Custom expiration time in minutes.
 * @param {boolean} [options.useStandardRules=true] - Whether to use standard expiration rules.
 * @returns {boolean} True if the METAR has expired, false otherwise.
 */
export declare function isMetarExpired(metar: Metar, options?: {
    customMinutes?: number;
    useStandardRules?: boolean;
}): boolean;
/**
 * Gets the color associated with the flight rule category of a METAR.
 *
 * @param {Metar} metarData - The METAR data.
 * @returns {MetarFlightRuleColor} The color string ('green', 'blue', 'red', 'purple', 'black').
 */
export declare function metarFlightRuleColor(metarData: Metar): MetarFlightRuleColor;
/**
 * Determines the color code for a METAR based on visibility, ceiling, and wind conditions.
 *
 * The color code represents the severity of the weather conditions, with 'green' being the mildest
 * and 'red' being the most severe.
 *
 * @param {Metar} metarData - The METAR data to evaluate.
 * @returns {MetarColorCode} The color code representing the weather conditions.
 */
export declare function metarColorCode(metarData: Metar): MetarColorCode;