Area forecast

Description

• Visibility is always stated in statute miles
• Times are issued in UTC
• Comprise four sections
• *a. A communications and header section
• **i. Issue time of forecast
• **ii. Valid times of the synopsis and the visual flight rules CLOUDS/WX sections
• **iii. Area of coverage
• *b. A precautionary statement section
• **i. Warns users to check the AIRMET section for IFR and/or mountain obscuration
• **ii. Describes the hazards associated with all thunderstorm
• **iii. Reminds users that all altitudes are given in MSL, unless noted as AGL or CIG
• *c. A synopsis section
• **i. Brief summary of the location and movement of fronts, pressure systems and circulation patterns for an 18-hour period
• **ii. References to low ceilings, reduced visibility and/or strong winds may be included
• *d. A VFR CLOUDS/WX section
• **i. Contains a 12-hour specific forecast, followed by a 6-hour categorical outlook
• **ii. Broken down into geographical areas, and/or states
• **iii. Describes cloud and weather affecting VFR flight operations, including precipitation, thunderstorms, and sustained surface winds 20 Kts or greater. Also includes visibility when the forecast to visibility is between 3 and 6 SM and/or obstructions to visibility

• OCNL Occasional >50% chance for <1/2 of the forecast period
• ISOLD Isolated Single cells
• WDLY SCT Widely scattered <25% of the area affected
• SCT Scattered Areas of 25% to 54% of the area affected
• NMRS Numerous >55% of the area affected
• WDSPRD Widespread >55% of the area affected

• AMD Amended Includes AIRMETs, SIGMETs, and Convective SIGMETs
• COR Corrected
• RTD Delayed