8/15/19 3/15/07 1/30/20 AIM  7110.65R CHG 2 AIM 5. Status reports are issued as needed to show progress of storms and to delineate areas no longer under the threat of severe storm activity. Cancellation bulletins are issued when it becomes evident that no severe weather will develop or that storms have subsided and are no longer severe. h. Center Weather Advisories (CWAs)  1. CWAs are unscheduled inflight, flow control, air traffic, and air crew advisory. By nature of its short lead time, the CWA is not a flight planning product. It is generally a nowcast for conditions beginning within the next two hours. CWAs will be issued: (a) As a supplement to an existing SIGMET, Convective SIGMET or AIRMET. (b) When an Inflight Advisory has not been issued but observed or expected weather conditions meet SIGMET/AIRMET criteria based on current pilot reports and reinforced by other sources of information about existing meteorological condi- tions. (c) When observed or developing weather conditions do not meet SIGMET, Convective SIGMET, or AIRMET criteria; e.g., in terms of intensity or area coverage, but current pilot reports or other weather information sources indicate that existing or anticipated meteorological phenomena will adversely affect the safe flow of air traffic within the ARTCC area of responsibility. 2. The following example is a CWA issued from the Kansas City, Missouri, ARTCC. The “3” after ZKC in the first line denotes this CWA has been issued for the third weather phenomena to occur for the day. The “301” in the second line denotes the phenomena number again (3) and the issuance number (01) for this phenomena. The CWA was issued at 2140Z and is valid until 2340Z. EXAMPLE − ZKC3 CWA 032140 ZKC CWA 301 VALID UNTIL 032340 ISOLD SVR TSTM over KCOU MOVG SWWD 10 KTS ETC. 7 − 1 − 7. Categorical Outlooks a. Categorical outlook terms, describing general ceiling and visibility conditions for advanced planning purposes are used only in area forecasts and are defined as follows: 1. LIFR (Low IFR). Ceiling less than 500 feet and/or visibility less than 1 mile. 2. IFR. Ceiling 500 to less than 1,000 feet and/or visibility 1 to less than 3 miles. 3. MVFR (Marginal VFR). Ceiling 1,000 to 3,000 feet and/or visibility 3 to 5 miles inclusive. 4. VFR. Ceiling greater than 3,000 feet and visibility greater than 5 miles; includes sky clear. Meteorology 7 − 1 − 16 SOUTHERN MISSOURI FAR EASTERN OKLAHOMA *EFFECTIVE THIS MONDAY MORNING FROM 1250 AM UNTIL 600 AM CDT. ...THIS IS A PARTICULARLY DANGEROUS SITUA- TION... *PRIMARY THREATS INCLUDE NUMEROUS INTENSE TORNADOES LIKELY NUMEROUS SIGNIFICANT DAMAGING WIND GUSTS TO 80 MPH LIKELY NUMEROUS VERY LARGE HAIL TO 4 INCHES IN DIAMETER LIKELY THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES WEST NORTHWEST OF FORT LEONARD WOOD MISSOURI TO 45 MILES SOUTH- WEST OF HOT SPRINGS ARKANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2). REMEMBER...A TORNADO WATCH MEANS CONDI- TIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATH- ER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO WATCH NUMBER 237. WATCH NUMBER 237 WILL NOT BE IN EFFECT AFTER 1250 AM CDT. CONTINUE...WW 239...WW 240...WW 241...WW 242... DISCUSSION...SRN MO SQUALL LINE EXPECTED TO CONTINUE EWD...WHERE LONG/HOOKED HODOGRAPHS SUGGEST THREAT FOR EMBEDDED SUPERCELLS/POSSIBLE TORNADOES. FARTHER S...MORE WIDELY SCATTERED SUPERCELLS WITH A THREAT FOR TORNADOES WILL PERSIST IN VERY STRONGLY DEEP SHEARED/ LCL ENVIRONMENT IN AR. AVIATION...TORNADOES AND A FEW SEVERE THUN- DERSTORMS WITH HAIL SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 26045.