Typhoon 20W(ROKE)peaking above forecast//19W(KULAP)strong ETT//18W(NORU)peaked as a CAT5//09L(IAN)landfall at 135KT//29/15utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 20W(ROKE). 3HOURLY SATELLITE BULLETINS ARE STILL ISSUED ON 19W(KULAP). THEY WERE DISCONTINUED ON 02S(ASHELY) AND 18W(NORU) AT 29/00UTC.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A COMPACT SYSTEM THAT CONTINUED TO SIGNIFICANTLY DEEPEN AND INTENSIFY OVER THE LAST SIX HOURS. A RAGGED 10-NM ELONGATED EYE HAS INTERMITTENTLY APPEARED BUT THE CONVECTIVE TOPS ALONG THE SEMI-CIRCULAR EYEWALL REMAINED VERY COLD AT -82C. POLEWARD OUTFLOW ALSO REMAINED ROBUST AS EVIDENCE BY CIRRUS TRANSVERSE BANDING EXTENDING DEEP INTO THE PREVAILING WESTERLIES THAT, FOR NOW, OFFSETS THE INCREASING VERTICAL WIND SHEAR. THE INITIAL POSITION IS BASED ON THE INTERMITTENT EYE THAT LINED UP WELL WITH THE MICROWAVE EYE FEATURE IN THE 290859Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY OF 85KTS IS BASED ON OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE 6-HR RAPID INTENSIFICATION.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: SHORTENED THE SLOW STORM MOTION DURING THE MID-PORTION OF THE FORECAST FROM TAUS 36-72 AND SPED UP NORTHEASTWARD AFTER TAU 72. FORECAST DISCUSSION: TY ROKE HAS IS NOW ON THE POLEWARD SIDE OF THE STR AXIS AND WILL CONTINUE TO ACCELERATE NORTHEASTWARD. AFTER TAU 48, AN EXTENSION OF A LOW- TO MID-LAYER SECONDARY STR TO THE NORTHWEST WILL COMPETE FOR STEERING AND SLOW THE FORWARD MOTION OF THE CYCLONE. AFTER TAU 72, THE PRIMARY STR, NOW TO THE SOUTHEAST, WILL REGAIN STEERING AND RE-ACCELERATE THE SYSTEM NORTHEASTWARD. TY 20W HAS PEAKED INTENSITY AND WILL NOW GRADUALLY ERODE AS VWS INCREASES WITH FURTHER ADVANCE INTO THE STRONG WESTERLIES. ADDITIONALLY, WITH THE ENCROACHMENT OF THE SECONDARY STR, UPPER LEVEL SUBSIDENCE WILL ALSO SUPPRESS VERTICAL DEVELOPMENT. THESE, IN ADDITION TO COOLING SST SOUTHEAST OF JAPAN (BELOW 27C) WILL REDUCE THE SYSTEM TO 30KTS BY TAU 120.

COMPACT SYSTEM

MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH GRADUAL SPREADING TO JUST 162NM BY TAU 72. AFTERWARD, THE TRACKERS SIGNIFICANTLY DIVERGE ACROSS- AND ALONG-TRACK, LENDING HIGH CONFIDENCE IN THE NEAR- TO MID-PORTION OF THE FORECAST AND LOW CONFIDENCE AFTERWARD. THERE IS MEDIUM CONFIDENCE IN THE INTENSITY FORECAST UP TO TAU 72, THEN LOW CONFIDENCE AFTERWARD.

REMARKS: 282100Z POSITION NEAR 37.9N 154.7E. 28SEP22. TYPHOON (TY) 19W (KULAP), LOCATED APPROXIMATELY 603 NM EAST- SOUTHEAST OF MISAWA, JAPAN, HAS TRACKED NORTHEASTWARD AT 28 KNOTS OVER THE PAST SIX HOURS. TY 19W IS EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES, UNDER THE JET WITH STRONG VERTICAL WIND SHEAR. MODEL ANALYSIS DATA INDICATES A FRONTAL STRUCTURE WITH THICKNESS PACKING AND COLD AIR ADVECTION OVER THE WESTERN SEMICIRCLE; A WEAK COLD FRONT IS EVIDENT IN ENHANCED INFRARED (EIR) SATELLITE IMAGERY. CORE STRUCTURE IN EIR, HOWEVER, HAS PERSISTED WITH A LARGE EYE NOW BROADENING WITH WARMING CLOUD TOP TEMPERATURES. THE SYSTEM HAS THUS FAR BEEN ABLE TO COCOON ITSELF FROM THE HOSTILE ENVIRONMENT DUE TO STRONG POLEWARD OUTFLOW AND WARM SEA SURFACE TEMPERATURES. A 281543Z AMSR2 WINDSPEED IMAGE INDICATES AN ASYMMETRIC WINDFIELD WITH 65 TO 70 KNOT WINDS OVER THE EASTERN QUADRANT AND EXTENSIVE GALE-FORCE WINDS OVER THE SOUTHERN SEMICIRCLE. THE INITIAL INTENSITY REMAINS ASSESSED AT 65 KNOTS BASED ON THE PGTW DVORAK INTENSITY ESTIMATE OF T4.0 (65 KNOTS), WHICH IS SUPPORTED BY THE AMSR2 WINDSPEED DATA. TY 19W IS FORECAST TO RAPIDLY COMPLETE EXTRA-TROPICAL TRANSITION OVER THE NEXT 12 HOURS AS IT OCCLUDES AND ACCELERATES NORTHEASTWARD OVER COLD WATER (LESS THAN 20C). HOWEVER, THE SYSTEM WILL MAINTAIN TYPHOON-STRENGTH WINDS AS IT APPROACHES THE ALEUTIAN ISLAND CHAIN. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 281800Z IS 40 FEET.

REMARKS: 280300Z POSITION NEAR 16.1N 107.3E. 28SEP22. TYPHOON 18W (NORU), LOCATED APPROXIMATELY 29 NM WEST OF DA NANG, VIETNAM, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED RADAR DATA CONFIRMS THAT TY 18W MADE LANDFALL JUST SOUTH OF DA NANG, VIETNAM AT 272100Z AND HAS SINCE RAPIDLY MOVED INLAND. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP CONVECTION STILL PERSISTING, HOWEVER, IS INCREASINGLY BEING SHEARED TO THE SOUTHWEST. THE MSI, ANIMATED RADAR DATA, AND ANALYSIS OF WIND OBSERVATIONS ACROSS THE REGION PROVIDED HIGH CONFIDENCE TO THE INTIAL POSITION. THE INITIAL INTENSITY OF 80 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AN RJTD OVER LAND DVORAK CURRENT INTENSITY ESTIMATE OF T5.0, AND MSLP OBSERVATIONS SURROUNDING THE CENTER REPORTING 986MB. THE SYSTEM IS FORECASTED TO CONTINUE MOVING RAPIDLY INLAND TO THE WEST-NORTHWEST ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE NORTH AND ULTIMATELY DISSIPATING OVER SOUTHEAST ASIA NO LATER THAN TAU 36. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOIN TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION.

REMARKS: 272100Z POSITION NEAR 13.5S 78.0E. 27SEP22. TROPICAL CYCLONE 02S (ASHLEY), LOCATED APPROXIMATELY 518 NM SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER DUE TO HIGH NORTH-EASTERLY SHEAR. THE SYSTEM HAS PROGRESSED INTO GRADUALLY COOLING SEA SURFACE TEMPERATURES NOW BELOW 26C, INCREASING VERTICAL WINDSHEAR, AND SIGNIFICANT DRY AIR ENTRAINMENT, ALL LEADING TO THE GRADUAL DISSIPATION OF 02S BY TAU 24 IF NOT SOONER. NUMERICAL MODELS AS-WELL AS RELIABLE MODEL INTENSITY GUIDANCE ARE IN TIGHT AGREEMENT WITH THE JTWC FORECAST TRACK AND INTENSITY RESPECTIVELY, LENDING HIGH CONFIDENCE TO EACH. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 271800Z IS 12 FEET.

ZCZC MIATCDAT4 ALL TTAA00 KNHC DDHHMM Tropical Storm Ian Discussion Number 27 NWS National Hurricane Center Miami FL AL092022 500 AM EDT Thu Sep 29 2022 Ian's center continues to move northeastward across central Florida, and nearly all of the heavy rains are located to the north over northeastern Florida. NWS WSR-88D Doppler velocities from the Melbourne and Tampa radars have decreased significantly since last evening, and based on that data, Ian is now a tropical storm with maximum sustained winds of 55 kt. This intensity is also supported by wind observations across Florida, with the highest recent sustained wind being 52 kt at New Smyrna Beach. Ian's current motion is northeastward, or 040/7 kt. The tail end of a deep-layer trough is expected to detach from the main trough axis over the southeastern United States during the next 24 to 48 hours, and Ian is forecast to move around the eastern periphery of this feature, turning north-northeastward later today and then north-northwestward by Friday night. In this scenario, Ian should move off the east coast of Florida later today, and then swing northward toward the South Carolina coast during the next 36 hours or so. Although there is some cross-track spread in the guidance, they all agree on this general scenario, and the NHC track forecast lies where most of the models are packed. No significant changes were made to the previous prediction. Little change in intensity is forecast during the next 24 hours or so, mainly due to strong southwesterly shear. After 24 hours, global models are suggesting that Ian could have some favorable interaction with the eastern U.S. trough, all while it's moving over the warm 28-29 degree Celsius waters of the Gulf Stream. As a result, some slight strengthening is indicated in the official forecast by 36 hours, and Ian could be near hurricane intensity as it's approaching the coast of South Carolina. This possibility is accounted for by the Hurricane Watch that is effect for the area. After moving inland, Ian is expected to weaken quickly, and global models indicate it should dissipate or become absorbed by another broader area of low pressure over the Carolinas by day 3. Key Messages: 1. Coastal water levels continue to subside along the west coast of Florida. There is a danger of life-threatening storm surge today through Friday along the coasts of northeast Florida, Georgia, and South Carolina. Residents in these areas should follow any advice given by local officials. 2. Tropical-storm-force winds are expected to spread northward across northeastern Florida, Georgia, and the Carolina coasts through Friday. Hurricane conditions are possible through Friday along the coasts of northeastern Florida, Georgia and South Carolina where a Hurricane Watch in effect. 3. Widespread, life-threatening catastrophic flooding, with major to record river flooding, will continue today across portions of central Florida with considerable flooding in northern Florida, southeastern Georgia and eastern South Carolina expected today through the end of the week.