Météo974
Location: 13.0°N 109.6°E
Maximum Winds: 55 kt ( 100km/h)
Gusts: 70 kt ( 130km/h)
Minimum Central Pressure: 994 mb
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 25W (NAKRI), LOCATED APPROXIMATELY 195 NM SOUTH-SOUTHEAST OF DA NANG, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A LARGE SWATH OF CONVECTION DISPLACED TO THE SOUTHWEST OF A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). FURTHERMORE, A 101009Z SSMIS 91 GHZ MICROWAVE IMAGE SHOWS CONVECTIVE BANDING WRAPPING INTO THE CENTER OF THE SYSTEM, GIVING GOOD CONFIDENCE IN THE INITIAL POSITION. BASED ON A 100537Z SATCON ESTIMATE OF 55 KNOTS AND MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55 KNOTS), THE INITIAL INTENSITY IS SET AT 55 KTS. THE SYSTEM REMAINS IN A REGION WHERE MODERATE WESTWARD DIFFLUENCE IS CONSISTENTLY BEING OFFSET BY MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR (VWS). SEA SURFACE TEMPERATURES ARE WARM AT 28-29 CELSIUS. TS 25W CONTINUES TO TRACK WESTWARD ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 12, TS 25W WILL TRACK GENERALLY WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE AFOREMENTIONED STR. TS 25W IS EXPECTED TO SLOWLY WEAKEN AS CONTINUED MODERATE VWS AND OFFSET UPPER-LEVEL OUTFLOW PRECLUDE FURTHER DEVELOPMENT. TS 25W WILL BEGIN TO RAPIDLY WEAKEN AS IT TRAVERSES THE RUGGED TERRAIN OF INDOCHINA. THE SYSTEM WILL REMAIN ON THIS TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD, DISSIPATING OVER LAND BY TAU 36. NUMERICAL MODEL GUIDANCE IS IN OVERALL GOOD AGREEMENT IN THE NEAR-TERM. AS THE SYSTEM PROGRESSES, THERE ARE VARIATIONS IN FORWARD STORM MOTION WHICH RESULT IN INCREASING ALONG-TRACK MODEL SPREAD AFTER TAU 12. THE CROSS-TRACK SPREAD INCREASES AFTER LANDFALL, PRODUCING A BIFURCATION IN MODEL SOLUTIONS. THE MAJORITY OF THE MODEL SOLUTIONS TRACK WESTWARD ACROSS VIETNAM WHILE A FEW MODELS (AFUM, ECMWF, AND GALWEM) PURSUE A MORE NORTH-NORTHWESTWARD TRACK AFTER LANDFALL. THE OFFICIAL JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS, FOLLOWING THE WEST-NORTHWESTWARD TRACK SOLUTION WITH FAIR CONFIDENCE.//
NNNN
M974World
WESTERN NORTH PACIFICLocation: 13.0°N 109.6°E
Maximum Winds: 55 kt ( 100km/h)
Gusts: 70 kt ( 130km/h)
Minimum Central Pressure: 994 mb
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 25W (NAKRI), LOCATED APPROXIMATELY 195 NM SOUTH-SOUTHEAST OF DA NANG, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A LARGE SWATH OF CONVECTION DISPLACED TO THE SOUTHWEST OF A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). FURTHERMORE, A 101009Z SSMIS 91 GHZ MICROWAVE IMAGE SHOWS CONVECTIVE BANDING WRAPPING INTO THE CENTER OF THE SYSTEM, GIVING GOOD CONFIDENCE IN THE INITIAL POSITION. BASED ON A 100537Z SATCON ESTIMATE OF 55 KNOTS AND MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55 KNOTS), THE INITIAL INTENSITY IS SET AT 55 KTS. THE SYSTEM REMAINS IN A REGION WHERE MODERATE WESTWARD DIFFLUENCE IS CONSISTENTLY BEING OFFSET BY MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR (VWS). SEA SURFACE TEMPERATURES ARE WARM AT 28-29 CELSIUS. TS 25W CONTINUES TO TRACK WESTWARD ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 12, TS 25W WILL TRACK GENERALLY WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE AFOREMENTIONED STR. TS 25W IS EXPECTED TO SLOWLY WEAKEN AS CONTINUED MODERATE VWS AND OFFSET UPPER-LEVEL OUTFLOW PRECLUDE FURTHER DEVELOPMENT. TS 25W WILL BEGIN TO RAPIDLY WEAKEN AS IT TRAVERSES THE RUGGED TERRAIN OF INDOCHINA. THE SYSTEM WILL REMAIN ON THIS TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD, DISSIPATING OVER LAND BY TAU 36. NUMERICAL MODEL GUIDANCE IS IN OVERALL GOOD AGREEMENT IN THE NEAR-TERM. AS THE SYSTEM PROGRESSES, THERE ARE VARIATIONS IN FORWARD STORM MOTION WHICH RESULT IN INCREASING ALONG-TRACK MODEL SPREAD AFTER TAU 12. THE CROSS-TRACK SPREAD INCREASES AFTER LANDFALL, PRODUCING A BIFURCATION IN MODEL SOLUTIONS. THE MAJORITY OF THE MODEL SOLUTIONS TRACK WESTWARD ACROSS VIETNAM WHILE A FEW MODELS (AFUM, ECMWF, AND GALWEM) PURSUE A MORE NORTH-NORTHWESTWARD TRACK AFTER LANDFALL. THE OFFICIAL JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS, FOLLOWING THE WEST-NORTHWESTWARD TRACK SOLUTION WITH FAIR CONFIDENCE.//
NNNN
10/1402UTC
10/1307UTC
