CLICK ON THE IMAGERIES BELOW TO GET THEM ENLARGED
JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 27W, 25W, 26W. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON THE REMNANTS OF 24W AND ON INVEST 95S.
WESTERN NORTH PACIFIC: TY 27W(USAGI). 13/06UTC ESTIMATED INTENSITY IS 75 KNOTS/CAT 1 US: + 25 KNOTS OVER 24 HOURS
2724110906 71N1482E 15
2724110912 76N1472E 15
2724110918 82N1462E 15
2724111000 88N1454E 20
2724111006 97N1440E 20
2724111012 107N1425E 20
2724111018 115N1411E 20
2724111100 122N1394E 30
2724111106 124N1380E 35
2724111112 125N1365E 40
2724111118 129N1349E 45
2724111200 136N1337E 45
2724111206 140N1318E 50
2724111212 144N1304E 55
2724111218 148N1289E 65
2724111300 151N1278E 70
2724111306 156N1265E 75
2724110912 76N1472E 15
2724110918 82N1462E 15
2724111000 88N1454E 20
2724111006 97N1440E 20
2724111012 107N1425E 20
2724111018 115N1411E 20
2724111100 122N1394E 30
2724111106 124N1380E 35
2724111112 125N1365E 40
2724111118 129N1349E 45
2724111200 136N1337E 45
2724111206 140N1318E 50
2724111212 144N1304E 55
2724111218 148N1289E 65
2724111300 151N1278E 70
2724111306 156N1265E 75
WARNING 10 ISSUED AT 13/09UTC
CLICK ON THE IMAGERY BELOW TO GET IT ANIMATED AND ENLARGED
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A VERY COMPACT SYSTEM, WITH WELL DEFINED SPIRAL BANDING FEATURES AND A SMALL, SOMEWHAT ASYMMETRIC CENTRAL DENSE OVERCAST (CDO) FEATURE. THE FOCUS OF THE DEEP CONVECTION IS ON THE EASTERN SIDE OF THE CIRCULATION FOR THE TIME BEING, WITH THE NORTHWESTERN SIDE BEING DEVOID OF SIGNIFICANT CONVECTIVE ACTIVITY. A 13558 GMI 89GHZ MICROWAVE IMAGE AND A NEAR SIMULTANEOUS AMSR2 PASS REVEALED AN EXTREMELY SMALL INNER CORE OF CONVECTION, WITH WELL DEFINED, IF MORE SHALLOW, SPIRAL BANDS WRAPPING INTO THE CORE. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE MICROWAVE IMAGERY NOTED ABOVE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE, HEDGED TOWARDS THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T4.5 (77 KNOTS) AND THE CIMSS D-MINT. THE SMALL NATURE OF THE CORE MEANS THAT THE OBJECTIVE DVORAK-BASED ESTIMATES SUCH AS ADT, AIDT AND D-MINT ARE LIKELY A BIT TOO LOW. THE ENVIRONMENT REMAINS FAVORABLE WITH WARM SSTS, LOW VWS AND GOOD OUTFLOW ALOFT.
85 – 92 GHz Polarization-Corrected Brightness Temperature
TC Warning Graphic
SIGNIFICANT FORECAST CHANGES: THE FORECAST PHILOSOPHY HAS CHANGED SIGNIFICANTLY, WITH A CHANGE IN THE TAU 72 FORECAST POINT OF 230NM, THE TAU 96 FORECAST POINT OF 455NM AND THE TAU 120 FORECAST POINT OF 760NM. THE EXTREME UNCERTAINTY IN BOTH THE DETERMINISTIC (2100NM SPREAD) AND ENSEMBLE GUIDANCE (SIMILAR IF NOT GREATER) IS DRIVING THIS CHANGE, AS IT IS TOO EARLY TO MAKE A DEFINITIVE CALL ON WHICH SCENARIO WILL ULTIMATELY WIN OUT. FORECAST DISCUSSION: NO SIGNIFICANT CHANGE IS EXPECTED IN THE TRACK FORECAST FOR THE FIRST 24 HOURS, AND THE FORECAST REMAINS VERY CONSISTENT WITH THE PREVIOUS FORECAST THROUGH TAU 24. THE SYSTEM WILL TRACK NORTHWEST ALONG THE SOUTHWEST SIDE OF THE STRONG STR THROUGH THIS PERIOD. THE SYSTEM WILL BRUSH THE NORTHEASTERN TIP OF LUZON AROUND TAU 24 THEN MOVE INTO THE LUZON STRAIT BY TAU 36. AT THIS POINT, THE FORECAST BECOMES HIGHLY UNCERTAIN. WHAT MOST MODELS AGREE ON IS THAT THE STEERING RIDGE WILL MOVE THE EAST AND REORIENT SUCH THAT THE STEERING GRADIENT WEAKENS AND SHIFTS ONTO A MORE NORTH-SOUTH AXIS AS A DEEP TROF APPROACHES FROM THE WEST. THE MAIN DIFFERENCE BETWEEN THE GFS AND ECMWF (REPRESENTING THE TWO DISTINCT SIDES OF THE BIFURCATION) IS THE STRENGTH AND SIZE OF THE VORTEX AND THE IMPACT OF INCREASED SHEAR AND DRY AIR INTRUSION. THE GFS SHOWS THE SYSTEM 24MB WEAKER THAN THE ECMWF, WITH A VERY SMALL INNER CORE. THE GFS TAKES THE SYSTEM OVER LUZON AND EMERGES SIGNIFICANTLY WEAKENED. AS THE WEST-SOUTHWEST SHEAR PICKS UP AFTER TAU 48, IT HAS AN OUTSIZED IMPACT ON THE WEAKENED VORTEX IN THE GFS. THE RESULT IS A RAPID DECAPITATION AND WEAKENING OF THE SYSTEM, WHICH THEN TURNS SHARPLY SOUTHWESTWARD BY TAU 72, TRACKING FURTHER INTO THE SOUTH CHINA SEA ALONG THE NORTHERLY LOW-LEVEL FLOW. THE ECMWF ON THE OTHER HAND HAS A MUCH STRONGER AND LARGER VORTEX WHICH STAYS OVER WATER, SKIRTING THE TIP OF LUZON. THIS STRONGER AND LARGER VORTEX IS ABLE TO RESIST THE INCREASED SHEAR AFTER TAU 48, AT LEAST TO A BETTER DEGREE THAN THE GFS. THE SYSTEM TURNS NORTHWARD AND THEN RECURVES AROUND THE RIDGE AXIS, AHEAD OF THE APPROACHING TROF. AT THIS POINT, THE ULTIMATE TRACK THE SYSTEM TAKES WILL DEPEND ON THE HOW QUICKLY AND HOW MUCH IT INTENSIFIES AND THE EXACT TRACK OVER OR NEAR LUZON. THE JTWC FORECAST SLOWS THE SYSTEM DOWN AS IT MOVES INTO THE WEAKENED STEERING PATTERN, BUT GENERALLY FOLLOWS THE RECURVE SCENARIO. THE SYSTEM IS EXPECTED TO STEADILY INTENSIFY FOR THE NEXT 24 HOURS, THEN SLOWLY WEAKEN AS IT MOVES INTO RELATIVELY COOLER, LOWER OHC WATERS AND SLOWLY SUCCUMBS TO THE EFFECTS OF INCREASED SHEAR.
Model Diagnostic Plot
MODEL DISCUSSION: AS MENTIONED IN THE FORECAST CHANGES PARAGRAPH ABOVE, THE GUIDANCE CAN ONLY BE DESCRIBED AS EXTREMELY UNCERTAIN, WITH A CAPITAL E. THE DETERMINISTIC MEMBERS OF THE CONSENSUS SHOW 2100NM OF SPREAD AT TAU 120, WITH THE GFS AND GEFS SHOWING THE REMNANT SYSTEM MAKING LANDFALL IN CENTRAL VIETNAM, WHILE THE EMCWF, EGRR AND GALWEM HAVE THE SYSTEM SOUTH OF SHIKOKU ISLAND. ENSEMBLE GUIDANCE SHOWS A SIMILAR DEGREE OF UNCERTAINTY BETWEEN THE MODELS. THE 0000Z ECENS RUN NOW SHOWS ALL ENSEMBLE MEMBERS SHOWING A RECURVE, OVER OKINAWA AND SOUTH OF JAPAN. THE GEFS 0000Z RUN IS 180DEG OUT, WITH ALL BUT TWO MEMBERS SHOWING A TURN SOUTHWEST AFTER TAU 48. THE REASONS FOR THE ENSEMBLE DIFFERENCES ARE THE SAME AS FOR THE DETERMINISTIC TRACKERS; THE ECENS IS STRONGER AND BIGGER AND MORE RESISTANT TO THE SHEAR AND DRY AIR, WHILE THE GEFS IS WEAKER AND SMALLER AND THUS MORE SUSCEPTIBLE TO THE IMPACTS OF THE SHEAR AND DRY AIR. WITH THE EXTREME UNCERTAINTY IN THE TRACK GUIDANCE, THE JTWC IS SET WITH BASICALLY ZERO CONFIDENCE AT THIS POINT. INTENSITY GUIDANCE IS SIMILARLY UNCERTAIN AFTER TAU 24, WITH THE ULTIMATE INTENSITY BEING HIGHLY DEPENDENT UPON WHICH TRACK THE SYSTEM TAKES AND THE JTWC FORECAST IS SET WITH VERY LOW CONFIDENCE.
Multiplatform Satellite Surface Wind Analysis (Experimental)
13/0830UTC SATELLITE ANALYSIS
TPPN13 PGTW 130909
A. TYPHOON 27W (USAGI)
B. 13/0830Z
C. 15.77N
D. 125.96E
E. FIVE/GK2A
F. T4.5/4.5/D1.0/24HRS STT: S0.0/03HRS
G. IR/EIR/VIS/MSI
H. REMARKS: 40A/PBO SBC/ANMTN. LLCC EMBEDDED IN W YIELDS A DT OF
5.0. MET YIELDS 4.5. PT YIELDS 4.5. DBO PT.
I. ADDITIONAL POSITIONS:
13/0508Z 15.55N 126.60E AMS2
EL-NAZLY
A. TYPHOON 27W (USAGI)
B. 13/0830Z
C. 15.77N
D. 125.96E
E. FIVE/GK2A
F. T4.5/4.5/D1.0/24HRS STT: S0.0/03HRS
G. IR/EIR/VIS/MSI
H. REMARKS: 40A/PBO SBC/ANMTN. LLCC EMBEDDED IN W YIELDS A DT OF
5.0. MET YIELDS 4.5. PT YIELDS 4.5. DBO PT.
I. ADDITIONAL POSITIONS:
13/0508Z 15.55N 126.60E AMS2
EL-NAZLY
WESTERN NORTH PACIFIC: TS 25W(MAN-YI). 13/06UTC ESTIMATED INTENSITY IS 35 KNOTS: -5 KNOTS OVER 24 HOURS
2524110612 81N1766E 15
2524110618 82N1757E 15
2524110700 82N1743E 15
2524110706 83N1730E 20
2524110712 84N1711E 20
2524110718 91N1691E 20
2524110800 102N1670E 20
2524110806 113N1651E 20
2524110812 122N1632E 20
2524110818 130N1609E 25
2524110900 137N1599E 30
2524110906 143N1591E 35
2524110912 149N1584E 40
2524110918 160N1566E 45
2524111000 160N1560E 45
2524111006 159N1553E 45
2524111012 158N1546E 45
2524111018 151N1538E 40
2524111100 150N1528E 35
2524111106 143N1523E 40
2524111112 142N1517E 40
2524111118 143N1504E 40
2524111200 141N1492E 40
2524111206 141N1475E 40
2524111212 139N1463E 40
2524111218 130N1450E 40
2524111300 126N1437E 35
2524111306 123N1426E 35
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 12.3N 142.6E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 134 NM WEST-SOUTHWEST OF NAVSTA GUAM
MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 11 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
DISORGANIZED, WEAK AND PARTIALLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC), WITH MODERATE CONVECTIVE ACTIVITY CONFINED TO THE
EASTERN PORTION OF THE CIRCULATION. A 130329Z AMSR2 COLOR-ENHANCED
91GHZ MICROWAVE IMAGERY SHOWED LOW-LEVEL BANDS WRAPPING INTO AN
ILL-DEFINED AND IRREGULAR LLCC, AND DEEP CONVECTION DEVELOPING
ALONG A CONVERGENT ASYMPTOTE IN THE SOUTHEASTERN QUADRANT. THE
INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
PARTIALLY EXPOSED LLCC AND EXTRAPOLATION OF THE MICROWAVE-DERIVED
CENTER. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE,
ON THE HIGHER END OF THE SUBJECTIVE AND OBJECTIVE INTENSITY
ESTIMATES OUTLINED ABOVE. THE ENVIRONMENT IS GENERALLY FAVORABLE,
BUT THE DISORGANIZED NATURE OF THE LOW-LEVEL VORTEX AND THE WEAK
OUTFLOW ALOFT ARE OFFSETTING THE OTHERWISE FAVORABLE CONDITIONS OF
LOW NORTHERLY SHEAR AND ZESTY SSTS.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SOUTHEASTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE NORTHWEST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 39 KTS AT 130530Z
CIMSS AIDT: 34 KTS AT 130530Z
CIMSS D-MINT: 28 KTS AT 130331Z
CIMSS D-PRINT: 27 KTS AT 130700Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: WEAK EQUATORWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: THE STR TO THE NORTH WILL BE THE PRIMARY
STEERING MECHANISM FOR THE DURATION OF THE FORECAST PERIOD. THE STR
IS CURRENTLY CENTERED TO THE NORTHWEST, TO THE SOUTH OF KYUSHU AND
IS EXPECTED TO REMAIN QUASI-STATIONARY FOR THE NEXT 24 HOURS. THUS,
TS 25W WILL TRACK WEST-SOUTHWESTWARD THROUGH TAU 24. BY TAU 36, THE
RIDGE BEGINS TO SLIDE EASTWARD, AND BY TAU 48 WILL BE POSITIONED TO
THE NORTHEAST OF TS 25W AND THE SYSTEM WILL BEGIN TRACKING TOWARDS
THE WEST-NORTHWEST AFTER THIS POINT. THE MAIN DETERMINANT IN THE
FORECAST TRACK AFTER TAU 48 IS HOW FAR THE RIDGE MOVES TO THE EAST
AND HOW DEEP A MID-LATITUDE TROF PASSING OVER KOREA AND JAPAN WILL
BE. IF THE RIDGE PUSHES FURTHER EAST AND THE TROF PENETRATES
FURTHER SOUTHWARD, THE TRACK OF TS 25W WILL BE MORE NORTHWESTWARD.
IF THE RIDGE DOES NOT GO AS FAR EASTWARD AND THE TROF IS SHALLOWER,
THEN THE TRACK WILL REMAIN MORE WEST-NORTHWESTWARD. THE CURRENT
FORECAST A MORE NORTHWESTWARD TRACK. LANDFALL IS EXPECTED AROUND
TAU 96 IN NORTHERN LUZON, FOLLOWED BY A QUICK TRANSIT ACROSS THE
ISLAND AND INTO THE SOUTH CHINA SEA BY TAU 120. IN TERMS OF
INTENSITY, THE SYSTEM WILL SLOWLY INTENSIFY OVER THE NEXT 36 HOURS
AS THE VORTEX CONTINUES TO CONSOLIDATE UNDER FAVORABLE LOW SHEAR
CONDITIONS. RAPID INTENSIFICATION IS EXPECTED AFTER TAU 48 AS THE
SYSTEM MOVES OVER AN AREA OF EXTREMELY HIGH OHC (EXCEEDING 175 KJ
PER CM3). THE SYSTEM WILL LIKELY PEAK BETWEEN TAU 72 AND TAU 96,
WITH THE 115 KNOTS IN THE FORECAST BEING THE FLOOR OF THE POTENTIAL
INTENSITY. THE SYSTEM WILL LIKELY SLOW DOWN AS IT APPROACHES THE
SIERRA MADRE MOUNTAINS ON THE EAST COAST OF LUZON AND WEAKEN
SLIGHTLY AS IT STARTS TO FEEL THE IMPACT OF INCREASED FRICTION AND
OFFSHORE, DOWNSLOPE WINDS AS IT APPROACHES LANDFALL. AFTER CROSSING
LUZON, THE SYSTEM IS EXPECTED TO EMERGE INTO THE SOUTH CHINA SEA AS
A MINIMAL TYPHOON.
2524110618 82N1757E 15
2524110700 82N1743E 15
2524110706 83N1730E 20
2524110712 84N1711E 20
2524110718 91N1691E 20
2524110800 102N1670E 20
2524110806 113N1651E 20
2524110812 122N1632E 20
2524110818 130N1609E 25
2524110900 137N1599E 30
2524110906 143N1591E 35
2524110912 149N1584E 40
2524110918 160N1566E 45
2524111000 160N1560E 45
2524111006 159N1553E 45
2524111012 158N1546E 45
2524111018 151N1538E 40
2524111100 150N1528E 35
2524111106 143N1523E 40
2524111112 142N1517E 40
2524111118 143N1504E 40
2524111200 141N1492E 40
2524111206 141N1475E 40
2524111212 139N1463E 40
2524111218 130N1450E 40
2524111300 126N1437E 35
2524111306 123N1426E 35
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 12.3N 142.6E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 134 NM WEST-SOUTHWEST OF NAVSTA GUAM
MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 11 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
DISORGANIZED, WEAK AND PARTIALLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC), WITH MODERATE CONVECTIVE ACTIVITY CONFINED TO THE
EASTERN PORTION OF THE CIRCULATION. A 130329Z AMSR2 COLOR-ENHANCED
91GHZ MICROWAVE IMAGERY SHOWED LOW-LEVEL BANDS WRAPPING INTO AN
ILL-DEFINED AND IRREGULAR LLCC, AND DEEP CONVECTION DEVELOPING
ALONG A CONVERGENT ASYMPTOTE IN THE SOUTHEASTERN QUADRANT. THE
INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
PARTIALLY EXPOSED LLCC AND EXTRAPOLATION OF THE MICROWAVE-DERIVED
CENTER. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE,
ON THE HIGHER END OF THE SUBJECTIVE AND OBJECTIVE INTENSITY
ESTIMATES OUTLINED ABOVE. THE ENVIRONMENT IS GENERALLY FAVORABLE,
BUT THE DISORGANIZED NATURE OF THE LOW-LEVEL VORTEX AND THE WEAK
OUTFLOW ALOFT ARE OFFSETTING THE OTHERWISE FAVORABLE CONDITIONS OF
LOW NORTHERLY SHEAR AND ZESTY SSTS.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SOUTHEASTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE NORTHWEST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 39 KTS AT 130530Z
CIMSS AIDT: 34 KTS AT 130530Z
CIMSS D-MINT: 28 KTS AT 130331Z
CIMSS D-PRINT: 27 KTS AT 130700Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: WEAK EQUATORWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: THE STR TO THE NORTH WILL BE THE PRIMARY
STEERING MECHANISM FOR THE DURATION OF THE FORECAST PERIOD. THE STR
IS CURRENTLY CENTERED TO THE NORTHWEST, TO THE SOUTH OF KYUSHU AND
IS EXPECTED TO REMAIN QUASI-STATIONARY FOR THE NEXT 24 HOURS. THUS,
TS 25W WILL TRACK WEST-SOUTHWESTWARD THROUGH TAU 24. BY TAU 36, THE
RIDGE BEGINS TO SLIDE EASTWARD, AND BY TAU 48 WILL BE POSITIONED TO
THE NORTHEAST OF TS 25W AND THE SYSTEM WILL BEGIN TRACKING TOWARDS
THE WEST-NORTHWEST AFTER THIS POINT. THE MAIN DETERMINANT IN THE
FORECAST TRACK AFTER TAU 48 IS HOW FAR THE RIDGE MOVES TO THE EAST
AND HOW DEEP A MID-LATITUDE TROF PASSING OVER KOREA AND JAPAN WILL
BE. IF THE RIDGE PUSHES FURTHER EAST AND THE TROF PENETRATES
FURTHER SOUTHWARD, THE TRACK OF TS 25W WILL BE MORE NORTHWESTWARD.
IF THE RIDGE DOES NOT GO AS FAR EASTWARD AND THE TROF IS SHALLOWER,
THEN THE TRACK WILL REMAIN MORE WEST-NORTHWESTWARD. THE CURRENT
FORECAST A MORE NORTHWESTWARD TRACK. LANDFALL IS EXPECTED AROUND
TAU 96 IN NORTHERN LUZON, FOLLOWED BY A QUICK TRANSIT ACROSS THE
ISLAND AND INTO THE SOUTH CHINA SEA BY TAU 120. IN TERMS OF
INTENSITY, THE SYSTEM WILL SLOWLY INTENSIFY OVER THE NEXT 36 HOURS
AS THE VORTEX CONTINUES TO CONSOLIDATE UNDER FAVORABLE LOW SHEAR
CONDITIONS. RAPID INTENSIFICATION IS EXPECTED AFTER TAU 48 AS THE
SYSTEM MOVES OVER AN AREA OF EXTREMELY HIGH OHC (EXCEEDING 175 KJ
PER CM3). THE SYSTEM WILL LIKELY PEAK BETWEEN TAU 72 AND TAU 96,
WITH THE 115 KNOTS IN THE FORECAST BEING THE FLOOR OF THE POTENTIAL
INTENSITY. THE SYSTEM WILL LIKELY SLOW DOWN AS IT APPROACHES THE
SIERRA MADRE MOUNTAINS ON THE EAST COAST OF LUZON AND WEAKEN
SLIGHTLY AS IT STARTS TO FEEL THE IMPACT OF INCREASED FRICTION AND
OFFSHORE, DOWNSLOPE WINDS AS IT APPROACHES LANDFALL. AFTER CROSSING
LUZON, THE SYSTEM IS EXPECTED TO EMERGE INTO THE SOUTH CHINA SEA AS
A MINIMAL TYPHOON.
MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN MODERATE
AGREEMENT, THOUGH ALL OF THE CONSENSUS MEMBERS CONCUR ON THE
GENERAL TRACK SCENARIO. CROSS-TRACK SPREAD STEADILY INCREASES TO
100NM AT TAU 48 AND 200NM AT TAU 72, WITH THE GFS ON THE NORTHERN
EDGE OF THE ENVELOPE AND THE UKMET ENSEMBLE MEAN ON THE SOUTHERN
EDGE. A WEAK BIFURCATION BEGINS TO EMERGE AFTER TAU 72, WITH TWO
DISTINCT GROUPINGS OF MODELS TRACKERS DIVERGING FROM ONE ANOTHER.
THE SOUTHERN GROUP THE UKMET ENSEMBLE, THE EGRR, GALWEM, JGSM AND
ECMWF ON THE NORTHERN EDGE, TAKE THE SYSTEM ON A MORE WESTWARD
TRACK ROUGHLY CENTERED ON A TRACK PASSING VERY CLOSE TO MANILA BY
TAU 96. THE OTHER GROUP CONSISTING OF GFS, GEFS ENSEMBLE MEAN,
NAVGEM AND THE HAFS-A AND HWRF, TAKE THE SYSTEM ON A TRACK CENTERED
NEAR PALANAN, LUZON. THE GFS IS THE OUTLIER, KEEPING THE SYSTEM
OVER WATER OFF THE NORTHEAST TIP OF LUZON. THE JTWC FORECAST LIES
ON THE SOUTHERN EDGE OF THIS NORTHERN GROUP, JUST A BIT NORTH OF
THE 0000Z ECENS MEAN TRACK. CONFIDENCE IS HIGH THROUGH TAU 72,
DECREASING TO MEDIUM THEREAFTER. INTENSITY GUIDANCE IS IN GOOD
AGREEMENT THAT THE SYSTEM WILL STEADILY INTENSIFY FOR THE FIRST 24
TO 36 HOURS, FOLLOWED BY RAPID INTENSIFICATION (RI) THROUGH TAU 72.
THE HAFS-A AND CTCX PEAK THE SYSTEM AT 110-115 KNOTS. THE CTCX
ENSEMBLE INTENSITY PROBABILITIES INDICATE A 95 PERCENT PROBABILITY
OF RI BETWEEN TAU 48 AND TAU 72. THE JTWC IS ABOUT 5-10 KNOTS BELOW
THE CONSENSUS MEAN TO TAU 48, THEN TRACKS THE HWRF THROUGH THE
REMAINDER OF THE FORECAST. CONFIDENCE IS MEDIUM TO TAU 72 THEN LOW
THEREAFTER.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
AGREEMENT, THOUGH ALL OF THE CONSENSUS MEMBERS CONCUR ON THE
GENERAL TRACK SCENARIO. CROSS-TRACK SPREAD STEADILY INCREASES TO
100NM AT TAU 48 AND 200NM AT TAU 72, WITH THE GFS ON THE NORTHERN
EDGE OF THE ENVELOPE AND THE UKMET ENSEMBLE MEAN ON THE SOUTHERN
EDGE. A WEAK BIFURCATION BEGINS TO EMERGE AFTER TAU 72, WITH TWO
DISTINCT GROUPINGS OF MODELS TRACKERS DIVERGING FROM ONE ANOTHER.
THE SOUTHERN GROUP THE UKMET ENSEMBLE, THE EGRR, GALWEM, JGSM AND
ECMWF ON THE NORTHERN EDGE, TAKE THE SYSTEM ON A MORE WESTWARD
TRACK ROUGHLY CENTERED ON A TRACK PASSING VERY CLOSE TO MANILA BY
TAU 96. THE OTHER GROUP CONSISTING OF GFS, GEFS ENSEMBLE MEAN,
NAVGEM AND THE HAFS-A AND HWRF, TAKE THE SYSTEM ON A TRACK CENTERED
NEAR PALANAN, LUZON. THE GFS IS THE OUTLIER, KEEPING THE SYSTEM
OVER WATER OFF THE NORTHEAST TIP OF LUZON. THE JTWC FORECAST LIES
ON THE SOUTHERN EDGE OF THIS NORTHERN GROUP, JUST A BIT NORTH OF
THE 0000Z ECENS MEAN TRACK. CONFIDENCE IS HIGH THROUGH TAU 72,
DECREASING TO MEDIUM THEREAFTER. INTENSITY GUIDANCE IS IN GOOD
AGREEMENT THAT THE SYSTEM WILL STEADILY INTENSIFY FOR THE FIRST 24
TO 36 HOURS, FOLLOWED BY RAPID INTENSIFICATION (RI) THROUGH TAU 72.
THE HAFS-A AND CTCX PEAK THE SYSTEM AT 110-115 KNOTS. THE CTCX
ENSEMBLE INTENSITY PROBABILITIES INDICATE A 95 PERCENT PROBABILITY
OF RI BETWEEN TAU 48 AND TAU 72. THE JTWC IS ABOUT 5-10 KNOTS BELOW
THE CONSENSUS MEAN TO TAU 48, THEN TRACKS THE HWRF THROUGH THE
REMAINDER OF THE FORECAST. CONFIDENCE IS MEDIUM TO TAU 72 THEN LOW
THEREAFTER.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
SOUTHERN HEMISPHERE/SOUTH INDIAN OCEAN: INVEST 95S. ADVISORY ISSUED AT 12/18UTC
THE AREA OF CONVECTION (INVEST 95S) PREVIOUSLY LOCATED NEAR 9.0S 79.6E IS NOW LOCATED NEAR 10.4S 76.8E, APPROXIMATELY 360 NM SOUTHEAST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BROAD BUT SLOWLY CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DENSE FRAGMENTED CONVECTION ON THE SOUTHERN PERIPHERY. THE FRAGMENTED CONVECTION IS ALSO EVIDENT ON RECENT SSMIS 37 GHZ MICROWAVE IMAGE. THE ENVIRONMENT IS FAVORABLE FOR DEVELOPMENT WITH WARM (29-30 C) SEA SURFACE TEMPERATURES, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND A POINT SOURCE DIRECTLY OVER THE ANALYZED POSITION THAT SUPPORTS THE GOOD UPPER LEVEL OUTFLOW. GLOBAL DETERMINISTIC AND ENSEMBLE MODELS ARE IN AGREEMENT THAT INVEST 95S WILL CONTINUE TO TRACK WEST-SOUTHWESTWARD TOWARD MADAGASCAR AS IT INTENSIFIES OVER THE NEXT 24 TO 36 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.
GLOBAL DETERMINISTIC AND ENSEMBLE MODELS ARE IN AGREEMENT THAT INVEST 95S WILL CONTINUE TO TRACK WEST-SOUTHWESTWARD TOWARD MADAGASCAR AS IT INTENSIFIES OVER THE NEXT 24 TO 36 HOURS.
Last Updated - 11/12/24 3 WEEK TROPICAL CYCLONE FORMATION PROBABILITY
GTH Outlook Discussion Last Updated - 11/12/24 Valid - 11/20/24 - 12/03/24 The Madden Julian Oscillation (MJO) has been active during the past month, completing a full circumnavigation of the globe. Associated with the MJO is a pronounced wave-1 asymmetry pattern in the spatial upper-level velocity potential field with a clear eastward propagation during the past several weeks. Currently, the enhanced convective envelope stretches from the eastern Americas to Africa, with the suppressed phase beginning to move into the Western Hemisphere. The ECENS, CFS, and GEFS models indicate a relatively slower eastward propagation of the MJO compared to the past month, with the intraseasonal signal forecast to move across the Indian Ocean and Maritime Continent, and the GEFS depicting a faster propagation into the Western Pacific during early December. An MJO associated resurgence of enhanced low-level westerlies may develop across the Maritime Continent later in November but its eastward propagation is uncertain due to a predicted trade wind surge across the tropical Pacific which may destructively interfere with the incoming westerlies. The Western North Pacific has been active with three TC formations during the past week. Tropical Storm Man-Yi and Typhoon Toraji both developed on 11/9, with Tropical Storm Usagi forming on 11/11. According to the Joint Typhoon Warning Center (JTWC), Toraji is forecast to dissipate over the South China Sea. Man-Yi and Usagi are predicted to gradually strengthen and take similar tracks toward the northern Philippines and possibly Taiwan, with Usagi located to the west of Man-Yi. Following this burst of activity, TC formation chances are favored to diminish across the basin. However, a favorable convective environment aloft is forecast to return by week-3 as the main convective envelope moves closer to or over the Western Pacific. Therefore, a 20-40 percent chance of TC development is posted for week-3 stretching from the South China Sea eastward to the Mariana Islands. The MJO slowly moving over the Indian Ocean is forecast to lead to an uptick in TC activity. The JTWC is monitoring 95S over the Southern Indian Ocean for potential development during the next week. Conditions are forecast to remain conducive for additional TC development over this region into weeks 2 and 3, with 40-60 percent chances posted for both periods. By week-3, TC formation probabilities in the ECMWF increase toward Australia supporting an extension of the 20-40 percent probabilities to near the Kimberley Coast, although these higher chances may be delayed into week-4. TC formation is also possible across the Bay of Bengal, although models are borderline in terms of timing with TC formation being depicted in both periods. Therefore, only 20-40 percent chances are highlighted for both week-2 and week-3 despite some stronger signals in the guidance. The National Hurricane Center (NHC) indicates a 90 percent chance of TC formation across the Caribbean during the next 7-days. Given that this system is most likely to develop by the start of week-2, no related TC formation probabilities are highlighted over the region in this outlook. However, interests in the western Caribbean and Florida are advised to monitor updates from NHC regarding this system and any potential impacts.
Forecasts for above- and below-average rainfall during Weeks 2 and 3 are based on historical composites of Indian Ocean and Maritime Continent MJO events, a low frequency state leaning towards La Niña, and a skill-weighted consolidated blend of dynamical model guidance. Above-normal rainfall is forecast across much of the Indian Ocean and Maritime Continent during both periods, and spreading more into the Western Pacific by week-3. Below-normal rainfall is indicated across the equatorial and eastern Pacific tied to the suppressed phase of the MJO. Above-normal rainfall remains forecast across Central America and the Caribbean. Below-normal temperatures are favored across parts of the southwestern U.S. and the Southern Plains.
