Tropical Storm MALAKAS Advisory 08.04.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MALAKAS) WARNING
NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
   INITIAL POSITION: 5.1N 146.4E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 524 NM SOUTH OF ANDERSEN AFB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RELATIVELY
ELONGATED AND DISORGANIZED CIRCULATION, WITH FLARING CONVECTION
EXTENDING IN A LINEAR FASHION FROM NORTHWEST TO SOUTHEAST OF THE
ASSESSED LOW LEVEL CENTER. STRONG WESTERLY WINDS ARE EVIDENT IN THE
ANIMATED VISIBLE IMAGERY, STREAMING IN TO THE SOUTH OF THE SYSTEM,
WHILE MUCH WEAKER EASTERLY FLOW IS SEEN WRAPPING INTO THE NORTHERN
SIDE OF THE CIRCULATION. A 072331Z ASCAT-B SCATTEROMETER PASS
CONFIRMED THE ELONGATED AND DISORGANIZED NATURE OF THE CIRCULATION
CENTER AND THE STRONG, UP TO 40 KNOTS, WIND FIELD TO THE SOUTH.
HOWEVER, EVEN WITH THE SCATTEROMETER DATA, THE INITIAL POSITION IS
ASSESSED WITH LOW CONFIDENCE, AS THE BEST TRACK WAS PLACED IN THE
APPROXIMATE CENTROID OF THE ELONGATED CIRCULATION, ON THE NORTHERN
EDGE OF THE CONVECTIVE MASS, WHEN IN FACT THERE MAY BE MULTIPLE
VORTICITY CENTERS UNDER THE CONVECTION AS THE LATEST GFS AND HWRF
MODEL FIELDS WOULD SUGGEST. WHILE THE SYSTEM REMAINS DISORGANIZED,
IT IS SLOWLY INTENSIFYING, AS SHOWN IN THE SCATTEROMETER DATA, AS
WELL AS A 072006Z SMAP PASS BOTH OF WHICH SHOWED BROAD SWATHS OF 40
KNOT WINDS TO THE SOUTH AND WEST OF THE LLCC. AGENCY FIXES, WITH
THE EXCEPTION OF RJTD, ARE ALL AT T3.0 (45 KNOTS) BUT THE OBJECTIVE
ADT AND SATCON ARE UNREALISTICALLY HIGH.
INITIAL WIND RADII BASIS: SCATTEROMETER DATA
CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE TO THE NORTH.
AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T3.0 - 45 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T3.0 - 45 KTS
   CIMSS SATCON: 48 KTS AT 072024Z
   CIMSS ADT: 55 KTS AT 072340Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE WESTWARD
   OTHER FACTORS: ELONGATED AND RAGGED LOW LEVEL CIRCULATION CENTER
(LLCC).
ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING. HOWEVER THE POTENTIAL
DEVELOPMENT OF INVEST 94W INDUCES AN ALTERNATE FORECAST SCENARIO TO
BE DISCUSSED BELOW.
FORECAST DISCUSSION: AS MENTIONED ABOVE, TS MALAKAS IS STRUGGLING
TO CONSOLIDATE INTO A SINGULAR AND DISCREET LOW LEVEL CENTER. GFS
AND HWRF HAVE BEEN DEPICTING THIS SCENARIO FOR THE PAST COUPLE OF
RUNS, BUT THE RECENT SCATTEROMETER AND MOST RECENT ANIMATED MSI
CONFIRM IT. HENCE IN THE NEAR-TERM, WHILE SOME OF THE MODEL
GUIDANCE CONTINUES TO SUGGEST RAPID INTENSIFICATION (RI), THIS IS
BECOMING INCREASINGLY LESS LIKELY TO OCCUR AS THE SYSTEM WILL TAKE
TIME TO GET ITS ACT TOGETHER BEFORE IT CAN INTENSIFY AT MORE THAN A
CLIMATOLOGICAL RATE. THE FORECAST THUS CALLS FOR SLOW BUT STEADY
INTENSIFICATION THROUGH TAU 36, BUT BY THIS POINT THE SYSTEM IS
EXPECTED TO HAVE DEVELOPED A MORE COMPACT CORE, AND THE RATE OF
INTENSIFICATION WILL INCREASE THEREAFTER, TO A PEAK OF 100 KNOTS BY
TAU 120. IN TERMS OF TRACK, THERE ARE NO SIGNIFICANT CHANGES TO THE
OVERALL SYNOPTIC STEERING PATTERN, WHICH IS DOMINATED BY THE STR
CURRENTLY TO THE NORTH AND EAST. OVER THE COURSE OF THE FORECAST
PERIOD, THIS RIDGE WILL SLIDE FURTHER EAST, WHILE RIDGING TOWARDS
THE EQUATOR, EFFECTIVELY REORIENTING THE RIDGE AXIS MORE MERIDIONAL
AND ALLOWING TS 02W TO TRANSIT NORTHWEST THROUGH THE DURATION OF
THE FORECAST. WHILE THE SYNOPTIC LEVEL FORCING HAS NOT CHANGED, THE
PRIMARY DETERMINANT IN THE ULTIMATE TRACK WILL BE THE DEVELOPMENT,
OR NON-DEVELOPMENT, OF INVEST 94W, CURRENTLY LOCATED EAST OF
MINDANAO. THE GFS HAS BEEN BULLISH ON DEVELOPING 94W FOR SEVERAL
DAYS, WHILE ECMWF HAS IGNORED IT, THAT IS UNTIL NOW. WITH THE
LATEST RUN, ECMWF HAS NOW JUMPED ON THE BANDWAGON, WITH DEVELOPMENT
OF 94W INTO A TROPICAL CYCLONE WHICH THEN TRACKS NORTHEAST,
UNDERGOES BINARY INTERACTION AND FUJIWHARA WITH TS 02W, AND
ULTIMATELY IS ABSORBED WITHIN TS MAKALAS. GFS HAS SHOWN A
CONSISTENTLY SIMILAR SOLUTION FOR THE PAST SEVERAL RUNS. WHILE THIS
POSSIBILITY IS STILL CONSIDERED AS A RELATIVELY LOW PROBABILITY,
WITH THE RECENT CHANGE IN THE ECMWF MODEL TO COME ON BOARD, THE
POSSIBILITY IS INCREASING, LEADING TO AN ALTERNATE FORECAST
SCENARIO, WHICH REFLECTS TC DEVELOPMENT FROM 94W WHICH WOULD PULL
THE TRACK OF TS 02W FURTHER WEST, LINGERING NEAR 135E FOR A PERIOD
OF TIME BEFORE RACING NORTHWARD AFTER TAU 120.
MODEL DISCUSSION: THROUGH TAU 72, THE BULK OF THE DETERMINISTIC
GUIDANCE IS IN TIGHT AGREEMENT, WITH THE NOTABLE EXCEPTION OF THE
GFS, WHICH MAY BE JUMPING VORTICES WITHIN THE ELONGATED
CIRCULATION, AS IT TRACKS THE SYSTEM DUE NORTH THEN NORTHWEST
THROUGH TAU 24. THE REMAINDER OF THE GUIDANCE IS TIGHTLY PACKED,
BUT AS PRECISION DOES NOT EQUAL ACCURACY, THERE IS LOW CONFIDENCE
IN THE TAU 0-72 FORECAST DUE TO THE VERY LOW CONFIDENCE IN THE
INITIAL POSITION AND THE ELONGATED NATURE OF THE CIRCULATION
CENTER. IN THE LONG RANGE FORECAST, THE MODELS BEGIN TO DIVERGE,
WITH THE GFS BITING OFF ON THE BINARY INTERACTION WITH 94W, TURNING
THE SYSTEM TO THE WEST, LINGERING FOR 24 HOURS THEN SLOWLY DRIFTING
NORTHWARD. THE ECMWF SHOWS A SIMILAR JOG TO THE WEST BY TAU 120,
THOUGH TO A LESSER DEGREE. THE REMAINDER OF THE GUIDANCE CONTINUES
TO HOLD THE LINE ON THE STRAIGHT NORTHWESTWARD TRACK, THOUGH THE
GFS ENSEMBLE MEAN, GALWEM AND NAVGEM SHOW A SHARP RECURVE BY TAU
120, LEADING TO A NEARLY 600NM SPREAD BY THE END OF THE FORECAST.
OVERALL THERE IS LOW CONFIDENCE FOR THE DURATION OF THE FORECAST
PERIOD. IN TERMS OF INTENSITY, WHILE THE RI AIDS CONTINUE TO
TRIGGER, THE EVIDENT DISORGANIZATION OF THE CORE MEANS THAT ANY
NEAR-TERM RI IS HIGHLY UNLIKELY AND THESE AIDS ARE DISCARDED. THE
REMAINDER OF THE GUIDANCE SEEMS MORE LIKELY, WITH NEAR-TERM SLOW
INTENSIFICATION FOLLOWED BY A MORE RAPID INTENSIFICATION TO A PEAK
OF 100 KNOTS BY TAU 120. THE MAJORITY OF THE GUIDANCE, EXCEPT HWRF
AND COAMPS-TC, INDICATE RAPID WEAKENING AFTER TAU 96. THE JTWC LIES
CLOSE TO THE CONSENSUS MEAN THROUGH TAU 48 THEN DEPARTS WELL ABOVE
THE MEAN THEREAFTER. CONFIDENCE REMAINS LOW HOWEVER DUE TO THE
UNCERTAIN TIMING OF CORE CONSOLIDATION AND THE POTENTIAL FOR BINARY
INTERACTION AND MERGER WITH 94W, WHICH WOULD IMPACT A SIGNIFICANT
DOWNWARD PRESSURE ON THE ULTIMATE INTENSITY.
FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: LOW
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: LOW
   INTENSITY 72-120 HR: LOW//
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