Tropical Storm MALOU Advisory jue, 28-10

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (MALOU) WARNING NR 017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
   INITIAL POSITION: 23.5N 140.8E
   INITIAL INTENSITY: 80 KTS
   GEOGRAPHIC REFERENCE: 83 NM SOUTH-SOUTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A LARGE EYE 80-90
NM IN DIAMETER WITH MULTIPLE EMBEDDED MESOVORTICES. THE RING OF
DEEP CONVECTION ENCIRCLING THE EYE HAS ERODED ON THE SOUTHERN SIDE
DURING THE PAST SIX HOURS, AND THE INNER CORE MAINTAINS A
GENERALLY RAGGED APPEARANCE. GFS MODEL DIAGNOSTICS SHOW THAT THE
STRONGEST VERTICAL SHEAR IS IN THE 850-450 MB LAYER, COLOCATED
WITH A MID-LEVEL DRY AIR LAYER TO THE WEST OF THE TYPHOON. THE
RESULTING INWARD TRANSPORT OF DRY MID-LEVEL AIR INTO THE CORE OF
THE CYCLONE MAY BE CONTRIBUTING TO THE RAGGED CONVECTIVE
STRUCTURE. THE INITIAL INTENSITY IS HELD STEADY AT 80 KT BASED ON
A 272030Z SENTINNEL-1B SAR PASS SHOWING A BAND OF 75-80 KT WINDS
IN THE SOUTHEAST QUADRANT, BROADLY SUPPORTED BY SUBJECTIVE DVORAK
ESTIMATES OF T4.5 (77 KT) AND T5.0 (90 KT) FROM VARIOUS AGENCIES.
INITIAL WIND RADII BASIS: SAR AND SMOS DATA
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST
AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T5.0 - 90 KTS
   RJTD: T4.5 - 77 KTS
   RCTP: T4.5 - 77 KTS
   KNES: T5.0 - 90 KTS
   CIMSS SATCON: 69 KTS AT 272140Z
   CIMSS ADT: 74 KTS AT 272340Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: DRY MID-LEVEL AIR MASS TO THE WEST AND SOUTH
ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: HIGH
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TYPHOON 25W (MALOU) WILL CONTINUE TRACKING
NORTHEASTWARD, ACCELERATING DRAMATICALLY DURING THE FORECAST
PERIOD AS IT MOVES BENEATH A MID-LATITUDE JET STREAK EAST OF
JAPAN. THIS SAME JET STREAK IS CURRENTLY INTERACTING
CONSTRUCTIVELY WITH MALOU'S UPPER-LEVEL OUTFLOW, WHICH HAS LIKELY
CONTRIBUTED TO THE OBSERVED INTENSIFICATION OF THE TYPHOON OVER
THE PAST 24 HOURS. SOME FURTHER INTENSIFICATION IS POSSIBLE DURING
THE NEXT 12-24 HOURS WHILE MALOU TRACKS OVER WARM WATER AND
VERTICAL SHEAR REMAINS MODERATE. THE FORECAST PEAK INTENSITY IS 90
KT AT TAU 24, STAYING BELOW THE AGGRESSIVE HWRF MODEL, WHICH
THINKS THE INNER CONVECTIVE CORE IS MORE COMPLETE AND ROBUST THAN
IN REALITY. AFTER 24 HOURS, OCEAN TEMPERATURES BENEATH THE TYPHOON
WILL RAPIDLY DECREASE, COINCIDENT WITH AN INCREASE IN VERTICAL
SHEAR AS MALOU NEARS THE MID-LATITUDE JET, LEADING TO A RAPID
TRANSITION TO AN EXTRATROPICAL CYCLONE BY 48 HOURS WITH MAXIMUM
WINDS OF AROUND 50 KT.
MODEL DISCUSSION: MODEL GUIDANCE IS TIGHTLY CLUSTERED THROUGH 48
HOURS, WITH MODERATE ALONG-TRACK SPREAD AT 24-48 HOURS. THE JTWC
TRACK FORECAST IS SIMILAR TO THE PREVIOUS ONE. THE JTWC INTENSITY
FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS, STAYING BELOW THE
AGGRESSIVE HWRF AND COAMPS-TC MODELS BUT STRONGER THAN THE GFS.
FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM//
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