WDPN31 PGTW 270900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (MALOU) WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.3N 139.4E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 235 NM SOUTH-SOUTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) ANALYSIS REVEALS
THAT TY 25W IS UNDERGOING A FAIRLY RAPID CONSOLIDATION PHASE, WITH
DEEP CONVECTION FLARING AND WRAPPING INTO A RAGGED EYE FEATURE.
WHILE THE EYE IN THE VISIBLE AND INFRARED IMAGERY IS RAGGED AND
DISORGANIZED, A 270620Z GMI 37GHZ MICROWAVE IMAGE SHOWED A VERY
WELL-DEFINED MICROWAVE EYE WITH DEEP CONVECTION FORMING A SOLID
EYEWALL COMPLETELY ENCLOSING THE MICROWAVE EYE. ADDITIONALLY, AND
SOMEWHAT OMINOUSLY, THE 37GHZ COLOR COMPOSITE IMAGE REVEALED A
CLASSIC CYAN RING FEATURE, WHICH SUGGESTS THE POSSIBILITY OF
NEAR-TERM RAPID INTENSIFICATION. THE INITIAL POSITION IS PLACED
WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED MICROWAVE IMAGE.
THE INITIAL INTENSITY OF 65 KNOTS IS ASSESSED WITH HIGH CONFIDENCE,
IN LINE WITH THE MAJORITY OF THE AGENCY FIXES AND THE SATCON
ESTIMATE. THE ADT HAS YET TO PICK UP ON THE EYE FEATURE AND IS
USING THE CURVED BAND METHOD, AND THUS IS SIGNIFICANTLY LOWER THAN
ALL OTHER ESTIMATES AND IS DISCOUNTED. ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT, WITH WARM SSTS, LOW VWS AND ROBUST POLEWARD OUTFLOW
INTO THE RIGHT ENTRANCE REGION OF A 150 KNOT JET MAX EAST OF
HOKKAIDO. WHILE THE SYSTEM IS COCOONED WITHIN AN AREA OF RELATIVELY
DRIER AIR, IT APPEARS TO NO LONGER BE ENTRAINING THIS DRY AIR INTO
THE CORE, ALLOWING FOR THE CORE TO CONSOLIDATE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE EAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 64 KTS AT 270405Z
   CIMSS ADT: 43 KTS AT 270540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: FROM A TRACK PERSPECTIVE, THE FORECAST IS A
RELATIVE STRAIGHT-FORWARD RECURVE SCENARIO, WITH TY 25W STEADILY
ACCELERATING TO THE NORTHEAST AROUND THE PERIPHERY OF THE STR
THROUGH THE DURATION OF THE FORECAST. THE INTENSITY FORECAST IS A
BIT MORE UNCERTAIN HOWEVER. ENVIRONMENTALLY, ALL THE NECESSARY
INGREDIENTS INCLUDING VERY LOW VWS, WARM SSTS AND VERY STRONG
POLEWARD OUTFLOW, ARE IN PLACE TO SUPPORT FAST OR EVEN RAPID
INTENSIFICATION WITHIN THE NEXT 24 HOURS. THE KEY QUESTIONS REVOLVE
AROUND THE IMPACT OF MODERATE MID-LEVEL SHEAR, WHICH THE HIGH
RESOLUTION HWRF AND THE 0000Z SOUNDING FROM CHICHI-JIMA, INDICATE
IS RUNNING AT ABOUT 15-18 KNOTS FROM THE EAST, AND MID-LEVEL DRY
AIR WHICH THE CHICHI-JIMA SOUNDING SHOWED BETWEEN 550MB TO 780MB.
THESE TWO FACTORS ARE THE ONLY TWO FACTORS THAT COULD HINDER TY 25W
FROM EXPLODING. THE CURRENT FORECAST CALLS FOR FAST, BUT NOT RAPID,
INTENSIFICATION TO A PEAK OF 90 KNOTS BY TAU 36. SHORTLY AFTER THE
PEAK THE SYSTEM WILL CROSS THE 26C ISOTHERM, AND VWS WILL VERY
QUICKLY INCREASE TO BEYOND 30 KNOTS, WHICH WILL LEAD TO STEADY
WEAKENING IMMEDIATELY AFTER REACHING THE PEAK INTENSITY. THE SYSTEM
WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY TAU 48 WHILE
CONTINUING TO STEADILY WEAKEN. ETT IS FORECAST TO BE COMPLETE NO
LATER THAN TAU 72, BUT LIKELY AROUND TAU 60, AS THE SYSTEM BECOMES
EMBEDDED IN THE BAROCLINIC ZONE AND TRANSITIONS TO A COLD CORE LOW.
 

MODEL DISCUSSION: TRACK GUIDANCE IS VERY GOOD CROSS-TRACK AGREEMENT
THROUGH THE DURATION OF THE FORECAST, WITH SPREAD GRADUALLY
INCREASING TO A VERY MODEST 165NM AT TAU 72. ALONG-TRACK SPREAD IS
GOOD UP TO ABOUT TAU 48, WHERE AFTER IT DRAMATICALLY INCREASES AS
THE SYSTEM ACCELERATES NORTHEASTWARD WHILE UNDERGOING ETT. THE JTWC
FORECAST IS DOWN THE CENTER OF THE TRACK ENVELOPE BUT SLIGHTLY
SLOWER THAN THE CONSENSUS MEAN WITH HIGH CONFIDENCE. ALL MEMBERS OF
THE INTENSITY CONSENSUS AGREE ON THE INTENSIFICATION SCENARIO AND
THE BULK OF THE MEMBERS ARE TIGHTLY PACKED WITH A PEAK BETWEEN
75-85 KNOTS. THE HWRF IS THE SOLE OUTLIER, INDICATING RAPID
INTENSIFICATION TO A PEAK OF 105 KNOTS BY TAU 36. WHILE THE RAPID
INTENSIFICATION PREDICTION AID (RIPA) DID NOT TRIGGER WITH THIS
MODEL RUN, RIPA CALCULATIONS GENERATE ABOUT A 20 PERCENT CHANCE OF
RI. THE JTWC FORECAST LIES ABOVE THE CONSENSUS MEAN AS A NOD TO THE
LOW, BUT NOT ZERO, PROBABILITY RI, BUT ABOUT 10-15 KNOTS BELOW THE
AGGRESSIVE HWRF SOLUTION THROUGH TAU 36, THEN IS ABOUT FIVE KNOTS
ABOVE THE MEAN THEREAFTER.   

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM//
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