WDPN31 PGTW 210900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MAWAR) 
WARNING NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 7.6N 148.7E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 429 NM SOUTH-SOUTHEAST OF ANDERSEN AFB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RECENTLY
FORMED AND EXPANDING CENTRAL DENSE OVERCAST (CDO) MOSTLY OBSCURING
THE LLCC BENEATH. A RECENT 210541Z SSMIS 89GHZ COLOR COMPOSITE
MICROWAVE IMAGE REVEALS TWO KEY ELEMENTS ABOUT THE RAPIDLY
INTENSIFYING SYSTEM. THE FIRST IS THE IMPROVED CORE CONVECTION, IN
BOTH INTENSITY AND ORGANIZATION. THE SECOND ELEMENT IS THE RESULT
OF RECENT AND LIKELY SHORT-LIVED DRY AIR ENTRAINMENT INTO THE
SOUTHERN PERIPHERY OF THE SYSTEM, WHICH IS PARTIALLY REVEALING THE
LLCC. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED
ON MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF 60 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON A GENERAL CONSENSUS
AMONGST AGENCY DVORAK AND AUTOMATED INTENSITY ESTIMATES WHICH
INDICATE 55-61KTS. IN THIS STAGE OF TROPICAL CYCLONE DEVELOPMENT,
AS SCENE TYPES CHANGE AND THE PATH IS CLEARED FOR AND EYE TO FORM,
THE SUBJECTIVE NATURE OF THE DVORAK METHOD IS ON FULL DISPLAY.
OUTLIERS IN FINAL INTENSITY ESTIMATE ARE COMMON, HOWEVER THEIR
VERACITY SHOULD BE CLOSELY EXAMINED. IN THIS CASE, THE
PREPONDERANCE OF INTENSITY ESTIMATES SUPPORTS THE JTWC INITIAL
INTENSITY OF 60KTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE (NER) TO THE EAST
AND SUBTROPICAL RIDGE (STR) TO THE NORTHWEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T4.5 - 77 KTS
   CIMSS SATCON: 51 KTS AT 210355Z
   CIMSS ADT: 61 KTS AT 210530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: STRONG POLEWARD AND MODERATE WESTWARD OUTFLOW

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TS 02W (MAWAR) HAS RAPIDLY INTENSIFIED OVER
THE PAST SIX HOURS. AS THE SYSTEM CONTINUES TO PICK UP SPEED UNDER
THE STEERING INFLUENCE OF THE NER TO THE EAST, 02W IS FORECAST TO
MAINTAIN A GENERALLY NORTH-NORTHWESTWARD TRACK. THE ENVIRONMENT
SURROUNDING 02W IS FORECAST TO REMAIN FAVORABLE, CHARACTERIZED BY
WARM SSTS AND ROBUST OUTFLOW ALOFT BOTH POLEWARD AND WESTWARD
OVERWHELMING THE NEGATIVE AFFECTS OF LIMITED DRY AIR ENTRAINMENT
AND MODERATE MID-UPPER LEVEL VERTICAL WIND SHEAR (VWS). AFTER
REACHING TYPHOON STRENGTH BY TAU 12, THE SYSTEM WILL CONTINUE TO
DEVELOP, FUELED BY THE AFOREMENTIONED ROBUST OUTFLOW ALOFT AND WARM
SSTS. NEAR TAU 72, THE NER TO THE EAST REORIENTS AND BUILDS FURTHER
NORTHEAST OF THE SYSTEM, FORCING IT TO STEADY UP ON A GENERALLY
WEST-NORTHWESTWARD COURSE AFTER PASSING NORTH OF GUAM. BY TAU 120,
NOW OVER THE WARM WATERS AND DEEP OCEAN HEAT CONTENT (OHC) OF THE
PHILIPPINE SEA, 02W WILL REACH A PEAK INTENSITY OF 110KTS AS IT
CONTINUES WEST-NORTHWESTWARD.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH AN
EVER SHRINKING CROSS TRACK DISCREPANCY THROUGH TAU 72. AFUM IS NOW
THE SOLE OUTLIER INDICATING A WESTWARD APPROACH TO GUAM, WHILE THE
BULK OF THE GUIDANCE CLOSELY FOLLOWS THE JTWC FORECAST TRACK. AFTER
TAU 72, CROSS TRACK SPREADING REMAINS MINIMAL WHILE ALONG TRACK
VARIABILITY IS AN IMPORTANT FACTOR TO CONTINUE MONITORING. AS A
RESULT THE JTWC FORECAST TRACK IS PLACED WITH OVERALL HIGH
CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS ON GOOD AGREEMENT
WITH A BULK OF THE GUIDANCE AS WELL AS SEVERAL RAPID
INTENSIFICATION (RI) AIDS INDICATING ROBUST AND PERSISTENT
INTENSIFICATION THROUGH TAU 72. AS 02W ENTERS THE PHILIPPINE SEA IN
THE EXTENDED TRACK, INTENSIFICATION CONTINUES, SIMPLY AT A REDUCED
RATE. FOR THESE REASONS THE JTWC INTENSITY FORECAST IS PLACED WITH
OVERALL MEDIUM CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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