WDPN33 PGTW 230300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (ELEVEN)   
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.8N 120.5E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 254 NM NORTH OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL DEPRESSION (TD) 11W IS LOCATED ALONG THE WESTERN PERIPHERY
OF A LARGE, APPROXIMATELY 650NM DIAMETER LOW PRESSURE AREA, WHICH
IS FORECAST TO GRADUALLY DEEPEN AND STRENGTHEN INTO A MONSOON 
DEPRESSION AS IT TRACKS POLEWARD OVER THE NEXT FEW DAYS. THIS COMPLEX 
SYNOPTIC PATTERN IS EVIDENT IN THE CIMSS TOTAL PRECIPITABLE WATER (TPW) 
ANIMATION, WITH MULTIPLE TROPICAL SYSTEMS ROTATING CYCLONICALLY ALONG 
THE PERIPHERY (10W, 11W AND INVEST 90W). ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY DEPICTS A RAPIDLY CONSOLIDATING SYSTEM, WITH A 
CENTRAL DENSE OVERCAST FEATURE OBSCURING THE LOW-LEVEL CIRCULATION 
(LLC). A 222223Z WSFM 89GHZ COLOR COMPOSITE MICROWAVE IMAGE AND 
ANIMATED RADAR IMAGERY DEPICT TIGHTLY CURVED CONVECTIVE BANDING 
WRAPPING INTO A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC), WITH 
A DEVELOPING MICROWAVE EYE FEATURE. THE INITIAL POSITION IS PLACED WITH 
HIGH CONFIDENCE BASED ON THE MICROWAVE IMAGE AND RADAR IMAGERY. 
ENVIRONMENTAL CONDITIONS ARE HIGHLY FAVORABLE, WITH RADIAL OUTFLOW, LOW 
VERTICAL WIND SHEAR AND WARM SST VALUES. THE INITIAL INTENSITY OF 30 
KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON A 230141Z ASCAT-B 
BULLSEYE IMAGE SHOWING MULTIPLE 30 KNOT WIND VECTORS AND A WELL-DEFINED
CIRCULATION CENTER.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: SYSTEM IS TRACKING BETWEEN A LARGE LOW
PRESSURE AREA CENTERED EAST OF LUZON AND A WEAK STEERING RIDGE TO
THE WEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   KNES: T1.5 - 25 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TD 11W IS FORECAST TO TRACK CYCLONICALLY
AROUND THE SOUTHERN PERIPHERY OF THE AFOREMENTIONED LOW-PRESSURE
AREA THROUGH TAU 36. THIS OVER WATER TRACK WILL ALLOW THE COMPACT
SYSTEM TO INTENSIFY QUICKLY TO ABOUT 60 KNOTS BY TAU 36. AFTER TAU
36, THE LOW PRESSURE AREA WILL TRACK NORTHWARD AND REORIENT, WITH A
SWATH OF LOW-LEVEL GALE FORCE WINDS EXTENDING FROM LUZON TO
OKINAWA. CONSEQUENTLY, TD 11W WILL TURN SHARPLY NORTH-NORTHEASTWARD, 
TRACKING WITHIN THE LOW-LEVEL FLOW THROUGH TAU 72. RAPID WEAKENING WILL 
OCCUR AS THE SYSTEM TRACKS ACROSS THE MOUNTAINOUS TERRAIN OF LUZON, 
WITH ADDITIONAL WEAKENING THROUGH TAU 72 AS THE SYSTEM ENCOUNTERS 
INCREASING VERTICAL WIND SHEAR. TD 11W WILL OPEN UP INTO A SHARP TROUGH 
FEATURE WITHIN THE STRONG 25-30 KNOT SOUTHERLY FLOW AND WILL DISSIPATE 
BY TAU 72. THE INTENSITY OF 30 KNOTS AT DISSIPATION IS LINKED TO THE 
ENVIRONMENTAL FLOW.      

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGH TAU 36 BUT DIVERGES QUICKLY THROUGH THE REMINDER OF THE
JTWC FORECAST TRACK LENDING MEDIUM OVERALL CONFIDENCE. BOTH THE
GEFS AND ECENS ENSEMBLES SUPPORT THE TRACK PHILOSOPHY DEPICTING THE
SHARP POLEWARD TURN NEAR TAU 36 AND ACCELERATED POLEWARD TRACK
THROUGH THE REMAINDER OF THE FORECAST PERIOD.  RELIABLE INTENSITY
GUIDANCE INDICATES UNCERTAINTY IN THE PEAK INTENSITY, WITH PEAK
INTENSITY FROM 37 TO 55 KNOTS. HOWEVER, RAPID INTENSIFICATION
GUIDANCE HAS TRIGGERED SUPPORTING THE SHARP INTENSIFICATION TREND
THROUGH TAU 36.   

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