WDPN31 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 14W (KOINU) WARNING 
NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.4N 132.0E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 503 NM NORTHWEST OF YAP
   MOVEMENT PAST 6 HOURS: WESTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL VISIBLE IMAGERY (MSI) HAS HELPED REVEAL THE
CHAOTIC SURFACE FLOW OF TD KOINU, AS IT SLOWLY DEVELOPS. THE MSI
DEPICTS A SERIES OF SMALL TRANSIENT CIRCULATIONS WITHIN A BROADER
LOW LEVEL CIRCULATION (LLC) ANCHORED BY A CLUSTER OF DEEP
CONVECTION ON THE WESTERN FLANK. A DOMINANT CIRCULATION FEATURE
DEVELOPED JUST UNDER THE SOUTHEASTERN EDGE OF THE CONVECTIVE MASS,
AND HAS CONTINUED TO IMPROVE, DESPITE LIMITED CONVECTION BUILDING
OVERHEAD. A 292134Z SSMIS PASS ALSO DEPICTS THE DEEP CONVECTION
DISPLACED TO THE WEST OF THE LLC, LIKELY DUE TO MID-LEVEL SHEAR
THAT IS SOMEWHAT HIGHER THAN THE INTEGRATED DEEP-LAYER SHEAR
ESTIMATES ARE INDICATING.  THE INITIAL POSITION WAS PLACED WITH
HIGH CONFIDENCE BASED ON THE EXPOSED LLC. THE INTENSITY WAS HELD AT
30 KNOTS GIVEN THE LACK OF CORE CONVECTION, AND SUPPORTED BY BOTH
SUBJECTIVE AND OBJECTIVE ESTIMATES RANGING FROM 30 TO 34 KNOTS. THE
PRIMARY OUTFLOW CHANNEL IS STILL PREDOMINANTLY EQUATORWARD, HOWEVER
ANIMATED WATER VAPOR INDICATES POLEWARD OUTFLOW IS PICKING UP. TD
KOINU IS TRACKING WESTWARD UNDER A MID-LAYER SUBTROPICAL RIDGE TO
THE NORTH.

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

CURRENT STEERING MECHANISM: SUB-TROPICAL RIDGING TO THE NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   CIMSS ADT: 32 KTS AT 292330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD
   OTHER FACTORS: MID-LEVEL VERTICAL WIND SHEAR HAMPERING
SUSTAINMENT OF CENTRAL CONVECTION NECESSARY TO DEVELOP THE VORTEX

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TD 14W IS EXPECTED TO DEFLECT TO A MORE
NORTH-NORTHWESTERLY TRACK OVER THE NEXT 12 TO 24 HOURS IN RESPONSE
TO A MID-LATITUDE TROUGH PASSING BY TO THE NORTH, WHICH WILL ERODE
THE STEERING RIDGE. HOWEVER THERE IS HIGH UNCERTAINTY IN THE TIMING
OF THIS TURN. GFS SUGGESTS TD KOINU WILL SLOWLY CONSOLIDATE OVER
THE NEXT 12-24 HOURS, AS MID-LAYER SHEAR GRADUALLY IMPROVES. A
STAIR-STEP TYPE TRACK PATTERN IS INDICATED BEYOND TAU 48 AS A STR
BUILDS BACK IN TO THE NORTH, REORIENTING THE TRACK BACK TO THE WEST
THROUGH THE LUZON STRAIT. AFTER TAU 48, A GOOD POLEWARD CHANNEL
WILL BE ESTABLISHED AND STRONG 200 MB FLOW SETTING UP TO THE SOUTH
OF THE SYSTEM SHOULD ALSO PROVIDE A ROBUST EQUATORWARD OUTFLOW 
CHANNEL. AT AROUND THE SAME TIME, MID-LEVEL MOISTURE SHOULD INCREASE, 
LEADING TO VERY FAVORABLE CONDITIONS FOR RAPID INTENSIFICATION. THE 
PEAK INTENSITY WAS RAISED TO 105 KNOTS, WHICH IS NEAR THE TOP END OF 
THE GUIDANCE, BUT MAY BE ADJUSTED HIGHER IF TRENDS CONTINUE. 

MODEL DISCUSSION: ENSEMBLE AND MULTI-MODEL AGREEMENT CONTINUES TO
IMPROVE CONFIDENCE IN THE EXTENDED FORECAST TRACK. ONLY 3 OF 80 GEFS 
AND ECENS ENSEMBLE MEMBERS INDICATE AN EARLY RECURVATURE. NAVGEM
REMAINS A POLEWARD OUTLIER, WHILE THE REST OF THE CONSENSUS
GUIDANCE ALL FOLLOW INTO THE LUZON STRAIT, WITH AN ACROSS-TRACK
SPREAD OF 160 NM AT TAU 120. DURING THIS CYCLE, HWRF AND COAMPS-TC
DETERMINISTIC MODELS ARE BOTH VERY AGGRESSIVELY INDICATING RAPID
INTENSIFICATION AT OR AROUND TAU 48 TO 72. IF THIS TREND CONTINUES, 
THE PEAK WILL LIKELY BE ADJUSTED HIGHER. UNFORTUNATELY, THE REMAINING 
COAMPS-TC ENSEMBLE MEMBER TRACKS ARE NOT ALIGNED WITH THE CONTROL 
MEMBER AND OFFICIAL FORECAST, SO IT IS BEING DISCOUNTED FOR THE TIME 
BEING. 

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