WDPN32 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 10W (TEN) WARNING NR 
001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.9N 132.5E
   INITIAL INTENSITY: 25 KTS
   GEOGRAPHIC REFERENCE: 578 NM SOUTH-SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS CURVED
CONVECTIVE BANDING BUILDING AROUND THE LOW-LEVEL CIRCULATION CENTER
(LLCC) OF TROPICAL DEPRESSION (TD) 10W. AN EARLIER 220113Z METOP-C
ASCAT WIND VECTOR IMAGE REVEALS THE ASYMMETRY OF THE WIND FIELD OF
TS 10W. STRONGER 20-25KT WINDS ASSOCIATED WITH THE LARGER MONSOONAL
FLOW WRAP AROUND THE EASTERN PERIPHERY OF THE CIRCULATION, WHILE
THE WIND FIELD TO THE WEST IS WEAK YET CLOSED. WATER VAPOR IMAGERY
REVEALS STRONG POLEWARD OUTFLOW ENHANCED BY THE DIVERGENT REGION OF
AN UPPER-LEVEL TROUGH POSITIONED TO THE NORTHWEST AND EQUATORWARD
OUTFLOW DRIFTING SLIGHTLY SOUTHWESTWARD. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED
ANIMATED MSI. THE INITIAL INTENSITY OF 25 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE BASED ON THE AFOREMENTIONED SCATTEROMETRY AND IS
SUPPLEMENTED BY THE AGENCY FIXES LISTED BELOW.

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

CURRENT STEERING MECHANISM: DEEP-LAYER RIDGING TO THE EAST

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

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 10W IS CURRENTLY DEVELOPING WITHIN THE
NORTHERN PERIPHERY OF A BAND OF STRONG MONSOONAL FLOW AND IS
STEERED NORTH-NORTHWESTWARD BY A DEEP-LAYER RIDGE TO THE EAST FOR
THE NEXT 36 HOURS. BETWEEN TAU 36-48, THE STEERING INFLUENCE WILL
TRANSFER TO A SUBTROPICAL RIDGE CENTERED OVER THE SEA OF JAPAN.
BETWEEN TAU 48-72, THE MONSOONAL FLOW WILL CLOSE OFF, DEVELOPING
INTO A MONSOON DEPRESSION OVER THE EAST CHINA SEA. TS 10W IS
ANTICIPATED TO BECOME A WEAK AND BROAD SYSTEM AS AN UPPER-LEVEL
TROUGH IMPOSES ON THE SYSTEM STRUCTURE BETWEEN TAU 48-72,
ULTIMATELY CAUSING THE SYSTEM TO WEAKEN AND DISSIPATE INTO THE
LARGER MONSOONAL FLOW. TS 10W WILL INTENSIFY TO A PEAK OF 45KTS
WHILE IN A FAVORABLE ENVIRONMENT OF UPPER-LEVEL DIVERGENCE, LOW
VERTICAL WIND SHEAR, AND WARM SEA SURFACE TEMPERATURES. THE
APPROACHING UPPER-LEVEL TROUGH WILL INITIATE WEAKENING AT TAU 48,
BUT THE STRONG BAND OF GALE-FORCE WINDS ASSOCIATED WITH THE
MONSOONAL FLOW THAT TS 10W DISSIPATES INTO WILL PERSIST, ENDING THE
FORECAST AT 35KTS. 

MODEL DISCUSSION: THE JTWC MULTI-MODEL CONSENSUS IS IN GOOD
AGREEMENT, BUT NOT REPRESENTATIVE OF THE CURRENT FORECAST AS THE
VORTEX TRACKERS APPEAR TO TRACK THE CENTER OF VORTICITY OF THE
DEVELOPING MONSOON DEPRESSION RATHER THAN TS 10W. DETERMINISTIC
MODEL GUIDANCE OVER THE LAST FEW DAYS HAS NOT REPRESENTED THE
DEVELOPMENT TS 10W, INSTEAD FAVORING THE DEVELOPMENT OF A LARGE
MONSOON DEPRESSION. THE CONFIDENCE IN THE TRACK FORECAST IS LOW AS
A RESULT OF THE MINIMAL TRACK GUIDANCE, AND THE CURRENT TRACK
FORECAST LEANS CLOSELY TO THE SMALL VORTICITY FEATURES APPARENT IN
ECMWF AND EC-AIFS, BRINGING TS 10W ON THE NORTHERN PERIPHERY OF
VORTICITY SIGNATURE OF THE LARGER MONSOONAL FEATURE. THE INTENSITY
GUIDANCE PERFORMS QUESTIONABLY AS WELL DUE TO THE PERFORMANCE OF
THE JTWC MULTI-MODEL CONSENSUS, DISPLAYING A LARGE SPREAD OF PEAK
INTENSITIES. THE PEAK AND LENGTH OF THE FORECAST MAY VARY BASED ON
HOW STRONGLY THE UPPER-LEVEL TROUGH CAUSES THE SYSTEM TO SHALLOW
AND HOW QUICKLY, AND LONGER OR SHORTER FORECAST PERIODS MAY RESULT.

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