WDPN32 PGTW 131500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (PODUL) WARNING NR 027//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.4N 118.8E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 179 NM SOUTHWEST OF TAIPEI, TAIWAN
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 17 KTS
   SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 16W MOVED BACK OVER WATER AROUND 0700Z-0800Z, TO THE
NORTH OF TAINAN, TAIWAN AND NOW POSITIONED JUST ACROSS THE MID-LINE
OF THE TAIWAN STRAIT. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS A SIGNIFICANT DETERIORATION IN THE STRUCTURE OF THE
SYSTEM, WITH SPARSE CONVECTIVE ACTIVITY ACROSS THE NORTHERN FLANK
OF THE SYSTEM, AND A MASSIVE CONVECTIVE BURST TO THE SOUTHWEST, JUST 
OFFSHORE OF SHANTOU, CHINA. OF NOTE IS THE ABSOLUTELY MASSIVE AMOUNT 
OF LIGHTNING ACTIVITY ASSOCIATED WITH THIS CONVECTIVE BURST, EXCEEDING 
6500 FLASHES PER 5MIN PERIOD SINCE 1200Z. ANIMATED RADAR DATA SUGGESTS 
THE LOW LEVEL CIRCULATION CENTER (LLCC) IS ONCE AGAIN
TIGHTENING UP, WITH THE MOST RECENT RADAR DATA INDICATING
REFORMATION OF AN EYE. THE EYEWALL IS STRONGEST ON THE WESTERN
SIDE, AND OPEN TO THE NORTH, LIKELY DUE TO INGESTION OF DRY
DOWNSLOPE AIR INTO THE NORTHERN FLANK OF THE CIRCULATION. A 131219Z
PARTIAL ASCAT-B PASS REVEALS 45-50 KNOT WINDS IN THE EASTERN AND
NORTHEASTERN QUADRANTS, WITH VESTIGES OF THE DOWNSLOPE WINDS
FANNING OUT FROM THE WESTERN COAST OF TAIWAN TO THE NORTHEAST. THE
INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
ASCAT DATA AND THE TIGHT GROUPING OF AGENCY FIX POSITIONS. THE
INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE
AGENCY FINAL-T NUMBERS, ALL OF WHICH RANGE FROM T3.5-T4.0, AS WELL
AS THE DPRINT VALUE OF 66 KNOTS. ENVIRONMENTAL CONDITIONS ARE
MARGINAL AT BEST, WITH MODERATE SHEAR, WARM SSTS AND DECENT
OUTFLOW, OFFSET BY LIMITED TIME OVER WATER, AND DRY AIR INGESTION
INTO THE CORE OF THE SYSTEM.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) EXTENDING FROM CENTRAL CHINA, SOUTH OF
JAPAN AND INTO THE NORTHERN PACIFIC. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T4.5 - 77 KTS
   KNES: T4.5 - 77 KTS
   CIMSS ADT: 59 KTS AT 131130Z
   CIMSS AIDT: 55 KTS AT 131130Z
   CIMSS D-PRINT: 66 KTS AT 131200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE WESTWARD
   OTHER FACTORS: LIMITED TIME OVER WATER, VORTEX TILT, INGESTION
OF DRY DOWNSLOPE AIR INTO THE NORTHERN FLANK OF THE CIRCULATION. 

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TY 16W WILL CONTINUE TO TRACK NORTHWESTWARD
ALONG THE SOUTHERN SIDE OF THE STR TO THE NORTH THROUGH THE
FORECAST PERIOD. LANDFALL TO THE SOUTH OF XIAMEN, CHINA IS EXPECTED
WITHIN THE NEXT 6 HOURS. THE SYSTEM IS EXPECTED TO MAKE LANDFALL AS
A WEAK TYPHOON, HAVING LIMITED TIME TO ACHIEVE ANY SORT OF
SIGNIFICANT REORGANIZATION OR INTENSIFICATION. AFTER MAKING
LANDFALL, THE SYSTEM WILL MOVE INTO SOUTH-CENTRAL CHINA WHILE
STEADILY WEAKENING, ULTIMATELY DISSIPATING WITHIN THE NEXT 36
HOURS. 

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN STRONG
AGREEMENT, WITH MINIMAL CROSS- OR ALONG-TRACK SPREAD THROUGH TAU
12, THOUGH A MODEST OF CROSS-TRACK SPREAD APPEARS AFTER TAU 12 AS
THE MODELS BEGIN TO LOSE THE VORTEX AS THE SYSTEM DISSIPATES. THE
JTWC FORECAST IS POSITIONED WITH HIGH CONFIDENCE ALONG THE SOUTHERN 
EDGE OF THE GUIDANCE PACKAGE. INTENSITY GUIDANCE IS IN STRONG 
AGREEMENT AS WELL, WITH ALL MODELS INDICATING STEADY AND RAPID 
WEAKENING THROUGH THE FORECAST PERIOD, LENDING HIGH CONFIDENCE TO THE 
JTWC FORECAST. 

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
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