WDPN32 PGTW 160300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (MUIFA) WARNING NR 
039//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 37.8N 121.3E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 252 NM WEST OF INCHON, SOUTH KOREA
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ENVIRONMENTAL ANALYSIS INDICATES 14W IS IN A HIGHLY UNFAVORABLE
ENVIRONMENT WITH HIGH VERTICAL WIND SHEAR (VWS), FRICTIONAL EFFECTS
OF LAND INTERACTION, AND COOL SEA SURFACE TEMPERATURES (SSTS).
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS 14W CONTINUING
TO DETERIORATE AS THE SYSTEM IS CURRENTLY LOCATED BACK OVER THE
YELLOW SEA. THE ASSOCIATED CONVECTION HAS SHEARED FURTHER
NORTHWARD, THUS RESULTING THE SYSTEMS STRUCTURE TO BECOME EVEN MORE
RAGGED IN THE LOWER LEVELS. THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON AN ILL-DEFINED LOW LEVEL CIRCULATION
(LLC) IN THE MSI LOOP THAT MATCHED AN EQUALLY RAGGED LLC IN A
152250Z SSMIS 89GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY OF 35KTS
IS BASED ON SHIP OBSERVATIONS OF 32 KNOTS OVER THE YELLOW SEA
AROUND AND IS CONSISTENT WITH THE WEAKENING TREND.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE OVER JAPAN 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 30+ KTS
   SST: 23-24 CELSIUS
   OUTFLOW: WEAK POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 14W IS FORECAST TO CONTINUE TRACKING TOWARD
THE NORTHEASTWARD OVER THE YELLOW SEA BEFORE MAKING LANDFALL WITHIN
THE NEXT 12 HOURS. SIGNIFICANT LAND INTERACTION AND HIGH VERTICAL
WIND SHEAR (VWS) WILL CONTINUE TO WEAKEN THE SYSTEM, WITHOUT DEEP
CONVECTION IN THE INNER CORE, THE SYSTEM IS FORECAST TO CONTINUE TO
DECREASE IN INTENSITY. BY TAU 24, VERTICAL WIND SHEAR IS FORECAST
TO INCREASE EVEN FURTHER, THEREFORE, DISSIPATION OVER LAND IS
FORECAST SHORTLY THEREAFTER.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THAT 14W
WILL CONTINUE NORTHEASTWARD MAKING LANDFALL AROUND TAU 12 ALONG THE
NORTH SHORE OF THE YELLOW SEA, FOLLOWED BY DISSIPATION BY TAU 24.
THE JTWC TRACK FORECAST IS PLACED WITH HIGH CONFIDENCE. INTENSITY
GUIDANCE IS ALSO IN GOOD AGREEMENT, WITH STEADY WEAKENING FORECAST
AFTER LANDFALL WITH DISSIPATION SHORTLY AFTER.

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