WDPN31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 30W (NOCK-TEN) WARNING
NR 10//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 30W (NOCK-TEN), LOCATED APPROXIMATELY 594 NM EAST OF
MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A RAPIDLY-CONSOLIDATING LOW-LEVEL CIRCULATION CENTER
(LLCC) OBSCURED BY A SYMMETRIC CENTRAL DENSE OVERCAST FEATURE WITH A
NEWLY-FORMED 10-NM EYE (AS OF 23/1320Z). A 231235Z METOP-A 89GHZ
IMAGE SHOWS A SYMMETRIC EYEWALL WITH A BANDING FEATURE WRAPPING INTO
THE LLCC. TY NOCK-TEN REMAINS IN A VERY FAVORABLE ENVIRONMENT WITH
LOW (5-10 KNOTS) VERTICAL WIND SHEAR (VWS), NEARLY RADIAL OUTFLOW,
AND VERY WARM SEA SURFACE TEMPERATURES. THE CURRENT INTENSITY IS
ASSESSED AT 70 KNOTS, HEDGED SLIGHTLY HIGHER THAN THE DVORAK
INTENSITY ESTIMATES OF T4.0 (65 KNOTS) FROM ALL REPORTING AGENCIES,
BASED ON THE IMMINENT RAPID INTENSIFICATION (RI) PHASE. TY 30W IS
TRACKING WEST-NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-
LAYERED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE, HOWEVER, THE PEAK INTENSITY
HAS BEEN INCREASED TO 115 KNOTS WITH RI EXPECTED WITHIN THE NEXT 06
TO 24 HOURS.
   B. TY 30W WILL CONTINUE TO TRACK WEST-NORTHWESTWARD OVER THE NEXT
24 HOURS BEFORE LEVELING OUT ON A MORE WESTWARD TRAJECTORY THROUGH
TAU 72, MAKING LANDFALL OVER SOUTHERN LUZON. TY NOCK-TEN WILL
CONTINUE TO INTENSIFY UNDER THE VERY FAVORABLE ENVIRONMENTAL
CONDITIONS WITH THE POTENTIAL FOR A PERIOD OF RI AS PREVIOUSLY
MENTIONED. GRADUAL WEAKENING IS FORECAST AS THE SYSTEM BEGINS TO
INTERACT WITH LAND AFTER TAU 36, AND SIGNIFICANT WEAKENING IS
EXPECTED AS THE SYSTEM CROSSES SOUTHERN LUZON. WITH THE EXCEPTION OF
COAMPS-TC, DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH
THIS PORTION OF THE FORECAST WITH A SPREAD IN SOLUTIONS NEAR MANILA
AT TAU 72 OF ONLY 83-NM. THEREFORE, THERE IS VERY HIGH CONFIDENCE IN
THIS PHASE OF THE FORECAST TRACK.
   C. AFTER TAU 72, TY 30W IS FORECAST TO TURN SLIGHTLY WEST-
NORTHWESTWARD AS IT APPROACHES THE WESTERN EDGE OF THE STR. THE
SYSTEM WILL CONTINUE TO WEAKEN AS IT BEGINS TO INTERACT WITH COOLER,
DRIER AIR ASSOCIATED WITH THE NORTHEAST MONSOON SURGE, AND WILL
EVENTUALLY TURN SOUTHWESTWARD WITHIN THE DOMINANT NORTHEAST FLOW.
DYNAMIC MODEL GUIDANCE DIVERGES SLIGHTLY (BUT REMAINS IN GOOD
AGREEMENT) AS UNCERTAINTY INCREASES IN THE TIMING OF THE
SOUTHWESTWARD TRACK CHANGE. THE JTWC FORECAST TRACK IS POSITIONED
CLOSE TO THE MULTI-MODEL CONSENSUS AND REMAINS HIGHLY CONSISTENT
WITH THE PREVIOUS FORECASTS. OVERALL, THERE IS HIGH CONFIDENCE IN
THE JTWC FORECAST TRACK.//