Tropical Storm DUJUAN Advisory Sat Sep 26

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 21W (DUJUAN) WARNING NR 18//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 21W (DUJUAN), LOCATED APPROXIMATELY 361 NM SOUTH-
SOUTHEAST OF KADENA AB, HAS TRACKED NORTHWESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. RECENT ANIMATED MSI SHOWS TIGHTLY WRAPPED
CURVED BANDING INTO A LARGE 33-NM DIAMETER EYE. THIS LEADS TO HIGH
CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY HAS BEEN
RAISED TO 90 KNOTS BASED ON DVORAK INTENSITY ESTIMATES FROM ALL
AGENCIES. UPPER-LEVEL ANALYSIS INDICATES TY 21W REMAINS IN A
FAVORABLE ENVIRONMENT WITH LOW VWS BEING OFFSET BY GOOD OUTFLOW. TY
DUJUAN IS TRACKING SLOWLY ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP
LAYERED STR.
3. FORECAST REASONING.
   A. NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY DUJUAN WILL MAINTAIN A NORTHWESTWARD TRACK THROUGH THE END
OF THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF THE STR. DUE
TO PERSISTENT FAVORABLE ENVIRONMENTAL CHARACTERISTICS TO INCLUDE LOW
VWS, GOOD OHC AND GOOD OUTFLOW ALOFT, EXPECT CONTINUED
INTENSIFICATION THROUGH TAU 36 AT A CLIMATOLOGICAL RATE WITH A PEAK
OF 115 KNOTS. HOWEVER, BEYOND TAU 48, EXPECT TY DUJUAN TO BEGIN TO
WEAKEN DUE TO LOWER OHC, AN INCREASE IN VWS AND LAND INTERACTION
WITH THE MOUNTAINOUS TERRAIN OF TAIWAN. DUE TO THE HIGH LIKELIHOOD
OF A LEEWARD JUMP SCENARIO BETWEEN TAU 48 AND 72, THERE IS LIMITED
CONFIDENCE IN THE TAU 72 POSITION.
   C. TY 21W WILL DISSIPATE SIGNIFICANTLY AS IT MAKES LANDFALL IN
CHINA THROUGH THE EXTENDED FORECAST. DYNAMIC MODEL GUIDANCE IS IN
FAIRLY GOOD AGREEMENT THROUGHOUT THE FORECAST LEADING TO HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK.//
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