Tropical Storm SARIKA Advisory Fri Oct 14

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 24W (TWENTY-FOUR)
WARNING NR 04//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION 24W (TWENTYFOUR), LOCATED APPROXIMATELY 495
NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 06
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A PARTIAL 0359Z AMSR2 IMAGE DEPICTS A VERY BROAD LOW
LEVEL CIRCULATION CENTER, GIVING LOW CONFIDENCE TO THE INITIAL
POSITION, AND A BAND OF DEEP CONVECTION WRAPPING IN FROM THE
NORTHWEST QUADRANT. THE INITIAL INTENSITY ESTIMATE OF 30 KNOTS IS
BASED ON DVORAK ESTIMATES FROM ALL AGENCIES REPORTING T2.0 (30
KNOTS). UPPER-LEVEL ANALYSIS SHOWS IMPROVING OUTFLOW AS TD 24W IS
TAPPING INTO A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) LOCATED TO
THE NORTHWEST, HOWEVER ANOTHER TUTT CELL LOCATED TO THE NORTH EAST
IS SETTING UP HINDERING EASTERN OUTFLOW. SEA SURFACE TEMPERATURES
ARE VERY FAVORABLE BETWEEN 30 AND 31 CELSIUS. CURRENTLY TD 24W IS
TRACKING SLOWLY ALONG THE PERIPHERY OF A WEAK EXTENSION OF A DEEP-
LAYERED EAST-WEST ORIENTED SUBTROPICAL RIDGE EXTENDING ACROSS THE
ENTIRE WESTERN PACIFIC.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TD 24W WILL CONTINUE TO TRACK SLOWLY WEST-NORTHWESTWARD ALONG
THE RIDGE EXTENSION TROUGH TAU 48. BY TAU 48 THE FAR WESTWARD
PORTION OF THE RIDGE ARM WILL BUILD, DEVELOPING INTO THE DOMINANT
STEERING RIDGE MOVING NORTH OF LUZON AND ACCELERATING TD 24W
WESTWARD. STEADY INTENSIFICATION IS EXPECTED TROUGH TAU 60 AS
CONDITIONS IMPROVE, LARGELY BY THE EASTERN POSITIONED TUTT CELL
FILLING IN AND HAVING LESS INFLUENCE ON OUTFLOW. SOMETIME BETWEEN
TAU 60 AND 72 THE SYSTEM IS EXPECTED TO MAKE LANDFALL OVER LUZON AS
A TYPHOON.
   C. IN THE EXTENDED FORECAST TD 24W IS EXPECTED TO RESURFACE OVER
THE SOUTH CHINA SEA WEAKENED BUT LARGELY INTACT. THE STEERING RIDGE
WILL BE FULLY DEVELOPED AND CONTINUE TO TRACK TD 24 WESTWARD.
ENVIRONMENTAL CONDITIONS WILL BE FAVORABLE SUPPORTING A PEAK
INTENSITY OF 90 KNOTS BY TAU 120. DYNAMIC MODEL GUIDANCE IS SOMEWHAT
DIVERGENT IN BOTH TRACK AND SPEED DURING THE NEAR FORECAST DUE TO
THE WEAK STEERING PROVIDED BY THE RIDGE EXTENSION. THIS PLACES A
LARGE UNCERTAINTY WHERE THE SYSTEM WILL BE BY TAU 48, AND THE
RESULTANT TRACK AS THE DOMINANT RIDGE BUILDS. DUE TO THIS
UNCERTAINTY THERE IS LOW CONFIDENCE IN THE FORECAST TRACK.//
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