Tropical Storm MAYSAK Advisory Wed Apr 01

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 04W (MAYSAK) WARNING NR
21//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   SUPER TYPHOON (STY) 04W (MAYSAK), LOCATED APPROXIMATELY 76 NM NORTH-
NORTHWEST OF YAP, HAS TRACKED WEST-NORTHWESTWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE
SYSTEM HAS MAINTAINED A 20-NM AXIS-SYMMETRIC EYE THAT IS UNDERGOING
AN ANNULAR CYCLE: THE EYE IS SURROUNDED BY A UNIFORM RING OF DEEP
CONVECTION WITH A LACK OF CONVECTION OUTSIDE THE RING. THIS IS
READILY APPARENT ON A 312213Z 91 GHZ SSMIS COLOR COMPOSITE MICROWAVE
IMAGE. THE INITIAL POSITION IS BASED ON THE EYE FEATURE WITH HIGH
CONFIDENCE. THE INITIAL INTENSITY IS BASED ON AN OVERALL ASSESSMENT
OF CONCENTRIC DVORAK FIXES FROM PGTW, KNES, AND RJTD. UPPER LEVEL
ANALYSIS SHOWS THE SYSTEM IS IN AN AREA OF LOW (05 TO 10 KNOT)
VERTICAL WIND SHEAR (VWS). ADDITIONALLY, THE SYSTEM SUSTAINS ITS OWN
DIVERGENT POINT SOURCE ALOFT THAT IS PROVIDING EXCELLENT RADIAL
OUTFLOW. STY MAYSAK IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE
DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. STY 04W WILL CONTINUE TRACKING WEST-NORTHWESTWARD UNDER THE
INFLUENCE OF THE STEERING STR THROUGHOUT THE FORECAST PERIOD. AS
FAVORABLE ENVIRONMENTAL CONDITIONS PERSIST IN THE NEAR TERM, STY 04W
WILL LIKELY CONTINUE TO INTENSIFY OVER THE NEXT 12 HOURS, PEAKING AT
150 KNOTS. AFTERWARDS, EXPECT A WEAKENING TREND AS VWS INCREASES WITH
THE APPROACH OF A MID-LATITUDE TROUGH FROM THE NORTHWEST.
   C. IN THE EXTENDED TAUS, STY MAYSAK WILL CONTINUE TO WEAKEN AS
IT ENCOUNTERS UPPER-LEVEL CONVERGENCE AND INCREASING VWS ASSOCIATED
WITH THE AFOREMENTIONED TROUGH. HOWEVER, WHEN THE CYCLONE MAKES
LANDFALL SHORTLY NEAR TAU 96 OVER NORTHERN LUZON, PHILIPPINES, NEAR
PALANAN, ISABELA, IT WILL BE AN INTENSE 90-KNOT TYPHOON. MAYSAK WILL
THEN EMERGE IN THE SOUTH CHINA SEA WEAKENED BY THE ROUGH TERRAIN BUT
STILL AT A STRONG TROPICAL STORM INTENSITY. DYNAMIC NUMERICAL MODEL
GUIDANCE REMAINS IN OVERALL TIGHT AGREEMENT, LENDING HIGH CONFIDENCE
IN THE JTWC TRACK FORECAST WHICH IS LAID CLOSE TO THE MULTI-MODEL
CONSENSUS.//
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