Tropical Storm MAYSAK Advisory Sat Mar 28

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 04W (FOUR) WARNING
NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 04W (FOUR), LOCATED APPROXIMATELY 48 NM
WEST OF POHNPEI, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX
HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS
DEEPENED CENTRAL CONVECTION WITH FORMATIVE BANDS WRAPPING INTO A
CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC). A 270518Z SSMIS
MICROWAVE IMAGE REVEALS CONVECTIVE BANDING OVER THE NORTHERN SEMI-
CIRCLE WRAPPING INTO THE LLCC. THE CURRENT POSITION IS BASED ON THE
MSI AND SATELLITE FIXES FROM PGTW AND RJTD WITH FAIR CONFIDENCE. THE
INITIAL INTENSITY OF 30 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF
DVORAK INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES. UPPER-LEVEL
ANALYSIS INDICATES THE SYSTEM REMAINS IN AN AREA OF MODERATE (15 TO
20 KNOT) VERTICAL WIND SHEAR (VWS) BEING OFFSET BY EXCELLENT
POLEWARD OUTFLOW, AS EVIDENT ON THE WATER VAPOR IMAGERY. TD 04W IS
TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF AN EXTENSIVE
SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TD 04W WILL CONTINUE TRACKING ALONG THE SOUTHERN PERIPHERY OF
THE CURRENT STEERING STR THROUGH TAU 72. STEADY INTENSIFICATION IS
ANTICIPATED DUE TO STRONG DIFFLUENCE ALOFT AND PASSAGE OVER VERY
WARM WATER.
   C. AFTER TAU 72, WEST-NORTHWESTWARD MOTION IS EXPECTED AS TD 04W
IS UNDER THE STEERING INFLUENCE OF A WEAKNESS IN THE STR. STEADY
INTENSIFICATION IS ALSO ANTICIPATED AS VWS DECREASES AND OTHER
FAVORABLE FACTORS REMAIN IN PLACE. GIVEN THE STRAIGHTFORWARD
STEERING SCENARIO AND TIGHT MODEL AGREEMENT, JTWC TRACK FORECAST
CONFIDENCE LEVEL REMAINS HIGH.//
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