Tropical Storm MEKKHALA Advisory Sun Jan 18

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 01W (MEKKHALA) WARNING
NR 20//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 01W (MEKKHALA), LOCATED APPROXIMATELY 94 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-
NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM CONTINUING TO
DECAY DUE TO LAND INTERACTION WITH CALABARZON. THE INITIAL
 POSITION IS BASED ON THE MSI ANIMATION WITH LOW CONFIDENCE DUE TO
THE LOW LEVEL CIRCULATION CENTER BEING DISPLACED TO THE SOUTH OF THE
DEEP CONVECTION. THE INITIAL INTENSITY OF 35 KNOTS IS EXTRAPOLATED
FROM NEARBY SURFACE OBSERVATIONS. UPPER-LEVEL ANALYSIS DEPICTS
A MARGINAL ENVIRONMENT CHARACTERIZED BY STRONG (20 TO 30 KNOT)
SOUTHERLY VERTICAL WIND SHEAR (VWS) PARTLY OFFSET BY GOOD POLEWARD
OUTFLOW. THE CYCLONE IS CURRENTLY TRACKING ALONG THE SOUTHWESTERN
PERIPHERY OF A SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. EXPECT TS MEKKHALA WILL CONTINUE TO TRACK TO THE NORTHWEST
UNDER THE INFLUENCE OF THE AFOREMENTIONED STR. EXPECT FURTHER DECAY
OF THE SYSTEM AS THE VWS INCREASES AND TS 01W CONTINUES TO RUN OVER
THE MOUNTAINOUS TERRAIN OF EASTERN CENTRAL LUZON. THE SYSTEM WILL
EVENTUALLY DISSIPATE OVER NORTHERN CENTRAL LUZON BY TAU 36. MODEL
GUIDANCE CONTINUES TO HAVE A FAIRLY LARGE SPREAD BEYOND TAU 12 DUE
TO THE WEAKNESS OF THE SYSTEM WHICH LEADS TO LOW CONFIDENCE IN THE
JTWC TRACK.//
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