Tropical Storm DOLPHIN Advisory Mon May 18

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (DOLPHIN) WARNING NR 48//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 07W (DOLPHIN), LOCATED APPROXIMATELY 203 NM SOUTHWEST
OF IWO TO, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 08 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
SHOWS THE SYSTEM CONTINUES TO DEGRADE AND ELONGATE AS IT GETS
EMBEDDED DEEPER INTO THE STRONG MID-LATITUDE WESTERLIES. HOWEVER, A
STRONG POLEWARD OUTFLOW CONTINUES TO PROVIDE VENTILATION TO THE
ASSOCIATED CONVECTION. THE INITIAL POSITION IS BASED ON A RAGGED
MICROWAVE EYE FEATURE IN THE 180951Z 37 GHZ F18 IMAGE. THE INITIAL
INTENSITY OF 90 KNOTS IS BASED ON CONGRUENT DVORAK ESTIMATES FROM
PGTW AND KNES. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS NOW
FIRMLY ON THE POLEWARD SIDE OF THE SUBTROPICAL RIDGE IN AN AREA OF
INCREASING VERTICAL WIND SHEAR (UPWARDS OF 30 KNOTS).
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY DOLPHIN WILL BEGIN TO ACCELERATE NORTHEASTWARD AND DEEPER
INTO THE COLD BAROCLINIC AIRMASS AND BEGIN EXTRA TROPICAL TRANSITION
BY TAU 24. INCREASING VERTICAL WIND SHEAR AND COOLING SEA SURFACE
TEMPERATURES WILL RAPIDLY ERODE THE SYSTEM WITH THE INTENSITY
DROPPING TO A STORM-FORCE COLD CORE LOW BY TAU 48. THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH LIES SLIGHTLY AHEAD OF
THE MULTI-MODEL CONSENSUS GIVEN EXPECTATIONS FOR VERY STRONG
UPPER-LEVEL STEERING FLOW.//
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