Tropical Storm NOUL Advisory Tue May 05

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (NOUL) WARNING NR
11//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 06W (NOUL), LOCATED APPROXIMATELY 30 NM EAST
OF YAP, HAS TRACKED WESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A SLIGHT
DEEPENING OF THE CENTRAL DENSE OVERCAST (CDO) WITH CURVED CONVECTIVE
BANDING LOCATED ALONG THE NORTHERN AND WESTERN PERIPHERIES. A
050910Z SSMIS 91GHZ MICROWAVE IMAGE DEPICTS A MICROWAVE EYE FEATURE
WITH BROKEN DEEP CURVED CONVECTIVE BANDING. THE INITIAL POSITION IS
BASED ON THE AFOREMENTIONED MICROWAVE EYE FEATURE WITH HIGH
CONFIDENCE. THE INITIAL INTENSITY OF 60 KNOTS IS HEDGED SLIGHTLY
HIGHER THAN DVORAK INTENSITY ESTIMATES OF T3.5 (55 KNOTS) FROM PGTW
AND KNES BASED ON THE IMPROVED MICROWAVE EYE FEATURE AND THE COOLING
CLOUD TOPS ASSOCIATED WITH THE CDO. UPPER LEVEL ANALYSIS INDICATES A
FAVORABLE ENVIRONMENT WITH LOW (5-10 KNOT) VERTICAL WIND SHEAR
(VWS); HOWEVER, ONLY WEAK DIVERGENT OUTFLOW IS AVAILABLE WHICH IS
LIMITING INTENSIFICATION. TS 06W IS CURRENTLY MOVING SLOWLY WESTWARD
IN A WEAK STEERING ENVIRONMENT AS THE SYSTEM TRANSITIONS TO A
BUILDING SUB-TROPICAL RIDGE (STR) TO THE NORTHWEST.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS NOUL WILL MOVE SLOWLY WEST-NORTHWESTWARD OVER THE NEXT 12
TO 18 HOURS AS THE SYSTEM COMPLETES TRANSITION TO THE BUILDING STR.
THIS STR WILL BE THE DOMINANT STEERING MECHANISM THROUGHOUT THE
FORECAST PERIOD. UPPER LEVEL ENVIRONMENTAL CONDITIONS WILL REMAIN
MOSTLY UNCHANGED OVER THE NEXT 24 HOURS LEADING TO SLOW
INTENSIFICATION. BEYOND TAU 24, TS 06W WILL PICK UP TRANSLATIONAL
SPEED AND MOVE DOWNSTREAM FROM THE STR AXIS, WHERE POLEWARD OUTFLOW
WILL INCREASE ALLOWING TS NOUL TO INTENSIFY AT A QUICKER RATE.
   C. BEYOND TAU 72, TS 06W WILL BEGIN TO ROUND THE SOUTHWESTERN
PERIPHERY OF THE STEERING STR AND TRANSITION TO A MORE NORTHWESTWARD
TRACK. ENVIRONMENTAL CONDITIONS WILL REMAIN UNCHANGED THROUGH THE
REMAINDER OF THE FORECAST PERIOD, CONTINUING THE STEADY
INTENSIFICATION THROUGH TAU 96. DYNAMIC MODEL GUIDANCE HAS CONTINUED
TO IMPROVE, NOW WITH A 120NM SPREAD AT TAU 72 AND A 240NM SPREAD AT
TAU 120; WITH NO SIGNIFICANT OUTLIERS. DUE TO THE IMPROVING MODEL
SPREAD AND RECENT STABILITY IN THE MULTI-MODEL CONSENSUS, THERE IS
NOW HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.//
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