Rapid intensification continues...
WDPN35 PGTW 170900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W (SOULIK)
WARNING NR 08//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 22W (SOULIK), LOCATED APPROXIMATELY 111 NM SOUTH-
SOUTHWEST OF IWO TO, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 16
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A RAPIDLY-CONSOLIDATING SYSTEM WITH TIGHTLY-CURVED
BANDING WRAPPING INTO A WELL-DEFINED CENTER. A 170606Z SSMIS 37GHZ
COLOR IMAGE DEPICTS A THICK CYAN RING FEATURE, A TYPICAL PRECURSOR
TO AN IMMINENT RAPID INTENSIFICATION PHASE, SURROUNDING A ROUND
MICROWAVE EYE FEATURE. CONSEQUENTLY, THERE IS GOOD CONFIDENCE IN THE
INITIAL POSITION. TY 22W HAS RAPIDLY INTENSIFIED 30 KNOTS OVER THE
PAST 24 HOURS, INCREASING FROM 45 KNOTS TO THE CURRENT INTENSITY OF
75 KNOTS, WHICH IS BASED ON DVORAK INTENSITY ESTIMATES OF T4.5 FROM
KNES AND PGTW. UPPER-LEVEL ANALYSIS REVEALS A VERY FAVORABLE
ENVIRONMENT WITH RADIAL OUTFLOW ENHANCED BY TWO TUTT CELLS AND A
DEEP MIDLATITUDE SHORTWAVE TROUGH DIGGING EAST OF HONSHU. TY 22W IS
TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL
RIDGE (STR) TO THE EAST, TOWARD A BREAK IN THE STR ASSOCIATED WITH
THE AFOREMENTIONED DEEP SHORTWAVE TROUGH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE. PEAK INTENSITY HAS SHIFTED TO
TAU 48.
B. THE MIDLATITUDE SHORTWAVE TROUGH IS FORECAST TO LINGER EAST OF
HONSHU THROUGH TAU 24, WHICH WILL MAINTAIN A LARGE BREAK IN THE STR
RESULTING IN SLOW TRACK SPEEDS AND POSSIBLY A BRIEF PERIOD OF QUASI-
STATIONARY TRACK MOTION. AFTER TAU 24, THE SHORTWAVE TROUGH IS
FORECAST TO PROPAGATE NORTHEASTWARD, WHICH WILL ALLOW THE STR TO RE-
BUILD AND ACCELERATE TY SOULIK WEST-NORTHWESTWARD TO NORTHWESTWARD
TOWARD KYUSHU. DUE TO THE ROBUST OUTFLOW, TY 22W WILL CONTINUE TO
RAPIDLY CONSOLIDATE WITH A PEAK INTENSITY OF 115 KNOTS FORECASTED AT
TAU 48. NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU
72 WITH A 115NM SPREAD IN SOLUTIONS AT TAU 72. THEREFORE, CONFIDENCE
IS HIGH THROUGH TAU 72.
C. AFTER TAU 72, TY SOULIK IS EXPECTED TO RE-CURVE OVER OR TO THE
WEST OF KYUSHU AND BEGIN EXTRA-TROPICAL TRANSITION NEAR TAU 120.
GRADUAL WEAKENING IS FORECASTED BY TAU 96 AS TY 22W APPROACHES
KYUSHU DUE TO INCREASED INTERACTION WITH LAND AND SIGNIFICANT
WEAKENING AS IT TRACKS ACROSS KYUSHU. WITH THE EXCEPTION OF NAVGEM,
ALL MODELS INDICATE A RE-CURVE SCENARIO INTO THE EAST SEA, HOWEVER,
TRACK SPEEDS VARY. THE CROSS-TRACK SPREAD IN MODELS NEAR SASEBO IS
ONLY 150NM, WHICH IS REMARKABLY GOOD FOR A RE-CURVE SCENARIO. A
DETAILED ANALYSIS OF NAVGEM FIELDS REVEALS MAJOR DIFFERENCES FROM
THE OTHER MODELS. NAVGEM INDICATES A MORE WEST-NORTHWESTWARD TRACK
DESPITE A SUBSTANTIAL BREAK IN THE STR SIMILAR TO THE OTHER MODELS.
NAVGEM THEN TRACKS A DEVELOPING SYSTEM (INVEST 91W) QUICKLY POLEWARD
WITH A POSITION JUST SOUTH OF SHIKOKU AND BUILDS THE STR NORTH OF
THE SYSTEM, WHICH EFFECTIVELY BLOCKS TY 22W FROM RE-CURVING. THIS
SCENARIO IS ASSESSED AS UNLIKELY. OVERALL, THERE IS LOW CONFIDENCE
IN THE JTWC FORECAST DUE TO UNCERTAINTY IN THE TIMING OF THE RE-
CURVE AND SIGNIFICANT DIFFERENCES IN TRACK SPEEDS AFTER TAU 72.//
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