WDPN35 PGTW 180300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W (SOULIK) 
WARNING NR 11//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 22W (SOULIK), LOCATED APPROXIMATELY 72 NM WEST OF IWO TO,
HAS TRACKED NORTHWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED 
MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN EMERGING EYE FEATURE AND 
IMPROVING POLEWARD OUTFLOW. THE INITIAL POSITION IS PLACED WITH HIGH 
CONFIDENCE BASED ON THE EYE FEATURE IN MULTISPECTRAL SATELLITE 
IMAGERY, AS WELL AS A DIMPLE FEATURE IN A 172145Z SSMIS 37GHZ IMAGE. 
THE CURRENT INTENSITY IS ASSESSED AT 90 KNOTS, IN LINE WITH THE PGTW 
DVORAK CURRENT INTENSITY ESTIMATE OF T5.0 (90 KTS), BETWEEN THE KNES 
AND RJTD ESTIMATES OF T6.0 (115 KTS) AND T4.5 (77 KTS), 
RESPECTIVELY. UPPER-LEVEL ANALYSIS REVEALS A VERY FAVORABLE 
ENVIRONMENT WITH LOW VERTICAL WIND SHEAR (5-10 KTS), WARM SEA 
SURFACE TEMPERATURES (29-30 CELSIUS), AND NEAR-RADIAL OUTFLOW BEING 
AIDED BY TUTT CELLS TO THE EAST AND WEST AND A MIDLATITUDE LONGWAVE 
TROUGH PASSING TO THE NORTH, WHICH HAS ALLOWED TY 22W TO STEADILY 
INTENSIFY. TY 22W IS TRACKING SLOWLY NORTHWARD IN A WEAK STEERING 
ENVIRONMENT, AS THE STEERING SUBTROPICAL RIDGE TO ITS EAST HAS 
TEMPORARILY BEEN ERODED BY THE PASSING LONGWAVE TROUGH.  
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE 
PREVIOUS PROGNOSTIC REASONING MESSAGE. 
   B. AS THE MIDLATITUDE TROUGH PASSES THROUGH, THE STR WILL RECEDE 
TO THE EAST, ENABLING TY 22W TO CONTINUE ITS PERIOD OF SLOW 
NORTHWARD OR EVEN QUASI-STATIONARY MOTION. AFTER TAU 24, THE TROUGH 
IS FORECAST TO PROPAGATE NORTHEASTWARD OUT OF THE AREA, WHICH WILL 
ALLOW THE STR TO RE-BUILD AND ACCELERATE TY 22W WEST-NORTHWESTWARD 
TO NORTHWESTWARD TOWARD KYUSHU. DUE TO THE ROBUST OUTFLOW, TY 22W 
WILL CONTINUE TO INTENSIFY, ALTHOUGH THE RATE OF INTENSIFICATION 
WILL SLOW ONCE THE TROUGH MOVES OUT OF THE AREA AND DEPRIVES 22W OF 
SIGNIFICANT POLEWARD OUTFLOW. AFTER TAU 48, TY 22W WILL START A 
GRADUAL WEAKENING TREND. NUMERICAL MODEL GUIDANCE AND THE MULTI-
MODEL CONSENSUS HAVE SHIFTED TO THE SOUTH, BUT REMAIN IN TIGHT 
AGREEMENT THROUGH TAU 72, DEPICTING A WEST-NORTHWESTWARD TRACK. 
THEREFORE, CONFIDENCE IN THE JTWC TRACK FORECAST IS HIGH THROUGH TAU 
72.   
   C. AFTER TAU 72, A SHORTWAVE TROUGH IS FORECAST TO MOVE INTO THE 
AREA, ERODING THE STR AND ALLOWING TY 22W TO RECURVE AROUND TAU 96. 
MODEL TRACKERS AND THE MULTI-MODEL CONSENSUS HAVE SHIFTED TO THE 
SOUTH OF THE PREVIOUS FORECAST TRACK, RANGING BETWEEN AMAMI OSHIMA 
ISLAND AND THE SOUTHERN END OF KYUSHU AT TAU 96. NAVGEM AND ECMWF 
REMAIN THE SOUTHWESTERN OUTLIERS, PREDICTING A MORE WESTWARD TRACK, 
AND TAKE LONGER TO RECURVE TY 22W. ECMWF AND NAVGEM DEPICT THE 
AFOREMENTIONED SHORTWAVE TROUGH AS MUCH WEAKER THAN IS SHOWN IN GFS, 
RESULTING IN THE STR BEING MAINTAINED AND TY 22W TRACKING MORE 
WESTWARD IN THE ECMWF AND NAVGEM SOLUTIONS, ONLY REACHING ITS 
RECURVE POINT AT TAU 120. LAND INTERACTION WITH KYUSHU WILL 
CONTRIBUTE TO WEAKENING TY 22W BETWEEN TAU 72-96, ALTHOUGH THE NEW 
FORECAST TRACK TAKES 22W MORE OVER WATER THAN PREVIOUSLY FORECAST. 
HOWEVER, THERE IS STILL A MODERATE AMOUNT OF UNCERTAINTY IN THE 
TIMING OF THE RECURVE AND ASSOCIATED TRACK SPEEDS? THERE IS 
CURRENTLY A 400 NM CROSS-TRACK SPREAD IN SOLUTIONS NEAR SASEBO AT 
TAU 96 BETWEEN NAVGEM TO THE SOUTH AND HWRF ACCELERATING TO THE 
NORTH. TY 22W WILL BRIEFLY TAP INTO THE PASSING TROUGH, ENHANCING 
OUTFLOW. AFTER TAU 96, COOLING SSTS AND INCREASING VERTICAL WIND 
SHEAR AND BAROCLINICTY FROM THE MIDLATITUDE TROUGH WILL FURTHER 
WEAKEN TY 22W AND CONTRIBUTE TO IT BEGINNING EXTRATROPICAL 
TRANSITION AT TAU 120. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC 
TRACK FORECAST DUE TO SIGNIFICANT DIFFERENCES IN THE TIMING AND 
LOCATION OF THE RECURVE, AND IN TRACK SPEED IN THE EXTENDED PERIOD.//
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