
WDPN31 PGTW 192100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 23W (CIMARON) WARNING
NR 09//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 23W (CIMARON), LOCATED APPROXIMATELY 232 NM EAST-
NORTHEAST OF SAIPAN, HAS TRACKED NORTHWESTWARD AT 12 KNOTS OVER
THE PAST SIX HOURS. THE INITIAL POSITION IS PLACED WITH LOW
CONFIDENCE BASED ON INFLOW WRAPPING INTO AN OBSCURED LOW LEVEL
CIRCULATION CENTER (LLCC) IN ENHANCED INFRARED SATELLITE IMAGERY,
AND IN A 191813Z SSMIS 91GHZ MICROWAVE IMAGE. THE AFOREMENTIONED
SSMIS IMAGE HIGHLIGHTS THE IMPROVED OUTFLOW AND CONVECTIVE BANDING.
THE CURRENT INTENSITY IS ASSESSED AT 60 KNOTS, SLIGHTLY ABOVE THE
PGTW AND KNES DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55 KTS),
BASED ON IMPROVING OUTFLOW, AND AGREES WITH A 191538Z SATCON
ESTIMATE OF 62 KTS. WARM SEA SURFACE TEMPERATURES (29-30 C), ROBUST
EQUATORWARD OUTFLOW, AND A REDUCTION IN VERTICAL WIND SHEAR TO 15-20
KTS HAVE ENABLED INTENSIFICATION. A TUTT CELL TO THE EAST IS
ENHANCING POLEWARD OUTFLOW AND FUELING CONVECTION. THE CYCLONE IS
TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE
(STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 23W IS FORECAST TO TRACK NORTHWESTWARD ALONG THE WESTERN
PERIPHERY OF THE STR THROUGH TAU 72. STEADY INTENSIFICATION IS
EXPECTED AS VWS HAS EASED OVER THE SYSTEM AND AS THE TUTT CELL TO
THE EAST CONTINUES TO ENHANCE OUTFLOW, WITH 23W REACHING A PEAK OF
80 KTS BY TAU 36. AFTER TAU 48, 23W WILL BEGIN TO WEAKEN SLIGHTLY
AFTER TAU 48, AS 23W MOVES AWAY FROM THE TUTT CELL AND ITS OUTFLOW
IS REDUCED. NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT ON STORM
TRACK. THE JTWC FORECAST TRACK IS PLACED CLOSE TO THE MULTI-MODEL
CONSENSUS WITH HIGH CONFIDENCE.
C. AFTER TAU 72, THE CYCLONE WILL BEGIN A GRADUAL TURN NORTHWARD
AND TRACK NORTH-NORTHEASTWARD BY TAU 120 AS IT ROUNDS THE STR AXIS
AND BEGINS TO UNDERGO EXTRATROPICAL TRANSITION (ETT). UNCERTAINTY IN
THE TRACK CONTINUES TO GROW AS THE DEGREE OF TURNING AND THE ALONG-
TRACK SPEED VARIES CONSIDERABLY AMONG THE MODELS, ALTHOUGH THE MULTI-
MODEL CONSENSUS TRACK HAS REMAINED CONSISTENT OVER THE PAST SEVERAL
RUNS. 23W WILL WEAKEN MORE RAPIDLY AS IT TRACKS OVER HONSHU INTO
COOLER WATER IN THE SEA OF JAPAN AND INTERACTS WITH A PASSING
MIDLATITUDE TROUGH AND THE REMNANTS OF TY 22W. THE JTWC INTENSITY
FORECAST IS PLACED IN AGREEMENT WITH THE INTENSITY CONSENSUS. THE
JTWC FORECAST TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS
WITH LOW CONFIDENCE.//
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