Tropical Storm GUCHOL Advisory Tue Jun 12

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (FIVE) WARNING
NR 05//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 05W (FIVE), LOCATED APPROXIMATELY 210 NM
SOUTH-SOUTHWEST OF GUAM, HAS TRACKED WESTWARD AT 09 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
IMPROVED CONVECTIVE BANDING WRAPPING INTO A LOW LEVEL CIRCULATION
CENTER. THE INITIAL POSITION WAS INTERPOLATED FROM A CONVECTIVE HOOK
IN A 112006Z TRMM MICROWAVE IMAGE WITH FAIR CONFIDENCE. THE INITIAL
INTENSITY IS BASED ON THE PGTW AND KNES DVORAK ESTIMATES OF 35
KNOTS. UPPER LEVEL ANALYSIS INDICATES A BAND OF DRY, CONVERGENT FLOW
TO THE NORTH AND NORTHWEST IS INHIBITING OUTFLOW. THERE IS WEAK
OUTFLOW INTO A FILLING TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT)
CELL TO THE NORTHEAST. TS 05W IS CURRENTLY TRACKING WESTWARD ALONG
THE SOUTHERN PERIPHERY OF A DEEP, EAST-WEST ORIENTED SUBTROPICAL
RIDGE (STR) POSITIONED TO THE NORTH. UPPER-AIR SOUNDINGS FROM GUAM,
KOROR AND YAP INDICATE EASTERLY FLOW AND SUPPORT THE MODEL DEPICTION
OF THE STR.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TS 05W IS FORECAST TO TRACK WESTWARD TO WEST-NORTHWESTWARD
DURING THE INITIAL FORECAST TIME PERIOD. THERE IS HIGH CONFIDENCE IN
THIS TRACK DUE TO THE TIGHT MODEL PACKING. HOWEVER, THE UKMO AND
NOGAPS MODELS TRACK THE SYSTEM FURTHER NORTHWARD, WHICH IS UNLIKELY
DUE TO THE ANALYZED STRONG RIDGE TO THE NORTH. THIS FORECAST FAVORS
A GRADUAL INTENSIFICATION AS IT TRACKS OVER WARM WATER AND OUTFLOW
IMPROVES INTO AN APPROACHING MID-LATITUDE TROUGH.
   C. IN THE EXTENDED PERIOD, TS 05W IS FORECAST TO TRACK MORE
NORTHWESTWARD AS IT ROUNDS THE SOUTHWESTERN PERIPHERY OF THE STR AND
BEGINS TO TURN MORE POLEWARD AHEAD OF THE APPROACHING MID-LATITUDE
TROUGH EXPECTED TO DEEPEN OVER EASTERN CHINA NEAR TAU 72. AVAILABLE
MODEL GUIDANCE DIVERGES AROUND TAU 72 AND THERE IS LOW CONFIDENCE IN
THE RE-CURVE POINT. NOGAPS TURNS THE SYSTEM POLEWARD AT TAU 96,
WHICH IS UNLIKELY DUE TO THE STRONG STR. THE JTWC FORECAST IS IN
AGREEMENT WITH MODEL CONSENSUS BUT POSITIONED SLIGHTLY LEFT OF
CONSENSUS TO OFF-SET THE UNLIKELY UKMET AND NOGAPS SOLUTIONS,
FAVORING A MORE WESTWARD TRACK. THE INTENSITY FORECAST IS IN
AGREEMENT WITH INTENSITY MODEL GUIDANCE.//
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