WDPN31 PGTW 040900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 03W (HAGUPIT)
WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 03W (HAGUPIT), LOCATED APPROXIMATELY 104 NM
SOUTHWEST OF SHANGHAI, CHINA, HAS TRACKED NORTHWARD AT 10 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
AN OBSCURED LOW LEVEL CIRCULATION (LLC) WITH PERSISTENT CONVECTION THAT
IS BECOMING INCREASINGLY SHEARED TO THE SOUTHEAST OF THE LOW LEVEL
CIRCULATION CENTER. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE LLC FEATURES PRESENT IN A 040206Z AMSU
COMPOSITE IMAGE AND THE COMPOSITE RADAR LOOP. THE INITIAL INTENSITY
OF 30 KNOTS IS PLACED WITH FAIR CONFIDENCE BASED ON NEARBY SURFACE
OBSERVATIONS FROM SHENGXIAN 30 NM TO THE EAST-SOUTHEAST, HANGZHOU
27 NM TO THE NORTH-NORTHEAST AND QU XIAN 80 NM TO THE SOUTHWEST. THE
ENVIRONMENT IS HOSTILE AND WILL LEAD TO FURTHER WEAKENING AS TD HAGUPIT
CONTINUES TO MOVE INLAND OVER RUGGED TERRAIN AND UNDER MODERATE (20-25
KTS) VERTICAL WIND SHEAR. ADDITIONALLY, MUCH OF THE SYSTEM'S UPPER
LEVEL SUPPORT HAS ERODED OVER THE PAST 6 HOURS. TD 03W IS TRACKING
ALONG THE WESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR)
TO THE EAST-NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD HAGUPIT WILL CONTINUE TO TRACK NORTHWARD THROUGH THE NEXT 12
HOURS OVER THE RAGGED TERRAIN OF EASTERN CHINA AND BEGIN TO ROUND THE
STR AXIS AS IT PASSES WEST OF SHANGHAI. STRONG (25+ KTS) VWS AND THE
FRICTIONAL EFFECTS OF THE TERRAIN WILL LEAD TO CONTINUED WEAKENING TO
25 KTS BY TAU 12. AFTER TAU 12, THE SYSTEM WILL BEGIN TO TRACK NORTH-
NORTHEASTWARD AND ENTER THE YELLOW SEA. COOL (<26 CELSIUS) SEA SURFACE
TEMPERATURES AND THE HOSTILE SHEAR ENVIRONMENT WILL LEAD TO FURTHER
WEAKENING TO 20 KTS AND DISSIPATION OVER WATER BY TAU 36. NUMERICAL
MODELS ARE IN TIGHT AGREEMENT BUT GIVEN THE UNCERTAINTY OF LAND
PASSAGE, THERE IS MODERATE CONFIDENCE IN THE FORECAST TRACK, WHICH IS
POSITIONED NEAR THE MULTI-MODEL CONSENSUS.//
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