WDPN31 PGTW 111500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W
/WARNING NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL DEPRESSION (TD) 08W, LOCATED APPROXIMATELY 775 NM
EAST-NORTHEAST OF ANDERSEN AB, HAS TRACKED WESTWARD AT 03 KNOTS OVER
THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS A
BROAD, ELONGATED LOW LEVEL CIRCULATION CENTER WITH ENHANCED, DEEP
CONVECTIVE BANDING ALONG THE SOUTHERN AND EASTERN QUADRANTS. A 110928Z
SSMIS MICROWAVE PASS CONFIRMS THE CURRENT POSITION WITH FAIR CONFIDENCE
AND ALSO SHOWS DEEP CONVECTION PRIMARILY ALONG THE AFOREMENTIONED
QUADRANTS. THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES
RANGING FROM 25 TO 30 KNOTS FROM PGTW AND KNES, AS WELL AS A 110742Z
PARTIAL WSAT PASS SHOWING 30 KNOT WINDS WRAPPING INTO THE LLCC IN THE
WESTERN QUADRANT. UPPER LEVEL ANALYSIS REVEALS THAT 08W IS LOCATED IN
A REGION OF STRONG DIFFLUENCE ALOFT AND LOW VERTICAL WIND SHEAR.
ANIMATED WATER VAPOR IMAGERY SHOWS GOOD EQUATORWARD OUTFLOW AS WELL AS
ENHANCED OUTFLOW INTO A TUTT CELL TO THE NORTHEAST. UPPER LEVEL
TROUGHING AND A TUTT CELL TO THE NORTHWEST OF THE SYSTEM CONTINUE TO
CAUSE SUBSIDENCE AND SUPPRESS CONVECTIVE DEVELOPMENT ALONG THE NORTHERN
PERIPHERY OF THE LLCC.
3. FORECAST REASONING.
A. THIS IS THE FIRST PROGNOSTIC REASONING BULLETIN.
B. TD 08W IS SLOWLY TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY
OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) AND IS FORECAST TO GRADUALLY
INTENSIFY AND TRACK GENERALLY WEST-NORTHWESTWARD THROUGH TAU 48. AVAILABLE
NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE TRACK FORECAST.
C. AFTER TAU 72, TD 08W WILL TRACK INCREASINGLY WESTWARD AND CONTINUE
TO INTENSIFY AS IT TRACKS OVER HIGH SEA SURFACE TEMPERATURES AND WITHIN
A FAVORABLE UPPER LEVEL ENVIRONMENT. NEAR TAU 120, INTERACTION WITH A
DEVELOPING TROPICAL DISTURBANCE EAST OF THE PHILIPPINES WILL CAUSE A SLIGHT
SOUTHWEST DIP IN THE FORECAST TRACK. OVERALL, NUMERICAL MODEL GUIDANCE IS
IN GOOD AGREEMENT WITH THE EXTENDED FORECAST TRACK, THEREFORE THE JTWC
TRACK FORECAST IS CLOSE TO MODEL CONSENSUS.//
NNNN
So a decent TD at last...
