WDPN31 PGTW 022100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (KIROGI) WARNING 
NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 29.3N 142.8E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 709 NM EAST-SOUTHEAST OF SASEBO, JAPAN
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 19 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED CIRA PROXY VISIBLE ENHANCEMENT OF HIMAWARI-9 IMAGERY
DEPICTS THE GRADUAL DEFORMATION OF AN EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC) WITH PATCHY, DEEP CONVECTION FUELED BY NIGHTTIME
COOLING ALOFT FLARING TO THE NORTH AND ALONG A GROWING TAIL
STRETCHING TO THE SOUTHEAST. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON MULTI-AGENCY FIXES OF THE EXPOSED LLCC,
WITH A 021636Z VIIRS NIGHT TIME VISIBLE IMAGE ADDING ADDITIONAL
DETAIL TO HELP INTERPRET THE PROXY VISIBLE IMAGERY. BASED ON THIS
POSITION, THE TRACK APPEARS TO BE TURNING TOWARD THE
WEST-NORTHWEST, AS EXPECTED. THE INITIAL INTENSITY OF 30 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON MULTI-AGENCY SUBJECTIVE
DVORAK CURRENT INTENSITY VALUES IN THE 25-30 KNOT RANGE, WHILE
OBJECTIVE ESTIMATES RANGE FROM 31 TO 39 KNOTS. THE RECENT ASCAT
CASE MISSED THE CENTER. WHILE A 021903Z SSMIS 37 GHZ COLOR IMAGE
SHOWS A POCKET OF STRONG CONVECTION TO THE NORTHEAST WHICH MAY CONTAIN 
HIGHER WINDS, THIS AREA IS OUTSIDE THE ASSESSED RADII OF OUTERMOST 
CLOSED ISOBAR AND NOT CONSIDERED REPRESENTATIVE OF THE LLCC. TD KIROGI 
IS WEAKENING STEADILY UNDER THE INFLUENCE OF STRONG SOUTHERLY VERTICAL 
WIND SHEAR.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: LOW TO MID LEVEL SUB-TROPICAL RIDGING
TO THE EAST AND NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T1.5 - 25 KTS
   KNES: T1.5 - 25 KTS
   CIMSS ADT: 33 KTS AT 021740Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 25-30 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL DEPRESSION 11W WILL CONTINUE ITS TURN
TO PUT IT ON A WESTWARD TRACK OVER THE NEXT 12 TO 24 HOURS AS IT
FOLLOWS THE FLOW BETWEEN SUB-TROPICAL RIDGING TO THE EAST AND NORTH
AND A DEEP TROUGH TO THE WEST AND SOUTH. TRANSIENT DEEP CONVECTION
ASSOCIATED WITH THE CIRCULATION, SUPPORTED BY DIVERGENT FLOW ALOFT,
WILL LIKELY CONTINUE TO FLAIR, HOWEVER, PROXIMITY AND ALIGNMENT
WITH THE TROUGH WILL CONTINUE TO PROVIDE UNFAVORABLE VERTICAL WIND
SHEAR, DRIVING DISSIPATION BY TAU 48. 

MODEL DISCUSSION: THROUGHOUT THE FORECAST PERIOD, MULTI-MODEL
CONSENSUS ALONG-TRACK SPREAD IS GENERALLY LOW, REACHING 75 NM AT TAU
48, WITH THE EXCEPTION OF NAVGEM AND EGRR WHICH CONTINUE ON A
NORTHWESTWARD TRAJECTORY DESPITE A LOW LEVEL SURGE OF NORTHEASTERLY
FLOW ALONG THE COAST OF JAPAN AND THE LOW TO MID-LEVEL STEERING RIDGE
IN PLACE OVER THE ISLAND CHAIN. COAMPS-TC AND HAFS-A SOLUTIONS ARE
INDICATING THE POTENTIAL FOR LIMITED RE-INTENSIFICATION AS 11W
NEARS THE COAST, PERHAPS BY ENHANCEMENT OF THE LOW LEVEL FLOW,
HOWEVER, THIS IS UNLIKELY GIVEN OVERALL POOR ENVIRONMENTAL
CONDITIONS. DESPITE RELATIVELY STRAIGHTFORWARD STEERING PATTERN AND
A MAJORITY OF CONSENSUS MEMBERS ALIGNED WITH THE FORECAST,
UNCERTAINTY REMAINS ABOUT TIMING OF DISSIPATION AND WHAT EFFECT IF
ANY LOW LEVEL SURGE FLOW MAY HAVE ON TRACK AND INTENSITY.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM//
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