MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01C (HALOLA)
WARNING NR 35//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 01C (HALOLA), LOCATED APPROXIMATELY 770
NM EAST-SOUTHEAST OF IWO TO, HAS TRACKED WESTWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS AN AREA OF DISORGANIZED DEEP CONVECTION PERSISTING OVER A
BROAD, ILL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). A 181831Z
SSMIS IMAGE INDICATES LIMITED CURVED DEEP CONVECTIVE BANDING OVER
THE SOUTHEAST QUADRANT OF THE LLCC; HOWEVER, THERE IS LITTLE
EVIDENCE OF AN ORGANIZED LLCC ELSEWHERE. RECENT TOTAL PRECIPITABLE
WATER IMAGERY CONTINUES TO SHOW A CORE OF DEEP MOISTURE, HOWEVER,
VALUES HAVE DECREASED OVER THE PAST TWO DAYS, WHICH SUGGESTS SOME
DRY AIR INTRUSION HAS OCCURRED. DUE TO THE WEAK NATURE OF THE LLCC
AND LACK OF VISIBLE IMAGERY, THERE IS POOR CONFIDENCE IN THE CURRENT
POSITION. THE CURRENT INTENSITY IS ASSESSED AT 30 KNOTS BASED ON THE
RECENT SSMIS WIND PRODUCT, HOWEVER, THE IMAGE ALSO REVEALS A HIGHLY
ASYMMETRIC WIND FIELD. ANIMATED WATER VAPOR IMAGERY SHOWS THAT THE
TUTT CELL REMAINS DIRECTLY TO THE NORTH OF THE LLCC WHICH IS
PRODUCING CONVERGENT FLOW OVER THE NORTHERN SEMI-CIRCLE AND MODERATE
WESTERLY VERTICAL WIND SHEAR (VWS). TD 01C IS TRACKING ALONG THE
SOUTHERN PERIPHERY OF THE DEEP-LAYERED STR.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TD HALOLA WILL CONTINUE TRACKING ON A WESTWARD TO WEST-
NORTHWESTWARD TRAJECTORY UNDER THE STEERING INFLUENCE OF THE
DOMINANT STR THROUGH TAU 72. DUE TO THE WEAK NATURE OF THE SYSTEM
AND THE STRONG LOW-LEVEL STR, THE SYSTEM MAY CONTINUE TO MOVE
SLIGHTLY EQUATORWARD PRIOR TO INTENSIFYING AND GAINING LATITUDE.
OVER THE NEXT 12 TO 24 HOURS, TD 01C WILL CONTINUE TO STRUGGLE TO
INTENSIFY DUE TO THE EFFECTS OF THE TUTT CELL. BEYOND TAU 24, THE
TUTT CELL IS FORECAST TO DISSIPATE, REDUCING THE SUBSIDENCE ALOFT
AND ALLOWING THE SYSTEM TO SLOWLY BEGIN TO INTENSIFY. IN ADDITION,
TD HALOLA IS FORECAST TO GAIN A STRONG EQUATORWARD OUTFLOW CHANNEL
AND ENCOUNTER REDUCED VWS.
C. BEYOND TAU 72, EXPECT A MORE NORTHWESTWARD TRACK AS THE SYSTEM
APPROACHES THE WESTERN PERIPHERY OF THE STR. THIS WILL ALLOW THE
SYSTEM TO GAIN A POLEWARD OUTFLOW CHANNEL DOWNSTREAM FROM THE
STEERING STR; CONTINUING THE INTENSIFICATION. DYNAMIC MODEL GUIDANCE
DIVERGES AFTER TAU 72 DUE TO THE INCREASING UNCERTAINTY IN THE
TIMING AND SPEED OF THE RE-CURVE. OVERALL CONFIDENCE IN THE JTWC
FORECAST TRACK IS LOW DUE PRIMARILY TO THE POSITIONAL UNCERTAINTY
AND INCREASING UNCERTAINTY IN THE RE-CURVE PHASE. LOW CONFIDENCE
REMAINS IN THE INTENSITY FORECAST DUE TO THE COMPLEX INTERACTION
BETWEEN TD HALOLA AND THE TUTT CELL.//
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