Tropical Storm NARI Advisory Qui, 25-07

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION TROPICAL
DEPRESSION 07 (SEVEN) WARNING NR 001//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 07W (SEVEN), LOCATED APPROXIMATELY 220 NM
WEST-NORTHWEST OF IWO TO, HAS TRACKED NORTHWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS AN EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION DISPLACED TO THE EAST OF THE LLCC AND SHALLOW RAIN BANDS
STARTING TO WRAP IN FROM THE NORTH. THE INITIAL POSITION IS PLACED
WITH GOOD CONFIDENCE BASED ON THE LLCC SEEN IN THE MSI LOOP AND A
250005Z METOP-B ASCAT PASS. A 242141Z F-17 SSMIS 91 GHZ MICROWAVE
IMAGE SHOWS CONVECTIVE BANDING WITHIN THE EASTERN SEMI-CIRCLE WITH
LIMITED BANDING TO THE WEST. THE INITIAL INTENSITY OF 25 KTS IS
CONSISTENT WITH THE MULTI-AGENCY DVORAK INTENSITY OF T1.0-1.5 (25
KTS) AND THE AFOREMENTIONED ASCAT PASS WHICH SHOWED 25-30 KT WINDS
IN THE CONVECTION TO THE NORTH AND EAST OF THE LLCC WITH 10-20 KTS
IN THE SOUTHWEST QUADRANT. ENVIRONMENTAL CONDITIONS FOR TD 07W ARE
MARGINAL WITH GOOD POLEWARD OUTFLOW SLIGHTLY TO THE EAST OF THE LLCC
AND WARM SEA SURFACE TEMPERATURES (28-30 CELSIUS) BEING OFFSET BY
MODERATE TO STRONG VERTICAL WIND SHEAR (VWS) (20-25 KTS). TD 07W IS
TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST
PHILOSOPHY.
   B. BY TAU 48, TD 07W SHOULD BE TRACKING NORTHEASTWARD AS IT ROUNDS
THE STR AXIS. THE JTWC TRACK FORECAST CLOSELY FOLLOWS THE CONSENSUS
TRACK WITH TRACK SPREAD LIMITED TO 50NM AT TAU 48. CONTINUED HIGH VWS
AND OFFSET UPPER LEVEL DIVERGENCE WILL PREVENT TD 07W FROM
INTENSIFYING SIGNIFICANTLY THROUGH TAU 48. AFTER TAU 48, LAND
INTERACTION AND COOL SEA SURFACE TEMPERATURES ARE EXPECTED TO
SIGNIFICANTLY HINDER ANY FURTHER DEVELOPMENT OF TD 07W. THE JTWC
INTENSITY FORECAST CLOSELY FOLLOWS THE INTENSITY GUIDANCE THROUGH TAU
72.
   C. AFTER TAU 72, TD 07W IS EXPECTED TO CONTINUE TRACKING ALONG THE
NORTHERN PERIPHERY OF THE STR AS IT BRUSHES THE SOUTHERN COAST OF
JAPAN AND GRADUALLY DISSIPATES BELOW WARNING THRESHOLD OVER COOLER
SEAS (24-26 DEGREES CELSIUS).  THE JTWC TRACK FORECAST CLOSELY
FOLLOWS THE CONSENSUS TRACK WITH TRACK SPREAD LIMITED TO UNDER 40NM
AT TAU 96. FOR THIS PORTION OF THE FORECAST, THERE IS HIGH CONFIDENCE
IN THE JTWC TRACK FORECAST DUE TO LOW UNCERTAINTY IN THE MODEL
GUIDANCE AND THE INITIAL POSITION OF THE SYSTEM.//
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