Tropical Depression 04W is forecast to intensify gradually next 3 days while slowly approaching Taiwan


Warning 2/JTWC


PEAK INTENISTY NEAR 50KNOTS IS FORECAST BY 72H
PEAK INTENISTY NEAR 50KNOTS IS FORECAST BY 72H
https://www.meteo974.re/M974World_r7.html
https://www.facebook.com/groups/1817419381676514/

WESTERN NORTH PACIFIC

TD 04W
As of 00:00 UTC Jun 29, 2019:

Location: 14.1°N 132.2°E
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)

Minimum Central Pressure: 1004 mb
INTENSIFYING

WDPN31 PGTW 290300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 04W (FOUR)
WARNING NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION 04W (FOUR), LOCATED APPROXIMATELY 652 NM EAST
OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 05 KNOTS
OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON LOW-LEVEL
BANDING EVIDENT IN RECENT MICROWAVE SATELLITE IMAGERY INCLUDING A
282145Z CORIOLIS PASS. THE INTENSITY OF 30 KNOTS IS SUPPORTED BY
RECENT SUBJECTIVE DVORAK ESTIMATES OF T2.0 FROM PGTW AND KNES, AND IS
CONSISTENT WITH LEVEL STRUCTURE EVIDENT IN SATELLITE DATA. TD 04W HAS
TRACKED WEST-NORTHWESTWARD ALONG THE PERIPHERY OF A SUBTROPICAL
STEERING RIDGE SITUATED TO THE NORTH AND EAST OVER THE PAST SIX
HOURS. DEEP CONVECTION CONTINUES TO FLARE AND WANE OVER THE
SOUTHWESTERN PORTION OF THE LOW LEVEL CIRCULATION AS THE SYSTEM
EXPERIENCES PERSISTENT NORTHEASTERLY VERTICAL WIND SHEAR (VWS). THE
SEA SURFACE TEMPERATURE IN VICINITY OF THE LLCC IS VERY SUPPORTIVE AT
29 TO 30 DEGREES CELSIUS.
3. FORECAST REASONING.
   A. EXTENDED RANGE FORECAST INTENSITIES HAVE BEEN REDUCED FROM THE
PREVIOUS WARNING. HOWEVER, THERE IS NO MAJOR CHANGE TO THE FORECAST
PHILOSOPHY FROM THE PREVIOUS WARNING.
   B. TD 04W IS EXPECTED TO TRACK NORTHWESTWARD IN THE NEAR TERM
UNDER THE CONTINUED STEERING INFLUENCE OF THE SUBTROPICAL RIDGING TO
THE NORTH AND EAST. VWS WILL PERSIST THROUGH TAU 72, LIMITING
INTENSIFICATION TO A SLOW RATE DESPITE PASSAGE OVER VERY WARM WATER
AN FAVORABLE SOUTHWESTWARD DIFFLUENCE ALOFT. NUMERICAL MODEL TRACK
FORECAST GUIDANCE REMAINS SPLIT, WITH A GROUPING CONSISTING OF THE
GEFS ENSEMBLE AND HWRF MODELS PREDICTING A TRACK TO THE SOUTH OF
TAIWAN AND THE UKMET, NAVGEM AND ECMWF PREDICTING A TRACK FARTHER TO
THE NORTH. THE CURRENT FORECAST IS CONSERVATIVELY CONSISTENT WITH THE
PREVIOUS JTWC TRACK FORECAST AND CURRENT MULTI-MODEL CONSENSUS
THROUGH TAU 72. THE EXACT TRACK WILL DEPEND ON THE AS YET UNCERTAIN
ORIENTATION OF THE SUBTROPICAL STEERING RIDGE DURING THIS PERIOD.
   C. TD 04W IS EXPECTED TO BEGIN WEAKENING IN THE EXTENDED RANGE IN
RESPONSE TO INCREASING VERTICAL WIND SHEAR AND POTENTIAL LAND
INTERACTION. NUMERICAL MODEL TRACK FORECAST SPREAD IS PARTICULARLY
PRONOUNCED IN THE EXTENDED RANGE. A FEW CONSENSUS MODELS DEPICT TD
04W TURNING WESTWARD AND INTERACTING WITH A DEVELOPING CIRCULATION IN
THE NORTHERN SOUTH CHINA SEA, WHILE OTHER MODELS DEPICT TD 04W
MAINTAINING A NORTHWESTWARD TRACK OR TURNING POLEWARD ALONG THE
STEERING RIDGE PERIPHERY. THE CURRENT TRACK FORECAST IS WEIGHTED
TOWARD THE NORTHWESTWARD AND POLEWARD TRACK GROUPING BASED ON
EXPECTATIONS OF SLOW BUT SUFFICIENT NEAR TERM INTENSIFICATION.
OVERALL, THERE IS LOW CONFIDENCE IN THE CURRENT JTWC TRACK FORECAST.//
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TRACK AND INTENSITY GUIDANCE
TRACK AND INTENSITY GUIDANCE
Rédigé par PATRICK HOAREAU le Samedi 29 Juin 2019 à 06:56