Latest analysis show that 90A has drifted North and has intensified into a Depression now.
Position is 13.46 N , 62.44 E
Pressure is around 1000.3mb
1am, IR shows moderate convective activity around the system
JTWC, GFS and HWRF expects the system to move North, N-W and then to N-E during next 3 days.
JTWC warning at 8:30pm
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TROPICAL CYCLONE (TC) 04A (FOUR), LOCATED APPROXIMATELY 471 NM SOUTH-
SOUTHEAST OF MASIRAH ISLAND, HAS TRACKED NORTHEASTWARD AT 13
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS A CONSOLIDATING SYSTEM AS THE LOW LEVEL CIRCULATION
CENTER HAS BECOME BETTER DEFINED AND MORE TIGHTLY WRAPPED DESPITE
BROKEN AND UNORGANIZED CONVECTION. HOWEVER, A RECENT 251356Z SSMIS
37GHZ MICROWAVE IMAGE REVEALS A DEVELOPING MICROWAVE EYE FEATURE AS
SHALLOW CONVECTIVE BANDING HAS BECOME BETTER DEFINED. THE INITIAL
POSITION IS BASED UPON THIS MICROWAVE IMAGE WITH INCREASING
CONFIDENCE. THE INITIAL INTENSITY OF 35 KNOTS IS BASED UPON THE
INCREASING STRUCTURE SEEN SEVERAL RECENT MICROWAVE PASSES AND A
DVORAK INTENSITY ESTIMATE OF THE SAME VALUE FROM KNES. UPPER LEVEL
ANALYSIS SHOWS THE SYSTEM IS LOCATED UNDER THE RIDGE AXIS WHICH IS
PROVIDING LOW TO MODERATE (10 TO 20 KNOTS) VERTICAL WIND SHEAR (VWS)
AND GOOD OUTFLOW. TC 04A IS CURRENTLY TRACKING TO THE NORTHEAST
ALONG A LOBE OF THE SUBTROPICAL RIDGE (STR) TO THE SOUTH OF THE
SYSTEM. OVER THE NEXT 12 HOURS, THIS LOBE OF THE STR IS EXPECTED TO
WEAKEN AND RETRACT WHICH WILL RESULT IN THE SYSTEM SLOWING AND
DRIFTING NORTH WHILE A TROUGH WELL TO THE NORTH MODIFIES THE STR.
AFTER TAU 24, THIS TROUGH WILL MOVE OUT OF THE AREA AND THE STR IS
EXPECTED TO REBUILD NORTH OF THE SYSTEM AND DEFLECT THE SYSTEM ON A
MORE NORTHWEST TRACK THROUGH TAU 72. AFTER WHICH, ANOTHER TROUGH IS
EXPECTED TO MOVE INTO THE AREA AND FORCE THE SYSTEM TO TURN BACK TO
THE NORTHEAST. A STEADY INTENSIFICATION IS EXPECTED THROUGH TAU 72
AS ENVIRONMENTAL CONDITIONS OF WARM SEA SURFACE TEMPERATURES, GOOD
OUTFLOW AND VWS REMAIN FAVORABLE. AFTER TAU 72, INCREASING VWS FROM
THE APPROACHING TROUGH WILL WEAKEN THE SYSTEM AS IT BEGINS TO
ENCOUNTER THE MID-LATITUDE WESTERLIES. DYNAMIC MODEL GUIDANCE IS
BECOMING IN BETTER AGREEMENT WITH THE FORECAST TRACK BUT THERE IS
STILL A FAIR AMOUNT OF SPREAD DUE TO THE COMPLEX STEERING
ENVIRONMENT. OVERALL THERE IS LOW CONFIDENCE IN THE FORECAST WHICH
IS POSITIONED CLOSE TO MULTI-MODEL CONSENSUS. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 251200Z IS 10 FEET. NEXT WARNINGS AT 252100Z,
260300Z, 260900Z AND 261500Z.
