Updated 2300UTC, Monday 2nd November, 2015
Tropical Cyclone 04A (Chapala), which rapidly became a strong tropical cyclone (hurricane) in the Arabian Sea a few days ago (see here), is now in the Gulf of Aden, south of Al Mukalla, Yemen. It has reduced to 90 knots from its highest 145 knots, and is starting weaken under the effects of increased windshear and the Yemeni terrain. It will make landfall as a minimal hurricane at about 0600Z Wednesday (0900 local time) and will bring life-threatening rainfall over a wide area.
JTWC Latest (2100Z)
Location: 13.6N, 49.6E
Movement: 280 degrees (WNW) at 11 knots.
Winds: 90 knots, gusting 110 knots.
022100Z POSITION NEAR 13.7N 49.2E.
TROPICAL CYCLONE 04A (CHAPALA), LOCATED APPROXIMATELY 50 NM SOUTHEAST OF MUKALLA, YEMEN, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON A 021730Z PGTW SATELLITE FIX AND A 021538Z SSMIS IMAGE. THE INTENSITY OF 90 KNOTS IS CONSISTENT WITH DVORAK CURRENT INTENSITY ESTIMATES FROM MULTIPLE REPORTING AGENCIES. TC 04A HAS BECOME LESS ORGANIZED AND WEAKENED OVER THE PAST SIX HOURS DUE TO AN INCREASE IN EASTERLY VERTICAL WIND SHEAR AND INTERACTION OF THE NORTHERN PORTION OF THE LOW-LEVEL CIRCULATION WITH LAND. TC 04A IS TRACKING GENERALLY
WESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STEERING RIDGE TO THE NORTH. THE SYSTEM IS EXPECTED TO CONTINUE TRACKING WESTWARD TO NORTHWESTWARD ALONG THE RIDGE PERIPHERY AND MAKE LANDFALL ALONG THE CENTRAL COAST OF YEMEN AROUND TAU 12. STEADY WEAKENING IS EXPECTED PRIOR TO LANDFALL AS VERTICAL WIND SHEAR AND LAND INTERACTION CONTINUE TO IMPACT THE SYSTEM. RAPID DISSIPATION OVER LAND IS ANTICIPATED FOLLOWING LANDFALL. NUMERICAL MODELS REMAIN IN GOOD AGREEMENT. THE JTWC FORECAST TRACK LIES SLIGHTLY SOUTH OF THE MULTI-MODEL CONSENSUS, CONSISTENT WITH THE FORECASTED DIRECTION OF THE LOW TO MID-LEVEL FLOW THAT WILL STEER THE SYSTEM AS IT WEAKENS. THERE IS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 021800Z IS 28 FEET. NEXT WARNINGS AT 030300Z, 030900Z, 031500Z AND 032100Z.
Latest observations from two ships in the area (click):
Environmental influences affecting the storm from now:
Dry air-entrainment: Dry air from the Arabian peninsula is wrapping around the storm and is causing it to weaken considerably before landfall.
Shear: is increasingly affecting the storm as it moves in a more northerly direction.
Ocean Heat-Content (OHC): has been very high but the storm is now entering lower values in the Gulf of Aden.