Original source: http://tgftp.nws.noaa.gov/data/raw/wt/wtin20.dems..txt, recovered at: 2017-12-07 0645Z

WTIN20 DEMS 070650

SPECIAL TROPICAL WEATHER OUTLOOK

DEMS-RSMC TROPICAL CYCLONES NEW DELHI DATED 07.12.2017
SPECIAL TROPICAL WEATHER OUTLOOK FOR NORTH INDIAN OCEAN
(THE BAY OF BENGAL AND ARABIAN SEA) VALID FOR NEXT 72 HOURS
ISSUED AT 0600 UTC OF 07.12.2017 BASED ON 0300 UTC OF 07.12.2017.
BAY OF BENGAL & ANDAMAN SEA:

THE DEPRESSION OVER SOUTHEAST BAY OF BENGAL &
NEIGHBOURHOOD MOVED NORTHWARDS WITH A SPEED OF
ABOUT 35 KMPH DURING PAST 6 HOURS AND LAY CENTRED
AT 0300 UTC OF TODAY, THE 07 DECEMBER, 2017 NEAR
LATITUDE 12.0� N AND LONGITUDE 88.0 �E, ABOUT 870
KM SOUTHEAST OF GOPALPUR (43049) AND 875 KM TO THE
EAST-SOUTHEAST OF MACHILLIPATNAM (43185). THE SYSTEM
IS VERY LIKELY TO MOVE NORTH-NORTHWESTWARDS AND REACH
NORTH ANDHRA PRADESH AND SOUTH ODISHA COASTS AROUND
9TH DECEMBER MORNING. THE SYSTEM IS LIKELY TO INTENSIFY
FURTHER INTO A DEEP DEPRESSION DURING NEXT 24 HOURS.
HOWEVER, THERE IS A PROBABILITY OF SLIGHT WEAKENING
OF THE SYSTEM WHEN IT REACHES NEAR NORTH ANDHRA PRADESH
AND SOUTH ODISHA COASTS 09TH DECEMBER.

THE ESTIMATED CENTRAL PRESSURE IS ABOUT 1004 HPA AND
THE MAXIMUM SUSTAINED SURFACE WIND SPEED IS 25 KNOTS
GUSTING TO 35 KNOTS. SEA CONDITION IS ROUGH TO VERY
ROUGH AROUND SYSTEM CENTRE. ACCORDING TO THE LATEST
SATELLITE IMAGERY THE INTENSITY IS T1.5. ASSOCIATED
BROKEN LOW TO MEDIUM CLOUDS WITH INTENSE TO VERY
INTENSE CONVECTION LIE OVER SOUTHEAST BAY OF BENGAL
AND ADJOINING CENTRAL BAY, SOUTHWEST BAY AND SOUTH
ANDAMAN SEA. SATELLITE IMAGERY INDICATES THE CONVECTIVE
CLOUDS HAVE ORGANISED DURING PAST 6 HOURS. HOWEVER THE
MAJORITY OF CONVECTION IS DISPLACED NORTHWARD FROM LOW
LEVEL CIRCULATION CENTER.

THE SEA SURFACE TEMPERATURE OVER THE SYSTEM REGION
IS 28-29 0C. SST IS DECREASING TO THE NORTH AND TO
THE WEST. THE OCEAN THERMAL ENERGY IS ABOUT 60-80
KJ/CM2 OVER THE SYSTEM AREA. IT IS DECREASING FURTHER
TO THE NORTH AND WEST. WHEN THE SYSTEM REACHES NEAR
TO THE COAST IT WILL ENCOUNTER COLDER SEA, LOWER OCEAN
THERMAL ENERGY AND INCREASED SHEAR DUE TO THE STRONG
UPPER LEVEL WINDS IN ASSOCIATION WITH A DEEP TROUGH
IN WESTERLIESTHE VERTICAL WIND SHEAR IS LOW TO MODERATE
AROUND THE SYSTEM CENTER AND IT IS INCREASING TO NORTH
AND TO THE WEST. THE LOW LEVEL RELATIVE VORTICITY IS
AROUND 100 X 10 -6 S-1 TO THE SOUTH OF THE SYSTEM CENTRE.
LOW LEVEL CONVERGENCE IS AROUND 20 X 10 -5 S-1 TO THE
NORTHWEST OF THE SYSTEM CENTRE. UPPER LEVEL DIVERGENCE
IS ABOUT 40 X 10 -5 S-1 TO THE NORTHWEST OF THE SYSTEM
CENTER. MADDEN JULIAN OSCILLATION (MJO) LIES IN PHASE 5
WITH AMPLITUDE MORE THAN 1 AND IS LIKELY TO MOVE TO
PHASE 6 IN NEXT TWO DAYS. CONSIDERING ALL THESE,
INTENSIFICATION OF THE SYSTEM WILL BE LIIMITED UPTO
DEEP DEPRESSION. THERE IS POSSIBILITY OF WEAKENING OF
THE SYSTEM WHEN IT REACHES NEAR THE COAST. UNDER THE
INFLUNCE OF ANTI CYCLONIC CIRCULATION OVER EASTCENTRAL
BAY OF BENGAL, THE SOUTHEASTERLY TO SOUTH-SOUTHEASTRLY
WINDS PREVAIL OVER THE SYSTEM AT UPPER LEVEL, WHICH
SUGGEST THE NORTH-NORTHWESTWARD MOVEMENT OF THE SYSTEM.
DEEP LAYER MEAN WIND ALSO SUGGEST SIMILAER MOVEMENT OF
THE SYSTEM. ALL THE NWP MODELS ARE IN AGREEMENT WITH
THE ABOVE CONCLUSIONS.