Skip Navigation Links
NOAA NOAA United States Department of Commerce

Tropical Storm DELTA


ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM DELTA DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT WED NOV 23 2005
 
THE 2005 ATLANTIC TROPICAL CYCLONE SEASON REFUSES TO END AS MODERATE
TO DEEP CONVECTION HAS PERSISTED FOR MORE THAN 12 HOURS AND HAS
WRAPPED ABOUT 75 PERCENT OF THE WAY AROUND THE CIRCULATION CENTER
OF THE LARGE NON-TROPICAL LOW PRESSURE SYSTEM LOCATED ABOUT 1000
NMI SOUTHWEST OF THE AZORES ISLANDS. AN EYE-LIKE FEATURE HAS
OCCASIONALLY APPEARED IN VARIOUS SATELLITE IMAGERY AS THE
INTENSIFYING CIRCULATION HAS WRAPPED IN DRY AIR FROM THE SOUTHWEST.
THE INITIAL INTENSITY OF 50 KT IS BASED ON A 0852Z QUIKSCAT
OVERPASS SHOWING A FEW 50-KT UNCONTAMINATED WIND VECTORS TO THE
NORTH... AND A 986.5 MB PRESSURE REPORT FROM BUOY 62556 LOCATED
ABOUT 50 NMI EAST OF THE CENTER AT 23/16Z. THAT BUOY PRESSURE ALSO
MAINTAINS CONTINUITY WITH THE 23/02Z PRESSURE OF 984.4 MB FROM BUOY
13534 WHEN IT WAS LOCATED ABOUT 40 NMI EAST OF THE CENTER. THE
50-KT INTENSITY OF TROPICAL STORM DELTA IS ALSO SUPPORTED BY A
TROPICAL SATELLITE INTENSITY ESTIMATE OF T3.0/45 KT FROM TAFB.
 
THE INITIAL MOTION ESTIMATE IS 165/08 KT. THE GLOBAL AND REGIONAL
MODELS ARE IN UNUSUALLY GOOD AGREEMENT ON DELTA BOTTOMING OUT IN
LATITUDE BY ABOUT 24 HOURS...BEFORE TURNING BACK TO THE NORTH. THE
MAN DIFFERENCE BETWEEN THE MODELS IS WHETHER DELTA TURNS EAST OR
WEST OF 40W LONGITUDE BEFORE IT TURNS BACK TO THE NORTH. I HAVE
OPTED TO TURN THE TRACK COUNTERCLOCKWISE TO THE EAST AND THEN
NORTH... GIVEN THAT DELTA IS EMBEDDED WITHIN A LARGER AND
VERTICALLY DEEP CYCLONIC GYRE. THE FORECAST TRACK IS SIMILAR IN
SPEED TO... BUT IS RIGHT OF... THE NHC MODEL CONSENSUS.
 
THE 850-200 MB VERTICAL SHEAR ACROSS DELTA IS FORECAST TO DECREASE
FROM THE CURRENT 50 KT DOWN TO 22 KT IN 36 HOURS. HOWEVER...GIVEN
THAT DELTA IS SHALLOWER THAN CLASSICAL TROPICAL CYCLONES... LESS
SHEAR IS SUGGESTED BY UW-CIMSS WATER VAPOR WINDS OF 20-30 KT AT 300
MB...WHICH IS ABOUT 10-20 KT LESS THAN AT 200 MB. ANTICYCLONIC
OUTFLOW HAS ALSO BECOME ESTABLISHED IN ALL QUADRANTS...SO SOME
ADDITIONAL SLIGHT STRENGTHENING IS POSSIBLE AS DELTA MOVES
SOUTHWARD OVER SLIGHTLY WARMER SSTS OF 25.5C FOR THE NEXT 36 HOURS.
 
FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/2100Z 25.9N  40.5W    50 KT
 12HR VT     24/0600Z 25.1N  40.2W    55 KT
 24HR VT     24/1800Z 24.7N  39.7W    60 KT
 36HR VT     25/0600Z 25.0N  39.4W    60 KT
 48HR VT     25/1800Z 26.0N  39.5W    55 KT
 72HR VT     26/1800Z 28.0N  39.5W    55 KT...BECOMING EXTRATROPICAL
 96HR VT     27/1800Z 32.0N  40.0W    50 KT...EXTRATROPICAL
120HR VT     28/1800Z 36.0N  42.0W    50 KT...EXTRATROPICAL

$$
NNNN