Tropical Storm ADRIAN

ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM ADRIAN DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 AM PDT WED MAY 18 2005
 
CENTRAL DEEP CONVECTION HAS BECOME A LITTLE RAGGED THIS MORNING AS
DRY AIR NOTED IN WATER VAPOR IMAGERY HAS BEEN DRAWN INTO THE WEST
SIDE OF THE CYCLONE. IN ADDITION...AN 18/0920Z TRMM OVERPASS
INDICATED THE MID-LEVEL CIRCULATION WAS DISPLACED ABOUT 45-60 NMI
SOUTHEAST OF THE ALLEGED LOW-LEVEL CIRCULATION CENTER. THERE IS
ALSO CONSIDERABLE SCATTER IN THE VARIOUS SATELLITE FIX POSITIONS...
SO THE INITIAL POSITION IS BASED LARGELY ON CONTINUITY WITH THE
PREVIOUS MOTION AND FORECAST TRACK...AND LOW-LEVEL CLOUD LINES SEEN
IN 37GHZ TRMM MICROWAVE DATA AND THE FIRST FEW VISIBLE SATELLITE
IMAGES. THE INITIAL INTENSITY HAS BEEN INCREASED TO 45 KT BASED ON
A BLEND OF SATELLITE INTENSITY ESTIMATES OF 55 KT...45 KT...AND 35
KT FROM TAFB...AFWA...AND SAB...RESPECTIVELY.

THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 055/07. IT IS POSSIBLE
THAT A NEW CENTER COULD FORM FARTHER EAST UNDER THE AFOREMENTIONED
MID-LEVEL CIRCULATION CENTER. HOWEVER...CONVECTION SURROUNDING THAT
FEATURE HAS DECREASED...SO I DO NOT WANT TO MAKE ANY SIGNIFICANT
CHANGES TO THE OVERALL TRACK MOTION AT THIS TIME. THE GLOBAL AND
GFDL MODELS REMAIN IN STRONG AGREEMENT THAT A PRONOUNCED MID- TO
UPPER-LEVEL TROUGH WILL GRADUALLY DEVELOP DURING THE NEXT FEW DAYS
ACROSS THE GULF OF MEXICO AND MEXICO...WHERE A RIDGE IS USUALLY
LOCATED THIS TIME OF THE YEAR. INCREASING SOUTHWEST TO WESTERLY
STEERING FLOW AHEAD OF THE TROUGH SHOULD HELP TO DRIVE ADRIAN
ACROSS CENTRAL AMERICA ON DAY 2 AND POSSIBLY INTO THE NORTHWEST
CARIBBEAN SEA BY DAY 3. WHETHER OR NOT ADRIAN MAKES IT ACROSS
CENTRAL AMERICA INTACT AS A TROPICAL CYCLONE WILL DEPEND IN PART ON
JUST HOW STRONG THE CYCLONE IS WHEN IT MAKES LANDFALL. THE OFFICIAL
FORECAST TRACK IS SIMILAR TO THE PREVIOUS THREE FORECASTS AND IS A
LITTLE TO THE RIGHT OF THE MODEL CONSENSUS.
 
DRY AIR ENTRAINMENT HAS TEMPORARILY DISRUPTED THE CENTRAL DEEP
CONVECTIVE PATTERN. HOWEVER...BANDING FEATURES REMAIN QUITE
PRONOUNCED AND THE UPPER-LEVEL OUTFLOW PATTERN IS EXCELLENT. AT
LEAST SLOW INTENSIFICATION IS IN ORDER GIVEN THE VERY WARM
SEA-SURFACE TEMPERATURES BENEATH AND AHEAD OF THE CYCLONE AND ALL
OF THE MODELS ARE FORERCASTING A VERY FAVORABLE OUTFLOW PATTERN...
ESPECIALLY TO THE NORTH. THE SHIPS INTENSITY MODEL BRINGS ADRIAN UP
TO ABOUT 55 KT IN 24 HOURS AND THEN LEVELS IT OFF UNTIL LANDFALL.
THE GFDL IS NOT AS ROBUST AS IT WAS YESTERDAY...BUT IT STILL MAKES
ADRIAN A 95-KT HURRICANE IN 24-36 HOURS. THE CLOSE PRESENCE OF DRY
AIR TO THE WEST REQUIRES THAT THE GFDL INTENSITY FORCAST BE
TEMPERED SOMEWHAT AT THIS TIME...BUT MINIMAL HURRICANE INTENSITY
PRIOR TO LANDFALL IS STILL A VERY DISTINCT POSSIBILITY.

TROPICAL STORM FORCE WINDS WINDS COULD BE NEARING THE COASTS OF
GUATEMALA AND EL SALVADOR IN ABOUT 30-36 HOURS...SO A TROPICAL STORM
WARNING MAY BE REQUIRED FOR THESE AREAS LATER TODAY.
 
ADRIAN ALSO HAS THE POTENTIAL TO PRODUCE TORRENTIAL RAINS THAT COULD
CAUSE FLOODING AND MUD SLIDES ACROSS PARTS OF CENTRAL AMERICA OVER
THE NEXT FEW DAYS.  
 
FORECASTER STEWART
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/1500Z 11.1N  93.5W    45 KT
 12HR VT     19/0000Z 11.6N  92.6W    50 KT
 24HR VT     19/1200Z 12.6N  91.3W    55 KT
 36HR VT     20/0000Z 13.6N  89.8W    60 KT
 48HR VT     20/1200Z 15.0N  88.0W    30 KT...INLAND
 72HR VT     21/1200Z 18.0N  84.0W    30 KT
 96HR VT     22/1200Z 21.0N  79.5W    30 KT
120HR VT     23/1200Z 24.0N  73.0W    30 KT
 
 
$$
NNNN