| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

---

Tropical Storm ANDRES (Text)

ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM ANDRES DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022009
200 PM PDT MON JUN 22 2009
 
GEOSTATIONARY AND MICROWAVE SATELLITE IMAGERY INDICATE THAT ANDRES
HAS CONTINUED TO BECOME BETTER ORGANIZED TODAY. THE INITIAL
INTENSITY IS SET TO 50 KT...A BLEND OF THE 1800 UTC DVORAK
ESTIMATES FROM SAB AND TAFB.
 
ANDRES HAS BEEN MOVING UNSTEADILY OVER THE LAST 12 TO 18 HOURS...
ALTERNATING BETWEEN A MORE NORTHERLY AND WESTERLY HEADING. THE
12-HOUR INITIAL MOTION ESTIMATE IS 315/04. THE UNSTEADY MOTION IS
LIKELY DUE TO THE RELATIVELY WEAK DEEP-LAYER FLOW BETWEEN THE
SUBTROPICAL RIDGE EAST OF ANDRES AND AN UPPER-TROUGH SOUTHWEST OF
CALIFORNIA. THE GLOBAL MODELS SHOW THE SUBTROPICAL RIDGE BUILDING
NORTH OF THE CYCLONE IN 2 TO 3 DAYS. THIS WILL FORCE ANDRES TOWARD
THE WEST...BUT NOT BEFORE IT TRACKS CLOSE TO THE SOUTHWESTERN COAST
OF MEXICO IN THE NEXT 24 TO 48 HOURS. THE MAIN CHANGE IN THE TRACK
MODEL GUIDANCE FOR THIS CYCLE IS AN INCREASE IN FORWARD SPEED
DURING THE FIRST 48 HOURS. THE CURRENT FORECAST IS FASTER THAN THE
PREVIOUS PACKAGE...BUT NOT AS FAST AS THE MODEL CONSENSUS. BEYOND
72 HOURS...THIS PACKAGE IS ESSENTIALLY AN UPDATE OF THE PREVIOUS
FORECAST.
 
WHILE THE SHIPS MODEL ANALYZES NEARLY 20 KT OF SHEAR...IT DOES NOT
APPEAR TO BE HAVING ANY ADVERSE IMPACT ON THE CYCLONE. ANDRES WILL
REMAIN OVER WARM SSTS THROUGH 36 HOURS...AND THE CYCLONE IS
FORECAST TO BECOME A HURRICANE A LITTLE FASTER NOW DUE TO THE STEADY
INTENSIFICATION SEEN TODAY. BEYOND 36 HOURS...THE CYCLONE WILL BE
MOVING OVER COOLER SSTS AND INGESTING MORE STABLE AIR...RESULTING
IN SLOW WEAKENING AND DEGENERATION INTO A REMNANT LOW BY THE END OF
THE PERIOD. IF ANDRES MOVES TO THE RIGHT OF THE FORECAST TRACK AND
INTERACTS WITH LAND...IT COULD WEAKEN MORE QUICKLY THAN INDICATED
HERE.
 
THE INCREASE IN INTENSITY AND THE FASTER FORWARD SPEED IN THIS
PACKAGE REQUIRES THE ISSUANCE OF A HURRICANE WARNING FOR A PORTION
OF THE COAST OF MEXICO AT THIS TIME.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/2100Z 16.2N 102.4W    50 KT
 12HR VT     23/0600Z 17.1N 103.2W    60 KT
 24HR VT     23/1800Z 18.4N 104.5W    65 KT
 36HR VT     24/0600Z 19.6N 105.8W    65 KT
 48HR VT     24/1800Z 20.6N 107.5W    55 KT
 72HR VT     25/1800Z 21.5N 110.0W    45 KT
 96HR VT     26/1800Z 22.0N 113.0W    35 KT
120HR VT     27/1800Z 22.0N 116.5W    25 KT...REMNANT LOW
 
$$
FORECASTER BRENNAN/BLAKE
 
NNNN