Tropical Depression ONE-E

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TROPICAL DEPRESSION ONE-E DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP012007
800 PM PDT SAT MAY 26 2007
 
CONVECTION ASSOCIATED WITH THE LOW PRESSURE AREA WELL SOUTHWEST OF
MANZANILLO MEXICO HAS INCREASED SIGNIFICANTLY DURING THE PAST
SEVERAL HOURS...WITH TOPS OF COLDER THAN -80C DEVELOPING OVER THE
CENTER.  SATELLITE INTENSITY ESTIMATES ARE 30 KT FROM TAFB AND 25
KT FROM SAB.  BASED ON ALL THIS...ADVISORIES ARE INITIATED ON
TROPICAL DEPRESSION ONE-E.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 265/4.  WATER VAPOR
IMAGERY SHOWS A LARGE AND COMPLEX MID/UPPER-LEVEL TROUGH OVER
MEXICO AND THE ADJACENT PACIFIC WATERS NORTH OF 20N EAST OF 115W...
WITH A LARGE MID/UPPER-LEVEL RIDGE COVERING THE REGION WEST OF
115W.  THIS LEAVES THE DEPRESSION IN AN AREA OF WEAK STEERING FLOW. 
THE LARGE-SCALE MODELS FORECAST THE TROUGH TO MOVE EASTWARD AND THE
RIDGE TO SLOWLY BUILD NORTH OF THE DEPRESSION DURING THE FORECAST
PERIOD.  THIS SHOULD ALLOW A SLOW WESTWARD MOTION AS FORECAST BY
THE GFDL...THE ECMWF...AND THE CANADIAN MODELS.  THE OFFICIAL
FORECAST FOLLOWS THIS SCENARIO...CALLING FOR A SLOW WESTWARD MOTION
UNDER THE RIDGE THROUGH 120 HR.  A POTENTIAL COMPLICATING FACTOR IS
THE POSSIBILITY THAT ANOTHER TROPICAL CYCLONE WILL FORM EAST OF THE
DEPRESSION...AS FORECAST BY THE GFS...NOGAPS...AND UKMET MODELS. 
SHOULD THIS OCCUR...THIS COULD CAUSE TROPICAL DEPRESSION ONE-E TO
HAVE ERRATIC MOTION.

THE DEPRESSION IS CURRENTLY IN AN ENVIRONMENT OF DIFLUENT
SOUTHEASTERLY UPPER-LEVEL WINDS AND MODERATE VERTICAL SHEAR.  THE
DEPRESSION SHOULD REMAIN IN A LIGHT-TO-MODERATE SHEAR ENVIRONMENT
OVER WARM WATER FOR 48-72 HR...WHICH SHOULD ALLOW STRENGTHENING. 
THE INTENSITY FORECAST CALLS FOR THE CYCLONE TO REACH 60 KT IN 72
HR...WHICH IS SLIGHTLY ABOVE THE SHIPS AND GFDL FORECASTS.  AFTER
THAT...THE FORECAST TRACK TAKES THE SYSTEM OVER GRADUALLY COOLING
SEA SURFACE TEMPERATURES...WHICH SHOULD START A WEAKENING TREND.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/0300Z 12.6N 110.8W    30 KT
 12HR VT     27/1200Z 12.5N 111.5W    35 KT
 24HR VT     28/0000Z 12.4N 112.6W    45 KT
 36HR VT     28/1200Z 12.3N 113.5W    50 KT
 48HR VT     29/0000Z 12.3N 114.4W    55 KT
 72HR VT     30/0000Z 12.5N 116.0W    60 KT
 96HR VT     31/0000Z 12.5N 118.0W    60 KT
120HR VT     01/0000Z 13.0N 121.0W    55 KT
 
$$
FORECASTER BEVEN
 
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