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

---

Hurricane JIMENA (Text)

ZCZC MIATCDEP3 ALL
TTAA00 KNHC DDHHMM
HURRICANE JIMENA DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP132009
800 PM PDT TUE SEP 01 2009
 
SINCE THE AIR FORCE PLANE LEFT THIS AFTERNOON...VISIBLE AND INFRARED
SATELLITE IMAGES INDICATE THAT JIMENA HAS CONTINUED TO WEAKEN.  THE
EYE HAS BECOME OBSCURED AND THERE HAS BEEN A GRADUAL SHRINKING OF
THE CONVECTIVE COVERAGE.  FURTHERMORE...THERE HAS BEEN AN APPARENT
DETERIORATION TO THE INNER CORE.  DVORAK T-NUMBERS HAVE FALLEN TO
T4.5 AND T5.0 FROM SAB AND TAFB...RESPECTIVELY.  BASED UPON THE
DEGRADED SATELLITE APPEARANCE BUT ALSO USING CONTINUITY...THE
INITIAL INTENSITY IS LOWERED TO 100 KT.
 
THE INITIAL MOTION ESTIMATE IS 345/11...SLIGHTLY TO THE RIGHT THAN
BEFORE.  THE TRACK FORECAST PHILOSOPHY IS UNCHANGED.  ACCORDING TO
THE TRACK MODEL GUIDANCE...JIMENA SHOULD CONTINUE MOVING NORTH-
NORTHWESTWARD BETWEEN A MID- TO UPPER-LEVEL LOW WEST OF THE BAJA
PENINSULA AND A MID-LEVEL RIDGE OVER NORTHERN MEXICO FOR AT LEAST
FOR THE NEXT 24 TO 36 HOURS.  INCREASINGLY DIVERGENT MODEL
SOLUTIONS SUGGEST A FORECAST OF LOWER CONFIDENCE BEYOND 48 HOURS.
A MINORITY OF GLOBAL MODELS TAKES JIMENA NORTHEASTWARD OR EASTWARD
INTO NORTHWESTERN MEXICO...WITH ONLY ONE TAKING IT INTO THE
SOUTHWESTERN UNITED STATES. A LARGER NUMBER OF MODEL RUNS EITHER
STALL JIMENA OVER CENTRAL BAJA CALIFORNIA...LIKE THE GFDL...OR TURN
THE CYCLONE NORTHWESTWARD OR EVEN WESTWARD INTO THE EAST PACIFIC IN
RESPONSE MID-LEVEL RIDGING BUILDING TO ITS NORTH.  THE NEW OFFICIAL
FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY BUT SHIFTED
INITIALLY TO THE RIGHT DUE TO THE CURRENT MORE NORTHERLY MOTION.
THE FORECAST IS SOMEWHAT SLOWER AND TO THE LEFT OF THE PREVIOUS
TRACK BEYOND 72 HOURS AS A RESULT OF THE MODEL CONSENSUS WHICH HAS
BEEN TRENDING MORE WESTWARD.
 
THE WEAKENING CAUSED BY AN EARLIER EYEWALL REPLACEMENT CYCLE HAS
CONTINUED...LIKELY AS A RESULT OF GRADUALLY COOLER SSTS AND
INCREASING WESTERLY SHEAR.  UW CIMSS ANALYSES SUGGESTS 10-15 KT OF
WESTERLY SHEAR OVER JIMENA...WHICH SEEMS BELIEVABLE GIVEN THE MORE
ASYMMETRIC ORGANIZATION OF THE CORE CONVECTION DURING THE LAST FEW
HOURS. PRIOR TO LANDFALL IN 12 TO 24 HOURS...THE GUIDANCE AGREES
WELL ON A CONTINUED...STEADY WEAKENING.  THEREAFTER...STRONGER
WESTERLY SHEAR AND THE CENTER TRACKING MOVING OVER LAND SHOULD LEAD
TO A MORE RAPID WEAKENING... WITH THE OFFICIAL FORECAST NOW CALLING
FOR JIMENA TO BECOME A REMNANT LOW BY 96 HR.  THERE REMAINS A
CHANCE THAT JIMENA COULD WEAKEN FASTER THAN FORECAST AFTER
LANDFALL.
 
INTERESTS IN THE HURRICANE WARNING AREA ARE ADVISED THAT STRONG
WINDS WILL PRECEDE THE ARRIVAL OF THE CENTER BY SEVERAL HOURS...SO
PREPARATIONS NEED TO BE COMPLETED VERY SOON. REMEMBER NOT TO FOCUS
ON THE EXACT FORECAST TRACK SINCE DANGEROUS IMPACTS EXTEND SOME
DISTANCE FROM THE CENTER. THE FORECAST TRACK OF JIMENA IS ALMOST
PARALLEL TO THE COAST OF BAJA CALIFORNIA...AND SMALL DEVIATIONS
LEFT OR RIGHT OF THE TRACK COULD RESULT IN LARGE ERRORS IN BOTH THE
LOCATION AND TIMING OF LANDFALL.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/0300Z 23.2N 111.3W   100 KT
 12HR VT     02/1200Z 24.6N 112.0W    90 KT
 24HR VT     03/0000Z 26.2N 112.6W    75 KT
 36HR VT     03/1200Z 27.3N 112.9W    60 KT...INLAND
 48HR VT     04/0000Z 28.0N 113.2W    40 KT...INLAND
 72HR VT     05/0000Z 28.5N 113.5W    30 KT...INLAND
 96HR VT     06/0000Z 29.5N 114.0W    20 KT...REMNANT LOW
120HR VT     07/0000Z 30.0N 114.0W    20 KT...REMNANT LOW
 
$$
FORECASTER KIMBERLAIN
 
NNNN