000
WTNT43 KNHC 232033
TCDAT3

TROPICAL DEPRESSION EIGHTEEN DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
500 PM EDT SUN OCT 23 2011

THE HURRICANE HUNTER AIRCRAFT INVESTIGATING THE LOW PRESSURE AREA
OVER THE WESTERN CARIBBEAN SEA HAS FOUND A WELL-DEFINED CENTER AND
SATELLITE IMAGERY INDICATES THAT THE DISTURBANCE HAS ACQUIRED JUST
ENOUGH CONVECTIVE ORGANIZATION FOR THE SYSTEM TO BE CLASSIFIED AS A
TROPICAL DEPRESSION.  THE INITIAL WIND SPEED IS SET AT 30 KT...
BASED ON A FEW BELIEVABLE 27 TO 28 KT SFMR WIND MEASUREMENTS.  THE
DEPRESSION IS OVER WARM WATER BUT IN AN AREA OF MODERATE
SOUTHEASTERLY VERTICAL SHEAR WITH DRY AIR TO THE NORTH AND WEST.
THE ENVIRONMENT DURING THE NEXT COUPLE OF DAYS IS NOT FORECAST TO
BE CONDUCIVE FOR SIGNIFICANT STRENGTHENING...BUT SHOULD NOT BE
HOSTILE ENOUGH TO PREVENT THE SYSTEM FROM BECOMING A TROPICAL
STORM. THE OFFICIAL FORECAST IS JUST SLIGHTLY ABOVE THE
STATISTICAL/DYNAMICAL SHIPS AND LGEM GUIDANCE.

THE INITIAL MOTION ESTIMATE IS A SOMEWHAT UNCERTAIN 335/5.  THE
CYCLONE IS FORECAST TO TURN WESTWARD DURING THE NEXT DAY OR TWO
TO THE SOUTH OF A MID-LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO.
THE UNCERTAINTY IN THE TRACK FORECAST INCREASES GREATLY IN THE 3
TO 5 DAY TIME FRAME.  THE GFS AND NOGAPS MODELS MOVE THE SYSTEM
INLAND OVER CENTRAL AMERICA IN A FEW DAYS. CONVERSELY...THE
HWRF...ECMWF...AND UKMET MODELS TAKE THE CYCLONE INTO THE
SOUTHEASTERN GULF OF MEXICO IN THE LATTER PART OF THE FORECAST
PERIOD IN RESPONSE TO AN EASTWARD SHIFT OF THE ABOVEMENTIONED
RIDGE.  THE OFFICIAL FORECAST LIES BETWEEN THESE TWO EXTREMES...
AND IS CLOSE TO THE GFDL TRACK.


FORECAST POSITIONS AND MAX WINDS

INIT  23/2100Z 15.9N  81.9W   30 KT  35 MPH
 12H  24/0600Z 16.4N  82.2W   35 KT  40 MPH
 24H  24/1800Z 16.8N  82.9W   40 KT  45 MPH
 36H  25/0600Z 17.0N  83.5W   45 KT  50 MPH
 48H  25/1800Z 17.1N  84.3W   50 KT  60 MPH
 72H  26/1800Z 17.3N  86.0W   50 KT  60 MPH
 96H  27/1800Z 17.7N  87.0W   50 KT  60 MPH
120H  28/1800Z 19.0N  88.0W   50 KT  60 MPH

$$
FORECASTER BROWN

Habemus Rina !!
Oficialmente ya tenemos a la tormenta tropical Rina.

 El sistema registra esta noche vientos máximos sostenidos de 65 km/hr y lleva una trayectoria hacia el noroeste avanzando a 13km/hr. Se ubica a unos 650 kilómetros al este de las costas de Quintana Ro.

El NHC ha elevado un poco más al norte su trayectoria.

000
WTNT43 KNHC 240243
TCDAT3

TROPICAL STORM RINA DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1100 PM EDT SUN OCT 23 2011

EARLIER REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT
INDICATED BELIEVABLE SFMR WINDS OF 33-35 KT OUTSIDE OF THE
CONVECTION IN THE SOUTHWESTERN QUADRANT OF THE CYCLONE...BUT THESE
WINDS COULD HAVE BEEN GUSTS. THE AIRCRAFT ALSO HAD TO AVOID STRONG
THUNDERSTORMS TO THE NORTH OF THE CENTER AND WAS... THEREFORE...
UNABLE TO SAMPLE THE WINDS IN THAT AREA. SINCE THEN... HOWEVER...
DEEP CONVECTION HAS INCREASED MARKEDLY IN THE NORTHERN SEMICIRCLE
AND CONVECTION HAS ALSO DEVELOPED IN THE SOUTHWESTERN QUADRANT...
WHICH IS LIKELY HELPING TO SUSTAIN THE STRONGER WINDS IN THAT
REGION AS REPORTED PREVIOUSLY. UW-CIMSS ADT ESTIMATES HAVE BEEN
STEADILY INCREASING...AND THE MOST RECENT 2-HOUR AVERAGE IS T2.7/39
KT. AS A RESULT...THE DEPRESSION HAS BEEN UPGRADED TO TROPICAL
STORM RINA...THE SEVENTEENTH NAMED STORM OF THE SEASON.

RINA IS FORECAST TO REMAIN OVER SSTS OF NEAR 30C FOR THE NEXT 72-96
HOURS. IN ADDITION...DURING THE 24-48 HOUR TIME PERIOD...THE
CYCLONE WILL BE MOVING OVER SOME VERY HIGH UPPER-OCEAN CONTENT THAT
IS MORE THAN 10 TIMES THE VALUE THE STORM IS CURRENTLY TRAVERSING.
THE UPPER-LEVEL OUTFLOW HAS BEEN STEADILY INCREASING AND IS
EXPECTED TO IMPROVE EVEN MORE THROUGH 72 HOURS AS RINA MOVES UNDER
AN UPPER-LEVEL RIDGE AXIS THAT WILL PRODUCE OUTFLOW CHANNELS TO THE
NORTH AND SOUTH. SO THERE IS PLENTY OF HEAT AND VENTILATION
AVAILABLE FOR STRENGTHENING TO OCCUR. THE ONLY POSSIBLE INHIBITING
FACTOR IS VERY DRY MID-LEVEL AIR LOCATED OVER THE SOUTHERN GULF OF
MEXICO AND YUCATAN CHANNEL...WHICH COULD BE ENTRAINED INTO THE
CYCLONE AT 48 HOURS AND BEYOND. AS A RESULT...THE INTENSITY
FORECAST WILL REMAIN ON THE CONSERVATIVE SIDE AND LIES CLOSE TO THE
INTENSITY CONSENSUS MODEL ICON...AND THE STATISTICAL-DYNAMICAL
MODEL...LGEM.

THE INITIAL MOTION ESTIMATE IS 335/7 KT BASED ON RECON FIXES. THE
FORECAST TRACK DEPENDS HEAVILY ON THE INTENSITY FORECAST. SINCE THE
OFFICIAL INTENSITY FORECAST IS MUCH MORE ROBUST THAN WHAT THE
GFS...NOGAPS...CANADIAN...AND GFDL MODELS ARE FORECASTING FOR THE
NEXT 48 HOURS AND BEYOND...THOSE MODEL SOLUTIONS OF A WESTWARD OR
EVEN WEST-SOUTHWESTWARD MOTION FROM THE CURRENT POSITION HAVE BEEN
DISCOUNTED. IN CONTRAST...THE HWRF AND UKMET MODELS ARE FORECASTING
A STRONGER AND DEEPER CYCLONE THROUGHOUT THE THE FORECAST PERIOD...
WHICH LOOKS MORE LIKELY GIVEN THE RECENT UPWARD TRENDS IN SATELLITE
AND UPPER-AIR DATA. AS A RESULT...THE EXPECTED FORECAST SCENARIO
CALLS FOR RINA TO MOVE NORTHWESTWARD THROUGH A WEAKNESS IN THE
SUBTROPICAL RIDGE FOR THE NEXT 12 HOURS OR SO. AS A VIGOROUS
SHORTWAVE TROUGH CURRENTLY MOVING EASTWARD ACROSS THE CENTRAL AND
EASTERN GULF OF MEXICO PASSES EAST OF FLORIDA TOMORROW...THE RIDGE
SHOULD BUILD BACK IN TO THE NORTH OF RINA...FORCING THE CYCLONE ON
A SLOW WEST-NORTHWESTWARD TRACK UNTIL DAY 4. AFTER THAT...ANOTHER
STRONG SHORTWAVE TROUGH IS FORECAST TO DIG SOUTHEASTWARD FROM THE
SOUTHERN PLAINS AND INTO THE GULF OF MEXICO...WHICH IS EXPECTED TO
WEAKEN THE SUBTROPICAL RIDGE ONCE AGAIN AND ALLOW RINA TO TURN
NORTHWARD NEAR THE YUCATAN PENINSULA. THE OFFICIAL FORECAST TRACK
LIES TO THE RIGHT OF THE PREVIOUS ADVISORY TRACK AND THE CONSENSUS
MODELS..AND IS CLOSE TO A BLEND OF THE UKMET...HWRF...AND ECMWF
MODEL TRACKS.

IN THE SHORT TERM...HEAVY RAINFALL AND FLOODING WILL BE SIGNIFICANT
THREATS FOR NORTHERN HONDURAS WHERE 8-15 INCHES OF RAIN HAVE
ALREADY FALLEN DURING THE PAST 3 DAYS.


FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 16.4N  82.2W   35 KT  40 MPH
 12H  24/1200Z 16.8N  82.6W   40 KT  45 MPH
 24H  25/0000Z 17.3N  83.4W   45 KT  50 MPH
 36H  25/1200Z 17.5N  84.3W   50 KT  60 MPH
 48H  26/0000Z 17.7N  85.1W   55 KT  65 MPH
 72H  27/0000Z 17.9N  86.2W   60 KT  70 MPH
 96H  28/0000Z 18.9N  87.4W   65 KT  75 MPH
120H  29/0000Z 20.0N  87.4W   65 KT  75 MPH

$$
FORECASTER STEWART