comitan - 10-15-2007 at 11:15 AM
Tropical Depression FIFTEEN-E Forecast Discussion
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000
WTPZ45 KNHC 151500
TCDEP5
TROPICAL DEPRESSION FIFTEEN-E DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152007
800 AM PDT MON OCT 15 2007
EARLY MORNING VISIBLE SATELLITE IMAGERY INDICATES THAT THE
CENTER IS EXPOSED EAST OF THE LARGE AREA OF COLD CLOUDS TOPS...DUE
TO MODERATE EASTERLY SHEAR. THIS POSITION IS SLIGHTLY SOUTHEAST OF
THE EARLIER ESTIMATES AND SUGGESTS THAT THE DEPRESSION MOVED VERY
LITTLE OVERNIGHT. LIGHTNING DATA REVEAL THAT THE AREA OF ACTIVE
CONVECTION IS RATHER SMALL...WITH MOST OF THE COLD CLOUDS BEING
ASSOCIATED WITH CIRRUS OUTFLOW TO THE WEST.
DVORAK INTENSITY ESTIMATES FROM BOTH AGENCIES SUPPORT TROPICAL STORM
STRENGTH...BUT THE CENTER LOCATIONS OF THESE FIXES WERE CLOSER TO
THE DEEP CONVECTION. SINCE THE VISIBLE IMAGERY SHOWS THE CENTER IS
FARTHER EAST...THE INITIAL INTENSITY WILL REMAIN 30 KT. MOST OF
THE DYNAMICAL MODELS AND THE SHIPS GUIDANCE ARE LESS BULLISH IN
DECREASING THE EASTERLY SHEAR OVER THE CYCLONE. IN FACT...THE
SHIPS GUIDANCE KEEPS THE SHEAR 15 KT OR GREATER THROUGHOUT MOST OF
THE FIVE-DAY FORECAST PERIOD. THE NEW INTENSITY FORECAST IS
LOWERED SLIGHTLY FROM THE PREVIOUS ADVISORY AND IS IN CLOSE
AGREEMENT WITH THE ICON CONSENSUS.
THE INITIAL MOTION IS ESTIMATE IS 330/2. THE DEPRESSION IS FORECAST
TO MOVE VERY LITTLE DURING THE NEXT 2-3 DAYS. THE WEAK STEERING
CURRENTS RESULT FROM THE LACK OF A STRONG SUBTROPICAL RIDGE TO THE
NORTH OF THE TROPICAL CYCLONE...DUE TO A TROUGH APPROACHING THE
WEST COAST OF THE UNITED STATES. AS MENTIONED IN THE PREVIOUS
DISCUSSION...IT WOULD NOT BE SURPRISING TO SEE SOME EASTWARD MOTION
OF THE DEPRESSION DURING THE NEXT COUPLE OF DAYS...AS IT COULD GET
PULLED EASTWARD BY A LARGE LOW- TO MID-LEVEL CYCLONIC GYRE NEAR
MEXICO. LATER IN THE FORECAST PERIOD...AS THE TROUGH
MOVES EASTWARD...WEAK RIDGING IS FORECAST BUILD NORTH OF THE
CYCLONE....WHICH SHOULD INDUCE A SLOW NORTHWESTWARD MOTION. THE
OFFICIAL FORECAST GENERALLY FOLLOWS THE GFDL...HWRF...AND GFS
SOLUTIONS. HOWEVER...THERE IS A LARGE SPREAD IN THE FORWARD MOTION
OF THE CYCLONE IN THESE MODELS. FOR NOW...THE OFFICIAL FORECAST IS
NEAR THE CONSENSUS OF THOSE MODELS...WHICH IS ALSO CLOSE TO THE
PREVIOUS NHC FORECAST.
FORECAST POSITIONS AND MAX WINDS
[Edited on 10-15-2007 by comitan]
[Edited on 10-15-2007 by comitan]
BajaBruno - 10-15-2007 at 11:52 AM
The NHC seems to be uncharacteristically unimpressed by this cyclone. Let's hope that is not misplaced optimism.
comitan - 10-15-2007 at 12:03 PM
They did say they thought it would head east, that might possibly bring it over us with rain.
BajaBruno - 10-15-2007 at 01:00 PM
They seem to believe it will peak at 45k and die from there, if I am interpreting this table correctly. Look at the location in 3 1/2 days--only
about 110 miles away from where it is now, if my math is correct, which means they expect it to only move at less than 1 knot during that time. That
would be quite slow, and considering that it is sitting over water of about 29C, the strength estimates seem quite conservative. Of course, I am
certainly no weather god and they have fooled me before!
FORECAST POSITIONS AND MAX WINDS
INITIAL 15/1500Z 15.2N 108.9W 30 KT
12HR VT 16/0000Z 15.3N 108.9W 35 KT
24HR VT 16/1200Z 15.6N 108.9W 40 KT
36HR VT 17/0000Z 15.9N 108.9W 45 KT
48HR VT 17/1200Z 16.3N 109.0W 45 KT
72HR VT 18/1200Z 16.9N 109.4W 45 KT
96HR VT 19/1200Z 17.5N 110.0W 45 KT
120HR VT 20/1200Z 18.3N 111.0W 40 KT
2 p.m. update 15-e
tortuga - 10-15-2007 at 06:27 PM
forecast discussion
tortuga - 10-15-2007 at 06:34 PM
Tropical Depression FIFTEEN-E Forecast Discussion
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000
WTPZ45 KNHC 152039
TCDEP5
TROPICAL DEPRESSION FIFTEEN-E DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152007
200 PM PDT MON OCT 15 2007
DEEP CONVECTION HAS DECREASED DURING THE PAST FEW HOURS...EXPOSING
THE LOW-LEVEL CIRCULATION THAT IS NOT EXCEPTIONALLY WELL-DEFINED.
A QUIKSCAT OVERPASS AT AROUND 1330Z PROVIDED SEEMINGLY RELIABLE
WIND RETRIEVALS OF 25-30 KT...WITH HIGHER VALUES IN THE WESTERN
SEMICIRCLE THAT WERE LIKELY INFLATED BY THE CONVECTION AT THE TIME.
THE ADVISORY INTENSITY IS MAINTAINED AT 30 KT BASED ON THE QUIKSCAT
DATA. THE EASTERLY SHEAR IS FORECAST BY THE DYNAMICAL MODELS TO
PERSIST AT ROUGHLY ITS CURRENT MAGNITUDE THROUGHOUT THE NEXT FIVE
DAYS...SO SIGNIFICANT STRENGTHENING APPEARS UNLIKELY. MOST OF THE
OBJECTIVE INTENSITY MODELS FORECAST A LITTLE STRENGTHENING. THE
OFFICIAL FORECAST DOES TOO...BUT LEANS TOWARD THE WEAKER SOLUTIONS
GIVEN HOW MUCH THE SYSTEM IS CURRENTLY STRUGGLING IN THE SHEARED
ENVIRONMENT.
THE CENTER OF THE DEPRESSION HAS BEEN ESSENTIALLY STATIONARY DURING
THE PAST 12-18 HOURS. STEERING CURRENTS ARE OBVIOUSLY WEAK...AND
MOST OF THE DYNAMICAL MODELS FORECAST LITTLE CHANGE IN THE
SURROUNDING SYNOPTIC PATTERN FOR THE NEXT SEVERAL DAYS. THERE IS A
WEAK AND NARROW MID-LEVEL RIDGE TO THE NORTH OF THE TROPICAL
CYCLONE...BUT THE SYSTEM IS NOT DEEP ENOUGH TO RESPOND...AND THERE
ARE NO LOW-LEVEL STEERING MECHANISMS IN PLAY. THE MODEL GUIDANCE
TRACKS GO IN ALL KINDS OF DIRECTIONS. SOME OF THEM...INCLUDING THE
GFS...FORECAST NO SIGNIFICANT NET MOTION THROUGH THE ENTIRE
FORECAST PERIOD...WHICH SUPPORTS THE OFFICIAL FORECAST OF A NEARLY
STATIONARY CYCLONE FOR THE NEXT FIVE DAYS.
FORECAST POSITIONS AND MAX WINDS
INITIAL 15/2100Z 15.1N 108.7W 30 KT
12HR VT 16/0600Z 15.1N 108.7W 35 KT
24HR VT 16/1800Z 15.1N 108.7W 35 KT
36HR VT 17/0600Z 15.1N 108.7W 35 KT
48HR VT 17/1800Z 15.1N 108.7W 35 KT
72HR VT 18/1800Z 15.0N 108.5W 35 KT
96HR VT 19/1800Z 15.0N 108.5W 35 KT
120HR VT 20/1800Z 15.0N 108.5W 35 KT
$$
FORECASTER KNABB
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BajaBruno - 10-16-2007 at 02:37 PM
She is now TROPICAL STORM KIKO. She's still just aimlessly hanging around the bar, but not getting drunk with power in the process.