HPC extended forecasts discussion

[ameriwx2003]

Here is an excerpt from the HPC extended discussion about the wave... Link to full discussion below also..

IN THE NERN CARRIB...THE 12Z GFS CONTINUES TO CARRY THE MID LVL
ENERGY ASSOC WITH THE WAVE CURRENTLY AROUND 57W NWWD INTO THE SERN
BAHAMAS EARLY IN THE MEDR WHERE IT MEETS UP WITH THE WEAKENING H8
BNDRY PASSING SEWD AND THE TUTT LOW CURRENTLY NEAR 28N 62W. VIS
SAT IMAGERY INDICATES THAT THE 06Z AND EARLIER OP MODELS WERE TOO
SLOW FORECASTING THE WWD PROGRESSION OF THE SYS. AT THE CLIP IT
IS CURRENTLY MOVING...WOULD ASSUME THE SYS WOULD NOT BE ABLE TO
MAKE AS SHARP OF A NLY TURN AS THE MODELS INDICATE. THE 12Z GFS
HAS TRENDED A BIT MORE SLY WITH THE H8 ENERGY. HOWEVER...FEEL IT
STILL MAY SHEER TOO MUCH OF THE ENERGY NWD TOWARD THE H8 BNDRY
MOVING IN FROM THE NW. THIS IS ALSO TRUE OF THE 00Z ECMWF WHICH
CONTINUES TO CARRY A SIG LOW OFF THE SE COAST BY DAY 6/SUN. AFTER
COORD WITH TPC...DECIDED TO KEEP THE SYS ON A MORE WLY TRACK THRU
THE CARIB THRU DAY 5/SAT UPON WHICH CONDITIONS BECOME LESS
FAVORABLE FOR SUSTAINING A SFC SYS. OFF THE SE COAST...HAVE
LITTLE CONFIDENCE IN ANY OF THE MODEL SOLNS SINCE THEY ALL SEEMS
TO RELY ON A SIG AMT OF ENERGY FROM THIS WAVE INTERACTING WITH THE
MID LVL BNDRY AND UPR LOW. DID NOT MAKE CHANGES TO THE PREVIOUS
PROGS WHICH ABIDED BY THE WASHES OUT 00Z NCEP ENS MEAN.

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

[kevin]

DECIDED TO KEEP THE SYS ON A MORE WLY TRACK THRU THE CARIB THRU DAY 5/SAT UPON WHICH CONDITIONS BECOME LESS FAVORABLE FOR SUSTAINING A SFC SYS.<< are they saying that the dry air will kill this system?

[Aquawind]

Yet in the same Discussion..

OFF THE SE COAST...THE 00Z GFS SEEMS TO TAKE THE TROP WAVE
CURRENTLY NEAR 55W WWD INTO THE BAHAMAS WHERE IS MEETS UP WITH THE
TAIL END OF A DISSIPATING LOW LVL BNDRY EARLY IN THE PD. THE 06Z
GFS HAS TRENDED SIG STRONGER WITH THE SFC CIRC HERE AND TAKES A
RELATIVELY STRONG LOW TOWARD THE SC COAST BY THE END OF THE PD.
THIS IS THE MOST AGGRESSIVE OP SOLN...WITH ONLY THE 00Z CAN GLOB
SOMEWHAT NEAR THE 06Z GFS STRENGTH THRU THE END OF ITS FORECAST
PD. THE ECMWF SUPPORTS THE GENERAL PATTERN OF CARRYING THE WAVE TO
THE BAHAMAS THIS PD. THEREFORE...THERE IS REASONABLE AGREEMENT IN
THE OP MODELS FOR A SYS. THE 00Z NCEP ENS MEMBS ARE ALL OVER THE
MAP WITH THE SFC REFLECTION OF THE SYS THRU THE END OF THE MEDR.
ONLY TWO MEMBS SEEM TO SUPPORT A CLOSED CIRC LIKE THE 06Z GFS BY
DAY 7/MON. THEREFORE...WITH LITTLE CERTAINTY IN THE PSN AND
STRENGTH OF ANY SYS...WILL LEAN TOWARD THE 00Z NCEP ENS MEAN UNTIL
COORD WITH TPC.