000 
FXCA20 KWBC 091804
NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION TROPICAL DESK
1800 UTC APR 09 1996

MODEL COMPARISON (THROUGH 72 HOURS FROM 00 UTC 09 APR 1996) THE
MODELS ARE IN GOOD AGREEMENT THIS CYCLE. THEY FORECAST A WAKENING
MID-UPPER LEVEL TROUGH FROM NRN FLORIDA SW TO THE BAY OF CAMPECHE
TO MOVE E. THE MODELS ALSO FORECAST ANOTHER MID-UPPER TROUGH SW
FROM THE ATLANTIC TO FR GUIANA TO MOVE E OUT OF THE FCST AREA
WHILE
WEAKENING AT THE MID LEVELS BY 48 HRS. A SFC FRONT IS EXPECTED TO
EXTEND SW FROM THE NRN BAHAMAS TO MOVE SE DURING THE PERIOD.

THE MODELS FORECAST A DEEP MID-UPPER LEVEL TROUGH SW FROM THE
ATLANTIC TO FR GUIANA AT 24 HRS TO ENHANCE CONVECTIVE ACTIVITY IN
THE ITCZ. BY 48 HRS...THE MID LEVEL TROUGH WILL WEAKEN BUT THE
UPPER TROUGH WILL PERSIST AND MOVE E OUT OF THE AREA BY 72 HRS.
THIS TROUGH WILL FAVORABLY INTERACT WITH THE ATLANTIC ITCZ NORTH
OF
BRASIL...WITH DEEP CONVECTION/HEAVY SHOWERS IN CLUSTERS EXPECTED
TO
PRODUCE RAINFALL IN EXCESS OF 56MM/DAY THROUGH 72 HRS.

AT 24 HRS...THE MODELS PREDICT THE SUBTROPICAL RIDGE AT 500 HPA
THROUGH THE PERIOD TO EXTEND SW THROUGH A HIGH AT 22N60W TO THE E
PACIFIC. THE HIGH WILL DRIFT NE OUT OF THE AREA BY 72 HRS WHILE
ANOTHER CELL FORMS OVER HONDURAS. BROADSCALE SUBSIDENCE ASSOCIATED
WITH THE RIDGE/HIGHS WILL MINIMIZE DEEP CONVECTION OVER THE
AFFECTED AREA TO 72 HRS. THE MODELS MOVE SHORT WAVE TROUGHS ALONG
BOTH SIDES OF THE RIDGE THROUGH THE CYCLE...INCITING
ISOLATED/LIGHT
SHOWERS/RAINFALL OF 08MM/DAY OVER THE N CARIBBEAN AND S AMERICA.

THE OTHER MID-UPPER LEVEL TROUGH WILL EXTEND FROM N FLORIDA SW TO
THE BAY OF CAMPECHE AT 24 HRS AND MOVE E TO THE CENTRAL BAHAMAS
THROUGH 72 HRS WHILE WEAKENING/FILLING...REDUCING SUPPORT TO THE
SFC FRONT AFTER 48 HRS. THE MODELS PREDICT AN INTENSE N/S
MID-UPPER
RIDGE ALONG 100W (FOLLOWING THE TROUGH) TO COLLAPSE BY THE END OF
THE PERIOD AS SHORT WAVE TROUGHS MOVE AROUND IT.

AT THE SFC...THE MODELS FCST A FRONT FROM NRN BAHAMAS SW TO THE
YUCATAN AT 24 HRS TO MOVE SE TO THE SRN BAHAMAS/CUBA/BELIZE BY 48
HRS AS A 1020HPA SFC HIGH MOVES TO THE NRN GULF OF MEXICO. THE
HIGH
WILL MOVE E ACROSS FLORIDA REDUCING THE SWRD PUSH OF THE FRONT.
THE
FRONT BECOMES MORE E-W ORIENTED EXTENDING FROM JUST N OF
HISPANIOLA
TO THE YUCATAN BY 72 HRS. THE MRF EXPECTS MID/UPPER PVA OVER
FLORIDA/BAHAMAS/CUBA TO ENHANCE CONVECTION/HEAVY SHOWERS ALONG THE
FRONT WITH RAINFALL IN EXCESS OF 36MM/DAY TO 48 HRS. THE FRONT
WILL
THEN GRADUALLY WEAKEN AND ISOLD LIGHT SHOWERS/RAINFALL OF 08-20MM/
DAY IS THEN FCST. THE FRONT WILL INDUCE A SFC TROUGH OVER THE WRN
CARIBBEAN AT 24 HRS...MOVING TO THE CNTRL CARIBBEAN BY 48 HRS THEN
WEAKENING. SLIGHT/MODERATE SHOWERS IS FCST FROM THE YUCATAN TO WRN
HONDURAS TO 60 HRS...THEN SPREADING TO THE W CARIBBEAN. RAINFALL
OF
20-36MM/DAY IS FCST TO 36 HRS THEN REDUCING TO LESS THAN 20MM/DAY.

THE MRF PERSISTS WITH TWO BANDS OF ITCZ IN THE PACIFIC. THE NORTH
BRANCH IS FCST SOUTH OF 10N 05-10 DEG WIDE WHILE THE OTHER BRANCH
WILL LIE ALONG 05S...HEAVY SHOWERS IN ISOL CLUSTERS WITH RAINFALL
20MM OR MORE PER DAY IS EXPECTED.
PERSAD......TTMS (TRINIDAD & TOBAGO)
DAVISON.....NCEP