Wave? In Eastern Caribbean

[cycloneye]

000
FXCA62 TJSJ 152010
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
410 PM AST SUN JUL 15 2007

.SYNOPSIS...AT UPPER LEVELS...A RIDGE EXTENDS SOUTHWEST ACROSS
HAITI FROM A TUTT LOW NEAR 29 NORTH 57 WEST. A SECOND LOW WILL
DEEPEN NEAR 30 NORTH 39 WEST ON MONDAY. HIGH PRESSURE NEAR 18 NORTH 48
WEST WILL BUILD WEST OVER THE LOCAL AREA MONDAY AND TUESDAY AND
DISPLACE THE TROUGH TO THE WEST. THE FOCUS OF THE TUTT WILL BECOME
MORE EAST-WEST BY FRIDAY ALONG AN AXIS NEAR 26 NORTH AND HIGH
PRESSURE WILL CONTINUE SOUTH OF IT OVER THE LOCAL AREA.

AT MID LEVELS...HIGH PRESSURE OVER THE CENTRAL ATLANTIC LIES JUST
NORTHEAST OF A WEAK LOW CENTER NEAR 29 NORTH 57 WEST. THE LOW
PRESSURE WILL SLOWLY DRIFT TOWARD THE NORTHERN BAHAMAS DURING THE
NEXT SEVEN DAYS WHILE THE HIGH PRESSURE BUILDS SOMEWHAT AND DRIFTS
NORTHEAST. THIS WILL MAINTAIN A MODEST EAST OR EAST SOUTHEAST FLOW
OVER THE AREA. A GENERAL DRYING TENDENCY WILL BE NOTED ONLY AFTER
FRIDAY.

AT LOWER LEVELS...A STRONG HIGH PRESSURE CENTERED IN THE ATLANTIC
DOMINATES THE OCEAN FROM COAST TO COAST. IT WILL SLOWLY DRIFT EAST
NORTHEAST AND BUILD THROUGH SATURDAY. BUT LOW LEVEL FLOW WILL
REMAIN EASTERLY THROUGHOUT THE PERIOD HERE. A STRONGLY TILTED
TROPICAL WAVE IS ADVANCING THROUGH THE LESSER ANTILLES AND THE
FIRST SHOWERS FROM THIS WAVE ARE APPROACHING SAINT CROIX. A SECOND
TROPICAL WAVE IS IN THE MID TROPICAL ATLANTIC AND SHOULD PUSH
THROUGH THE LOCAL AREA ON THURSDAY. A THIRD WAVE IS STILL EXPECTED
ON MONDAY.

&&

.DISCUSSION...CONVECTIVE ACTIVITY WAS ENHANCED THIS MORNING BY THE
PROXIMITY OF THE TUTT TO OUR WEST. THE DRY SLOT MOVED INTO THE AREA
DURING THE MID MORNING HOURS AND MOST PRECIPITATION DISSIPATED.
THE AFTERNOON ACTIVITY MAY ALSO HAVE FALLEN VICTIM TO THIS AS IT
WAS JUST FORMING AS OF 4 PM AST. THE WAVE IS FORMING
NORTHEAST/SOUTHWEST BANDS OF CONVECTION OUT AHEAD OF IT. CURRENTLY
THE WAVE APPEARS TO BE CENTERED FROM 19.4 NORTH 60 WEST TO 9
NORTH 76 WEST. WIND SHIFTS HAVE BEEN NOTED IN
BARBADOS...GUADELOUPE AND ANTIGUA AND ARE IN PROGRESS AT SAINT
KITTS AND SAINT MARTIN. NO CURRENT RAIN RATE PRODUCTS WERE
AVAILABLE ON THE NOAA PAGE BUT SATELLITE TOPS INDICATE SOME AREAS
OF STRONG CONVECTION AND SHOWERS ARE NOTED IN THE OBSERVATIONS IN
THE LESSER ANTILLES. IN ADDITION THE 12Z GFS TODAY IS SHOWING
STRONG DIVERGENCE ALOFT OVER EASTERN PUERTO RICO AT BOTH 00Z AND
12Z MONDAY. THEREFORE HAVE UPPED THE POPS AND TO SOME EXTENT THE
AMOUNT OF PRECIPITATION EXPECTED ACROSS THE SOUTHEAST HALF OF OUR
FORECAST AREA. WOULD EXPECT SOME OVERNIGHT EARLY MORNING URBAN AND
SMALL STREAM FLOODING FROM THIS ACTIVITY BUT AT THIS TIME DO NOT
FEEL SUFFICIENTLY CONFIDENT TO ISSUE A FLASH FLOOD WATCH.

DRYING AFTER THE WAVE IS NOT AS DRAMATIC AS EARLIER MODEL RUNS LED
US TO BELIEVE...AND HAVE RAISED BY A SMALL AMOUNT THE POP OVERNIGHT
MONDAY. SATELLITE IMAGERY...SAL PRODUCTS AND AEROSOL OPTICAL
THICKNESS CHARTS STILL INDICATE A GREAT DEAL OF AFRICAN DUST
BEHIND THIS WAVE FOR TUESDAY AND BEYOND...BUT HAVE NOT YET ENTERED
IT INTO THE GRIDS. THE TREND TO INCREASING CONVECTION AND MOISTURE
BEHIND THE WAVE WOULD REDUCE THE AMOUNT OF DUST IN THE AIR AND SO
WILL LEAVE THIS UNTIL A LATER CYCLE. WAVES MOVING ACROSS THE
ATLANTIC FOR THURSDAY AND MONDAY ARE STILL MOVING MUCH AS FORECAST
AND THE TROPICAL PREDICTION CENTER IS CLASSIFYING THE NEXT WAVE AS ONE
WITH A VERY LARGE AMPLITUDE. THE GFS CONTINUES ALSO TO BRING ONE
ACROSS THE LOCAL AREA ON MONDAY. THUNDERSTORM ACTIVITY IN AFRICA
WOULD ALSO SUPPORT THIS.

Wow,what a long and complete discussion by the San Juan NWS about this complex system of trough/wave.The discussion says it all about all the features that are in all the area of Caribbean and Western Atlantic.But nothing that will organize as the interaction between the wave and the TUTT trough will not let it occur. However,a rather wet night and monday for the NE Caribbean islands.

[NDG]

Right now south and a little west, and north of Hispanola do not look unfavorable for development by my amatuer eyes,

You are looking at the axis of the TUTT, if you are looking at the windshear map, which even if the there's low windshear, is not good for tropical development anyway. Believe it or not the best spot for tropical development is just to the east of the tropical wave axis, though the TUTT is creating windshear is also helping in ventilating the area, the wave has a decent surface convergence also.

[HurricaneMaster_PR]

Showers and thunderstorms are now entering the east coast of Puerto Rico...It await us a very rainy night as well as a wet Monday...

[caribepr]

Oh I wish I knew how to post pictures on this forum! Watching the wave move over us was so awesome!! The clouds were racing and tumbling over each other with the sunset lighting them up in amazing colors. Then it went to black. The power has gone out about three times and the rain is starting now. It's going to be a happy night for the gardens

[Starburst]

Enjoy Caribepr! That sounds amazing a great sleeping night for most

[caribepr]

Well, as it turned out, it was a bit more of a bust than a burst! But the plants did get some good rain water and for that I'm grateful

[Comanche]

If this is the same wave the Canadian has been trying to develop, JB says to watch it close this weekend as whatever it becomes (if anything) will be in the Gulf. He has not bad his eye on much over the last several weeks, so this is noteworthy.

[Sanibel]

A weak "bear's watch" for this one if it persists.

[gatorcane]

thunderstorm activity is flaring up as the wave is interacting with a ULL. Still may need to watch this as it heads through the northern Caribbean...

[Opal storm]

A weak "bear's watch" for this one if it persists.

How about a "baby bear watch"?

[Steve]

The Canadian jumped the gun with its puzzling intensity forecast. But most of the other globals seem to show a ripple at the surface pressure heading toward and possibly across Florida and into the Gulf as Atlantic ridging pulses westward. I guess we'll see.

Steve

[MGC]

This will not develope in the short run. Maybee in a few days once it get in the GOM but I'm still doubtfull. My son leaves Saturday from Mobile on the Carnival Holiday. I'd hate for it to rain on his cruise.....MGC

[chadtm80]

thunderstorm activity is flaring up as the wave is interacting with a ULL. Still may need to watch this as it heads through the northern Caribbean...

[Tampa Bay Hurricane]

I'd say a slight chance of development. If it develops
and maintains convection, becomes more organized,
and also if the shear decreases in its path.
Convection fires up, but we have to see if
the convection is persistent and must also
look to the shear. The oceanic heat content
could certainly support development, but ONLY
if other factors allow it.

[DESTRUCTION5]

The Canadian jumped the gun with its puzzling intensity forecast. But most of the other globals seem to show a ripple at the surface pressure heading toward and possibly across Florida and into the Gulf as Atlantic ridging pulses westward. I guess we'll see.

Steve

Im surprised no FL forecasts have incuded this wave in thier discussions?

[windstorm99]

I think tropical cyclone development chances are quite low as most of this convection is actually being inhanced by an ULL in the area.

[storms in NC]

thunderstorm activity is flaring up as the wave is interacting with a ULL. Still may need to watch this as it heads through the northern Caribbean...

I think this has a better chance than the Gulf does. This don't look too bad in the flarups.

[hial2]

I'd say a slight chance of development. If it develops
and maintains convection, becomes more organized,
and also if the shear decreases in its path.
Convection fires up, but we have to see if
the convection is persistent and must also
look to the shear. The oceanic heat content
could certainly support development, but ONLY
if other factors allow it.

And if my grandmother had wheels,she'd be a bicycle...J/K

[windstorm99]

8:05pm NHC Discussion...

TILTED TROPICAL WAVE IS OVER THE FAR SW ATLANTIC AND ERN
CARIBBEAN ALONG 21N67W 8N72W MOVING WEST 15 KT. THE WAVE IS
UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH OVER THE SOUTHWEST
NORTH ATLANTIC AND CENTRAL CARIBBEAN WITH DIFLUENT FLOW E OF THE
TROUGH AXIS ENHANCING SCATTERED MODERATE CONVECTION OVER
HISPANIOLA FROM 16N-22N BETWEEN 67W-74W.

[TheRingo]

this sure does seem like the northern part of this wave could enter into the gulf.
If this ull keeps enhancing the wave. This thing could sustain itself when it hits warmer
waters.