Strong wave near Leeward Islands - Is Invest 97L

[ROCK]

Wont be anytime soon IMO.....that ULL still has about 30knts of shear in the way....

[cycloneye]

I already posted this very long discussion at the Caribbean thread, but I wanted to post it here as it has interesting things about this wave that the members may want to know.

000
FXCA62 TJSJ 181844
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
244 PM AST SUN JUL 18 2010

.SYNOPSIS...AT UPPER LEVELS...TUTT LOW WITHDRAWS TO NORTHEAST AND
RETURNS OVER THE COURSE OF THE WORK WEEK. OVER THE WEEKEND IT SETS
OUT FOR THE FLORIDA STRAITS WHILE HIGH PRESSURE FILLS IN FROM THE
WEST ALONG 30 NORTH. AN INVERTED TROUGH NEAR 39 WEST WILL MOVE
SOUTH OF THE AREA SATURDAY FOLLOWED BY ANOTHER SUNDAY NIGHT.

AT MID LEVELS...HIGH PRESSURE SHIFTS EAST AT 30 NORTH WHILE A LOW
NEAR 35 WEST MOVES SOUTHWEST AND THEN WEST...CROSSING THE WINDWARD
ISLANDS ON THURSDAY AND THE LOCAL AREA ON FRIDAY NIGHT...BUT A
WEAK AND DISORGANIZED INVERTED TROUGH REMAINS OVER THE EASTERN AND
CENTRAL CARIBBEAN AREA UNTIL NEXT WEEKEND.

AT LOWER LEVELS... A BROAD AND VIGOROUS TROPICAL WAVE CROSSING THE
LEEWARD ISLANDS HAS BEGUN AFFECTING SAINT CROIX AND SAINT THOMAS
AND WILL SOON BE FELT IN PUERTO RICO. EFFECTS FROM THIS WAVE MAY
BE FELT AS LATE AS WEDNESDAY. A WEAK WIND SURGE MAY BE IN THE
WORKS FOR NEXT SUNDAY.

&&

.DISCUSSION...SHOWERS HAVE BEEN SLOW TO DEVELOP DESPITE UNSTABLE
CONDITIONS...AND SUSPECT THAT UPPER LEVELS HAVE MODERATED AS
MENTIONED IN THE PREVIOUS DISCUSSION. HEAVY SHOWERS CONTINUE IN
SOUTHWEST PUERTO RICO AND A FEW SHOWERS WERE MOVING ACROSS EAST
CENTRAL PUERTO RICO. AND ACTIVITY MAY CONTINUE TO DEVELOP OVER
PUERTO RICO APART FROM THE WAVE THROUGH 6 PM. BUT BY FAR THE MOST
ACTIVITY IS NOW ENTERING THE FORECAST AREA FROM THE EAST AND IS
CROSSING THE U.S. VIRGIN ISLANDS. IST AND ISX HAVE REPORTED GUSTS
OF 20 TO 27 KNOTS SO FAR AND EXPECT GUSTS ONLY A LITTLE HIGHER
NEAR THE STRONGER THUNDERSTORMS FOR NOW. THE ASCAT PASS AT 18/1338Z
SHOWED WINDS OF 15 TO 19 KNOTS IN MOST OF THE AREA UNDER THE WAVE
WHERE IT WAS VISIBLE. THE ECMWF APPEARS TO BE ON A WINNING STREAK.
THE CONTINUED MOISTURE IT FORECAST FOR EASTERN PUERTO RICO LAST NIGHT
VERIFIED WELL. LIGHT AMOUNTS WERE HAD IN ABOUT 80 PERCENT OF THE
EASTERN THIRD OF THE ISLAND. SHOWERS ARE NOW PASSING THROUGH THE
VIRGIN ISLANDS AND MAY ARRIVE BEFORE 6 PM AST IN EASTERN PUERTO
RICO...AND WILL ALMOST CERTAINLY WET MUCH OF THE EASTERN HALF OF
PUERTO RICO AS WELL AND CONTINUE WITH THE INCLEMENT WEATHER IN THE
VIRGIN ISLAND TONIGHT AND TOMORROW. THEREFORE HAVE CONTINUED WITH
THE ECMWF FORECAST THROUGH MUCH OF THE WEEK. AS POINTED OUT BY THE
PREVIOUS SHIFT...THE WIDE TROPICAL WAVE MAY BE COMPRISED OF TWO
SEPARATE VORTICES WHICH ROTATED AROUND EACH OTHER IN THEIR JOURNEY
ACROSS THE ATLANTIC. THE ECMWF APPEARS TO DEPICT THIS IN THE
PASSAGE OF TWO WAVES...ONE ON MONDAY MORNING WITH GOOD MOISTURE
AND ONE ON TUESDAY MORNING WITH VERY GOOD MOISTURE. THEN LOW LEVEL
CONVERGENCE CONTINUES ON WEDNESDAY MORNING ALSO WITH VERY GOOD
MOISTURE. THEREFORE CONSIDER THAT RAINY WET WEATHER WILL CONTINUE
THROUGH AT LEAST WEDNESDAY WITH THE BEST AMOUNTS IN EASTERN PUERTO
RICO. THERE IS SOME DRYING ON THURSDAY AND THEN THESE LESSER LEVELS
OF MOISTURE CONTINUE FRIDAY...STILL GOOD FOR SCATTERED SHOWERS.
FEATURES ARE MUCH LESS DISTINCT FOR THE LATTER PART OF THE WEEK
AND NEXT WEEKEND AND WILL TAKE THIS AS A SIGN OF AN AT LEAST
TEMPORARY RETURN TO SOME SEMBLANCE OF NORMALCY FOR THE MONTH OF
JULY.

WITH ALL THIS RAIN THE POSSIBILITY OF SOME FLOODING IS BEGINNING
TO LOOM. WHETHER IT OCCURS WITH THE FIRST WAVE OR THE SECOND IS
UNCERTAIN AND MAY HAVE MORE TO DO WITH THE TIMING OF THE PASSAGE
OF THE FIRST WAVE DURING THE NORMALLY MORE INACTIVE NIGHTTIME
PERIOD. THEREFORE WILL DEFER TO THE EVENING SHIFT WHETHER TO PUT
UP A FLASH FLOOD WATCH FOR MONDAY MORNING OR NOT.


&&

.AVIATION...TEMPO MVFR CONDS AND MOUNTAIN OBSCURATIONS EXPECTED IN AND
AROUND TJMZ IN SHRA OR TSRA THROUGH 18/21Z. THEN...AN APPROACHING
TROPICAL WAVE WILL INCREASE SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE LOCAL AREA. THEREFORE...MVFR OR EVEN IFR CONDS NOW PRESENT IN
TNCM/TKPK...THEN SPREADING IN AND AROUND TIST/TISX AFT 18/20Z AND
TJSJ 19/00Z. ALL HIGHER TERRAIN IS EXPECTED TO BE OBSCURED AFT
19/08Z.

&&

.MARINE...SEAS AT BUOY 41043 HAVE REMAINED ABOVE 7 FEET SINCE
18/12Z AND ARE EXPECTED TO INCREASE SOMEWHAT AS TROPICAL WAVE
APPROACHES. SMALL CRAFT ADVISORIES SHOULD REMAIN CONFINED TO
ATLANTIC WATERS AND THE ANEGADA PASSAGE. HOWEVER STRONG GUSTS
SHOULD BE EXPECTED NEAR THUNDERSTORMS...AND SOME MAY EXCEED 35 KNOTS.

[ROCK]

Yep EURO nada.....and its been that way for some time.....tend to lean at the CMC for developing TC and track wisefor the EURO......but the high in the SE is the kicker....this aint going to plow right through it....

[Ivanhater]

[Ivanhater]

That curvature band on the NE side is really interesting. The "look" of the wave leads me to think it has what it needs in a few days to get going...

[KWT]

Yep EURO nada.....and its been that way for some time.....tend to lean at the CMC for developing TC and track wisefor the EURO......but the high in the SE is the kicker....this aint going to plow right through it....

Actually the ECM shows what looks like a sharp wave close to Florida at 120hrs, wouldn't take much to get a weak closed low from that at all. Models all quite close by.

[Ivanhater]

[Gustywind]

[ronjon]

Wow u can tell the tropics are heating up now - 3 areas of disturbed weather = two that broke off from the caribbean monsoon trough (one over w cuba, the other east of JAM) and our vigorous wave from Africa near the LA. Wouldn't surprise me to see 2 or 3 INVESTs over the next few days.

[Blown Away]

I am surprised and frustrated this has not received Invest status.

[HurrMark]

I am surprised and frustrated this has not received Invest status.

Give it a chance...I think we want to see a little more organization before that can be discussed.

[KWT]

It really is only a matter of time before they decide to invest this system if it can keep the convection developing.

[hurricaneCW]

So what's going to make this develop in a few days? All I see is disorganized weakening convection that's being sheared off.

[ConvergenceZone]

So what's going to make this develop in a few days? All I see is disorganized weakening convection that's being sheared off.

Well, the reason you just mentioned is why it's not forecasted to develop right now. In a few days, it will be in a much better environment.

[KWT]

Yeah the models develop a weak area of low shear, indeed thats already showing its hand to the south of this system. As the ULL slightly lifts out a little that upper high that is allowing a slackening of winds in the E.Caribbean will lift up a little and bring lower shear, though how far north it all retreats is key.

[Ivanhater]

DGEX really likes this wave

[Dean4Storms]

Going to have to really watch this one in a couple days, right now just too much shear and no organization to speak of. It does look like more favorable conditions down the road by Wed/Thur time frame.

[KWT]

Yeah thats real agressive Ivanhater, way too over agressive you've gotta think, I think it ramps up storms even more then the NAM lol!

[Plant grower]

Katrina all over again well the closer we get to August anything is possible, and l I am not counting anything out this season because all the stew in the pot is coming together for a big explosion from August through early October.

[SFLcane]