INVEST 97L: Near Puerto Rico :Discussions & Images

[gatorcane]

Notice how our invest as an upper anyticyclone over it at this time. BUT -- looks like conditions down the road may not be as favorable.

[Gustywind]

convection continues to become better organized tonight. Looks like we will see this form into our next depression soon as it continues to move WNW. Expect models to shift some to the right and aim more at the SE Bahamas as the energy has shifted farther north.

Absolutely agree with you Gatorcane that seems more credible, chance to see a td tommorow are much higher, we will see tommorow but looking better organized during the last hour with more concentrated convection...could be something huge if this trend continues tonight!

[gatorcane]

Latest mean mid-level steering flow. Notice the Big High over the Eastern US is not quite as strong as earlier today and it does look like there is a weakness north of our invest. I wonder if it will feel it and start moving NW soon?

[Vortex]

Barbados

Pressures continue to fall and winds are now out of the NNE


184 ft / 56 m

79 °F / 26 °C
Scattered Clouds
Humidity: 89%
Dew Point: 75 °F / 24 °C
Wind: 7 mph / 11 km/h / 3.1 m/s from the NNE
Pressure: 29.83 in / 1010 hPa (Falling)

[Gustywind]

Fresh news by Jeff Masters
http://www.wunderground.com/blog/JeffMa ... amp=200709
Posted by: JeffMasters, 8:11 PM EDT on September 23, 2007

Lesser Antilles disturbance 97L
Of greater concern is a tropical wave (97L) about 300 miles east of Barbados in the Lesser Antilles Islands. This wave has not gotten any better organized during the past 12 hours, as seen in the latest Satellite imagery. The wave is under about 10 knots of wind shear. The shear is forecast to remain below 10 knots through Tuesday, and there is some favorable anticyclonic outflow at high levels, and 97L has a good chance of developing into a tropical depression by Tuesday. At that point, the future evolution of the storm depends strongly on how far north it is. If 97L moves northwest over Puerto Rico on Wednesday, as the GFDL and some of the global models predict, it may encounter a zone of high wind shear associated with the bottom part of a trough of low pressure positioned to the north of Puerto Rico. This shear should keep the storm from becoming a hurricane. If 97L stays on a more west-northwest track and penetrates into the Caribbean Sea south of Puerto Rico, as predicted by the simpler BAMM model, the storm is likely to encounter less shear, and could grow into a hurricane. Regardless, 97L will bring heavy rain and gusty winds to most of the Lesser Antilles Islands tonight through Tuesday.
we will see

[gatorcane]

Unlike Ingrid, invest 97L does not have a barrage of Upper-Level lows out ahead of it. Unfortunately those TUTT lows have retograded west and have left the door open for this invest.

Water Vapor imagery shows this here:
http://www.ssd.noaa.gov/goes/east/carb/loop-wv.html

Another thing to note is that on the far upper-left hand corner of that loop, you can see ridging building into the Eastern CONUS. So this invest could continue to track WNW but probably won't bend to the north anytime soon. It *could* very well be our next Caribbean Hurricane.

Note there is one to the NNW of our invest about 800+ miles. You can see it diving to the SE. That is the one that if our invest took a NW track it would probably get sheared to bits. But if it follows the shallow BAMS it would miss this shear to the south. That is the consensus with JB.

[HurricaneMaster_PR]

DATE/TIME LAT LON CLASSIFICATION STORM
23/2345 UTC 9.7N 56.5W TOO WEAK 97L

[wxmann_91]

Don't worry about the conditions in front of it being unfavorable. The upper anticyclone is forecast to move in tandem with this system for at least the next 5 days.

IF (this is actually a big if) the storm enters and stays in the Caribbean, the conditions look very favorable for a significant hurricane to develop. BUT if it ends up near the islands or moves into the shear zone just to the north, this will be another '07 dud.

The models suck at handling ULL's, and that will make a huge difference as to the track and intensity for this system.

[Vortex]

Barbados as of 9pm

winds have been coming around from the ene, ne, nne, and now north....

*LLC may be forming to the e/ese of the island


:00 PM 78.8 °F / 26.0 °C 75.2 °F / 24.0 °C 89% 29.86 in / 1011 hPa 6.2 miles / 10.0 kilometers North 6.9 mph / 11.1 km/h / 3.1 m/s - N/A

[RL3AO]

There is defiantly something east of Barbados.

[gatorcane]

There is defiantly something east of Barbados.

Yes there is some kind of turning but it is hard to see the lower levels at night. I think the LLC maybe ESE of Barbados by about 200 miles just SE of the latest convective burst. We will be able to see more tomorrow.

Anybody have any new model runs for this invest?

Latest IR showing deep convection blowing up tonight:

[Vortex]

Time next models:

00Z
Nam between 10-11
GFS between 1130-1230
CMC 12-1
Nogaps 12-1
UKmet 1
Euro 330

6Z
Hurricane models between 2-3

[Gustywind]

There is defiantly something east of Barbados.

Yes there is some kind of turning but it is hard to see the lower levels at night. I think the LLC maybe ESE of Barbados by about 200 miles just SE of the latest convective burst. We will be able to see more tomorrow.

Anybody have any new model runs for this invest?

Latest IR showing deep convection blowing up tonight:

Absolutely hope it will not deepen quickly during the night because this continues shows up cleary a decent bursting shot by hour!

[Derecho]

Yes there is some kind of turning but it is hard to see the lower levels at night. I think the LLC maybe ESE of Barbados by about 200 miles just SE of the latest convective burst. We will be able to see more tomorrow.

As of 6:11PM Eastern today, there was no circulation per QUIKSCAT:

[MiamiensisWx]

The future path of 97L will likely depend on the formative location of a definite LLC within the next ~24-48 hours. If the low-level circulation forms near ~14N + faster organization occurs before the Windwards = 97L may feel the transient weakness left behind by the UL trough. Model prognostications indicate unfavorable NW/westerly shear N of the Greater Antilles. If 97L establishes a circulation S of ~14N, a Caribbean cruiser appears more likely based on 1) the steering currents at ~500-850 hPa and 2) a retrograding upper low in the central Caribbean Sea (click here). Currently, I'm banking on an initial WNW motion into the E Caribbean, which is followed by a westward turn just S of the larger islands in the Greater Antilles (i.e. Hispaniola).

700-850 hPa

500-850 hPa

Conditions could be quite optimal, especially because of the tendency for a building UL anticyclone. Ex-94L could induce a weakness in the NW Caribbean (see shortwave imagery), so the jury is still out with respect to a potential United States impact. GFS ensembles and the Euro deepen a s/w trough over the Pacific NW around ~120 hours, with a possible vort max over SW Canada/British Columbia. The downstream 500 mbar pattern would tend to support a possible Dean redux.

12Z GFS ensembles

Overall, I think we have (right now) a decent shot at a Caribbean system. Timing will be a key in the medium to long term.

[HurricaneMaster_PR]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1030 PM EDT SUN SEP 23 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM JERRY...LOCATED ABOUT 1045 MILES WEST OF THE AZORES.

DISORGANIZED SHOWERS AND THUNDERSTORMS EXTEND FROM A WEAK AREA OF
LOW PRESSURE NEAR THE YUCATAN PENINSULA NORTHWARD ACROSS THE
CENTRAL GULF OF MEXICO. STRONG SOUTHERLY UPPER-LEVEL WINDS IN THE
WESTERN GULF OF MEXICO SHOULD KEEP DEVELOPMENT...IF ANY...SLOW TO
OCCUR.

AN AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS LOCATED
ABOUT 200 MILES EAST OF THE SOUTHERN WINDWARD ISLANDS. THIS SYSTEM
HAS CHANGED LITTLE IN ORGANIZATION TODAY...BUT HAS THE POTENTIAL TO
DEVELOP INTO A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. THIS
SYSTEM IS EXPRECTED TO BRING SQUALLY WEATHER TO THE WINDWARD
ISLANDS ON MONDAY...AND THIS WEATHER COULD SPREAD NORTHWESTWARD
INTO THE LEEWARD ISLANDS ON TUESDAY. INTERESTS IN THE LESSER
ANTILLES SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

AN AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS LOCATED
ABOUT 650 MILES SOUTH-SOUTHWEST OF THE CAPE VERDE ISLANDS. THIS
LARGE SYSTEM CONTINUES TO SHOW SIGNS OF ORGANIZATION...AND COULD
BECOME A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO AS IT MOVES
WEST-NORTHWESTWARD AT ABOUT 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
PUBLIC ADVISORIES ON JERRY ARE ISSUED UNDER WMO HEADER WTNT31 AND
UNDER AWIPS HEADER MIATCPAT1. FORECAST/ADVISORIES ON JERRY ARE
ISSUED UNDER WMO HEADER WTNT21 AND UNDER AWIPS HEADER MIATCMAT1.
$$
FORECASTER FRANKLIN

[MWatkins]

Yes there is some kind of turning but it is hard to see the lower levels at night. I think the LLC maybe ESE of Barbados by about 200 miles just SE of the latest convective burst. We will be able to see more tomorrow.

As of 6:11PM Eastern today, there was no circulation per QUIKSCAT:

Nope...no west winds yet...but not a horrible QSCAT presentation either. Convection had faded this afternoon but seems to be firing on the north and south side of that elongated axis this evening. It's getting closer..and in fact I am pretty sure that pass is why the NHC moved the center up a little and initialized the models at 30 knots this evening.

MW

[HurricaneMaster_PR]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1026 PM AST SUN SEP 23 2007

TROPICAL WAVE EAST OF THE WINDWARD ISLANDS TONIGHT HAS SEVERAL
FACTORS IN ITS FAVOR TO INTENSIFY INTO A TROPICAL DEPRESSION
DURING THE NEXT 48 HOURS...WITH SEVERAL MODEL FORECASTS BRINGING A
SURFACE LOW ACROSS OR VERY NEAR THE LOCAL AREA. LOCAL INTERESTS
SHOULD CLOSELY MONITOR THIS ACTIVE TROPICAL WAVE. WHETHER OR NOT
IT DEVELOPS INTO A T.D. IT COULD CERTAINLY BE AN EFFICIENT RAIN
MAKER AS IT MOVES ACROSS THE AREA TUESDAY NIGHT THROUGH WEDNESDAY.

[Brent]

If the current trend continues, I expect TD 12 from this tomorrow.

[deltadog03]

The 9pm pass looks even better. ""center"" is becoming much better defined. here is a pic of it...