OLGA'S remnants : Discussions & Images

[RL3AO]

94LINVEST.35kts-1009mb

But still no signs of any surface circulation.

[Vortex]

If this were September LOOK out! Either way it's very impressive for December and with strong ridging to the North for the next 3-5 days it will continue west. The set-up is actually similar to Hurricane Kate in 85' We'll C.

[wxman57]

This might be silly to ask but does Florida have to be concerned about this? The high north of this is building and is supposed to be with us through out the upcoming week. This looks like a depression already. It has a nice circulation to it.
http://www.ssd.noaa.gov/goes/east/watl/loop-avn.html

With high pressure building over the eastern U.S. in it's path, a WSW track across PR/DR and generally toward Central America may be most likely - just as the Canadian and European models are forecasting.

[cycloneye]

The NAM tracks just South of Puerto Rico at 30 Hours.

00z NAM at 30 Hours

00z NAM at 42 Hours South of Hispanola.

00x GFS at 60 Hours South of Haiti.

00z NAM at 84 Hours Just Southwest of Jamaica.

[CrazyC83]

If this were September LOOK out! Either way it's very impressive for December and with strong ridging to the North for the next 3-5 days it will continue west. The set-up is actually similar to Hurricane Kate in 85' We'll C.

An off-season hurricane could be disastrous as people would not be prepared...

[CrazyC83]

If they upgrade, the advisory would be in about 20 minutes, since 10 pm EST = 11 pm EDT.

[boca]

More amazingly Central America will get hit by another storm because of the SE ridge according to wxman57.

[artist]

thanks for the update.

[BatzVI]

In case anyone is wondering...here on the northside of St. Thomas, it's been windy all day with occassional showers....I guess it will get uglier tomorrow....I'm about 900 ft up above Magen's Bay for reference.....

[BatzVI]

And also, after having "wrong way Lenny" a few years back, a December storm wouldn't surprise me at all....

[cycloneye]

And also, after having "wrong way Lenny" a few years back, a December storm wouldn't surprise me at all....

You got that right.The tropics are full of surprises many times,but in this case is not a big shock.

[MGC]

The pattern down in the Western Atlantic looks almost summer like with a large ridge from Bermuda to the SE USA. Quite simular to 1985 where two November tropical system impacted the north GOM. Convection has become concentrated today and there is a chance a surface circulation could be forming. The disturbance should remain north of Puerto Rico and perhaps threaten the Bahamas in a few days if it developes. At least this will be something weather wise to look at considering it is expected to be in the mid 70's here on the Mississippi Coast for the next few days....MGC

[wxman57]

GFS forecasts strong westerly winds in the upper levels across the northern Caribbean and PR/DR. 500mb flow is moderate from the east (30kts or so). So if the GFS is correct, wind shear looks a bit strong in its path. The only low wind shear is north of PR/DR, and that small pocket of lower shear may not be around long.

[cycloneye]

The latest from the San Juan NWS:

000
AWCA82 TJSJ 100235
RWSPR

WEATHER SUMMARY FOR PUERTO RICO
NATIONAL WEATHER SERVICE SAN JUAN PR
1035 PM AST SUN DEC 9 2007

BASED ON INFORMATION RECEIVED FROM THE NATIONAL HURRICANE CENTER...AN
AREA OF SHOWERS AND THUNDERSTORMS HAS BECOME BETTER ORGANIZED
TODAY ABOUT 500 MILES EAST-NORTHEAST OF PUERTO RICO...IN
ASSOCIATION WITH A SHARP SURFACE TROUGH AND A LARGE UPPER-LEVEL
LOW. THE SYSTEM IS ALREADY PRODUCING GALE FORCE WINDS...MAINLY TO
THE NORTH AND NORTHEAST OF THE MAIN AREA OF THUNDERSTORMS. THE
SURFACE TROUGH HAS BEEN MOVING WESTWARD AT ABOUT 15 TO 20
MPH...AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE OVER THE
NEXT DAY OR TWO. WATER TEMPERATURES ARE STILL WARM ENOUGH IN THIS
AREA TO SUPPORT TROPICAL CYCLONE FORMATION...AND UPPER-LEVEL WINDS
ARE NOT ESPECIALLY PROHIBITIVE FOR DEVELOPMENT. THIS SYSTEM HAS
THE POTENTIAL TO BECOME A TROPICAL OR SUBTROPICAL STORM DURING THE
NEXT 24 HOURS...AND INTERESTS IN THE NORTHERN LEEWARD
ISLANDS...THE VIRGIN ISLANDS...PUERTO RICO...HISPANIOLA...AND THE
EASTERN BAHAMAS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

FURTHER SPECIAL TROPICAL DISTURBANCE STATEMENTS WILL BE ISSUED AS
NECESSARY.

OVERNIGHT...SHOWERS AND FEW ISOLATED THUNDERSTORMS WILL CONTINUE
TO AFFECT NEARLY ALL OF THE LOCAL AREA. BY MONDAY AFTERNOON THE
MAIN AREA OF THUNDERSTORM ACTIVITY ASSOCIATED WITH THE LOW PRESSURE
SYSTEM WILL BE VERY CLOSE TO THE AREA. EXPECT NUMEROUS SHOWERS
WITH VERY HEAVY RAIN AND ISOLATED THUNDERSTORMS FOR THE GRAND
MAJORITY OF THE AREA. AS THE WEEK PROGRESSES...RIVERS AND URBAN
AREAS WHICH ARE LIKELY TO RECEIVE HEAVY RAIN WILL HAVE A
SIGNIFICANT FLOOD THREAT DURING THE PASSAGE OF THIS SYSTEM. RESIDENTS
AND VISITORS OF THE LOCAL ISLANDS SHOULD CLOSELY MONITOR THE
PROGRESS OF THIS SYSTEM AND ARE URGED NOT TO FOCUS ON EXACT
FORECAST TRACKS...OR WIND SPEEDS...AS THIS SYSTEM HAS THE
POTENTIAL TO BECOME A DANGEROUS RAIN EVENT.

MARINERS SHOULD EXPECT INCREASING WINDS AND SEAS THROUGH THE FIRST
PART OFF THE UPCOMING WORK WEEK...WITH SEAS BUILDING IN EXCESS OF 10
FEET IN THE OFFSHORE ATLANTIC WATERS BY MONDAY AFTERNOON. SMALL CRAFT
ADVISORIES REMAIN IN EFFECT THROUGH TUESDAY MORNING FOR ALL LOCAL
ATLANTIC AND CARIBBEAN WATERS AND PASSAGES. SMALL CRAFT OPERATORS SHOULD
EXERCISE CAUTION ACROSS THE NEAR SHORE WATERS OF WESTERN PUERTO
RICO.

$$

RA

[MiamiensisWx]

First, there IS a sfc circulation. Look at the shortwave loops.

Well, the system is currently moving quickly W. Current shortwave satellite imagery indicates a low-level circulation near 19.1N and 60W. The low-level 850 mb steering currents are strong from east to west, thus implying a faster west motion. I tend to prefer the Euro in this situation: it holds the 500 mb SE ridge in place through ~72 hours, thus bringing the system near western Hispaniola or the far southern Bahamas at the time. Although the Euro holds a well-known bias (refuses to eject energy from the SW CONUS), most models have been underestimating the recent strong SE ridging. Although I certainly do not expect a United States landfall, I think it may be a closer call than anticipated. In a nutshell, I think a general westward movement N of the Antilles to ~66-70W is reasonable, followed by the following scenarios.

1) System is sheared apart via the UL westerlies, thus leading to a naked swirl moving WSW with the LL steering currents
2) System feels the tug and turns NNW. This scenario would be more probable with a stronger system under weaker shear, especially if the UL anticyclone is stronger and the system remains in a favorable "venting" environment

I would lean toward a solution between these outcomes (i.e. system is sheared as it starts to turn NNW). Regardless, there is considerable uncertainity. These two scenarios (highlighted above) would be plausible if the operational 18Z GFS is correct. It keeps the 500 mb ridging in place, although it slowly weakens by ~84 hours. Simultaneously, a new s/w digs in the Plains, preceded by a strong PV vort max in SE Canada that produces NW shear at 200 mb. The GFS is more progressive than the Euro.

200 mb:

http://www.nco.ncep.noaa.gov/pmb/nwprod/an...fs_200_084l.gif

500 mb:

http://www.nco.ncep.noaa.gov/pmb/nwprod/an...fs_500_084l.gif

Currently, I think this system will definitely become a STS or TS.

I just wanted to add my two cents.

Interestingly, this is one of the few systems where the Canadian handled the setup and formation very nicely. This fact definitely offers some lessons about the volatility of the atmosphere and its learning process. FWIW, I think this system could transition to a warm-core TC faster than expected because of the thermal environment. The comparisons to Kate (in terms of formation) are quite valid, thus I believe this system could transition to a tropical (not subtropical) storm. Regardless, I think it will definitely be classified as a TS or STS.

[wxman57]

I couldn't find any evidence of a closed circulation on observations. Satellite loops can be VERY deceiving. You're not looking at the surface. Here's the latest NHC statement:

SPECIAL TROPICAL DISTURBANCE STATEMENT
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1030 PM EST SUN DEC 9 2007

THE AREA OF DISTURBED WEATHER ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE CENTERED ABOUT 425 MILES EAST OF PUERTO RICO REMAINS
FAIRLY WELL-ORGANIZED...BUT SATELLITE IMAGES AND SURFACE
OBSERVATIONS SUGGEST THAT THIS SYSTEM HAS NOT DEVELOPED A CLOSED
CIRCULATION YET. THIS SYSTEM IS MOVING WESTWARD AT 15 TO 20 MPH
AND IS PRODUCING HEAVY SQUALLS WITH GALE FORCE WINDS TO THE NORTH
OF THE SHOWER ACTIVITY. ENVIRONMENTAL CONDITIONS APPEAR TO BE
FAVORABLE FOR SOME DEVELOPMENT AND A TROPICAL OR SUBTROPICAL STORM
COULD FORM DURING THE NEXT 24 HOURS. INTERESTS IN THE NORTHERN
LEEWARD ISLANDS...THE VIRGIN ISLANDS...PUERTO RICO...HISPANIOLA...
AND THE EASTERN BAHAMAS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

FURTHER SPECIAL TROPICAL DISTURBANCE STATEMENTS WILL BE ISSUED AS
NECESSARY. FOR INFORMATION SPECIFIC TO YOUR AREA...CONSULT
STATEMENTS ISSUED BY YOUR LOCAL WEATHER OFFICE.

$$
FORECASTER AVILA

[boca]

So basically your saying no shot at rain on the horizon for Florida.

[MiamiensisWx]

94LINVEST.35kts-1009mb

But still no signs of any surface circulation.

Well, it looks like a LLC is attempting to close.

http://www.ssd.noaa.gov/goes/flt/t1/loop-ir2.html

I see a clear LLC (broad low-level turning) near 19.2N and 60W. Regardless, I tend to agree with the TPC; the system has not met the essential standards, but I think it's very close.

[MiamiensisWx]

So basically your saying no shot at rain on the horizon for Florida.

You're correct. This system won't taste mainland United States soil. The islands should closely monitor 94L.

[RL3AO]

ASCAT shows a little turning. About 4 hours old.