ATL: MARIA - Post-Tropical - Discussion

[tobol.7uno]

Here are the intensity models I mentioned in the last post...

[Aric Dunn]

TVCN keeps shifting right I noticed. Has a good chance of passing well east of the Bahamas.

At the rate the models are shifting, may just lift out north of Puerto Rico or even miss the Leewards all together (though looks like the Leewards are going to get impacted)....there just is no steering mechanism to get this west. Looks more like October out there with the pattern.

no steering mechanism... ??? thats a strong ridge and if you look at the trend of that ridge it is filling in behind katia. if you notice the western edge of the ridge is at the lon of PR and will likely expand westward a little once katia lifts out in the next 24 to 36 hours. Also note that since there is no DIGGING trough that the western portion of the ridge has nothing to erode it so the chance of Maria missing the islands is very low even as a deep system...

loop to see the trend of the ridging/steering at the 500 mb level ( this same steering goes all the way up at what to take note of is the ridging filling in behind Katia)
http://tropic.ssec.wisc.edu/real-time/a ... 2java.html


low level steering ( current)


mid level if it deepens

[cycloneye]

New data from bouy 41041.

http://www.ndbc.noaa.gov/station_page.php?station=41041

Wind Direction (WDIR): E ( 80 deg true )
Wind Speed (WSPD): 36.9 kts
Wind Gust (GST): 46.6 kts

Continuous Winds TIME
(GMT) WDIR WSPD
0150 E ( 80 deg ) 36.7 kts
0140 E ( 79 deg ) 35.5 kts
0130 E ( 79 deg ) 39.0 kts
0120 E ( 80 deg ) 38.3 kts
0110 E ( 79 deg ) 37.3 kts
0100 ENE ( 77 deg ) 33.2 kts

Supplemental Measurements Highest 1-minute Wind Speed
Time (GMT) WSPD WDIR
0126 42.7 kts E ( 80 deg true )

Peak gust during the measurement hour
TIME
(GMT) GDR GST
0126 ENE ( 70 deg ) 52.4 kts

[BigA]

Models are not dissipating this thing, as a matter of fact, the NHC's intensity forecast lies well below the majority of the models.

I'm not saying it's going to dissipate, but models often badly underestimate the effect that wind shear has on tropical cylones. The NHC keeps Maria's intensity at 45 mph for 5 days for this reason. Actually, a forecast of constant weak intensity for 5 days often means they think dissipation is a good possibility but they are not sure.

[meriland23]

Since it keeps going westward at this pace, what does mean for the chances of it hitting the united states.

Probably low, unless it dissipates for a while. Whether it moves west or wnw, the trough on the east coast is still there to turn it away. Actually, the faster movement makes it more likely to be turned away by the trough before the trough starts lifting out.

However, if Maria degenerated into a tropical wave, it would likely move more westward, perhaps even into the central or western Caribbean sea. Then if it redeveloped, it would be a totally new ballgame. This, however, is a rather unlikely scenario.

What if it dissipates to TD status?

[Aric Dunn]

Since it keeps going westward at this pace, what does mean for the chances of it hitting the united states.

Probably low, unless it dissipates for a while. Whether it moves west or wnw, the trough on the east coast is still there to turn it away. Actually, the faster movement makes it more likely to be turned away by the trough before the trough starts lifting out.

However, if Maria degenerated into a tropical wave, it would likely move more westward, perhaps even into the central or western Caribbean sea. Then if it redeveloped, it would be a totally new ballgame. This, however, is a rather unlikely scenario.

What if it dissipates to TD status?

basically right now its being steered by the low levels anyway since the center is so exposed. so its pretty much the same as if it were a TD and not much different if it were a open wave.

[Aric Dunn]

lets go with 13.3N 46.2W

[painkillerr]

lets go with 13.3N 46.2W

Maria is approaching the 15N, 50W benchmark well to the south. What are your thoughts about a PR, Virgin island's strike?

[cpdaman]

i think its possible that she just dies off ....and doesnt recover

[Aric Dunn]

lets go with 13.3N 46.2W

Maria is approaching the 15N, 50W benchmark well to the south. What are your thoughts about a PR, Virgin island's strike?

actually im going to go with 45.8 to 46.0 W...... but given they will probably just extrapolate the motion they will likely go with 13.4N .... since its night.

as for your question. I posted in the model thread about it

[Fego]

URGENT - IMMEDIATE BROADCAST REQUESTED
TROPICAL STORM MARIA LOCAL STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
1042 PM AST WED SEP 7 2011

...MARIA RACING WESTWARD ACROSS THE TROPICAL ATLANTIC...

.STORM INFORMATION...
AT 11 PM AST...THE CENTER OF TROPICAL STORM MARIA WAS LOCATED NEAR
LATITUDE 13.4N...LONGITUDE 46.2W. THIS WAS ABOUT 1490 MILES EAST
OF SAN JUAN PR...OR ABOUT 1420 MILES EAST-SOUTHEAST OF SAINT
THOMAS VI. STORM MOTION WAS W OR 275 DEGREES AT 23 MPH. STORM
INTENSITY WAS 50 MPH.

[Aric Dunn]

URGENT - IMMEDIATE BROADCAST REQUESTED
TROPICAL STORM MARIA LOCAL STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
1042 PM AST WED SEP 7 2011

...MARIA RACING WESTWARD ACROSS THE TROPICAL ATLANTIC...

.STORM INFORMATION...
AT 11 PM AST...THE CENTER OF TROPICAL STORM MARIA WAS LOCATED NEAR
LATITUDE 13.4N...LONGITUDE 46.2W. THIS WAS ABOUT 1490 MILES EAST
OF SAN JUAN PR...OR ABOUT 1420 MILES EAST-SOUTHEAST OF SAINT
THOMAS VI. STORM MOTION WAS W OR 275 DEGREES AT 23 MPH. STORM
INTENSITY WAS 50 MPH.

darn... should not have second guessed myself..

[FireRat]

Models are not dissipating this thing, as a matter of fact, the NHC's intensity forecast lies well below the majority of the models.

I'm not saying it's going to dissipate, but models often badly underestimate the effect that wind shear has on tropical cylones. The NHC keeps Maria's intensity at 45 mph for 5 days for this reason. Actually, a forecast of constant weak intensity for 5 days often means they think dissipation is a good possibility but they are not sure.

It's kind of funny that these type of intensity forecasts are the ones that bust the most, having it blow up like Irene for instance. we should just continue keeping a close eye on it.....................and as for a recurve, man we're still too early to call that as it will likely keep heading in the general direction of the Bahamas by Sept. 12.

The trend is the friend (or fiend), and whatever the trend does between now and Friday will give much more insight to those of us in the U.S. or Bahamas as to what Maria should do. It's easy for us to get used to the recurve pattern after seeing it all year, but that pattern is not eternal and is subject to change. Hopefully it remains in place because you do not want a storm approaching the U.S. or Bahamas from the SE during the PEAK OF HURRICANE SEASON.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[Aric Dunn]

avg 6 hour motion 5pm to 11pm .... 276 degrees at 22mph...

12 hour avg motion 275 degrees at 23mph

[cycloneye]

First TS Watches issued

TROPICAL STORM MARIA FORECAST/ADVISORY NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011
0300 UTC THU SEP 08 2011

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE GOVERNMENT OF ANTIGUA HAS ISSUED A TROPICAL STORM WATCH FOR THE
ISLANDS OF ANTIGUA...BARBUDA...MONTSERRAT...NEVIS...AND SAINT KITTS
IN THE LEEWARD ISLANDS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* THE LEEWARD ISLANDS OF ANTIGUA...BARBUDA...MONTSERRAT...NEVIS...
AND SAINT KITTS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

INTERESTS ELSEWHERE IN THE LEEWARD ISLANDS...THE VIRGIN
ISLANDS...AND PUERTO RICO SHOULD MONITOR THE PROGRESS OF MARIA.

[Aric Dunn]

Also it is south of the 5pm forecast track for this time..

[Aric Dunn]

from discussion

"MARIA IS CURRENTLY ON THE
SOUTH SIDE OF A STRONG LOW/MID-LEVEL SUBTROPICAL RIDGE...AND THIS
SHOULD KEEP THE STORM MOVING QUICKLY WESTWARD FOR THE NEXT
24 HOURS OR SO."

[HurricaneWarning92]

They will probably shift the track to the west a bit in the medium to long range id think.

[cycloneye]

TROPICAL STORM MARIA DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011
1100 PM AST WED SEP 07 2011

MARIA HAS CHANGED LITTLE IN ORGANIZATION OVER THE PAST SEVERAL
HOURS...WITH THE LOW-LEVEL CENTER DISPLACED TO THE SOUTHWESTERN
EDGE OF THE DEEP CONVECTION BY SOUTHWESTERLY VERTICAL WIND SHEAR.
SATELLITE INTENSITY ESTIMATES ARE 45 KT FROM TAFB AND 35 KT FROM
SAB...WHILE NOAA BUOY 41041 JUST REPORTED 1-MINUTE MEAN WINDS OF
43 KT. BASED ON THIS THE INITIAL INTENSITY REMAINS 45 KT.

THE INITIAL MOTION IS A FAST 275/20. MARIA IS CURRENTLY ON THE
SOUTH SIDE OF A STRONG LOW/MID-LEVEL SUBTROPICAL RIDGE...AND THIS
SHOULD KEEP THE STORM MOVING QUICKLY WESTWARD FOR THE NEXT
24 HOURS OR SO. FROM 24-72 HOURS...MARIA SHOULD APPROACH A WEAKNESS
IN THE RIDGE CAUSED BY AN UPPER-LEVEL LOW...WHICH SHOULD ALLOW THE
CYCLONE TO TURN WEST-NORTHWESTWARD WITH SOME DECREASE IN FORWARD
SPEED. THE FORECAST TRACK IS MORE UNCERTAIN AFTER 72 HOURS AS
MARIA APPROACHES THE WESTERN END OF THE SUBTROPICAL RIDGE AND A
DEEP-LAYER TROUGH MOVES EASTWARD THROUGH THE EASTERN UNITED STATES.
WHILE THE GUIDANCE GENERALLY SHOWS A TURN TOWARD THE NORTHWEST...
THERE IS A SIGNIFICANT SPREAD BETWEEN THE MORE WESTERLY GFDL/ECMWF
AND THE MORE EASTERLY GFS/NOGAPS. THE NEW FORECAST TRACK IS
SHIFTED A LITTLE TO THE SOUTH OF THE PREVIOUS TRACK DURING THE
FIRST 48 HOURS...THEN IS CLOSE TO THE THE PREVIOUS TRACK AFTER THAT
TIME. THE NEW TRACK LIES CLOSE TO THE CENTER OF THE GUIDANCE
ENVELOPE AND THE VARIOUS CONSENSUS MODELS.

SIGNIFICANT SOUTHWESTERLY TO WESTERLY SHEAR IS EXPECTED TO CONTINUE
FOR THE NEXT 48-72 HOURS...AND THE NEW INTENSITY FORECAST CONTINUES
TO CALL FOR LITTLE CHANGE IN STRENGTH DURING THAT TIME. AFTER THAT
THERE IS A POSSIBILITY THAT MARIA MAY FIND A DECREASED SHEAR
ENVIRONMENT...ALTHOUGH THE FORECAST PRESENCE OF THE UPPER-LEVEL LOW
NEAR THE STORM MAKES THIS UNCERTAIN. ALL THE INTENSITY GUIDANCE
SHOWS STRENGTHENING AFTER 72 HOURS...SO THE INTENSITY FORECAST NOW
CALLS FOR SOME MODEST STRENGTHENING DURING THAT TIME.


FORECAST POSITIONS AND MAX WINDS

INIT 08/0300Z 13.4N 46.2W 45 KT 50 MPH
12H 08/1200Z 13.7N 49.2W 45 KT 50 MPH
24H 09/0000Z 14.3N 53.3W 45 KT 50 MPH
36H 09/1200Z 15.1N 56.7W 45 KT 50 MPH
48H 10/0000Z 16.1N 59.7W 45 KT 50 MPH
72H 11/0000Z 19.0N 64.5W 45 KT 50 MPH
96H 12/0000Z 22.5N 68.5W 50 KT 60 MPH
120H 13/0000Z 25.5N 71.0W 60 KT 70 MPH

$$
FORECASTER BEVEN

[cycloneye]

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