ATL: MARIA - Post-Tropical - Discussion

[cycloneye]

An excerpt from this afternoons discussion by NWS San Juan:

TROPICAL STORM MARIA IS FORECAST TO AFFECT THE USVI/PUERTO RICO ON
THE EVENING HOURS ON SATURDAY/EARLY SUNDAY. BASED ON THE LATEST
BULLETIN...THE CENTER OF TROPICAL STORM MARIA WAS LOCATED NEAR
LATITUDE 13.0 NORTH...LONGITUDE 42.0 WEST AND IS MOVING TOWARD THE
WEST NEAR 23 MPH. THIS GENERAL MOTION IS EXPECTED TO CONTINUE
DURING THE NEXT TWO DAYS. REGARDLESS DEVELOPMENT...SHOWERS WITH
THUNDERSTORMS AND GUSTY WINDS ARE ANTICIPATED DURING THE WEEKEND.
ALL LOCAL RESIDENTS AND VISITORS SHOULD CLOSELY MONITOR THE PROGRESS
OF THIS SYSTEM.

[cycloneye]

Aric,the wave in front of Maria continues to move westward. You said yesterday that TD14/Maria would follow it. Are you on the same thinking today?



Saved image.

[KWT]

It probably will recurve but the key is WHERE, it makes a big difference for the islands and possibly even the Bahamas/east coast.

Models aren't in agreement though there seems to be a lower spread overall of the dependable models.

[KWT]

Models are indeed quite keen on keeping the shear high as the LL flow looks quite strong.

models forecast of keeping it weak till at least 55-60W seems very reasonable to me...

[Gustywind]

Loop. Maria continues its trip westward...

[Aric Dunn]

Aric,the wave in front of Maria continues to move westward. You said yesterday that TD14/Maria would follow it. Are you on the same thinking today?

[img]http://img801.imageshack.us/img801/5060/tagant.jpg[/ig]

Saved image.

For the most part yeah. the main wave axis is still on the southern side of that convection so dont think its actually heading the direction the convection is building. look at the 850mb vort to see where it is. if you remember yesterday the area was moving due west near the 17N line and thats exactly where the main vort still is and is still heading almost due west.

And of course since Maria is at a lower Lat the track will be adjusted south but similar motion.

850mb loop.. you can see almost due west from beyond yesterday
http://tropic.ssec.wisc.edu/real-time/a ... 4java.html






sat loop
http://www.ssd.noaa.gov/goes/east/pr/flash-rgb.html

[WeatherOrKnot]

New to the site and have what might be a silly question. But is there any chance the wave out front of Maria will turn into anything?

[KWT]

Yep LLC is a little to the SW of the main convection, could well be some weakening in the next day or two unless it can cover itself up better.

[cycloneye]

TROPICAL STORM MARIA DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011
500 PM AST WED SEP 07 2011

THE OVERALL CLOUD PATTERN IS APPARENTLY WELL ORGANIZED ON VISIBLE
IMAGES...BUT NOT REALLY. THE LOW-LEVEL CENTER IS LOCATED ON THE
SOUTHWEST EDGE OF THE CONVECTION AND MOST OF THE ORGANIZED
RAINBANDS ARE SHIFTING TO THE NORTHEASTERN PORTION OF THE CYCLONE.
THIS WAS CONFIRMED BY RECENT MICROWAVE IMAGES. THE OUTFLOW IS
BECOMING DISRUPTED DUE A DEVELOPING WIND SHEAR AS FORECAST BY
GLOBAL MODELS AND THE SHIPS GUIDANCE. THE SHEAR IS INCREASING...BUT
IS NOT EXPECTED TO BE COMPLETELY HOSTILE TO THE CYCLONE. THE SHEAR
IN COMBINATION WITH THE RAPID FORWARD SPEED SUPPORT KEEPING MARIA
WITH LITTLE CHANGE IN INTENSITY THROUGH FIVE DAYS AS SUGGESTED BY
THE LGEM. ONLY THE GFDL MODEL INSISTS ON INTENSIFICATION. THE
CYCLONE IS APPROACHING NOAA BUOY 41041...SO WE WILL LIKELY KNOW
MORE ABOUT THE STRUCTURE OF MARIA LATER TONIGHT.

THE AVERAGE MOTION HAS BEEN TOWARD THE WEST OR 275 DEGREES AT 20
KNOTS. FOR THE NEXT 24 TO 36 HOURS...ALL MODELS ARE IN EXCELLENT
AGREEMENT FORECASTING MARIA TOWARD THE WEST OR WEST-NORTHWEST AT A
RAPID PACE. THEREAFTER...IT IS DEJA VU ALL OVER AGAIN WITH THE
TROUGH ALONG THE EAST COAST OF THE UNITED STATES AND THE
SUBTROPICAL RIDGE TO THE NORTH OF THE CYCLONE. THIS HAS BEEN THE
SCENARIO OBSERVED DURING THE TWO OR THREE PREVIOUS RECURVING
CYCLONES THIS SEASON. GIVEN THIS PATTERN...SOME MODELS LIKE THE GFS
AND HWRF TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD AND THE ECMWF
AND UK PROLONGING THE EVENTUAL NORTHWARD TURN A LITTLE LONGER. THE
OFFICIAL FORECAST IS...AS USUAL...A BLEND OF THESE GUIDANCE.


FORECAST POSITIONS AND MAX WINDS

INIT 07/2100Z 13.2N 44.2W 45 KT 50 MPH
12H 08/0600Z 13.6N 47.1W 45 KT 50 MPH
24H 08/1800Z 14.5N 51.5W 45 KT 50 MPH
36H 09/0600Z 15.0N 55.0W 45 KT 50 MPH
48H 09/1800Z 16.0N 58.5W 45 KT 50 MPH
72H 10/1800Z 18.5N 63.5W 45 KT 50 MPH
96H 11/1800Z 22.0N 68.0W 45 KT 50 MPH
120H 12/1800Z 25.0N 70.0W 45 KT 50 MPH

$$
FORECASTER AVILA

NNNN

[HurrMark]

Quoting Yogi Berra...

THE AVERAGE MOTION HAS BEEN TOWARD THE WEST OR 275 DEGREES AT 20
KNOTS. FOR THE NEXT 24 TO 36 HOURS...ALL MODELS ARE IN EXCELLENT
AGREEMENT FORECASTING MARIA TOWARD THE WEST OR WEST-NORTHWEST AT A
RAPID PACE. THEREAFTER...IT IS DEJA VU ALL OVER AGAIN WITH THE
TROUGH ALONG THE EAST COAST OF THE UNITED STATES AND THE
SUBTROPICAL RIDGE TO THE NORTH OF THE CYCLONE. THIS HAS BEEN THE
SCENARIO OBSERVED DURING THE TWO OR THREE PREVIOUS RECURVING
CYCLONES THIS SEASON. GIVEN THIS PATTERN...SOME MODELS LIKE THE GFS
AND HWRF TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD AND THE ECMWF
AND UK PROLONGING THE EVENTUAL NORTHWARD TURN A LITTLE LONGER. THE
OFFICIAL FORECAST IS...AS USUAL...A BLEND OF THESE GUIDANCE.

[Aric Dunn]

Yep LLC is a little to the SW of the main convection, could well be some weakening in the next day or two unless it can cover itself up better.

yeah and has been riding the 13N line all day... i would go with 275 on this advisory.

[cycloneye]

I always love Avilas discussions like this one at 5 PM.

IT IS DEJA VU ALL OVER AGAIN WITH THE
TROUGH ALONG THE EAST COAST OF THE UNITED STATES AND THE
SUBTROPICAL RIDGE TO THE NORTH OF THE CYCLONE. THIS HAS BEEN THE
SCENARIO OBSERVED DURING THE TWO OR THREE PREVIOUS RECURVING
CYCLONES THIS SEASON. GIVEN THIS PATTERN...SOME MODELS LIKE THE GFS
AND HWRF TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD AND THE ECMWF
AND UK PROLONGING THE EVENTUAL NORTHWARD TURN A LITTLE LONGER. THE
OFFICIAL FORECAST IS...AS USUAL...A BLEND OF THESE GUIDANCE.

[cycloneye]

Yep LLC is a little to the SW of the main convection, could well be some weakening in the next day or two unless it can cover itself up better.

yeah and has been riding the 13N line all day... i would go with 275 on this advisory.

TROPICAL STORM MARIA FORECAST/ADVISORY NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011
2100 UTC WED SEP 07 2011

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

TROPICAL STORM CENTER LOCATED NEAR 13.2N 44.2W AT 07/2100Z
POSITION ACCURATE WITHIN 40 NM

PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 20 KT

[Aric Dunn]

that was a interesting sarcastic discussion... lol

[cycloneye]

5 PM Track:

[Aric Dunn]

18z NAm
http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... mageSize=M

[KWT]

Stronger curve up which goes along with some of the models, ECM is to the left of the models due to keeping it weaker for longer.

[cycloneye]

5 PM closest point from San Juan is a little more away than at 11 AM.

Results for San Juan, Puerto Rico (18.45N, 66W):
The approximate Closest Point of Approach (CPA) is located near 19.6N, 65.0W or about 106.2 miles (170.9 km) from your location. The estimated time of when the center of the storm will be at that location is in about 79.9 hours (Sunday, September 11 at 0:54AM AST).

[Hurricaneman]

Its hard to believe the GFS when it has Maria going north through the ridge which is not likely

[cycloneye]

Results for St.Maarten/St.Martin (18.05N, 63.12W):
The approximate Closest Point of Approach (CPA) is located near 18.2N, 63.0W or about 8.6 miles (13.9 km) from your location. The estimated time of when the center of the storm will be at that location is in about 78.3 hours (Saturday, September 10 at 5:18PM AST).

The 5 PM track is a little bit away.

Results for St.Maarten/St.Martin (18.05N, 63.12W):
The approximate Closest Point of Approach (CPA) is located near 18.3N, 63.0W or about 15.8 miles (25.5 km) from your location. The estimated time of when the center of the storm will be at that location is in about 69.7 hours (Saturday, September 10 at 2:42PM AST).