2011 ATL Hurricane Season: Coming to an End

[perk]

Wave between 45 and 50W and south of 15N looks to have some turning going on.

[srainhoutx]

The 12z Euro and GFS ensemble charts continue to advertise lower pressures across the Atlantic MDR and Caribbean in the 6-10 day time frame...

[srainhoutx]

The 00Z and 06Z GFS suggest something a bit closer to home...

[srainhoutx]

The 12Z Euro suggests a disturbance heading W into the Caribbean later this week/weekend. The GFS, as wxman57 stated in the ex 92L thread, depicts a strong storm crossing the Caribbean and entering the S Gulf. Something to watch in the days ahead.

[rnmm]

The 12Z Euro suggests a disturbance heading W into the Caribbean later this week/weekend. The GFS, as wxman57 stated in the ex 92L thread, depicts a strong storm crossing the Caribbean and entering the S Gulf. Something to watch in the days ahead.

Is it ex 92L the 12Z Euro is picking up on or a different disturbance?

[wxman57]

The 12Z Euro suggests a disturbance heading W into the Caribbean later this week/weekend. The GFS, as wxman57 stated in the ex 92L thread, depicts a strong storm crossing the Caribbean and entering the S Gulf. Something to watch in the days ahead.

Is it ex 92L the 12Z Euro is picking up on or a different disturbance?

As far as what? I see the 12Z Euro starts to develop 92L then loses it.

[srainhoutx]

The 12Z Euro suggests a disturbance heading W into the Caribbean later this week/weekend. The GFS, as wxman57 stated in the ex 92L thread, depicts a strong storm crossing the Caribbean and entering the S Gulf. Something to watch in the days ahead.

Is it ex 92L the 12Z Euro is picking up on or a different disturbance?

As far as what? I see the 12Z Euro starts to develop 92L then loses it.

168 = weak vortisity near/over Hispaniola...

The attachment 08082011 12Z 12zeurotropical850mbVortSLP168.gif is no longer available

240 = weak vortisity near the S Bahamas and another disturbance just W of the Windwards...

[wxman57]

Definitely NOT 92L on the Euro, then. 12Z GFS has it a day from the Caribbean at 168 hrs and SE of Jamaica at 240 hrs.

[srainhoutx]

Definitely NOT 92L on the Euro, then. 12Z GFS has it a day from the Caribbean at 168 hrs and SE of Jamaica at 240 hrs.

Yeah, I agree. The ITCZ seems to be the source of the activity and with waves exiting Africa this week, any number of possibilities appears to be prudent. Tis that time of year I suppose...

[rnmm]

Thank you Srain, I apologize if my question seemed dumb, I was just trying to see where the wave was coming from, I still have so much to learn!

[srainhoutx]

Thank you Srain, I apologize if my question seemed dumb, I was just trying to see where the wave was coming from, I still have so much to learn!

Not dumb at all. This is the place to learn and ask questions after all. Others are watching and reading what we post daily. That's why we are here...a weather message board, rnmm...

[sleetstorm]

I take it that until that dome of high pressure moves out of the way, say east, then we can forget about receiving any very much needed beneficial rain whether via continental showers and thunderstorms or a tropical depression, tropical storm, or hurricane?

[srainhoutx]

SYNOPSIS 2011080900

P14L … 92L
12N, 24W
700 hPa


ECMWF: Monsoonal "sit and spin" for the first couple days with only slow motion toward the west. Then, 92L weakens and devolves into a large, stationary ITCZ-like circulation with multiple centers. I stop tracking at 60 hours once the original pouch weakens. Meanwhile, the subtropical OW max that was noted in yesterday's run is still being depicted, and it is a small, weak pouch heading toward the Caribbean in five days.

GFS: Similar to ECMWF. Slight difference: After the ECMWF weakening, the multiple centers are relatively weak. GFS, on the other hand, depicts one of them to be quite strong that quickly moves westward on the northern side of the "subtropical-origin" pouch. I don't track anything after the weakening at 72 hours.

UKMET: Similar to GFS. Hints at a pouch moving north of the "subtropical-origin" pouch, but it is only an OW max. Also depicts an ITCZ pouch "reforming" around Day 3 that then moves slowly westward.

NOGAPS: Similar to other models, but all of the circulations are weaker.

HWRF-GEN: A-ha! The uncertainty with a weakening pouch in ECMWF and GFS is not in HWRF-GEN. The eventually strong GFS pouch that moves northward of the "subtropical-origin" pouch is depicted quite clearly by HWRF-GEN to be P14L with a smooth track the entire 5 days.

ECMWF -3.7 v700 & RH/TPW 60h
GFS -4.4 v700 & TPW 72h
UKMET -4.3 v700 48h
NOGAPS -4.2 v7/8 48h
HWGEN -6.0 v700 120h

[srainhoutx]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT TUE AUG 9 2011

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

1. THE REMNANTS OF EMILY ARE LOCATED ABOUT 830 MILES EAST-NORTHEAST OF
BERMUDA...MOVING TOWARD THE NORTHEAST AT ABOUT 25 MPH. THE
ASSOCIATED SHOWER ACTIVITY IS CURRENTLY MINIMAL...AND ENVIRONMENTAL
CONDITIONS ARE NOT CONDUCIVE FOR SIGNIFICANT DEVELOPMENT. THIS
SYSTEM HAS A LOW CHANCE...10 PERCENT...OF REGENERATING INTO A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

2. AN AREA OF DISTURBED WEATHER...ASSOCIATED WITH A TROPICAL WAVE...HAS
FORMED ABOUT 300 MILES SOUTHWEST OF THE SOUTHERN CAPE VERDE
ISLANDS. SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT
COUPLE OF DAYS AS IT MOVES WESTWARD AT ABOUT 10 TO 15 MPH. THIS
SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN

[srainhoutx]

The GFS and Euro are suggesting an uptick in activity as we begin to approach the middle of August.

Past history suggests that we should be seeing this increased activity and it appears to be on schedule...



The CPC TC genesis probability charts are suggesting the area just E of the Caribbean Islands may be the favored area in the near term regarding development. While a recurving track would be the more likely scenario early on, a threat to the East Coast may not be out of the question as well.



What raises an eyebrow is the TC genesis probabilities suggested by Roundy as we head toward the 20th or so of August and on into the beginning of September. The Caribbean and Gulf could become areas we will need to watch closely. It is getting that time of year folks and we have seen the seasonal forecasts suggesting an active season. I know we've grown tired of the long stretch of boring hot weather, but things may be moving toward a change. We will see...

[srainhoutx]

A new wave has splashed into the E Atlantic riding along 10N. It has gained a pouch designation of P15L...



SYNOPSIS 2011081000

P15L
11N, 10W
700 hPa

ECMWF: After moving off of Africa and weakening slightly, P15L then intensifies into the strongest storm of the season so far. It maintains at least 15 degrees separation to the southeast of P14L/92L.

GFS: Gradually intensifies.

UKMET: Faster than other models, and UKMET does not intensify P15L much.

NOGAPS: OUTLIER! P15L crawls off the African coast and eventually dissipates, becoming only an OW max after 84 hours.

HWRF-GEN: Similar to ECMWF. The only difference is that at later periods, HWRF-GEN depicts a much smaller, compact area of high OW values close to the center of a large pouch.

ECMWF -7.3 v700 & TPW 120h
GFS -7.6 v700 & RH/TPW 120h
UKMET -8.4 v700 & RH 120h
NOGAPS -4.3 v700 108h
HWGEN -6.6 v700 & RH 120h

[srainhoutx]

Things are getting just a touch busy in the tropics. I'd keep an eye out W of FL in the days ahead. Frontal boundaries draped across the Gulf in August do raise an eyebrow...

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED AUG 10 2011

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

1. A LARGE AREA OF DISTURBED WEATHER IS ASSOCIATED WITH A TROPICAL WAVE
AND A BROAD AREA OF LOW PRESSURE CENTERED ABOUT 475 MILES
WEST-SOUTHWEST OF THE SOUTHERN CAPE VERDE ISLANDS. THIS SYSTEM HAS
BECOME A LITTLE BETTER ORGANIZED OVER THE PAST 24 HOURS...AND
ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR ADDITIONAL GRADUAL
DEVELOPMENT OVER THE NEXT SEVERAL DAYS. THIS SYSTEM HAS A MEDIUM
CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WESTWARD AT 10 TO 15 MPH.

2. DISORGANIZED SHOWERS AND THUNDERSTORMS EXTENDING FROM THE EASTERN
GULF OF MEXICO ACROSS THE FLORIDA PENINSULA INTO THE ATLANTIC ARE
ASSOCIATED WITH A BROAD TROUGH OF LOW PRESSURE LOCATED A COUPLE
HUNDRED MILES EAST OF THE NORTHEAST COAST OF FLORIDA. ANY
DEVELOPMENT OF THIS SYSTEM WILL BE SLOW TO OCCUR AS IT MOVES
EASTWARD AND THEN NORTHEASTWARD AT AROUND 15 MPH. THIS SYSTEM HAS
A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS.

3. THE REMNANTS OF EMILY ARE LOCATED ABOUT 650 MILES SOUTH-SOUTHEAST OF
CAPE RACE NEWFOUNDLAND...MOVING TOWARD THE NORTHEAST AT ABOUT
10 MPH. THE ASSOCIATED SHOWER ACTIVITY SHOWS SOME SIGNS OF
ORGANIZATION. HOWEVER...ENVIRONMENTAL CONDITIONS ARE NOT CONDUCIVE
FOR SIGNIFICANT DEVELOPMENT AS THIS SYSTEM MOVES OVER COOLER WATERS
AND BEGINS TO INTERACT WITH A FRONTAL ZONE. THIS SYSTEM HAS A LOW
CHANCE...10 PERCENT...OF REGENERATING INTO A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

4. A NEW AREA OF DISTURBED WEATHER HAS EMERGED FROM THE COAST OF AFRICA
AND IS LOCATED ABOUT 600 MILES SOUTHEAST OF THE SOUTHERN CAPE VERDE
ISLANDS. SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT
COUPLE OF DAYS AS IT MOVES WESTWARD AT 10 TO 15 MPH. THIS SYSTEM
HAS A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN

[unome]

Marine Forecast graphics show a low in the east Atlantic this morning http://www.nhc.noaa.gov/marine_forecasts.shtml




000
AXNT20 KNHC 111154
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU AUG 11 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...

A 1010 MB LOW CENTERED NEAR 13N33W IS WELL EMBEDDED WITHIN THE
MONSOON TROUGH ACROSS THE TROPICAL ATLC MOVING W AT 10 KT.
ENERGY ASSOCIATED WITH THE LOW-LEVEL CYCLONIC MONSOON GYRE
CONTINUES TO CONSOLIDATE AND COVERS A SMALL AREA FROM 08N-18N
BETWEEN 28W-41W...OF WHICH ENCOMPASSES A TROPICAL WAVE ANALYZED
ALONG 12N36W TO 22N39W AND IS FORECAST TO CONTINUE WESTWARD OVER
THE NEXT 24-48 HOURS. THE LOW CONTINUES TO POSITION ITSELF ON
THE SOUTHWESTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONE
CENTERED NEAR 20N31W. LOW-LEVEL CONVERGENCE ALONG WITH A
FAVORABLE MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT IS
SUSTAINING SCATTERED MODERATE CONVECTION S OF THE LOW CENTERED
FROM 07N-14N BETWEEN 30W-37W. NO SIGNIFICANT DEEP CONVECTION IS
NORTH OF THE LOW CENTER OR ASSOCIATED WITH THE TROPICAL WAVE.
ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR SOME SLOW
DEVELOPMENT INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS
AS IT MOVES WESTWARD 10 TO 15 MPH.

...TROPICAL WAVES...

TROPICAL WAVE IS ANALYZED FROM 10N20W TO 17N20W MOVING W AT
10-15 KT. A 1010 MB LOW IS CENTERED NEAR THE SOUTHERN EXTENT
OF THE WAVE AXIS NEAR 10N20W. EXAMINING UPPER AIR TIME-SECTION
ANALYSES FROM DAKAR SENEGAL SHOWS THIS WAVE PASSED AFTER
11/0000 UTC. FURTHERMORE...GLOBAL MODEL ANALYSIS AND FORECAST
STREAMLINES AT 850 MB AND 700 MB INDICATE THE WAVE IS LARGELY
LOCATED ALOFT AND THAT IT IS ANTICIPATED TO CONTINUE PROPAGATING
WESTWARD OVER THE NEXT FEW DAYS. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION IS FROM 09N-14N BETWEEN 19W-25W. SLOW
DEVELOPMENT INTO A TROPICAL CYCLONE IS POSSIBLE DURING THE
NEXT 48 HOURS.

TROPICAL WAVE IS ANALYZED FROM 12N71W TO 20N66W MOVING W AT 15
KT. THE WAVE REMAINS WITHIN AN AREA OF HIGHER TOTAL PRECIPITABLE
WATER VALUES ADVECTING ACROSS THE EASTERN CARIBBEAN SEA FROM
14N-21N BETWEEN 62W-70W. WHILE AN UNFAVORABLE UPPER LEVEL
ENVIRONMENT IS IN THE VICINITY OF THE WAVE...THUS INHIBITING ANY
SIGNIFICANT DEEP CONVECTION...LOW-LEVEL MOISTURE CONVERGENCE IS
GENERATING A FEW LOW-TOPPED ISOLATED SHOWERS FROM 15N-19N
BETWEEN 66W-71W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 19N16W
ALONG 12N17W TO 10N19W TO 14N28W TO 05N45W. THE INTERTROPICAL
CONVERGENCE ZONE AXIS EXTENDS FROM 05N45W TO 03N51W. ASIDE FROM
CONVECTION ASSOCIATED WITH THE TWO TROPICAL WAVES NOTED
ABOVE...NO SIGNIFICANT DEEP CONVECTION IS NOTED ON SATELLITE
IMAGERY.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE CENTRAL GULF
NEAR 26N91W AND CONTINUES TO SUPPORT A SURFACE RIDGE AXIS
EXTENDING FROM THE SW NORTH ATLC THROUGH THE FLORIDA STRAITS TO
A 1014 MB HIGH CENTERED NEAR 25N83W THEN NW OF THE TEXAS COAST
NEAR 30N94W. SHORTWAVE INFRARED SATELLITE IMAGERY INDICATES MUCH
OF THE GULF IS UNDER CLEAR SKIES AND FAIR CONDITIONS THIS
MORNING...AS MUCH OF THE CONVECTION INITIATED LAST
AFTERNOON/EVENING HAS DISSIPATED OVER THE EASTERN GULF WATERS
AND THE FLORIDA PENINSULA. A SURFACE TROUGH REMAINS ANALYZED
OVER CENTRAL FLORIDA FROM DAYTONA BEACH TO THE TAMPA BAY REGION
WITH ONLY A FEW ISOLATED SHOWERS NOTED ON MOSAIC DOPPLER RADAR
IMAGERY OVER THE FLORIDA STRAITS SOUTH OF THE FLORIDA KEYS. THE
SURFACE RIDGE IS FORECAST TO REMAIN ACROSS THE GULF ALONG 24N
THROUGH FRIDAY AND GRADUALLY SHIFT NORTHWARD TO 26N/27N BY
SATURDAY INTO SUNDAY.

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS A WEAK UPPER LEVEL TROUGH AXIS
EXTENDING FROM THE SW NORTH ATLC ACROSS EASTERN CUBA NEAR 21N77W
TO THE YUCATAN PENINSULA NEAR 19N89W. AT THE SURFACE...MOSTLY
FRESH TO MODERATE EASTERLY TRADES CONTINUE WITH ONLY A FEW
ISOLATED SHOWERS DUE TO LOW-LEVEL MOISTURE CONVERGENCE OCCURRING
OVER WESTERN PORTIONS OF THE CARIBBEAN FROM 13N-17N BETWEEN
73W-85W. THE MONSOON TROUGH EXTENDS NORTH OF PANAMA ALONG 10N
WITH ISOLATED SHOWERS AND TSTMS OCCURRING S OF 12N. FARTHER
EAST...A TROPICAL WAVE CONTINUES TO MOVE WESTWARD INTO THE
CENTRAL CARIBBEAN WITH ISOLATED SHOWERS OCCURRING FROM 15N-19N
BETWEEN 66W-71W. THE EASTERLY TRADES ACROSS CENTRAL PORTIONS OF
THE CARIBBEAN ARE EXPECTED TO REMAIN STRONG THROUGH FRIDAY DUE
TO A HIGH PRESSURE RIDGE ALONG 24N IN THE W ATLC.

ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY
ACROSS THE SE CONUS THAT EXTENDS EASTWARD INTO ATLC OFFSHORE
ZONES N OF 30N W OF 70W. WHILE A COLD FRONT IS SUPPORTED BY THIS
UPPER LEVEL TROUGHING NORTH OF THE DISCUSSION AREA...A PAIR OF
SURFACE TROUGHS ARE OVER THE W ATLC WATERS AND FLORIDA PENINSULA
THIS MORNING. ONE SURFACE TROUGH IS ANALYZED FROM 29N78W TO
24N79W AND THE OTHER IS ANALYZED FROM 31N81W ACROSS THE NORTHERN
FLORIDA PENINSULA TO THE TAMPA BAY REGION. LOW-LEVEL MOISTURE
CONVERGENCE IS GENERATING ISOLATED SHOWERS AND TSTMS OVER THE W
ATLC WATERS W OF A LINE FROM 32N70W TO 22N78W. FARTHER EAST...AN
UPPER LEVEL LOW IS CENTERED NEAR 38N46W WITH THE ASSOCIATED
UPPER LEVEL TROUGH AXIS EXTENDING SOUTHWARD TO 29N51W. THIS
UPPER LEVEL FEATURE SUPPORTS A SURFACE TROUGH ANALYZED FROM
32N47W TO 24N56W. ISOLATED SHOWERS AND TSTMS COVER THE AREA FROM
21N-28N BETWEEN 45W-56W. THE REMAINDER OF THE EASTERN ATLC IS
UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB
HIGH CENTERED OVER THE AZORES NEAR 38N26W. THE RIDGE AXIS
EXTENDS FROM THE HIGH ALONG 32N33W TO 20N50W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
HUFFMAN

[ramona01]

Question for the experts...how much protection, if any, does this high pressure ridge that has brought us all the heat this summer, provide for tropical systems coming in from the GOM? It would seem that the ridge would likely steer any but the strongest systems to the south and west of us. Is that reasonable?

[srainhoutx]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU AUG 11 2011

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

1. A BROAD AREA OF LOW PRESSURE CENTERED ABOUT 750 MILES WEST OF
THE SOUTHERN CAPE VERDE ISLANDS IS PRODUCING A LARGE AREA OF
DISORGANIZED SHOWERS AND THUNDERSTORMS. THIS DISTURBANCE IS
SHOWING SIGNS OF ORGANIZATION...AND ENVIRONMENTAL CONDITIONS
APPEAR FAVORABLE FOR GRADUAL DEVELOPMENT OVER THE NEXT SEVERAL
DAYS. THIS SYSTEM HAS A MEDIUM CHANCE...40 PERCENT...OF BECOMING
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES TOWARD
THE WEST-NORTHWEST AT 15 MPH.

2. A WELL-DEFINED LOW PRESSURE SYSTEM LOCATED ABOUT 275 MILES SOUTH
OF THE SOUTHERN CAPE VERDE ISLANDS IS PRODUCING A LARGE AREA OF
CLOUDINESS AND SCATTERED THUNDERSTORMS. ENVIRONMENTAL CONDITIONS
ARE EXPECTED TO GRADUALLY BECOME MORE CONDUCIVE FOR DEVELOPMENT
OVER THE NEXT SEVERAL DAYS AS IT MOVES WESTWARD AT 15 TO 20 MPH.
THE SYSTEM HAS A MEDIUM CHANCE...40 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

3. DISORGANIZED SHOWERS AND A FEW THUNDERSTORMS LOCATED OVER THE
ATLANTIC ABOUT MIDWAY BETWEEN THE CAROLINAS AND BERMUDA ARE
ASSOCIATED WITH A BROAD TROUGH OF LOW PRESSURE. ANY DEVELOPMENT OF
THIS AREA OF DISTURBED WEATHER SHOULD BE SLOW TO OCCUR AS IT MOVES
NORTHEASTWARD AT 15 TO 20 MPH. THIS SYSTEM HAS A LOW CHANCE...10
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART