Alex may head north to Texas or Louisiana

By: Dr. Jeff Masters , 6:36 PM GMT on June 27, 2010

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Tropical Depression Alex has held together fairly well during its passage over Mexico's Yucatan Peninsula, and stands poised to re-intensify back into a tropical storm once it emerges from the coast tonight. Alex brought heavy rains to northern Honduras, Mexico's Yucatan Peninsula, and Belize over the weekend. It was not a good beach day in Cozumel yesterday, as 9.25" of rain fell. Cancun received 2.05" over the weekend, and Belize City received 4.57". Satellite loops show that Alex's heavy thunderstorms are mostly gone near the center, though there are some impressive bands of precipitation well away from the center. There is an upper-level high pressure system a few hundred miles west of Alex, and the clockwise flow air around this high is bringing upper-level winds out of the northwest of about 5 knots over the storm, contributing to the 5 knots of wind shear observed in this afternoon's wind shear analysis from the University of Wisconsin's CIMSS group. Sea Surface Temperatures are very warm, 29 - 30°C, and dry air is currently not a problem for Alex.


Figure 1. Afternoon satellite image of Alex.

Forecast for Alex: which model should you trust?
While the track forecast for Alex today through Monday is fairly well-assured, the longer range forecast has become highly uncertain. An increasing number of our reliable models are now indicating Alex may take a more northerly track beginning on Tuesday, with possible landfall on the Texas coast near Galveston on Friday (according to the 8am run of the GFS model) or into western Louisiana on Wednesday (the 8am run of the Canadian model.) The key question remains how Alex will react to the trough of low pressure expected to swing down over the Eastern U.S. on Monday and Tuesday. Most of the models were predicting that the trough would not be strong enough to swing Alex to the north, and several of them continue to predict this. The 8am runs of the NOGAPS and ECMWF models, for example, take Alex into the Gulf coast of Mexico 150 miles south of Texas, on Wednesday. The GFDL and HWRF models split the difference, with the GFDL predicting a Thursday landfall in southern Texas near Brownsville, and the HWRF predicting a Thursday landfall near Corpus Christi. Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston. So which model should you trust? Last year, the best performing models at the 3 - 4 day forecast range were the GFS and the Canadian, and these are the models that are currently calling for the more northerly track towards the upper Texas coast and Louisiana. Residents of those areas should review their hurricane preparedness plans and anticipate that Alex could make landfall as early as Wednesday in their vicinity. Residents of the Mexican coast south of Brownsville should make similar plans, as Alex could just as easily hit there.

Re-intensification of Alex is likely once the center of Alex moves offshore, though this will initially be slow due to the current disorganized state of the storm and the relatively low total ocean heat content in the 100-mile-wide stretch of water on the west side of the Yucatan Peninsula. Once Alex moves more than 100 miles from the Yucatan, total heat content of the ocean increases substantially, and Alex will have the opportunity to intensify significantly. A longer time spent over water will give Alex more of a chance to strengthen, and it is possible Alex could intensify into a major hurricane if landfall is delayed until Thursday or Friday. However, Alex's intensification may be limited the farther north it gets, as water vapor satellite images show plenty of dry air over Texas that might interfere with development. Wind shear might also be an issue for Alex if it pushes far enough north, and a slow-moving storm tends to pull up cold water from the depths, limiting intensification. In short, Alex has the potential to intensify into a major hurricane, but there are plenty of roadblocks that make this only a 10% probability in my estimation.


Figure 2. Skill of computer model forecasts for Atlantic named storms during 2009. OFCL=Official NHC forecast; GFS=Global Forecast System model; GFDL=Geophysical Fluid Dynamic Laboratory model; HWRF=Hurricane Weather Research Forecasting model; NOGAPS=Navy Operational Global Prediction System model; UKMET+United Kingdom Met Office model; ECMWF=European Center for Medium Range Weather Forecasting model; CMC=Canadian GEM model; TVCN=one of the consensus models that lends together all (or most) of the above models; BAMM=Beta and Advection Model (Medium Layer.) Image credit: National Hurricane Center 2009 verification report.

Elsewhere in the tropics
A tropical wave (Invest 94L) a few hundred miles north of the northernmost Lesser Antilles Islands has been pretty much torn apart, and is no longer a threat to develop.

Next post
Wunderground's severe weather expert Dr. Rob Carver will likely be posting an update on Alex late tonight. My next update will be Monday by 10am EDT.

Jeff Masters

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Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.


here comes IKE part 2
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Quoting nrtiwlnvragn:


Ensemble models are run at a lower resolution and with different initial conditions than the parent model such as the GFS. The different initial conditions are an attempt to account for uncertainty since you can't capture an instantaneous snapshot of the atmosphere globally.


Thank you.
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Quoting homelesswanderer:


Thanks DRM. SmileyCentral.com


Hi Homeless...
Member Since: July 2, 2009 Posts: 0 Comments: 2811
485. jpsb
Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters
Galveston here, is it time to panic yet? I was planing on not hitting the panic button until Tuesday AM.
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Quoting Hurricanes101:
NHC track did not shift it appears
I was wondering maybe they are waiting to make sure it can push the ridge out before scaring everyone..altho..the earlier they change it..the earlier everyone else knows...they must think it wont push it enough.
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Quoting hydrus:
................... This trough (the best image I could find) makes me think of a more northerly path.


Lol, look at Celia, dying. RIP, Celia, once a great queen. *sniff* I think I'm about to cry! :(
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Quoting Levi32:
Impressive pressure falls going on as Alex's center moves over the west coast of the Yucatan....very distinguished for a system that just spent the better part of a day over land and was only a borderline TS/hurricane at landfall.

I didn't expect the pressure to remain sub-1000mb.


If those are coming from Mexican Weather stations, double check it. Last night one had a pressure of 977mb.
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481. xcool
GlobalWarming HAHA
Member Since: September 26, 2009 Posts: 2 Comments: 15684
guys, we need to realize that the nhc will not budge because they know that this will be a mexico affair, and that's final, no two buts about it. soutehrn tx will receive some of teh fringe affects of aex and that's it, however, thye will deff. not see a direct landfall from it, or anything of that sorts, as a matter of fact.
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Quoting nweatherlover:


That is interesting because it would appear that the oil spill area has not heated up more than the rest of the gulf, as some had expected.


What do you expect when you have supercooled oil boiling up to the surface. Temperatures at the bottom of the gulf are near or below 32 degrees, it would have some effect, and the oil sheen increases the amount of light reflected, a black patch of oil would heat in the sun, but the sheen is like a mirror as long as the winds are calm like they were about this time last year when I sailed from New Orleans to Mexico it was like a sheet of glass. Calmest gulf crossing I ever had the pleasure of vacationing on.
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Floater - Rainbow Color Infrared Loop
Member Since: July 3, 2005 Posts: 426 Comments: 129088
476. amd
Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters


uh oh. thanks for the update. any idea on possible strength or is that proprietary information?
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Impressive pressure falls going on as Alex's center moves over the west coast of the Yucatan....very distinguished for a system that just spent the better part of a day over land and was only a borderline TS/hurricane at landfall.

I didn't expect the pressure to remain sub-1000mb.
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Quoting southlouisiana:
What is the "ensemble models"? I can find no definition of it and it makes no logical sense to me.


Ensemble models are run at a lower resolution and with different initial conditions than the parent model such as the GFS. The different initial conditions are an attempt to account for uncertainty since you can't capture an instantaneous snapshot of the atmosphere globally.
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improved experimental version of the GFDL

Nice !
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Couldn't figure out how to post the loop, but this should give you and idea of the current setup:

http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html
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nevermind, xcool, you're safe.
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Quoting LouisianaWoman:
John--for a point of reference, when Ike hit Galveston---we felt the impact way over here in Delcambre with flooding averaging around 5 ft.


Thank you for sharing!
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The second act should more climactic...
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stay safe, xcool.
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NHC track did not shift it appears
Member Since: March 10, 2010 Posts: 1 Comments: 7866
If Alex takes a path similiar to Brett in 1999 hopefully it can strike a less populated area of Texas.Although the bigger size of Alex the effects will be felt further away. Brett was a Cat 4 at landfall.

http://en.wikipedia.org/wiki/Hurricane_Bret_(1999)
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BTW im first again, mwuh ha ha
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Quoting kmanislander:
Dr. M sure knows how to time his entrances LOL.

That will put the cat amongst the pigeons !


U betcha..LOL
Member Since: July 3, 2005 Posts: 426 Comments: 129088
Quoting tkeith:
lol...afternoon Kman


Good afternoon to you as well. Alex Part 2 about to begin.
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Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters


Thanks DRM. SmileyCentral.com
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1000.7mb at Cuidad del Carmen, 50 miles southwest of the center. 999mb central pressure is not out of the question.

Ciudad del Carmen
Temperature: 82 F
Dew Point: 77 F
Humidity: 84%
Wind: N at 21mph
Pressure: 29.55in
Precipitation: -in
Daily Precip.: 0.00in
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Quoting unf97:


Thanks Dr. Masters for providing this info.


Yep, a real ray of sunshine in his lastest thoughts. Lot of respect for his forecast, but hope Alex just stays on the current nhc tract. Sorry MX, but I'm just saying.
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Dr. M sure knows how to time his entrances LOL.

That will put the cat amongst the pigeons !
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John--for a point of reference, when Ike hit Galveston---we felt the impact way over here in Delcambre with flooding averaging around 5 ft.
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Quoting Levi32:
Alex's central pressure could very well have lowered while over the central Yucatan last night, when it had an eye, and was not near any weather stations.
It definetly seems like a likely possibility at this point.
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83350
wtnt41 knhc 272035
tcdat1

tropical depression alex discussion number 9
nws tpc/national hurricane center miami fl al012010
400 pm cdt sun jun 27 2010

satellite images show that alex continues to have a large and well-defined circulation with plenty of banding features. near the center...however...convection has decreased...probably due to the influence of land. the mexican navy surface station at isla perez recently reported 30 kt winds...so the initial wind speed is kept at 30 kt. an air force reserve hurricane hunter aircraft is scheduled to investigate alex this evening after the center moves offshore.

the initial motion of alex is a little slower...with a 12-hr average yielding an estimate of 300/8. the pivotal question for the long-term forecast track of the tropical cyclone appears to hinge on the strength of mid-level ridging over the northern gulf coast.
the models that show a weaker ridge...such as the cmc/gfs/hwrf...
allow the tropical cyclone to turn toward the north-northwest and north and approach the northwestern gulf coast in several days.
other models...such as the ecmwf/ukmet/nogaps...have a stronger ridge and keep alex moving to the northwest or west-northwest into mexico. overall the model guidance has shifted slightly to the north...and the official forecast is a little to the right of the previous one. since there is considerable model spread...this track forecast is thought to be of below-average confidence.

while there is a large disagreement on the track of alex...the global models are in much better agreement with the large-scale environment. these models show an upper-ridge axis sitting very near the tropical cyclone for the next several days...in a favorable position for intensification. combined with the warm waters of the gulf of mexico...strengthening is likely...especially after alex moves farther away from the yucatan peninsula. given the overall environmental conditions...it is surprising that the gfdl/hwrf do not show more intensification...leaving the system as a tropical storm for many days. the statistical guidance seems more reasonable and the nhc forecast is close to the ships model...and is not too dissimilar from the previous forecast.

forecast positions and max winds

initial 27/2100z 19.2n 90.9w 30 kt
12hr vt 28/0600z 19.9n 91.8w 35 kt
24hr vt 28/1800z 20.6n 92.6w 45 kt
36hr vt 29/0600z 21.5n 93.3w 55 kt
48hr vt 29/1800z 22.3n 94.2w 65 kt
72hr vt 30/1800z 23.2n 96.3w 80 kt
96hr vt 01/1800z 24.0n 98.5w 55 kt...inland
120hr vt 02/1800z 24.5n 100.5w 20 kt...dissipating inland
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454. xcool
from tx to LA HURRICANE preparedness plans
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting kmanislander:


You're back ??. Well, nothing going on there at this time. Just thundershowers.
lol...afternoon Kman
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not quite, if he makes alndfall somewhere in Tx, La will see some affects from alex, in some shape, way, or form, that's for sure.
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000
WTNT31 KNHC 272033
TCPAT1
BULLETIN
TROPICAL DEPRESSION ALEX ADVISORY NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010
400 PM CDT SUN JUN 27 2010

...ALEX MOVING INTO THE SOUTHWESTERN GULF OF MEXICO...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...19.2N 90.9W
ABOUT 55 MI...90 KM SSW OF CAMPECHE MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/HR
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/HR
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 400 PM CDT...2100 UTC...THE CENTER OF TROPICAL DEPRESSION ALEX
WAS LOCATED NEAR LATITUDE 19.2 NORTH...LONGITUDE 90.9 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 9 MPH...15
KM/HR. A MOTION GENERALLY TOWARD THE NORTHWEST IS EXPECTED FOR THE
NEXT COUPLE OF DAYS AT A SLOWER FORWARD SPEED.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND
ALEX IS EXPECTED TO BECOME A TROPICAL STORM AGAIN ON MONDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB...29.50 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...ALEX IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF
4 TO 8 INCHES OVER THE YUCATAN PENINSULA...SOUTHERN MEXICO...AND
GUATEMALA THROUGH MONDAY AFTERNOON. ISOLATED MAXIMUM AMOUNTS OF 15
INCHES ARE POSSIBLE OVER MOUNTAINOUS AREAS. THESE RAINS COULD
CAUSE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1000 PM CDT.

$$
FORECASTER BLAKE
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Granted, realize there are a lot of variables at play and no 100%.. but in general, how many days out until you think models will be able to lock in a somewhat reliable cone for landfall?
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I did a post at Blogger.

Here is my post
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Quoting nrtiwlnvragn:


ATCF used 999mb for the 18Z data.
Honestly didn't expect pressure to be so low but it seems it is.
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Alex's central pressure could very well have lowered while over the central Yucatan last night, when it had an eye, and was not near any weather stations.
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Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters


I'm in Corpus, guess it is time to load up the supply closet.
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Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters


Thanks Doc
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Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters





Wowsa...
Member Since: July 3, 2005 Posts: 426 Comments: 129088
Quoting GlobalWarming:


afternoon, kman! i hope all is well with you this afternoon, sir. what the heck is that AOI forming around the panama canal? is it anything noteworthy or not? thanks, :).


You're back ??. Well, nothing going on there at this time. Just thundershowers.
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000
WTNT21 KNHC 272033
TCMAT1
TROPICAL DEPRESSION ALEX FORECAST/ADVISORY NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010
2100 UTC SUN JUN 27 2010

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

TROPICAL DEPRESSION CENTER LOCATED NEAR 19.2N 90.9W AT 27/2100Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 8 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 999 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 19.2N 90.9W AT 27/2100Z
AT 27/1800Z CENTER WAS LOCATED NEAR 18.9N 90.7W

FORECAST VALID 28/0600Z 19.9N 91.8W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 45NE 30SE 30SW 45NW.

FORECAST VALID 28/1800Z 20.6N 92.6W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 70NE 50SE 50SW 70NW.

FORECAST VALID 29/0600Z 21.5N 93.3W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 45NE 30SE 30SW 45NW.
34 KT... 90NE 75SE 75SW 90NW.

FORECAST VALID 29/1800Z 22.3N 94.2W
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 50NE 40SE 40SW 50NW.
34 KT...120NE 90SE 90SW 120NW.

FORECAST VALID 30/1800Z 23.2N 96.3W
MAX WIND 80 KT...GUSTS 100 KT.
50 KT... 60NE 45SE 45SW 60NW.
34 KT...120NE 90SE 90SW 120NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 200 NM
ON DAY 4 AND 250 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 01/1800Z 24.0N 98.5W...INLAND
MAX WIND 55 KT...GUSTS 65 KT.

OUTLOOK VALID 02/1800Z 24.5N 100.5W...DISSIPATING INLAND
MAX WIND 20 KT...GUSTS 25 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.2N 90.9W

NEXT ADVISORY AT 28/0300Z

$$
FORECASTER BLAKE
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Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters


Good afternoon Dr. Jeff Masters! What is your thinking on Alex?
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440. unf97
Quoting JeffMasters:
Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston.

Jeff Masters


Thanks Dr. Masters for providing this info.
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disturbing, yet interesting! Thank you, Doc.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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