Tropical Storm Arlene--a heavy rainfall threat for Mexico

By: Dr. Jeff Masters , 1:48 PM GMT on June 29, 2011

Share this Blog
9
+

The 2011 Atlantic hurricane season has its first named storm, Tropical Storm Arlene, which rapidly spun up last night from a tropical wave that had emerged into Mexico's Bay of Campeche. An Air Force hurricane hunter aircraft is currently in the storm, and has found that Arlene is strengthening. At the plane's flight altitude of 1,000 feet, top winds reported as of 9:30am EDT were 54 mph, on Arlene's south side. The aircraft's SFMR instrument that remotely measures surface wind speeds found top surface winds of 67 mph on southeast side of the storm. This reading was probably a gust, since top winds of 45 - 50 mph have been more characteristic of the SFMR winds. The measured central pressure at 9am EDT was 1000 mb, which is a 2mb drop from the pressure estimate from 5am. Satellite loops show a marked increase in the intensity and organization of Arlene's heavy thunderstorms, with more prominent spiral bands. Mexican radar out of Alvarado also shows this trend. Wind shear has fallen to the moderate range, 10 - 15 knots, and is predicted to fall to the low range, 5 - 10 knots, by tonight. This should allow Arlene to continue to organize, and storm could be approaching hurricane strength by the time it makes landfall Thursday morning in Northeast Mexico. Arlene has moistened its environment enough so that the dry air over Mexico should no longer be a problem for it, and the topography surrounding the Bay of Campeche tends to boost counter-clockwise air flow, enabling systems there to spin up faster than in any other portion of the Atlantic. Arlene is bigger than most Bay of Campeche tropical storms, though, so it may not have time to spin up into a hurricane because of its large size. NHC's 5am EDT advisory was giving Arlene a 9% chance of reaching hurricane strength before landfall. These odds should probably be bumped up to 30%, in light of Arlene's recent intensification.


Figure 1. Microwave satellite image of Tropical Storm Arlene taken at 4:07am EDT June 29, 2011 showed that several spiral bands had formed. Image credit: N avy Research Lab, Monterey.

Rainfall forecast for Arlene
The major threat from Arlene is heavy rainfall, particularly since the portion of coast that will be affected is under extreme drought. Without much vegetation to absorb Arlene's rains and slow down run-off, the expected heavy rains are more likely to cause damaging flooding. NHC is currently estimating that 4 - 8 inches will fall, with isolated areas of up to 15 inches over the mountains. These predicted amounts will probably need to be revised upwards, given Arlene's recent increase in organization. At this time, it appears that Texas will not see any rain from Arlene.


Figure 2. Cumulative rainfall expected along the path of Arlene, as predicted by this morning's 2am EDT (06 UTC) run of the HWRF model. This model predicts a large region of 8+ inches of rain (yellow colors) will affect Mexico. These rainfall amounts are probably too high, as our other models are not showing such heavy rainfall amounts. Image credit: Morris Bender, NOAA/GFDL.

June hurricane climatology
Long-term hurricane records going back to 1851 show that on average, we see just one Atlantic named storm every two years in June. Only one major hurricane has made landfall in June--Category 4 Hurricane Audrey of 1957, which struck the Texas/Louisiana border area on June 27 of that year, killing 550. The highest number of named storms for the month is three, which occurred in 1936 and 1968. In the sixteen years since the current active hurricane period began in 1995, there have been twelve June named storms (if we include 2008's Tropical Storm Arthur, which really formed on May 31). Thus, recent history suggests the Atlantic hurricane season is becoming more active earlier in the season, in line with recent research that found that the Atlantic hurricane season is getting longer.

Arlene: the most common Atlantic storm name of all-time
This year marks the tenth appearance of a storm named Arlene in the Atlantic, making it the most recycled storm name of all-time. The other nine appearances: 1959, 1963, 1967, 1971, 1981, 1987, 1993, 1999, and 2005. It's pretty likely we'll see Arlene again in 2017--no storm that has formed in the Bay of Campeche and made landfall in Mexico has ever had its name retired. Hurricane Audrey of June 1957 formed in the Bay of Campeche and hit Texas as a Category 4 hurricane, killing 550 people, making Audrey one of only two June storms to get its name retired Hurricane Agnes of 1972 was the other. There have been seven storms beginning with the letter "A" that have had their names retired since 1950:

Allison (2001)
Andrew (1992)
Alicia (1983)
Allen (1980)
Anita (1977)
Agnes (1972)
Audrey (1957)

Of the 21 letters in the alphabet we use to name storms, names beginning with the letters "C" have been retired the most--nine times. Second place goes to "F" and "I" names, with eight retirees. The only letter used that doesn't have a retired storm is "V". There has been only one storm with a name beginning with "V"--Hurricane Vince of 2005. The list of retired hurricane names currently has 76 members.

An amazing low temperature of 107°F in Oman
At Khasab Airport in the desert nation of Oman, a remarkable record was set yesterday--the low temperature for the day was a scorching 41.7°C (107°F). The record was brought to my attention by weather records researcher Maximiliano Herrera. The previous highest minimum temperature for the world he was able to find was set just last year at Khasab Airport, 41.2°C (106°F). The U.S. record high minimum temperature may be a 39.4°C (103°F) taken in Death Valley, California in 1970. Higher record high minimums were set there in the early 1920s, but the quality of the data is suspect. Mr. Herrera notes that Khasab Airport in Oman lies at the base of a mountain range, behind which is desert. Winds blowing from the desert towards Khasab Airport flow downhill, undergoing compression and warming, like the Santa Ana winds in California. Incredibly hot conditions in Oman in late June are common, due to a seasonal shift in winds caused by the onset of the Southwest monsoon in India.

Record California rainstorm
Yesterday was the wettest day ever recorded in the San Francisco Bay Area between June 15 - September 15. All-time precipitation records for the month of June (total for the month) were set at SFO (San Francisco Airport), Oakland Downtown, Oakland Airport, Santa Rosa, Napa, Santa Cruz, and San Jose. Thanks go to Christopher C. Burt for this data.

Internet radio show on Arlene at 4pm EDT
I'll be discussing Tropical Storm Arlene on a special edition of our Internet radio show, the Daily Downpour, today (Wednesday) at 4:00pm EDT. Fellow wunderground meteorologists Shaun Tanner and Angela Fritz will be hosting the show. Listeners can email in or call in questions. The email address to ask questions is broadcast@wunderground.com.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 969 - 919

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20Blog Index

969. JBirdFireMedic
9:47 AM GMT on June 30, 2011
NEW BLOG
Member Since: August 10, 2009 Posts: 0 Comments: 247
968. Bitmap7
2:43 AM GMT on June 30, 2011
Is there a new blog?
Member Since: May 4, 2011 Posts: 0 Comments: 429
967. sunlinepr
12:35 AM GMT on June 30, 2011


Mad Face...
Member Since: August 2, 2010 Posts: 21 Comments: 9814
966. sunlinepr
12:33 AM GMT on June 30, 2011
Member Since: August 2, 2010 Posts: 21 Comments: 9814
965. Patrap
12:29 AM GMT on June 30, 2011


Member Since: July 3, 2005 Posts: 424 Comments: 128284
964. KEEPEROFTHEGATE (Mod)
12:05 AM GMT on June 30, 2011
POSS T.C.F.A.
01L/TS/A/CX
MARK
21.95N/95.86W
Member Since: July 15, 2006 Posts: 171 Comments: 53838
963. Levi32
12:04 AM GMT on June 30, 2011
Quoting TomTaylor:
interesting to see such a large area of calm winds


Monsoonal depressions will do that sometimes.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
962. TomTaylor
12:02 AM GMT on June 30, 2011
Quoting Levi32:
Good evening everyone.

000
URNT12 KNHC 292331 CCA
VORTEX DATA MESSAGE AL012011
A. 29/23:11:10Z
B. 21 deg 45 min N
095 deg 50 min W
C. NA
D. 51 kt
E. 137 deg 55 nm
F. 178 deg 56 kt
G. 137 deg 55 nm
H. EXTRAP 996 mb
I. 19 C / 399 m
J. 25 C / 392 m
K. 22 C / NA
L. NA
M. NA
N. 1345 / 01
O. 0.02 / 15 nm
P. AF309 0301A ARLENE OB 07 CCA
MAX FL WIND 64 KT N QUAD 20:26:50Z
SLP EXTRAP FROM BELOW 1500 FT
MAX WINDS FL AND SFC ASSOC WITH AREAS OF CONVECTION WELL AWAY FROM CNTR.
LARGE AREA IN CNTR APPROX 40 NM ACROSS OF WIND SPEEDS LESS THAN 10 KTS.

;

Exactly what I've been saying all day has kept Arlene to only slow, gradual strengthening.

That also answers Jed's question from earlier. Thunderstorm gusts well removed from the center don't really count. It's the same as land-based thunderstorms in the lower 48. You might get TS-force winds, but does that truly reflect the pressure gradient from the low pressure area spawning those storms? Usually no.
interesting to see such a large area of calm winds
Member Since: August 24, 2010 Posts: 19 Comments: 4357
961. HurricaneHunterJoe
12:02 AM GMT on June 30, 2011
we have updates,advisorys,hh updates,vortex updates, center relocations, its all so confusing.........lol
Member Since: September 18, 2010 Posts: 0 Comments: 5222
960. Tropicsweatherpr
12:02 AM GMT on June 30, 2011
Hey folks,Dr Masters has a new blog!!
Member Since: April 29, 2009 Posts: 75 Comments: 14261
959. Levi32
12:01 AM GMT on June 30, 2011
Quoting HurricaneHunterJoe:


i thought the last advisory was west at 5 mph, and now its going wnw or nw?


It has clearly gained latitude, confirmed by vortex messages over the last several hours. The NHC will do some strange things with 12-hour average motions sometimes. I don't remember exactly how they do it, but long averages can keep the direction from changing suddenly.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
958. robert88
12:00 AM GMT on June 30, 2011
I have to say the GFS did an outstanding job sniffing out Arlene...considering all the energy that was bundled down there. The ECMWF has been playing catch up.
Member Since: May 22, 2010 Posts: 0 Comments: 907
957. MiamiHurricanes09
12:00 AM GMT on June 30, 2011
So next Recon into Arlene is tomorrow morning (12z)?
Member Since: September 2, 2009 Posts: 130 Comments: 21193
956. HurricaneHunterJoe
11:59 PM GMT on June 29, 2011
Quoting Levi32:


Still looks WNW to me. The last two recon vortex messages had it moving NW between the two, but I think that is just residual rotation of this new center location around where the old one used to be. The overall motion should still be WNW I think.


i thought the last advisory was west at 5 mph, and now its going wnw or nw?
Member Since: September 18, 2010 Posts: 0 Comments: 5222
955. Levi32
11:57 PM GMT on June 29, 2011
Quoting stormpetrol:
could be wrong but to my eye Arlene seems to be drifting more NNW at the momenthttp://www.ssd.noaa.gov/goes/flt/t1/loop-vis .html


Still looks WNW to me. The last two recon vortex messages had it moving NW between the two, but I think that is just residual rotation of this new center location around where the old one used to be. The overall motion should still be WNW I think.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
954. aquak9
11:56 PM GMT on June 29, 2011
((cloudburst2011))
Member Since: August 13, 2005 Posts: 165 Comments: 25927
953. Patrap
11:55 PM GMT on June 29, 2011
Floater - RGB Color Infrared Loop

Member Since: July 3, 2005 Posts: 424 Comments: 128284
952. HurricaneHunterJoe
11:54 PM GMT on June 29, 2011
Quoting TomTaylor:
well it's not one yet. That may be one could be trying to form, but I doubt it.


HH found like a 40 mile center with like less than 10mph wind, maybe thats what it is?
Member Since: September 18, 2010 Posts: 0 Comments: 5222
951. Levi32
11:54 PM GMT on June 29, 2011
West at 4mph isn't that fast, though it will likely get faster.

Given the center's recent relocation, landfall is likely to be closer to Tampico, instead of south of it like the forecast track was earlier.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
950. TomTaylor
11:53 PM GMT on June 29, 2011
Quoting robert88:
Upwelling could be a problem for Arlene if she continues to slow and drift around. Water temps are high...but heat content is very low in that area.
she will only be over water for another 12-15 or so hours, so upwelling shouldn't be much of an issue.
Member Since: August 24, 2010 Posts: 19 Comments: 4357
949. Patrap
11:53 PM GMT on June 29, 2011
TS Arlene Floater - Rainbow Color Infrared Loop,
Member Since: July 3, 2005 Posts: 424 Comments: 128284
948. stormpetrol
11:52 PM GMT on June 29, 2011
could be wrong but to my eye Arlene seems to be drifting more NNW at the momenthttp://www.ssd.noaa.gov/goes/flt/t1/loop-vis .html
Member Since: April 29, 2007 Posts: 0 Comments: 7862
947. Patrap
11:51 PM GMT on June 29, 2011
Member Since: July 3, 2005 Posts: 424 Comments: 128284
946. TropicalAnalystwx13
11:51 PM GMT on June 29, 2011
...TROPICAL-STORM-FORCE WINDS NEARING PORTIONS OF THE COAST OF EASTERN MEXICO...

7:00 PM CDT Wed Jun 29
Location: 21.4°N 95.8°W
Max sustained: 60 mph
Moving: W at 4 mph
Min pressure: 996 mb
Member Since: July 6, 2010 Posts: 113 Comments: 32046
945. TropicalAnalystwx13
11:51 PM GMT on June 29, 2011
Quoting robert88:
Upwelling could be a problem for Arlene if she continues to slow and drift around. Water temps are high...but heat content is very low in that area.


Nah, she is expected to make landfall tomorrow morning. Should cause little, if any, upwelling in that area.
Member Since: July 6, 2010 Posts: 113 Comments: 32046
944. HurricaneHunterJoe
11:51 PM GMT on June 29, 2011
Are there any miracle workers out there who want to run for president and know how to make it rain and at the same time reduce all federal and state budget defecits? while at the same time having enough monies to fund the NHC and NWS and other life saving governmental agencies?
Member Since: September 18, 2010 Posts: 0 Comments: 5222
943. Levi32
11:49 PM GMT on June 29, 2011
Quoting MiamiHurricanes09:
Arlene isn't even close to developing an eye.



Only half a core.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
942. robert88
11:49 PM GMT on June 29, 2011
Upwelling could be a problem for Arlene if she continues to slow and drift around. Water temps are high...but heat content is very low in that area.
Member Since: May 22, 2010 Posts: 0 Comments: 907
940. TomTaylor
11:48 PM GMT on June 29, 2011
Quoting TropicalAnalystwx13:


Kind of looks like an eye between 95-96W and 21-22N, but probably isn't.

well it's not one yet. That may be one could be trying to form, but I doubt it.
Member Since: August 24, 2010 Posts: 19 Comments: 4357
939. WeatherNerdPR
11:46 PM GMT on June 29, 2011
Quoting TropicalAnalystwx13:


That is what I just said :P

There wasn't anything else to say about it. By the time I thought about it, I already had posted it.
Member Since: July 7, 2010 Posts: 0 Comments: 5682
938. Levi32
11:46 PM GMT on June 29, 2011
Good evening everyone.

000
URNT12 KNHC 292331 CCA
VORTEX DATA MESSAGE AL012011
A. 29/23:11:10Z
B. 21 deg 45 min N
095 deg 50 min W
C. NA
D. 51 kt
E. 137 deg 55 nm
F. 178 deg 56 kt
G. 137 deg 55 nm
H. EXTRAP 996 mb
I. 19 C / 399 m
J. 25 C / 392 m
K. 22 C / NA
L. NA
M. NA
N. 1345 / 01
O. 0.02 / 15 nm
P. AF309 0301A ARLENE OB 07 CCA
MAX FL WIND 64 KT N QUAD 20:26:50Z
SLP EXTRAP FROM BELOW 1500 FT
MAX WINDS FL AND SFC ASSOC WITH AREAS OF CONVECTION WELL AWAY FROM CNTR.
LARGE AREA IN CNTR APPROX 40 NM ACROSS OF WIND SPEEDS LESS THAN 10 KTS.

;

Exactly what I've been saying all day has kept Arlene to only slow, gradual strengthening.

That also answers Jed's question from earlier. Thunderstorm gusts well removed from the center don't really count. It's the same as land-based thunderstorms in the lower 48. You might get TS-force winds, but does that truly reflect the pressure gradient from the low pressure area spawning those storms? Usually no.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
937. islander101010
11:45 PM GMT on June 29, 2011
notice in a couple days the nhc is speeding her up west
Member Since: September 11, 2010 Posts: 1 Comments: 4589
936. TropicalAnalystwx13
11:43 PM GMT on June 29, 2011
Quoting WeatherNerdPR:

It looks like one. But it's probably not.


That is what I just said :P
Member Since: July 6, 2010 Posts: 113 Comments: 32046
935. HurricaneHunterJoe
11:43 PM GMT on June 29, 2011
but the storm is gonna buttonhook north and slam into texas?
Member Since: September 18, 2010 Posts: 0 Comments: 5222
934. islander101010
11:42 PM GMT on June 29, 2011
guessing its inbetweeen the two bright balls of convection
Member Since: September 11, 2010 Posts: 1 Comments: 4589
933. WeatherNerdPR
11:42 PM GMT on June 29, 2011
Quoting TropicalAnalystwx13:


Kind of looks like an eye between 95-96W and 21-22N, but probably isn't.


It looks like one. But it's probably not.
Member Since: July 7, 2010 Posts: 0 Comments: 5682
932. HurricaneHunterJoe
11:41 PM GMT on June 29, 2011
do you mean even Gov Rick Perry renting a stadium and all them people praying for rain didnt work?
Member Since: September 18, 2010 Posts: 0 Comments: 5222
930. wxgeek723
11:40 PM GMT on June 29, 2011
Why have there been so many storms that go from nothing to impressive in a day lately...
Member Since: August 28, 2008 Posts: 79 Comments: 3574
929. Orcasystems
11:40 PM GMT on June 29, 2011
Complete Update

TS BUSTED FORECAST ALIBI





Member Since: October 1, 2007 Posts: 81 Comments: 26511
928. robert88
11:40 PM GMT on June 29, 2011
Based on the latest microwave imagery Arlene is not that well organized as thought. I still wouldn't be surprised if she hits minimal cane. The inner core has a lot of work to do overnight.
Member Since: May 22, 2010 Posts: 0 Comments: 907
927. TropicalAnalystwx13
11:39 PM GMT on June 29, 2011
Quoting TomTaylor:
an what??


Kind of looks like an eye between 95-96W and 21-22N, but probably isn't.

Member Since: July 6, 2010 Posts: 113 Comments: 32046
925. TomTaylor
11:37 PM GMT on June 29, 2011
Quoting TropicalAnalystwx13:
Is that an...?

an what??
Member Since: August 24, 2010 Posts: 19 Comments: 4357
924. HimacaneBrees
11:36 PM GMT on June 29, 2011
Quoting cloudburst2011:
the high is expected to weaken in the next 36 hours....this is one of the reasons why the steering currents are becoming weak around arlene and she is slowing down...there is a huge high over central mexico also that is blocking arlene from moving inland...something for us to watch very closely for the next 36 hours...everyone around the texas coast should watch arlene very closely...


I like this wish huh umm sorry i mean forecast lol. really I'm just joking. I'm a layman and don't know much but I've been thinking pretty close to the same thing you are saying. I just didn't want to say it because I like I said I am a layman but I really want to learn.
Member Since: August 23, 2010 Posts: 0 Comments: 1005
923. washingtonian115
11:36 PM GMT on June 29, 2011
Quoting shadoclown45:

I see it *gasps in horror*
(Puts forearm over eye puts palm in front of sreen).I can't see with her brilliant pin whole eye.
Member Since: August 14, 2010 Posts: 10 Comments: 16971
922. amd
11:34 PM GMT on June 29, 2011
Quoting MiamiHurricanes09:
Probably leaving.


yep, they have now climbed up to the 400mb level. I was hoping that they would make one more run in the NE or N quadrant of the storm to see if those 64 kt filght winds or 67 kts surface winds were truly legit.
Member Since: August 29, 2005 Posts: 0 Comments: 1024
921. MiamiHurricanes09
11:34 PM GMT on June 29, 2011
Arlene isn't even close to developing an eye.

Member Since: September 2, 2009 Posts: 130 Comments: 21193
919. stormpetrol
11:33 PM GMT on June 29, 2011
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 29th day of the month at 23:20Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 309)
Storm Number & Year: 01L in 2011
Storm Name: Arlene (flight in the North Atlantic basin)
Mission Number: 3
Observation Number: 07
A. Time of Center Fix: 29th day of the month at 23:11:10Z
B. Center Fix Coordinates: 21°45'N 95°50'W (21.75N 95.8333W)
B. Center Fix Location: 133 miles (215 km) to the ESE (104°) from Tampico, Tamaulipas, México.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 51kts (~ 58.7mph)
E. Location of the Estimated Maximum Surface Wind: 55 nautical miles (63 statute miles) to the SE (137°) of center fix
F. Maximum Flight Level Wind Inbound: From 178° at 56kts (From the S at ~ 64.4mph)
G. Location of Maximum Flight Level Wind Inbound: 55 nautical miles (63 statute miles) to the SE (137°) of center fix
H. Minimum Sea Level Pressure: 996mb (29.41 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 19°C (66°F) at a pressure alt. of 399m (1,309ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 25°C (77°F) at a pressure alt. of 392m (1,286ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 22°C (72°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 1,500 feet
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 15 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 64kts (~ 73.6mph) in the north quadrant at 20:26:50Z
Sea Level Pressure Extrapolation From: Below 1,500 feet
Remarks Section - Additional Remarks...
MAX WINDS FL AND SFC ASSOC WITH AREAS OF CONVECTION WELL AWAY FROM CNTR.
LARGE AREA IN CNTR APPROX 40 NM ACROSS OF WIND SPEEDS LESS THAN 10 KTS.

Looks like new center NNW of the previous one?
Member Since: April 29, 2007 Posts: 0 Comments: 7862

Viewing: 969 - 919

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
73 °F
Overcast