An African wave worth watching; 2nd warmest June on record

By: Dr. Jeff Masters , 17. heinäkuuta 2009 klo 13:51 (GMT)

Share this Blog
2
+

There's finally a African tropical wave worth mentioning, in what has been a very inactive June/July period for African waves with a potential to develop. A tropical wave near 12N 36W, about 1200 miles west of the coast of Africa, is triggering some modest heavy thunderstorm activity over the open ocean as the storm moves west at 10 - 15 mph. NHC designated this wave 97 L at noon today. Wind shear is a modest 15 knots over the disturbance, which is low enough to allow some slow development over the next few days. As long as the disturbance stays south of Puerto Rico's latitude (18°N), wind shear should remain low enough to allow development. However, there is a substantial amount of African dust and dry air surrounding the system on its west and north sides. This dry air will retard development, and may be able to completely disrupt the disturbance at some point over the next 3 - 4 days. None of the computer models develop the disturbance. The National Hurricane Center is giving this system a low (less than 30% chance) of developing into a tropical depression in the next 48 hours.


Figure 1. The first African wave of 2009 worth watching.

Second warmest June on record
The globe recorded its second warmest June on record, 0.02°C short of the record set in 2005, according to the National Climatic Data Center. The period January - June was the fifth warmest such period on record. Global temperature records go back to 1880. The most notable warmer-than-average temperatures were recorded across parts of Africa and most of Eurasia, where temperatures were 3°C (5°F) or more above average. The global ocean Sea Surface Temperature (SST) for June 2009 was the warmest on record, 0.59°C (1.06°F) above the 20th century average. This broke the previous June record set in 2005. The record June SSTs were due in part to the development of El Niño conditions in the Eastern Pacific. If El Niño conditions continue to strengthen during the coming months, we will probably set one or more global warmest-month-on-record marks later this year. The last time Earth experienced a second warmest month on record was in October 2008.


Figure 1. Departure of temperature from average for June 2009. Image credit: National Climatic Data Center.

June sea ice extent in the Arctic 4th lowest on record
June 2009 Northern Hemisphere sea ice extent was the 4th lowest since 1979, according to the National Snow and Ice Data Center. The record June low was set in 2006. This summer's melt is lagging behind the melting in the summer of 2007, which set the record for the lowest amount of summer sea ice in the Arctic. Forecasts of summer Arctic sea ice melt made in early June by two teams of German scientists put the odds of a new record sea ice minimum this year between 7% and 28%. With the amount of sunlight in the Arctic now on the wane, it appears unlikely that we will set a new record sea ice minimum in 2009. This year will probably have the 2nd or 3rd least sea ice extent on record come September, when the melting season ends. The ice-free seas that nearly surround Greenland now have contributed to temperatures of 2 - 3°C above average over the island over the past ten days. With clear skies and above-average temperatures likely over most of the island for at least the next week, we can expect near-record July melting over portions of the Greenland Ice Sheet this month.

Northwest Passage likely to open for the third consecutive year
The fabled Northwest Passage is more than half clear now, and has a good chance of melting free for the third consecutive year--and third time in recorded history. The first recorded attempt to find and sail the Northwest Passage was in 1497, and ended in failure. The thick ice choking the waterways thwarted all attempts at passage for the next four centuries. Finally, in 1905, Roald Amundsen completed the first successful navigation of the Northwest Passage. It took his ship two-and-a-half years to navigate through narrow passages of open water, and his ship spent two cold, dark winters locked in the ice during the feat.

We can be sure the Northwest Passage was never open from 1900 on, as we have detailed ice edge records from ships (Walsh and Chapman, 2001). It is very unlikely the Passage was open between 1497 and 1900, since this spanned a cold period in the northern latitudes known as "The Little Ice Age". Ships periodically attempted the Passage and were foiled during this time. The Northwest passage may have been open at some period during the Medieval Warm Period, between 1000 and 1300 AD.


Figure 3. Ice extent as measured by an AMSR-E microwave satellite sensor on July 15, 2009. Most of the famed Northwest Passage (red lines) has melted out. Image credit: University of Bremen.

References
Walsh, J.E and W.L.Chapman, 2001, "Twentieth-century sea ice variations from observational data", Annals of Glaciology, 33, Number 1, January 2001 , pp. 444-448.

I'll have an update on the African tropical wave at least once this weekend if the system doesn't fall apart.

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: 2123 - 2073

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43Blog Index

2123. weatherwatcher12
18. heinäkuuta 2009 klo 16:52 (GMT)
The vorticity on 97L isn't as broad as this morning:



Member Since: 16.05.2009 Posts: 1 Comments: 1231
2122. weatherwatcher12
18. heinäkuuta 2009 klo 16:25 (GMT)
Quoting hunkerdown:
ok, am I the only one here ??? *hearing crickets chirping*

new blog
Member Since: 16.05.2009 Posts: 1 Comments: 1231
2121. hunkerdown
18. heinäkuuta 2009 klo 16:21 (GMT)
ok, am I the only one here ??? *hearing crickets chirping*
Member Since: 15.08.2008 Posts: 0 Comments: 2515
2120. hunkerdown
18. heinäkuuta 2009 klo 16:19 (GMT)
Quoting tropicfreak:


How many times does wunderkidcayman have to say to everybody that shear will lessen. Just a friendly reminder, please read the comments posted on the blog( last 200 or less) before you start assuming or ask a question. thanks!
So it should be a very quiet blog in your opinion ? Almost everything that somebody says is repeated more than once. Its a discussion and not all people who come on at various times need to, nor are they required to, read all previous pages of the blog. This is a blog and thats what blogs are for. People are going to repeat themselves and repeat others, Thats the way it is and has been so you might as well deal with it.
Member Since: 15.08.2008 Posts: 0 Comments: 2515
2119. hunkerdown
18. heinäkuuta 2009 klo 16:14 (GMT)
Quoting 7544:


yeap and with all the local mets saying it will be approching so fla on wends but only as a wave for now but if the shar is lessening anything can happen close to land
They have it/them possibly approaching SFla due to their expected weak characteristics. If they were to strengthen I would expect them to transverse on a more Westerly path and be well below Florida.
Member Since: 15.08.2008 Posts: 0 Comments: 2515
2118. hunkerdown
18. heinäkuuta 2009 klo 16:12 (GMT)
Quoting AllStar17:
I expect all the models to shift south, and become in line with the LBAR.

Everybody, please understand what each models does before making predictions based on models.
Member Since: 15.08.2008 Posts: 0 Comments: 2515
2117. Grothar
18. heinäkuuta 2009 klo 15:59 (GMT)
Quoting nrtiwlnvragn:
Thanks for the info. In your opinion, which of the two disturbances has the best chance of developing? Invest 97L or the system closest to the islands?
Member Since: 17.07.2009 Posts: 64 Comments: 23755
2116. cg2916
18. heinäkuuta 2009 klo 15:55 (GMT)
New blog!!!
Member Since: 21.12.2007 Posts: 13 Comments: 3026
2115. wunderkidcayman
18. heinäkuuta 2009 klo 15:55 (GMT)
Quoting tropicfreak:


I have to agree with you on that. If the system to the west holds together, we could have 2 named storms.

yes ana, bill maybe
Member Since: 13.06.2009 Posts: 2 Comments: 9598
2112. tropicfreak
18. heinäkuuta 2009 klo 15:53 (GMT)
Quoting Funkadelic:
But even with shear ANNA is coming, albeit weak, we will have a storm to track.. heres why inmho"

The wave to the west has created HUGE amounts of moisture for 97L, regardless if it forms 97L will catch up to all of the moisture and tonight around dmax time 4-6am eastern time, we may see 1 system reall blow up. any thoughts?


I have to agree with you on that. If the system to the west holds together, we could have 2 named storms.
Member Since: 2.09.2006 Posts: 110 Comments: 6814
2111. cg2916
18. heinäkuuta 2009 klo 15:53 (GMT)
I can't believe the haven't named the area near ther Antilles an Invest.
Member Since: 21.12.2007 Posts: 13 Comments: 3026
2110. wunderkidcayman
18. heinäkuuta 2009 klo 15:52 (GMT)
Quoting tropicfreak:


How many times does wunderkidcayman have to say to everybody that shear will lessen. Just a friendly reminder, please read the comments posted on the blog( last 200 or less) before you start assuming or ask a question. thanks!

oook
Member Since: 13.06.2009 Posts: 2 Comments: 9598
2109. IKE
18. heinäkuuta 2009 klo 15:52 (GMT)
From the Miami,FL. early morning discussion...

"POPS WILL SIGNIFICANTLY INCREASE EARLY NEXT WEEK AS A TROPICAL
WAVE APPROACHES. THIS WAVE AT 00Z WAS ANALYZED BY TAFB AT 58W
APPROACHING THE LEEWARD ISLANDS. WITH A MOVEMENT WEST AT 15 KNOTS,
AND ACCORDING TO THE GFS40 AND ECMWF, BRING IT TO SOUTHEAST
FLORIDA BY WEDNESDAY. THE GFS40 TAKES THE BRUNT OF THE MOISTURE
AND HIGH PWATS UP THE WESTERN ATLANTIC COASTAL WATERS THROUGH
THURSDAY. THE MID LEVEL TROUGH THAT IS OVER THE NORTHEAST GULF OF
MEXICO LIFTS OUT OR WEAKENS BY WEDNESDAY AND THINK THAT THE WAVE
MAY ACTUALLY MOVE NORTHWEST THROUGH SOUTH FLORIDA RESULTING IN
RATHER HIGH POPS OVER MOST AREAS WEDNESDAY AND THURSDAY. HAVE
STAYED WITH 50 PERCENT FOR NOW BUT MAY BE ADJUSTED UPWARD TO THE
LIKELY CATEGORY IN LATER PACKAGES."
Member Since: 9.06.2005 Posts: 23 Comments: 37858
2108. canesrule1
18. heinäkuuta 2009 klo 15:52 (GMT)
Quoting Acemmett90:

good point but we in south florida and even the east coast need to watch both of these very very closely
true, hey accemett i live in Miami, just wondering where do u live in south florida?
2107. weatherwatcher12
18. heinäkuuta 2009 klo 15:52 (GMT)
Quoting canesrule1:
yeah but the BAMS actually shifted northward since yesterday.

Yeah. But won't the steering current carry it west.
Member Since: 16.05.2009 Posts: 1 Comments: 1231
2106. StormJunkie
18. heinäkuuta 2009 klo 15:52 (GMT)
Dr M has a new blog up

See y'all later
Member Since: 17.08.2005 Posts: 26 Comments: 15472
2104. tropicfreak
18. heinäkuuta 2009 klo 15:51 (GMT)
Quoting wunderkidcayman:
no way to much shear we could maybe keyword maybe get a td or a weak ts

wind shear is becoming weaker and weaker


How many times does wunderkidcayman have to say to everybody that shear will lessen. Just a friendly reminder, please read the comments posted on the blog( last 200 or less) before you start assuming or ask a question. thanks!
Member Since: 2.09.2006 Posts: 110 Comments: 6814
2103. canesrule1
18. heinäkuuta 2009 klo 15:50 (GMT)
Quoting weatherwatcher12:

They almost always shift south
yeah but the BAMS actually shifted northward since yesterday.
2102. 7544
18. heinäkuuta 2009 klo 15:49 (GMT)
Quoting Acemmett90:

good point but we in south florida and even the east coast need to watch both of these very very closely


yeap and with all the local mets saying it will be approching so fla on wends but only as a wave for now but if the shar is lessening anything can happen close to land
Member Since: 6.05.2007 Posts: 0 Comments: 6618
2101. KEEPEROFTHEGATE (Mod)
18. heinäkuuta 2009 klo 15:49 (GMT)
Quoting DaaiTouLaam:
Rain has started again. Wind picking up a bit and pressure dropping.

At Waglan Island the pressure is down to ~990 hPa and pushing down towards ~991hPa at the HK Observatory.

Another couple of hours for Typhoon Molave's eyewall to hit...




712

WTPN31 PGTW 181500

MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//

SUBJ/TROPICAL CYCLONE WARNING//

RMKS/

1. TYPHOON 07W (MOLAVE) WARNING NR 014

UPGRADED FROM TROPICAL STORM 07W

01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC

MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE

WIND RADII VALID OVER OPEN WATER ONLY

---

WARNING POSITION:

181200Z --- NEAR 22.3N 115.9E

MOVEMENT PAST SIX HOURS - 295 DEGREES AT 13 KTS

POSITION ACCURATE TO WITHIN 060 NM

POSITION BASED ON CENTER LOCATED BY A COMBINATION OF

SATELLITE AND RADAR

PRESENT WIND DISTRIBUTION:

MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT

WIND RADII VALID OVER OPEN WATER ONLY

RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT

030 NM SOUTHEAST QUADRANT

025 NM SOUTHWEST QUADRANT

045 NM NORTHWEST QUADRANT

RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT

070 NM SOUTHEAST QUADRANT

055 NM SOUTHWEST QUADRANT

060 NM NORTHWEST QUADRANT

REPEAT POSIT: 22.3N 115.9E

---

FORECASTS:

12 HRS, VALID AT:

190000Z --- 23.2N 113.2E

MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT

WIND RADII VALID OVER OPEN WATER ONLY

DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND

VECTOR TO 24 HR POSIT: 285 DEG/ 11 KTS

---

24 HRS, VALID AT:

191200Z --- 23.8N 111.0E

MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT

WIND RADII VALID OVER OPEN WATER ONLY

DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND

---

REMARKS:

181500Z POSITION NEAR 22.5N 115.2E.

TYPHOON (TY) 07W (MOLAVE), LOCATED APPROXIMATELY 95 NM EAST OF HONG

KONG, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS AND HAS INTENSIFIED

FROM A TROPICAL STORM OVER THE PAST SIX HOURS. ANIMATED INFRARED

IMAGERY SHOWS AN EYE DEVELOPING OVER THE PAST THREE HOURS AND LATEST

RADAR IMAGERY FROM HONG KONG DEPICTS A CLOSED CIRCULATION. THE

TYPHOON IS EXPECTED TO MAKE LANDFALL JUST NORTH OF HONG KONG AFTER

TAU 06 THEN TRACK INLAND INTO CHINA AND DISSIPATE BY TAU 24. MAXIMUM

SIGNIFICANT WAVE HEIGHT AT 181200Z IS 15 FEET. MAXIMUM SIGNIFICANT

WAVE HEIGHT AT 181200Z IS 15 FEET. NEXT WARNINGS AT 182100Z, AND

190300Z.//
Member Since: 15.07.2006 Posts: 165 Comments: 52406
2100. SomeRandomTexan
18. heinäkuuta 2009 klo 15:48 (GMT)
Allstar--
I agree... I don't think it's going to pick up that far north... it's too weak and will follow the steering current.. the models have called for a sharper WNW-Nw track the whole time and it hasn't really happened... its been pretty much west with a little movement just north of west..jmo
Member Since: 30.08.2007 Posts: 0 Comments: 1837
2099. AllStar17
18. heinäkuuta 2009 klo 15:48 (GMT)
Still spinning, but it needs convection to survive.



Member Since: 29.06.2009 Posts: 13 Comments: 5238
2097. canesrule1
18. heinäkuuta 2009 klo 15:47 (GMT)
Good morning everyone, still watching Invest 97L closely, but what is the huge blob around Puerto Rico, please explaine, thanks.
2096. errantlythought
18. heinäkuuta 2009 klo 15:47 (GMT)
I'm pretty sure the blob ahead of the wave is just diffluence from the sheer that (was) in the area. Unfortunately theres no way to tell for sure, but it does have a nice little almost 90 degree angle there in the northwest.

Member Since: 27.08.2005 Posts: 0 Comments: 191
2095. 7544
18. heinäkuuta 2009 klo 15:48 (GMT)
Quoting IKE:
12Z GFS has the wave that's approaching the islands continuing to move just north of west.


thats a little more north than the last run watch where it will go on the nest couple of frames
Member Since: 6.05.2007 Posts: 0 Comments: 6618
2094. AllStar17
18. heinäkuuta 2009 klo 15:46 (GMT)
Acemmett90

That probability, however, remember is only for the next 48 hours. It is not a probability that the storm will ever be named.
Member Since: 29.06.2009 Posts: 13 Comments: 5238
2093. weatherwatcher12
18. heinäkuuta 2009 klo 15:46 (GMT)
Quoting AllStar17:
I expect all the models to shift south, and become in line with the LBAR.


They almost always shift south
Member Since: 16.05.2009 Posts: 1 Comments: 1231
2091. DaaiTouLaam
18. heinäkuuta 2009 klo 15:45 (GMT)
Quoting HadesGodWyvern:

The Tropical Cyclone Warning Signal Number 8 is expected to
be issued at or before 11:30 p.m. today (18 Jul 2009).


Molave will get very close to Hong Kong. Winds locally
will significantly strengthen within the next few hours.



T8 is now up.
---
NO. 8 NORTH-WEST GALE OR STORM FORCE SIGNAL WAS ISSUED AT 23:30 HKT ON 18.07.2009
---
Member Since: 7.08.2007 Posts: 0 Comments: 110
2090. AllStar17
18. heinäkuuta 2009 klo 15:46 (GMT)
I expect all the models to shift south, and become in line with the LBAR.

Member Since: 29.06.2009 Posts: 13 Comments: 5238
2088. SomeRandomTexan
18. heinäkuuta 2009 klo 15:44 (GMT)
The convection does look impressive for the islands wave... It does look like 97L could catch up to it.. I dont think 97L will go quite as far north as the models say... thinking its going to maybe get into the northern part of the carrib
Member Since: 30.08.2007 Posts: 0 Comments: 1837
2087. RufusBaker
18. heinäkuuta 2009 klo 15:43 (GMT)
Oh here ya are Ruuuufus Baker!!
Member Since: 5.07.2009 Posts: 0 Comments: 578
2086. IKE
18. heinäkuuta 2009 klo 15:43 (GMT)
12Z GFS has the wave that's approaching the islands continuing to move just north of west.
Member Since: 9.06.2005 Posts: 23 Comments: 37858
2085. nrtiwlnvragn
18. heinäkuuta 2009 klo 15:43 (GMT)
OFFSHORE WATERS FORECAST FOR THE SW AND TROPICAL N ATLANTIC AND CARIBBEAN SEA

.SYNOPSIS...A TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES NEAR 60/61W...MOVING W AROUND 18 KT. THE TROPICAL WAVE WILL MOVE MORE W-NW ACROSS THE EASTERN CARIBBEAN TODAY...THEN REACH THE CENTRAL CARIBBEAN NEAR 69W BY EARLY MON...JAMAICA ON TUE...AND THE NICARAGUAN COAST WED. A SECOND TROPICAL WAVE CURRENTLY OVER THE CENTRAL ATLC IS FORECAST TO REACH THE EASTERN CARIBBEAN BY EARLY TUE...AND THE CENTRAL CARIBBEAN NEAR 68W BY EARLY WED. THE TRADE WINDS WILL FLUCTUATE IN RESPONSE TO THE PASSAGE OF THESE TWO TROPICAL WAVES...WITH HIGHEST WINDS AND SEAS EXPECTED ACROSS N PORTIONS OF THESE TROPICAL WAVES.
Member Since: 23.09.2005 Posts: 13 Comments: 10473
2084. wunderkidcayman
18. heinäkuuta 2009 klo 15:42 (GMT)
no way to much shear we could maybe keyword maybe get a td or a weak ts

wind shear is becoming weaker and weaker
Member Since: 13.06.2009 Posts: 2 Comments: 9598
2083. AllStar17
18. heinäkuuta 2009 klo 15:41 (GMT)
Acemmett90

The shear is supposed to lessen over the next few days....creating a more favorable environment for 97L
Member Since: 29.06.2009 Posts: 13 Comments: 5238
2081. 7544
18. heinäkuuta 2009 klo 15:40 (GMT)
possible Link
anything can happen even with shear
Member Since: 6.05.2007 Posts: 0 Comments: 6618
2080. weatherwatcher12
18. heinäkuuta 2009 klo 15:40 (GMT)
Quoting DaaiTouLaam:
Rain has started again. Wind picking up a bit and pressure dropping.

At Waglan Island the pressure is down to ~990 hPa and pushing down towards ~991hPa at the HK Observatory.

Another couple of hours for Typhoon Molave's eyewall to hit...

Stay safe
Member Since: 16.05.2009 Posts: 1 Comments: 1231
2077. DaaiTouLaam
18. heinäkuuta 2009 klo 15:38 (GMT)
Rain has started again. Wind picking up a bit and pressure dropping.

At Waglan Island the pressure is down to ~990 hPa and pushing down towards ~991hPa at the HK Observatory.

Another couple of hours for Typhoon Molave's eyewall to hit...
Member Since: 7.08.2007 Posts: 0 Comments: 110
2076. wunderkidcayman
18. heinäkuuta 2009 klo 15:38 (GMT)
Quoting reedzone:


It seems to me the wave near the islands is moistening the environment. I think 97L could make this DMAX tonight. Especially with that wave blowing up, it's creating more moisture in that area, it's really setting the stage for 97L.

maybe we see a strong ts or weak hurricane in central carribean from both systems very soon
Member Since: 13.06.2009 Posts: 2 Comments: 9598
2075. weatherwatcher12
18. heinäkuuta 2009 klo 15:36 (GMT)
It looks like 97L entered an area of 28-29 sst.

Go here and activate sst box
Member Since: 16.05.2009 Posts: 1 Comments: 1231
2073. Patrap
18. heinäkuuta 2009 klo 15:35 (GMT)
Seems someone misses somebody..LOL
Member Since: 3.07.2005 Posts: 415 Comments: 125752

Viewing: 2123 - 2073

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43Blog 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

Clear
52 °F
Selkeää