An African wave worth watching; 2nd warmest June on record
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
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 | 43 — Blog Index
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.//
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
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!
See y'all later
Yeah. But won't the steering current carry it west.
"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."
oook
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
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?
new blog
Viewing: 2101 - 2123
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 | 43 — Blog Index