July 2012: Earth's 4th warmest; update on 94L--a threat to the Antilles

By: Dr. Jeff Masters , 7:19 PM GMT on August 18, 2012

Share this Blog
43
+

July 2012 was the globe's 4th warmest July on record, according to the National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC). NASA rated it the 12th warmest. July 2012 global land temperatures were the 3rd warmest on record, breaking a streak of three months (April, May, and June) when global land temperatures were the warmest on record. July 2012 global ocean temperatures were the 7th warmest on record, and it was the 329th consecutive month with global temperatures warmer than the 20th century average. The last time global temperatures were below average was February 1985. Global satellite-measured temperatures in July for the lowest 8 km of the atmosphere were 7th or 5th warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of July in his July 2012 Global Weather Extremes Summary.



Figure 1. Departure of temperature from average for July 2012. Most areas of the world experienced much higher-than-average monthly temperatures, including most of the United States and Canada. Meanwhile, Australia, northern and western Europe, eastern Russia, Alaska, and southern South America were notably cooler than average. Image credit: National Climatic Data Center (NCDC) .

El Niño watch continues
Sea surface temperatures increased to 0.8°C above average as of August 13 in the equatorial Pacific off the coast of South America. Ocean temperatures have been near or above the 0.5°C above average threshold needed for a weak El Niño event since the beginning of July. However, winds, pressures, and cloud cover over the region have not responded in the fashion typically associated with an El Niño, and NOAA's Climate Prediction Center (CPC) said that "The lack of a clear atmospheric response to the positive oceanic anomalies indicates ongoing ENSO-neutral conditions," in their August 9 El Niño discussion. They have issued an El Niño watch, and give a 71% chance that an El Niño event will be in place by September. El Niño conditions tend to decrease Atlantic hurricane activity, by increasing wind shear over the tropical Atlantic. Wind shear has been close to average over the tropical Atlantic since the beginning of hurricane season in June, though.


Figure 2. Arctic sea ice extent in 2012 (black line) compared to the previous record low year of 2007 (blue line) shows that 2012 is fast approaching all-time record territory. A big Arctic storm with a central pressure of 963 mb affected the ice during the first two weeks of August, causing a temporary downward spike in sea ice extent. Image credit: Danish Meteorological Institute.


Figure 3. View of the North Pole on August 17, 2012 from the North Pole Environmental Observatory shows plenty of melt water pools from the warm summer the North Pole has had.

Arctic sea ice falls to 2nd lowest extent in July, nears all-time record low during August
July 2012 Arctic sea ice extent reached its 2nd lowest July extent in the 35-year satellite record, according to the National Snow and Ice Data Center (NSIDC). During the first half of August, sea ice has undergone a spectacular decline, and we are on pace to break the all-time lowest sea ice extent record set in September 2007. As of August 17, the University of Bremen was showing that sea ice extent has already broken the all-time record; the Danish Meteorological Institute put the ice loss in 2nd place behind September 2007; and the National Snow and Ice Data Center put Arctic ice loss in 3rd place behind September of 2007 and 2011.

Update on 94L
A large tropical wave (Invest 94L) located a few hundred miles southwest of the Cape Verde Islands off the coast of Africa is headed west at 15 - 20 mph. This storm is a threat to develop into a tropical storm that will affect the Lesser Antilles Islands as early as Wednesday. The storm is under moderate wind shear of 10 - 20 knots, and is over waters of 28°C. A large area of dry air lies just to the north of 94L, as seen on the latest Saharan Air Layer (SAL) analysis. Satellite loops show that 94L has increased in organization this afternoon, with a growing amount of heavy thunderstorm activity and spin at middle levels of the atmosphere.


Figure 4. Afternoon satellite image of Invest 94L.

Forecast for 94L
The latest 2 pm EDT run of the SHIPS model predicts that wind shear will be low, 5 - 10 knots, and ocean temperatures will fluctuate around 28°C over the next five days, as 94L tracks westwards towards the Lesser Antilles. As is typical with storms making the crossing from Africa to the Antilles, dry air to the north will likely interfere with development, and the SHIPS model predicts increased dry air as 94L approaches the Lesser Antilles. However, with shear expected to be low, dry air may be less of an issue for 94L than it was for Ernesto or TD 7. The storm should maintain a nearly due west track through Monday night, to a point near 50°W, about 700 miles east of the Lesser Antilles. At that point, a trough of low pressure passing to the north of 94L may be able to pull the storm to the northwest well to the northeast of the Lesser Antilles, as suggested by the latest 12Z (8 am EDT) run of the NOGAPS model. The 12Z UKMET model shows a more west-northwesterly motion resulting in a near miss of the Lesser Antilles on Thursday. Our two best performing models--the GFS and ECMWF--have both been taking 94L through the Lesser Antilles with every run for the past 24 hours, though. The latest 12Z run of both models now agree on the timing, with 94L arriving Wednesday night or Thursday morning. The BAMM model, which performed as well as the ECMWF and GFS at 5-day forecasts in 2011, is also showing a track through the Lesser Antilles. Given this agreement among our top three models for long-range forecasts, I give a 60% chance that 94L will pass through the Lesser Antilles. In their 2 pm EDT Tropical Weather Outlook, NHC gave 94L a 50% chance of developing into a tropical depression by Monday afternoon.

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: 55 - 5

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 | 37Blog Index

Quoting stormchaser19:
Gordon and 94L are in parallel


Erm... Helene?
Member Since: Posts: Comments:
Quoting trHUrrIXC5MMX:
old run...but...Hispaniola plays a role here with Isaac



i dont trust the 12z runs


i wait for the 18z runs
Member Since: May 21, 2006 Posts: 5091 Comments: 114758
Band of convection around the eye of Gordon is strengthening.
Member Since: Posts: Comments:
Quoting ncstorm:
94L


We finally got our floater, I see. Now we will have something to argue about, I mean discuss.
Member Since: July 17, 2009 Posts: 69 Comments: 25392
Quoting Hurricanes4life:


According to this, doubt they will actually take these numbers though, very conservative NHC today!

I think they will put it at 110.
Member Since: Posts: Comments:
Gordon and 94L are in parallel
Member Since: Posts: Comments:
Quoting Hurricanes101:


really?

because yesterday there were some saying they name a lot more things than they used to because of Helene; does not sound conservative to me


well, just because the HH were there.
Member Since: Posts: Comments:
Quoting trHUrrIXC5MMX:


I'll say ALWAYS conservative ALL THE TIME


Yeah, expect for maybe Helene lol, I added the very since Brennan didn't do anything at the 2pm update!
Member Since: Posts: Comments:
Gordon
Member Since: Posts: Comments:
Gordon's eye is shrinking as the northern eyewall cools.
Member Since: Posts: Comments:
old run...but...Hispaniola plays a role here with Isaac
Member Since: Posts: Comments:
957.4mb    WOW!!!
Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF
Weakening Flag was on on the last update on Gordon.
Member Since: Posts: Comments:
Quoting trHUrrIXC5MMX:


I'll say ALWAYS conservative ALL THE TIME


really?

because yesterday there were some saying they name a lot more things than they used to because of Helene; does not sound conservative to me
Member Since: Posts: Comments:
Does anybody think this Isaac storm could get the size of Katrina
Member Since: Posts: Comments:
Wow Gordon looks great.

Member Since: Posts: Comments:
If gordon was a cat 3 he only had a 1-2 %chance according to NHC wind probabilities!Link
Member Since: Posts: Comments:
From last blog


Quoting tatoprweather:
Hes looking northern islands....


But only at best on the Euro ,a depression ,which would be unmamed as Issac
Member Since: Posts: Comments:
Quoting Hurricanes4life:


According to this, doubt they will actually take these numbers though, very conservative NHC today!


I'll say ALWAYS conservative ALL THE TIME
Member Since: Posts: Comments:
Quoting CybrTeddy:
ADT believes Gordon is at 115mph, but the TAFB/SAB are saying ~105mph. A reasonable blend of the two would be 110mph.


This can't be good for the Azores.
Member Since: Posts: Comments:
Quoting trHUrrIXC5MMX:





so cat 3?


According to this, doubt they will actually take these numbers though, very conservative NHC today!
Member Since: Posts: Comments:
ADT believes Gordon is at 115mph, but the TAFB/SAB are saying ~105mph. A reasonable blend of the three would be 110mph.
Member Since: July 8, 2005 Posts: 259 Comments: 23606
Quoting Gearsts:
Im not so sure about that. Still needs abit more time to get better define.

Yeah, I am still giving it a day or 2. (or 3)
Member Since: Posts: Comments:
Even if it misses the Antilles, they are sure to get some weather from this one--big.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

ASCAT from earlier showed a few weak west winds to the south of the center of circulation. Given its improved structure since that time, it wouldn't surprise me if the low was closed.


Me neither, but it should still be broad, that's what I meant by tightening. It is a matter of time.
Member Since: Posts: Comments:
Quoting Hurricanes4life:
Gordon RAW up to 5.7!!!


UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 18 AUG 2012 Time : 184500 UTC
Lat : 33:55:45 N Lon : 37:01:07 W


CI# /Pressure/ Vmax
5.4 / 957.4mb/ 99.6kt


Final T# Adj T# Raw T#
5.4 5.7 5.7

Estimated radius of max. wind based on IR : 26 km

Center Temp : 14.4C Cloud Region Temp : -59.2C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 95km
- Environmental MSLP : 1015mb

Satellite Viewing Angle : 55.6 degrees

************************************************* ***




so cat 3? doubt the NHC is gonna go that far
Member Since: Posts: Comments:
Quoting Gearsts:
Can i get a link to that?


Sure. :) Link
Member Since: August 24, 2010 Posts: 0 Comments: 680
Quoting Articuno:

Yeah, but if HH were in Invest 94L right now they would probably find a closed circulation, this is what is so hard about tracking Cape Verde Systems.
Im not so sure about that. Still needs abit more time to get better define.
Member Since: Posts: Comments:
Why so much dry air this season? What's the reasoning for some seasons having a lot of dry air but others not as much?
Member Since: Posts: Comments:
Quoting Hurricanes101:
anyone have the 2pm update on 94L from the atcf?



AL, 94, 2012081818, , BEST, 0, 133N, 320W, 25, 1008, DB



and here is the link


Link
Member Since: May 21, 2006 Posts: 5091 Comments: 114758
Quoting AtHomeInTX:
I think Levi said this was the best of the FIM models.

Shows a stronger storm missing the Antilles.
Member Since: Posts: Comments:
I think this El Nino has acted like a delayed one

indications are that El nino is in fact here, but I do not think it is noticeable completely in the Atlantic

I doubt El Nino has a huge impact on the heart of the hurricane season
Member Since: Posts: Comments:
Thanks Jeff!
You should have mentioned Gordon, he's a Category 2 and strengthening according to the ATCF and he's headed right for the Azores.
Member Since: Posts: Comments:
Quoting Gearsts:
Had a close COC and 45mph winds?

Yeah, but if HH were in Invest 94L right now they would probably find a closed circulation, this is what is so hard about tracking Cape Verde Systems.
they are too far away
Member Since: Posts: Comments:
94L
Member Since: Posts: Comments:
Quoting JLPR2:


Should take a while for the LLC to tighten up due to its size, but it sure looks better today. With all that moisture it might clean the entire CATL of dust.

ASCAT from earlier showed a few weak west winds to the south of the center of circulation. Given its improved structure since that time, it wouldn't surprise me if the low was closed.
Member Since: Posts: Comments:
Quoting AtHomeInTX:
I think Levi said this was the best of the FIM models.

Can i get a link to that?
Member Since: Posts: Comments:
Derived from (NHC) ATCF data for CategoryTwo HurricaneGordon for 18August6pmGMT
MinimumPressure decreased from 983millibars to 969millibars
MaxSusWinds increased from 70knots(81mph)130km/h to 90knots(104mph)167km/h
Vector changed from 89.5*East@18.2mph(29.2km/h) to 89.4*East@20.1mph(32.3km/h)

CVU-Corvo :: SMA-SantaMaria :: PXO-PortoSanto :: FNC-Madeira :: SPC-LaPalma :: VDE-ElHierro

The westernmost dot marks Gordon's position at the start of its 2nd day as a TropicalStorm
The easternmost dot on the kinked line is where TS.Gordon became a Hurricane
The westernmost dot on the longest line is where H.Gordon became Cat.2, and its most recent position

The longest line is a straightline projection through H.Gordon's 2 most recent positions to its closest approach to the nearest coastline
17August6pmGMT: TS.Gordon had been headed for passage 365miles(587kilometres)SSWest of SantaMaria (bottom of the unconnected blob beneath the straightline projection)
18August12amGMT: TS.Gordon had been headed for passage 348miles(559kilometres)SSWest of SantaMaria (top of the unconnected blob beneath the straightline projection)
18August6amGMT: TS.Gordon had been headed for passage 413miles(664kilometres)SSWest of SantaMaria (lone unlabeled dot beneath the straightline projection)
18August12pmGMT: Cat.1 H.Gordon had been headed for passage 267miles(430kilometres)South of SantaMaria (blob hanging off the straightline projection)
18August6pmGMT: Cat2. H.Gordon was heading for passage 251miles(403kilometres)South of SantaMaria in ~1day9hours from now (when this was posted)

Copy&paste cvu, sma, pxo, fnc, 31.211n27.162w, 31.806n26.621w, 32.03n26.46w, 33.096n25.71w, spc, vde, 34.3n51.1w- 34.6n49.1w- 34.4n47.0w- 34.3n45.0w- 34.2n43.1w- 34.0n41.5w- 34.0n39.6w, 34.0n39.6w-34.0n37.5w, 34.0n39.6w-33.321n25.583w, 36.928n25.017w-33.321n25.583w into the GreatCircleMapper for a larger-scale map and other information
The previous mapping for comparison
Member Since: August 21, 2007 Posts: 0 Comments: 4860
Quoting Hurricanes101:
anyone have the 2pm update on 94L from the atcf?


ftp://ftp.nhc.noaa.gov/atcf/btk/
Member Since: Posts: Comments:
Gordon RAW up to 5.7!!!


UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 18 AUG 2012 Time : 184500 UTC
Lat : 33:55:45 N Lon : 37:01:07 W


CI# /Pressure/ Vmax
5.4 / 957.4mb/ 99.6kt


Final T# Adj T# Raw T#
5.4 5.7 5.7

Estimated radius of max. wind based on IR : 26 km

Center Temp : +14.4C Cloud Region Temp : -59.2C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 95km
- Environmental MSLP : 1015mb

Satellite Viewing Angle : 55.6 degrees

************************************************* ***
Member Since: Posts: Comments:
El Niño conditions tend to decrease Atlantic hurricane activity, by increasing wind shear over the tropical Atlantic. Wind shear has been close to average over the tropical Atlantic since the beginning of hurricane season in June, though.

thanks Dr. Masters
Member Since: Posts: Comments:
Thanks for the update Doc. I'm glad you're finally coming around to my way of thinking. j/k

Should be an interesting week.
Member Since: July 17, 2009 Posts: 69 Comments: 25392
Quoting Articuno:

That already looks like a depression.
How come the ugly stuff (Helene) get named instead of this?
Had a close COC and 45mph winds?
Member Since: Posts: Comments:
Getting that 'look'
Member Since: July 8, 2005 Posts: 259 Comments: 23606
anyone have the 2pm update on 94L from the atcf?
Member Since: Posts: Comments:
Wow Doc, its not like there is a strenthinging Hurricane threating a string of inhabited Islands in the Atlantic.
Member Since: Posts: Comments:
I think Levi said this was the best of the FIM models.

Member Since: August 24, 2010 Posts: 0 Comments: 680
Quoting Gearsts:

That already looks like a depression.
How come the ugly stuff (Helene) get named instead of this?
Member Since: Posts: Comments:
Thanks Dr. Masters.
Member Since: Posts: Comments:
Thanks DRM.
Member Since: August 24, 2010 Posts: 0 Comments: 680
Quoting Gearsts:


Finally! :D

Oh! And thank you for the update Dr. M!
Member Since: Posts: Comments:

Viewing: 55 - 5

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 | 37Blog 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.