July Atlantic hurricane outlook
It's mid-July, and we have yet to see a named storm form in the Atlantic this month. The computer models are not predicting any development through at least July 20, and if we make it all the way to the end of the month without a named storm forming, it will be the first July since 2009 without a named storm. Since the current active hurricane period began in 1995, 13 of 17 years (76%) have had a named storm form during July. The busiest July occurred in 2005, when five named storms and two major hurricanes formed. These included Hurricane Dennis and Hurricane Emily--the strongest hurricanes ever observed so early in the season. Only eight major hurricanes have formed in July since record keeping began in 1851. As seen in Figure 1, most of the last half of July activity occurs in the Gulf of Mexico and waters off the Southeast U.S. coast. These type of storms form when a cold front moves off the U.S. coast and stalls out, with the old frontal boundary serving as a focal point for development of a tropical disturbance (as happened for Alberto, Beryl, Chris, and Debby in 2012.) There will be at least two cold fronts moving off the U.S. Mid-Atlantic coast over the next two weeks. The first of these fronts will push offshore around July 20, and we will need to watch the waters offshore of North Carolina for development then. Formation potential will be aided by ocean temperatures that are about 0.7°C (1°F) above average along the U.S. East Coast.
Figure 1. Tracks of all tropical storms and hurricanes 1851 - 2006 that formed July 16-31. The U.S. coast from North to Texas are the preferred strike locations. Only a few storms have formed in the tropical Atlantic and Caribbean in July. Wind shear is typically too high and SSTs too cool in July to allow African waves in the Caribbean and tropical Atlantic to develop into tropical storms. However, a few long-track "Cape Verdes" hurricanes have occurred in July, spawned by tropical waves that came off the coast of Africa. African tropical waves serve as the instigators of about 85% of all major hurricanes.
Figure 2. The seasonal distribution of Atlantic hurricane activity shows that July typically has low activity. Image credit: NHC.
Sea Surface Temperatures: slightly above average
The departure of Sea Surface Temperatures (SST) from average over the tropical Atlantic between Africa and Central America was about 0.3°C above average during June (Figure 3.) This figure has not changed much over the first two weeks of July. These temperatures are not warm enough to appreciably affect the odds of a July named storm or hurricane. The strength of the Azores-Bermuda high has been near average over the past two weeks, driving near-average trade winds. The latest 2-week run of the GFS model predicts continued average-strength trade winds through late-July, so SSTs should remain about 0.3°C above average during this period, due to average amounts of cold water mixing up from below due to the wind action on the water.
Figure 3. Sea Surface Temperature (SST) departure from average for July 12, 2012. SSTs were 0.3°C above average over the tropical Atlantic's Main Development region for hurricanes, from Africa to Central America between 10° and 20° North Latitude. Note the large region of above average SSTs along the Equatorial Pacific off the coast of South America, the hallmark of a developing El Niño episode. Image credit: NOAA/NESDIS
El Niño on the way?
For two consecutive weeks, ocean temperatures 0.5 - 0.6°C above average have been present in the tropical Eastern Pacific, which is right at the threshold for a weak El Niño episode. NOAA's Climate Prediction Center has issued an El Niño Watch, and gives a 61% chance that El Niño conditions will be present during the August - September - October peak of the Atlantic hurricane season. The likely development of a full-fledged El Niño episode means that Atlantic hurricane activity will probably be suppressed in 2012, due to the strong upper-level winds and high wind shear these events typically bring to the tropical Atlantic.
Figure 4. Sea Surface Temperature (SST) departure from average for the the equatorial Eastern Pacific (the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region"). El Niño conditions exist when the SST in this region rises 0.5°C above average. As of July 9, 2012, SSTs in the Niño 3.4 region had risen to 0.5°C above average. To be considered an "El Niño episode", El Niño conditions must occur for five consecutive months, using 3-month averages. Image credit: NOAA Climate Prediction Center.
Wind shear: above average
Wind shear is usually defined as the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude). In most circumstances, wind shear above 20 knots will act to inhibit tropical storm formation. Wind shear below 12 knots is very conducive for tropical storm formation. High wind shear acts to tear a storm apart. The jet stream has two bands of strong high-altitude winds that are currently bringing high wind shear to the Atlantic. The southern branch (subtropical jet stream) is bringing high wind shear to the Caribbean, and the northern branch (polar jet stream) is bringing high wind shear to the waters offshore of New England. This configuration often leaves a "hole" of low shear between the two branches, off the Southeast U.S. coast and over the Gulf of Mexico. The jet stream is forecast to maintain this two-branch pattern over the coming two weeks. Wind shear has been about 10 - 20% higher than average over the first two weeks of July, and is predicted to be mostly above average for the coming two weeks. This will cut down on the odds of a July storm.
Figure 5. Vertical instability over the Caribbean Sea in 2012 (blue line) compared to average (black line.) The instability is plotted in °C, as a difference in temperature from near the surface to the upper atmosphere. Thunderstorms grow much more readily when vertical instability is high. Instability has been lower than average, due to an unusual amount of dry air in the atmosphere, reducing the potential for tropical storm formation. Image credit: NOAA/NESDIS/CIRA.
Dry air: above average
As seen in Figure 5, there has been an unusual amount of dry, stable air in the Caribbean this year creating low levels of vertical instability. This has occurred due to a combination of dry air from Africa, and upper-atmosphere dynamics creating large areas of sinking air that dry as they warm and approach the surface. The Gulf of Mexico and tropical Atlantic between the coast of Africa and the Lesser Antilles have also seen low vertical instability this summer. June and July are the peak months for dry air and dust coming off the coast of Africa, and the Saharan dust storms have been quite active over the past two weeks. Expect dry air to be a major deterrent to any storms that try to form in the tropical Atlantic during July.
Steering currents: average
The predicted steering current pattern for the next two weeks is a typical one for July. We have an active jet stream bringing many troughs of low pressure off the East Coast of the U.S. These troughs are frequent enough and strong enough to recurve any tropical storms or hurricanes that might penetrate north of the Caribbean Sea. Steering current patterns are predictable only about 3 - 5 days in the future, although we can make very general forecasts about the pattern as much as two weeks in advance. There is no telling what might happen during the peak months of August, September, and October--we might be in for a repeat of the favorable 2010 and 2011 steering current pattern, which recurved most storms out to sea--or the unfavorable 2008 pattern, which steered Ike and Gustav into the Gulf of Mexico.
Summary: a below average chance of a July tropical storm
Given that none of the computer models are forecasting tropical storm formation in the coming seven days, SSTs are only slightly above average, and wind shear and vertical stability are above average, I'll go with a 30% chance of a named storm forming in the Atlantic during the remainder of July.
Figure 6. Hurricane Emilia over the Eastern Pacific at 20:35 UTC July 10, 2012. At the time, Emilia was a Category 3 hurricane with 125 mph winds. Emilia peaked earlier in the day as a Category 4 storm with 140 mph winds--the strongest hurricane in the East Pacific so far in 2012. Image credit: NASA.
An active Eastern Pacific hurricane season
It's been a very active start to the Eastern Pacific hurricane season, where we've already had six named storms, four hurricanes, and three intense hurricanes. A typical season has 4 named storms, 2 hurricanes, and 0 intense hurricanes by July 14. The formation of Tropical Storm Fabio on July 12 marks the 4th earliest formation of the Eastern Pacific's season's sixth storm. The record is held by the year 1985, when the season's sixth storm formed on July 2. Record keeping began in 1949.
Have a great weekend, everyone, and I'll be back Monday with a new post.
Jeff Masters
Reader Comments
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Hey Nigel, I'm doing well... Trying to keep cool, lol... It'll be close to 90 up here for the next 5 days... I'm not used to that kind of stuff!
Bit of a spike on the magnetometer, lol...
i just think its funny that we call him MA which is like Ma
not saying its at the surface, but i can see it clear as day...as light as it may be. Storms in S fl are far more than expected, I think they are related.
see the spike:
http://www.swpc.noaa.gov/rt_plots/mag_3d.html
Added edit: OPe, I see WXweatherboyMA got it in already
(Updates every 5 minutes)
Very end of the run, about 15 days... We'll have to see if future runs pick up on it.
Below is the ACE spacecraft data measuring the latest Solar Wind and Bz Components.
Shouldn't that like... Not be happening?
north pole
The very active Eastern Pacific hurricane season is interesting in view that San Diego was chosen as the 2nd most vulnerable city overdue for a hurricane (see above link). Fabio may only reach San Diego area as a tropical depression, if that, but seeing this model makes the prediction very timely and realistic.
We do need the rain Fabio as a TD may bring considering the early wildfire season others have experienced so far.
Be careful what to wish for--eh?!
looks like what Beryl would have been with more time
Kyushu drenched by heavy rain
Torrential downpours continue to drench Japan's southwestern region of Kyushu. At least 22 people are dead and another person is in critical condition. 8 people are missing in Kumamoto, Oita and Fukuoka prefectures in what weather officials say is unprecedented heavy rain.
More than 246,000 people have been ordered to evacuate in Kumamoto, Oita, Fukuoka and Saga prefectures.
In Fukuoka Prefecture, in north Kyushu, more than 70,000 people have been urged to leave their homes in Yanagawa City.
In the northeast Kyushu prefecture of Oita, about 34,000 people in Hita City were ordered to depart by local authorities.
The intense rain caused by an active front has brought more than 800 millimeters of rain to a city in Kumamoto Prefecture since Wednesday. Weather officials note this amount of rain has not been seen before in such a short period of time.
The officials say additional precipitation of more than 80 millimeters per hour is likely in some areas. They warn of a high risk of floods and landslides in areas with saturated ground.
Jul. 14, 2012 - Updated 14:15 UTC (23:15 JST)
.
EP, 05, 2012071418, , BEST, 0, 155N, 1322W, 45, 997, TS
Cat 1 Fabio:
EP, 06, 2012071418, , BEST, 0, 162N, 1147W, 80, 978, HU
No change in intensity for both.
Emilia: 50 mph
Fabio: 90 mph
can't you see the signs
signs signs everywhere the signs
can't you see the signs......
P.s...this is my first time to blog on a smartphone....neat!
Smog advisory
Issued jointly by Environment Canada and the Ontario ministry of the
environment at 1:41 PM EDT Saturday 14 July 2012.
Special weather statement for:
City of Toronto
Windsor - Essex - Chatham-Kent
Sarnia - Lambton
Elgin
London - Middlesex
Simcoe - Delhi - Norfolk
Dunnville - Caledonia - Haldimand
Oxford - Brant
Niagara
City of Hamilton
Halton - Peel
York - Durham
Huron - Perth
Waterloo - Wellington
Dufferin - Innisfil
Grey - Bruce
Barrie - Orillia - Midland
Belleville - Quinte - Northumberland
Kingston - Prince Edward
Peterborough - Kawartha Lakes
Stirling - Tweed - South Frontenac
Bancroft - Bon Echo Park
Brockville - Leeds and Grenville
City of Ottawa
Gatineau
Prescott and Russell
Cornwall - Morrisburg
Smiths Falls - Lanark - Sharbot Lake
Parry Sound - Muskoka
Haliburton
Renfrew - Pembroke - Barry's Bay
Algonquin
Burk's Falls - Bayfield Inlet.
Smog advisory issued for..
City of Toronto
Halton - Peel
York - Durham
Dufferin - Innisfil
Barrie - Orillia - Midland
Belleville - Quinte - Northumberland
Kingston - Prince Edward
Peterborough - Kawartha Lakes
Humidex advisory for:
=new= Gatineau
=new= Brockville - Leeds and Grenville
=new= City of Ottawa
=new= Prescott and Russell
=new= Cornwall - Morrisburg
=new= Smiths Falls - Lanark - Sharbot Lake.
------------------------------------------------- --------------------
==discussion==
A long stretch of above normal temperatures in Southern Ontario is
forecast to continue through the middle of this coming week.
Today's high temperatures are again expected to reach the low to mid
30S in most locales, well above the normal highs which range between
25 and 28 Celsius at this time of year.
Sunday will bring increasing humidity, although patchy cloud cover
and the possibility of isolated showers and thunderstorms may keep
temperatures down a couple of degrees compared to today.
The hot and humid conditions will continue through Wednesday, after
which less humid and somewhat cooler air is expected.
Humidex values may reach or exceed Environment Canada's advisory
threshold of 40 in the coming days, and thus humidex advisories may
be issued.
Please monitor the latest forecasts and warnings from Environment
Canada at www.weatheroffice.gc.ca
END/OSPC
A discovery by NASA scientists in 2008 suggests that Earth’s power grid is even more vulnerable to space weather than previously thought. Much to their surprise, NASA scientists found an enormous hole- four times the size of the Earth- in our planet’s magnetic field. Five NASA satellites recorded the density of the breach in the magnetic field at 90% less than the norm. This discovery suggests that Earth’s power grid is even more susceptible to incoming solar flares and coronal mass ejections. In an interview with NASA science news, Jimmy Raeder, a physics professor at the University of New Hampshire stated that this breach in the magnetic field allows for “the perfect sequence for a really big event.”[7]
Speaking with National Geographic News, Daniel Baker of the University of Colorado’s Laboratory for Atmospheric and Space Physics said that a powerful solar storm could effectively leave entire cities without power for months or even years.[8] He noted that the large transformers that would likely be blown out during a solar storm are in short supply – a fact that could lead to serious complications when trying to restore power. Baker is just one among a growing chorus of researchers in the field of astrophysics who have gone on the record stating that a solar storm on the scale of the 1859 Carrington event would dramatically compromise our global communications systems and fry electrical power systems.
Is it still an x1.4 or is upgraded?
scary huh
how dangerous it really is
14/1800 UTC 16.1N 114.7W T4.5/4.5 FABIO -- East Pacific
14/1800 UTC 15.7N 131.8W T3.0/3.0 EMILIA -- East Pacific
CI# /Pressure/ Vmax
5.2 / 967.8mb/ 94.8kt
Final T# Adj T# Raw T#
5.2 5.8 5.8
Estimated radius of max. wind based on IR : 16 km
Center Temp : +4.0C Cloud Region Temp : -64.0C
Scene Type : EYE
Positioning Method : RING/SPIRAL COMBINATION
Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC
Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF
Tropical Cyclone Outlook
8:00 AM HST July 14 2012
=====================================
Weak low pressure, the remnant of Daniel, is centered about 15N 160W or about 475 miles south southwest of Lihue and is traveling to the west around 20 mph. Conditions are not favorable for re-development.
Viewing: 1151 - 1201
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