Dr. Jeff Masters on Desert Heat, Hot Rain, Tropical Developments

Hottest rain on record? Rain falls at 115°F in Needles, California
Posted by: Dr. Jeff Masters, 3:19 PM GMT on August 15, 2012 +19

A searing heat wave rare even for the Desert Southwest sent temperatures soaring to record levels on Monday, with Needles, California tying its record high for the date of 118°F (47.8°C). The temperature might have gone higher in Needles, but a thunderstorm rolled in at 3:20 pm, and by 3:56 pm PDT, rain began falling at a temperature of 115°F (46.1°C). Most of the rain evaporated, since the humidity was only 11%, and only a trace of precipitation was recorded in the rain gauge. Nevertheless, Monday’s rain at 115° in Needles sets a new world record for the hottest rain in world history. I don’t think many people were outside to experience to experience the feeling of rain falling at 115°, but if they were, it must have been an uncomfortable, sauna-like experience! Thanks go to Dr. Warren Blier of the NWS Monterey office for pointing out this remarkable event to me.

It is exceedingly rare to get rain when the temperature rises above 100°F, since those kind of temperatures usually require a high pressure system with sinking air that discourages rainfall. Monday’s rain in Needles was due to a flow of moisture coming from the south caused by the Southwest U.S. monsoon, a seasonal influx of moisture caused by the difference in temperature between the hot desert and the cooler ocean areas surrounding Mexico to the south. According to weather records researcher Maximiliano Herrera, the previous record for hottest rain, which I blogged about in June, was a rain shower at 109°F (43°C) observed in Mecca, Saudi Arabia on June 5, 2012 and in Marrakech, Morocco on July 10, 2010. The 11% humidity that accompanied Monday’s rain shower at 115° in Needles was the lowest humidity rain has ever occurred at anywhere on Earth in recorded history, according to Mr. Herrera.


Figure 1. True-color MODIS satellite image of California and Arizona taken at 1:25 pm PDT August 13, 2012. Developing thunderstorms surround Needles, CA, and the line of clouds to the southwest of the city would develop into a thunderstorm that brought rain to the city at 4 pm PDT, at a temperature of 115°F. Image credit: NASA.

A “very rare” heat wave for Phoenix
The heat wave that brought Needles’ record hot rain has broken an exceptional number of heat records in Phoenix, Arizona the past two weeks. According to the Phoenix NWS office, the “almost unbearable heat” of the first two weeks of August is a “very rare” event, and August 1 – 14, 2012 was the warmest such 2-week period in city history. The average temperature on August 6 – 13 was 100°F or higher each of the eight days, tying the record for most consecutive days with an average temperature of 100°. The temperature peaked at 116° on August 8, just 6° below Phoenix’s all-time record of 122° set on June 26, 1990. The forecast for Phoenix call for a bit of relief–highs are expected to be a relatively modest 105° today, and down near 100° by Friday.


Figure 2. Morning satellite image of 93L over the Central Atlantic.

93L close to tropical depression status
A large tropical wave (Invest 93L) is located in the Central Atlantic about 700 miles east of Bermuda. Satellite loops this morning show a surface circulation has formed, and heavy thunderstorm activity has increased to the point where 93L should be considered a tropical depression, if the heavy thunderstorms can persist through this afternoon. Wind shear is light, and ocean temperatures are warm, near 28°C. The latest Saharan Air Layer Analysis from the University of Wisconsin shows that 93L has moistened its environment considerably, and dry air should no longer be a significant impediment to development. The 8 am EDT run of the SHIPS model predicts that wind shear will remain in the low range through the weekend, and I expect this system will become Tropical Storm Gordon by Friday. The storm will not affect Bermuda, but residents of the Azores Islands should keep an eye on 93L, which could pass through the islands as early as Sunday night. In their 8 am Tropical Weather Outlook, NHC gave 93L an 80% chance of becoming a tropical depression by Friday morning.

Elsewhere in the tropics
In the Gulf of Mexico, a fall-like cold front is expected to stall out early next week, and the GFS model is predicting something could start to spin up near the Texas/Mexico border on Monday. Wind shear is predicted to be low to moderate, and cold fronts stalled out over the Gulf of Mexico often serve as the seed for tropical storms.

Most of the models predict development of a new tropical wave off the coast of Africa 6 – 7 days from now.

From:    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2186

Jeff Masters on Heat, TS Ernesto, etc.

Ernesto hit the Windward Islands; 128.5°F in Kuwait
Posted by: Dr. Jeff Masters, 1:49 PM GMT on August 03, 2012 +17

Tropical Storm Ernesto lashed the Windward Islands with strong winds and heavy rain early this morning, as it passed over St. Lucia near 7 am AST. Ernesto brought sustained winds of 43 mph to Barbados at 7 am AST, and sustained winds of 41 mph, gusting to 63 mph to St. Lucia at 6:15 am AST. Ernesto looks moderately well-organized on Martinique radar, with spiral bands to the north and south feeding into an echo-free center. Ernesto is beginning to show more organization on visible satellite loops, with the very limited heavy thunderstorm activity near its center now expanding, spiral banding increasing, and an upper-level outflow channel developing to the north. Ernesto is fighting moderate wind shear of 10 – 20 knots, and water vapor satellite loops show a large area of dry air to the west. Strong upper level winds from the west are driving this dry air into the core of the storm, disrupting it. It appears, though, that Ernesto has fended off the most serious challenges to its survival, as the pressure has fallen to 1002 mb, and the storm’s appearance on radar and satellite is gradually improving. The latest 7:30 am center report from the Hurricane Hunters also indicated that Ernesto was beginning to build an eyewall.


Figure 1. Radar image of Ernesto at 9:15 am EDT August 3, 2012. Image credit: Meteo France.


Figure 2. Morning satellite image of Ernesto.

Forecast for Ernesto
Ernesto’s survival into today means that the storm now potentially poses a formidable threat to the Western Caribbean. Wind shear is expected to drop to the low range, 5 – 10 knots, later today, and remain low for the next five days, according to the 8 am EDT run of the SHIPS model. With the storm entering a moister environment with increasing heat energy in the ocean, the official NHC forecast of Ernesto reaching hurricane strength by early Monday morning near Jamaica is a reasonable one. The reliable computer models predict a west to west-northwest motion through the Caribbean, with the storm’s heavy rains staying south of Puerto Rico and the Dominican Republic. The more southerly path predicted by the usually reliable ECMWF model, which brings Ernesto to a landfall in Belize on Wednesday, is being weighted less heavily by NHC, since they are assuming Ernesto will stay stronger than the ECMWF model is forecasting. Once Ernesto enters the Central Caribbean on Sunday, the storm’s outer spiral bands will likely cause flooding problems in Southwest Haiti, Jamaica, and the Cayman Islands. Of the major dynamical models NHC uses operationally–the ECMWF, GFS, NOGAPS, UKMET, GFDL, and HWRF–none clearly show Ernesto reaching hurricane strength in the Caribbean. However, some of the best statistical models, such as the LGEM and SHIPS, do show Ernesto becoming a hurricane in the Caribbean. By Monday, a trough of low pressure passing to the storm’s north may be capable of turning Ernesto more to the northwest, resulting in the storm entering the Gulf of Mexico by the middle of next week.

New African tropical disturbance 90L
A strong tropical wave is located just off the coast of Africa, about 175 miles south of the Cape Verde Islands. This disturbance, designated Invest 90L by NHC Friday morning, is headed west-northwest at 10 – 15 mph. Wind shear is a high 20 – 30 knots over 90L, but is expected to drop, and water temperatures are warm enough to support development. NHC gave 90L a 30% chance of developing into a tropical depression by Sunday morning in their 8 am Friday Tropical Weather Outlook.

Kuwait hits 53.6°C (128.5°F): 2nd hottest temperature in Asian history
An extraordinary high temperature of 53.6°C (128.5°F) was recorded in Sulaibya, Kuwait on July 31, the hottest temperature in Kuwait’s history, and the 2nd hottest temperature ever measured in Asia. According to weather records researcher Maximiliano Herrera, Sulaibya is in a location well-suited for recording extreme high temperatures, since high sand dunes surround the site, keeping the wind low and hampering sea breezes from cooling the city. Most record books list the 54°C (129.2°F) recorded on 21 June 1942 in Tirat Zvi Israel as the site of Asia’s all-time maximum temperature, but this record is disputed. The previous second warmest temperature in Asian history was set 53.5°C (128.3°F) at MohenjuDaro, Pakistan on May 26, 2010.

Extreme heat in Oklahoma
The most intense and widespread heat wave in Oklahoma since August, 1936 brought more than half of the state temperatures of 110° or higher for the second consecutive day on Thursday. The temperature at the Oklahoma City airport hit 112°, for the 2nd day in a row. These are the city’s 2nd highest temperatures since record keeping began in 1890. The only hotter day was August 11, 1936, when the temperature hit 113°. Thursday’s temperatures in Oklahoma were generally a degree or two cooler than Wednesday’s, with the hottest temperature reported a 116° reading from a location just south of Tulsa International Airport. The highest reading Thursday at any major airport was a 114° temperature at Tulsa Jones Airport. Oklahoma’s all-time state record is 120°, set in Tipton on June 27, 1994, and at three locations in 1936. Freedom, in the northwest part of the state, hit 121° on Wednesday, but this reading will need to be reviewed to see if the sensor was properly sited.

Jeff Masters

from:http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2170

Dr. Jeff Masters on Hurricane Outlook

July Atlantic hurricane outlook
Posted by: Dr. Jeff Masters, 12:55 PM GMT on July 13, 2012 +21

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

from:    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2152

And the Heat Goes On

The June 2012 U.S. heat wave: one of the greatest in recorded history
Posted by: Dr. Jeff Masters, 7:34 PM GMT on July 03, 2012 +35

Intense heat continues to bake a large portion of the U.S. this Tuesday, with portions of 17 states under heat advisories for dangerously high temperatures. The heat is particularly dangerous for the 1.4 million people still without power and air conditioning due to Friday’s incredible derecho event, which is now being blamed for 23 deaths. The ongoing heat wave is one of the most intense and widespread in U.S. history, according to wunderground’s weather historian, Christopher C. Burt. In his Sunday post, The Amazing June Heat Wave of 2012 Part 2: The Midwest and Southeast June 28-30, Mr. Burt documents that eighteen of the 298 locations (6%) that he follows closely because of their long period of record and representation of U.S. climate broke or tied their all-time heat records during the past week, and that “this is especially extraordinary since they have occurred in June rather than July or August when 95% of the previous all-time heat records have been set for this part of the country.” The only year with more all-time heat records than 2012 is 1936, when 61 cities of the 298 locations (20%) set all-time heat records. The summer of 1936 was the hottest summer in U.S. history, and July 1936 was the hottest month in U.S. history.

According to wunderground analysis of the National Climatic Data Center (NCDC) extremes database, during June 2012, 11% of the country’s 777 weather stations with a period of record of a century or more broke or tied all-time heat records for the month of June. Only 1936 (13% of June records broken or tied) and 1988 (12.5%) had a greater number of all-time monthly June records. I expect when NCDC releases their analysis of the June 2012 weather next week, they will rank the month as one of the top five hottest Junes in U.S. history.


Figure 1. Across the entire Continental U.S., 72% of the land area was classified as being in dry or drought conditions as of June 26, 2012. Conditions are not expected to improve much over the summer: the NOAA Climate Prediction Center’s latest drought outlook shows much of the U.S. in persistent drought conditions, with very few areas improving. The rains brought by Tropical Storm Debby did help out Florida and Georgia, however. Image credit: NOAA Environmental Visualization Laboratory.

The forecast: hot and dry
July is traditionally the hottest month of the year, and July 2012 is likely to set more all-time heat records. The latest predictions from the GFS and ECMWF models show that a ridge of high pressure and dry conditions will dominate the weather over about 80 – 90% of the country during the next two weeks, except for the Pacific Northwest and New England. This will bring wicked hot conditions to most of the nation, but no all-time heat records are likely to fall. However, around July 11, a sharp ridge of high pressure is expected to build in over the Western U.S., bringing the potential for crazy-hot conditions capable of toppling all-time heat records in many western states.

The intense heat and lack of rain, combined with soils that dried out early in the year due to lack of snowfall, have led to widespread areas of moderate to extreme drought over much of the nation’s grain growing regions, from Kansas to Indiana. The USDA is reporting steadily deteriorating crop conditions for corn and soybeans, and it is likely that a multi-billion dollar drought disaster is underway in the Midwest.

The wunderground Extremes page has an interactive map that allows one to look at the records for the 298 U.S. cities that Mr. Burt tracks. Click on the “Wunderground U.S. Records” button to see them.

Quiet in the Atlantic
There are no threat areas to discuss in the Atlantic, and none of the reliable computer models are developing a tropical cyclone over the next seven days.

Have a great 4th of July holiday, everyone, and I’ll be back Thursday with a new post.

Jeff Masters

fr/    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2144

Dr. Jeff Masters on Hurricanes & Tropical Storms

Today is my last day in Ponte Vedra Beach, Florida, where 700 of the world’s hurricane experts are gathered to attend the 30th Conference on Hurricanes and Tropical Meteorology of the American Meteorological Society. It’s been a great week of learning and catching up with old friends, and I present below a few final summaries of talks I attended.

Impact of Tropical Cyclones on drought alleviation in the Atlantic and Gulf Coasts
Dr. Pat Fitzpatrick of the Stennis Space Center in Mississippi discussed how landfalling tropical storms and hurricanes can alleviate drought. The biggest winner tends to be the Southeast U.S. states of Florida, Georgia, South Carolina, and North Carolina, where about 20% – 50% of all droughts between 1960 – 2009 were busted by a landfalling tropical storm or hurricane. It is uncommon for Texas to see a drought busted; less than 10% of all Texas droughts have been ended by a hurricane or tropical storm. This occurs because the Southeast U.S. can receive heavy rains from hurricanes moving up the East Coast, or moving through the Gulf of Mexico, while relatively few storms track over Texas. Over the course of a year, hurricanes and tropical storms contribute 15 – 20% of rain along the Gulf Coast, and 3 – 16% along the East Coast. The length of a drought does not seem to affect whether a drought can be ended by a hurricane or not. Hurricanes have been able to end both short (< 3 month) and long (> 12 month droughts) equally well.


Figure 1. Example of a drought-busting tropical storm. Moderate drought (Palmer Drought Severity Index, PDSI, ≤ –2.0) was present in 52 percent of the Florida, Georgia, South Carolina, and North Carolina climate divisions in May 2006. The percentage decreased to 29 percent after Tropical Storm Alberto passed through on June 11 – 15, 2006. Image credit: U.S. Drought Monitor.


Figure 2. Rainfall in inches from the passage of Tropical Storm Alberto in 2006. Image credit: NOAA/HPC.

According to the U.S. drought monitor, over 90% of the area of Florida, Georgia, South Carolina, and North Carolina are currently in moderate to exceptional drought. There is 1 – 2 inches of rain coming to much of the region over the next few days, but that will not be enough to bust the drought. Based on Dr. Fitzpatrick’s research, there is a 20% – 50% chance that the drought will be broken by a tropical storm or hurricane. The first storm on the list in 2012 is Alberto again; let’s hope we get another Alberto this year that imitates the 2006 version of Alberto.

Patterns of rapid intensification
Peter Yaukey of the University of New Orleans studied patterns of hurricane rapid intensification in the Atlantic from 1950 – 2009. The Gulf of Mexico and Caribbean saw the most rapid intensification events, and the Northeast Atlantic the fewest. Interestingly, he found that rapid intensification events did not peak in September, but tended to be more common in June and July. Hurricane are less likely to intensify in the late afternoon and early evening (near 00 UTC), and more likely to intensify just after midnight, at 06 UTC.

Jeff Masters

from:    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2076

Hurricane Season Update

Hurricane Season Hits Pause, But Isn’t Over

by Brett Israel
Date: 16 September 2011 Time: 04:05 PM ET
hurricane maria hits newfoundland

 

Hurricane Maria heads toward Newfoundland today, but there are no storms behind it….for now.
CREDIT: NOAA/NASA GOES-13 satellite.

Mid-August marked an uptick in the number of tropical storms and hurricanes forming in the Atlantic Ocean, with one storm always seeming to follow on the heels of another. But lately, the tropics have quieted down.

Hurricane Maria, the third hurricane of the 2011 season, is expected to hit Newfoundland, Canada, today (Sept. 16), but there are no other tropical cyclones (hurricanes and tropical storms) after this one the radar. But don’t think for a second that hurricane season is headed for an early exit, experts say.

“In no way, shape or form is this season over,” said Dennis Feltgen of the National Hurricane Center in Miami.

If, for some odd reason, no other tropical storms were to form this year, it would be the earliest end ever for an Atlantic hurricane season. The earliest date in the satellite era of the last active tropical cyclone in a given year was Sept. 21, 1993. Hurricane season officially ends Nov.1.

Feltgen and others say we’re not likely to set a new record this year.

“I would be incredibly surprised if Maria was the last tropical cyclone in the Atlantic,” said Phil Klotzbach, an atmospheric scientist at Colorado State University in Fort Collins. “While it looks like we’re going into a somewhat quieter period for a little bit, it’s not that unusual to have a quiet period during an active season,” Klotzbach said.

This season was predicted to be a doozy, with 14 to 19 named storms (which include tropical storms and hurricanes), seven to 10 hurricanes and three to five major hurricanes (Category 3 or higher). So far there have been 14 named storms (Nate formed shortly after Maria, but dissipated after striking Mexico shortly after it developed), three hurricanes and two major hurricanes (Irene and Katia).

The tropics seem to have quieted down as storms shift their birthplace to the west in the Atlantic basin. At the beginning of the season, tropical cyclones form near Cape Verde, off the coast of Western Africa. Toward the end of the season, they begin closer to the West Caribbean. This puts the southeastern United Sates in the crosshairs. October is typically an active month for that region.

Most of the global models suggest that another storm should develop in about nine days, Klotzbach said. And with the warm Atlantic waters and La Niña’s return — which has been linked to active hurricane seasons — more big storms could be on the way.

from:   http://www.livescience.com/16104-hurricane-season-lull.html

“It’s nice we got a little chance to breathe and collect our thoughts, but we are far from over,” Feltgen said.

New Tropical Depression—Maria

Hurricane Katia is not a problem, future Maria will be and she is right behind her

Published on September 5, 2011 11:40 am PT
– By Kevin Martin – Senior Meteorologist
– Article Editor and Approved – Warren Miller


No larger image

(TheWeatherSpace.com) — Hurricane Katia was never a problem for the Eastern United States here at TheWeatherSpace.com, however one area has been monitored for five days that might be.

Katia will move between the U.S. and Bermuda Island. Bermuda will get Tropical Storm force winds on Wednesday as the storm makes the closest approach.

A disturbance that should become the next named system; Maria, may actually become the problem in the next week.

The system is moving across the Central Atlantic right now and thunderstorms are building very quickly within it. Pressures are dropping as a result.

The system will continue to move toward the Northern Caribbean Islands and Puerto Rico by Friday and Saturday.

Because Former Tropical Storm Lee is now a deep trough in the Eastern U.S., the eastward flow will push the ridge in the Atlantic southward, flattening it. This flat pattern with the jet stream riding over it will be what brings these systems more westerly.

to read more, go to:   http://www.theweatherspace.com/news/TWS-09_05_2011_futuremaria.html

Gulf of Mexico Evacuations

Oil firms start U.S. Gulf evacuations due to weather

ReutersBy Kristen Hays and Erwin Seba | Reuters – Wed, Aug 31, 2011

  • HOUSTON (Reuters) – BP Plc on Wednesday became the first major oil producer to say it was evacuating some workers from Gulf of Mexico oil and gas platforms because of a tropical disturbance that could become a named storm this week.

Later on Wednesday, Anadarko Petroleum Corp joined BP saying it has evacuated non-essential workers from three platforms in the Gulf.

Royal Dutch Shell also was preparing to evacuate some workers and expected to decide whether to move forward with that during the day, spokeswoman Kelly op de Weegh said.

Shell was monitoring the system over the northwestern Caribbean Sea and the eastern Gulf. The National Hurricane Center said the weather formation had a 30 percent chance of becoming a cyclone in the next two days.

Chevron Corp, Exxon Mobil Corp, ConocoPhillips and Apache Corp also said they were monitoring the system.

BP, the biggest oil producer in the Gulf with eight company-operated oil and gas platforms, said it was evacuating from five platforms more than 500 “nonessential” workers, or those not directly involved in production, such as cooks.

The platforms involved are Thunder Horse, the world’s largest with capacity to produce up to 250,000 barrels of oil per day, and Na Kika, Mad Dog, Holstein and Atlantis.

“Essential personnel remain on board to continue safe operations and prepare the platforms for potential shut-in and full evacuation in the event it becomes necessary,” the company said in a statement.

Anadarko said the workers were taken from the Gunnison, Nansen and Boomvang platforms.

“We will continue to monitor the path of the weather and are prepared to evacuate all personnel and shut in production if necessary,” Anadarko said in a statement.

Shell is the second-largest producer in the Gulf, operating six oil and gas platforms.

Mexico’s state oil monopoly Pemex said it was monitoring the weather but not yet taking any emergency or precautionary steps.

The U.S. National Hurricane Center gives the disturbance, which would be called Lee if it becomes a tropical storm, a 60 percent chance of becoming a tropical cyclone in the next 48 hours, but said it could develop further when it reaches the western Gulf.

for more, go to:   http://news.yahoo.com/oil-firms-start-u-gulf-evacuations-due-weather-005732473.html

Here Comes Jose

Tropical Storm Jose forms near Bermuda

South Florida Sun-Sentinel8:56 a.m. EDT, August 28, 2011

Tropical Storm Jose has formed near Bermuda and is moving north at 16 mph, the National Weather Service said.

The northern motion is expected to continue Sunday. It currently has maximum sustained winds of 40 mph.

Little change in strength is forecast Sunday, but Jose could weaken Monday, the National Weather Service said.

Bermuda has issued a tropical storm warning, which means tropical storm conditions are expected somewhere within the warning area. In this case, it means within the next 12 hours. Tropical storm conditions are expected on Bermuda beginning Sunday morning.

Update on Harvey & 97L

Harvey drenching Belize; 97L a threat to the Caribbean and U.S.
Posted by: JeffMasters, 4:16 PM GMT on August 20, 2011 +21
Tropical Storm Harvey is closing in towards a landfall this afternoon in Belize, and is dumping very heavy rains on northern Honduras, northern Guatemala, and Belize as it steadily moves west near 12 mph. A personal weather station on Roatan Island on the north coast of Honduras has received 6.68″ of rain as of 10am EDT this morning from Harvey, and had a peak wind gust of 42 mph. The Roatan airport has received 3.55″, and had a peak wind gust of 40 mph. The first significant spiral band from Harvey moved over Belize City at 7am local time, dropping nearly an inch of rain on the city. Belize National Meteorological Service radar shows that Harvey has appeared to close off an eyewall as of 11:30am EDT, which may allow the storm to intensify another 10 – 15 mph before landfall. The 11am NHC wind probability forecast gave Harvey a 3% chance of making it to hurricane strength, but the discussion noted that it wouldn’t be that hard for Harvey to gain another 10 – 15 mph before landfall. I estimate there is a 30% chance that the winds along a 10-mile stretch of Belize coast where the eyewall makes landfall will reach hurricane force.


Figure 1. Radar image of Harvey taken at 11:30am EDT on Saturday, August 20, 2011, a few hours before landfall in Belize. A small closed eye is visible just south of the offshore islands of Belize. Image credit: Belize National Meteorological Service