Atlantic Sat Image

Atlantic Sat Image
Clouds over Atlantic

Wednesday, October 26, 2011

Hard to decipher "Rina"

I intentionally waited a good 24 hours from the last post to see if the models were agreeing more today on Rina's future. If you happened to catch my forecast last night after the X-Factor, I mentioned that a small kink had developed in Rina's armor in the form of dry air filtering into the center, and that we had to wait and see if it would have an impact.

Well the models are still all over the place and the kink appears to be a big one.


This is the latest on Rina:

  • The satellite shows a more ragged Rina than yesterday with its eye covered by clouds.  
  • It appears the eyewall has lost some of its shape. 
  • There is less rain than from early Wednesday morning.
  • The good outflow from yesterday has also diminished
  • We know what will happen over the next few days
  • Long range outlook is still a mystery

For the short term
Rina is sitting in the Northwest Caribbean Sea with a huge dome of high pressure to its East and some strong upper level winds coming in from the South. There is also a cold front over the Heartland moving into the Gulf of Mexico.


The models show the high moving east and the front entering the Gulf. This will cause Rina to move toward the Yucatan Peninsula. Given that it is not as healthy as it was a mere 24 hours ago, I do not foresee any more strengthening.

Long term
After 72 hours, the forecast becomes dicey. Rina will be impacted by stronger upper level winds pushing it east, at the same time, the winds near the surface will try to push it in the opposite direction. This tug-of-war should tear Rina apart. This sounds good, but the models will not tell us when this will take place. They give us a couple of case scenarios.

Scenario one: The shear is so strong that Rina won't even make it past the Yucatan and rain itself out.
Scenario two: The shear is weaker, Rina survives and eventually moves it in our general direction as a possible depression or tropical storm.

The rest of the models lay somewhere in between.



So the bottom line is as follows: Rina should move toward the Yucatan Peninsula. IF IT SURVIVES, then it may be a worry for South Florida.

This is the official forecast one from NHC



Monday, October 24, 2011

Hurricane Rina

Topical Storm Rina was classified as a Hurricane Monday afternoon. It appears nothing may stop its growth process over the next few days. Here are the reasons why.

  •  It's moving slowly absorbing plenty of tropical heat.
  • Sea surface temps are hovering in the mid-80's. This is the fuel for tropical engines to grow
  • Very little shear in the upper levels (As of now, could change later on)
  • Dry air to the North not impacting it (Could keep it in check in three days)


  
Models are still not in agreement. We expect a front to push into the Gulf Waters over the next 5 days. A few of the models bounce Rina off the front and into Central America, others keep it hovering in the Caribbean Sea, while others aim it toward South Florida.
Hopefully within the next few days, they will come into agreement as to where Rina will go.


  
The official forecast from NHC takes this into account and keeps Rina near Central America and Mexico over the next 3 days. By Friday it begins a turn East... but where it may end up is still uncertain. It could be anywhere between the Caribbean Sea, West Cuba, or even the Gulf of Mexico.

  

Monday, October 17, 2011

Wet Week Ahead

NHC is looking at an area of disturbed weather near the Yucatan Peninsula for further development. They are giving it a moderate chance that it will become a tropical system in the days ahead as it tracks toward Florida. This feature is loaded with moisture and it will continue to soak us at least through mid-week.


It continues to produce pockets of heavy rain from Mexico through Cuba, and South Florida.


This is what you can expect this Monday:

  • Mostly cloudy and rainy
  • Windy at the coast
  • Flood Watch for Miami-Dade and Broward counties through early evening, with the threat of ponding until 6 am Tuesday morning.
It has been raining non stop in many areas since Saturday and the ground is saturated. Any additional rain will surely lead to street flooding.

This threat will remain from the Keys through Broward at least through Wednesday as that area of disturbed weather continues to organize. A recon plane will check it out later today. Even if doesn't grow into a depression or a tropical storm it will keep us soggy.


This is what the latest suite of model runs is showing. It appears it will cut through Central Florida by Thursday. We'll keep watching it.

Sunday, October 16, 2011

Record Rain?

Rain is coming down across South Florida and it could lead to serious street flooding over the next 24 hours. We are expecting the heaviest of the rain from Sunday Night through Monday night.

We are stuck between three weather features:
  • High pressure to the north
  • Low pressure to the south
  • Plenty of moisture in the Caribbean

The first two will continue to keep us breezy and help syphon up moisture from the Caribbean pocket of rain.


NWS is suggesting we could see rainfall totals between 3-5 inches which are near record values for this time of year. They also stated:

"A FLOOD WATCH MAY BE REQUIRED FOR PORTIONS OF SOUTH FLORIDA BEGINNING SUNDAY NIGHT AND CONTINUING THROUGH AT LEAST MONDAY NIGHT."


At the same time, that pool of moisture in the Caribbean Sea is also being watched by NHC. They are now giving it a 50% chance it could grow into a tropical system over the next few days.



There is plenty of rain and thunderstorm activity over the Yucatan Channel. Much of it is being pushed over Cuba and ending up here.

Most models take this feature over Florida and then into the Atlantic.

Even if it doesn't get any stronger, it will help dump even more rain over the area in the days ahead.

NHC has deemed this INVEST 95.  Here is the latest suite of model runs. A recon plane is on stand-by to INVESTigate the system further on Monday if need be.

Thursday, October 13, 2011

Watching the Weekend

Interesting weekend setting up across South Florida. We are looking at a couple of features that may help draw up allot of tropical moisture leading to rain, specially on Sunday. Lets take a look.
  • Weak cold front heading South.
  • Area of disturbed weather sitting over the Yucatan Peninsula.

Lets start with the front. Satellite imagery shows clear skies from the plains out to the west coast. This is due to a push of cooler Canadian Air.

Ahead of the front, there is heat and humidity causing rain over the Great Lakes.

The leading edge of the front is expected to arrive here sometime Friday/Saturday. This will lead to a chance for showers on Saturday.

The front will then stall and slowly creep back up north on Sunday. Once this happens it will draw up tropical moisture which will lead to a better chance of rain for Sunday.

The second feature can be found on the lower right hand corner of the satellite picture. This is what's left of a Depression from the Eastern Pacific (old TD 12E). The remnants of this stretched out area of low pressure is presently causing plenty of rain over the region. NHC is giving it a 10% chance for growth.

Some models hint at the front tapping into this moisture on Sunday and if it does, it could mean a wetter Sunday. The chances of rain could stick around through the early part of the workweek as well.

A few models even hint at this disturbance turning into an area of low pressure and maybe even a tropical system in the days ahead. Climatology favors this area for tropical formation this time of year.


Usually during the month of October, if anything were to develop, it would do so in the NW Caribbean or Eastern Gulf of Mexico.

The typical path of anything forming here is toward Cuba and/or Florida.

We'll be watching this area of clouds and rain at WSVN over the next few days, just in case it decides to get its act together.

On a separate note, there is also another area NHC is following.



This is a surface low east of the Bahamas. It has plenty of rain, but as of Thursday night its chances for development have fallen from 30% to 20% . Models keep it along the favored track of most of the storms this year, along the Western Atlantic and then heading onto the Cold Waters of the Northern Atlantic and dying a quiet death in the long run.

Sunday, October 9, 2011

Hopefully Drier

What a wild Saturday! I received calls, e-mails, tweets, and facebook posts wondering if we had a hurricane over us. The answer was no, but with the torrential rainfall, the howling winds, and the rough seas... it sure felt like it.

Sunday should be drier, but any little rainfall will  be quick to flood streets since the ground is already saturated from yesterday's rain. NWS has several advisories in place.

  • FLOOD WATCH PALM BEACH, BROWARD, MIAMI DADE COUNTIES UNTIL 8 PM
  • HAZARDOUS MARINE CONDITIONS, STRONG RIPS AND ROUGH SURF ATLANTIC BEACHES.

Back to the rain. Many areas in South Florida received more rain in two days than we get in one month!
Here are some impressive rainfall totals from Midnight Thursday to Midnight Saturday.


City and amount
W. Kendall                    9.22"
Princeton                      8.62"
Homestead                   7.23"
Homestead AFB            5.80"
Miami Int'l Airport           5.78"
Hollywood                     5.36"
Sweetwater                   5.05"

Many areas received up to five inches. Of course
this heavy rain lead to street flooding all across South Florida.

Will we see more today? The answer is yes, but not as much.


The image below shows us where we can find the most water vapor in the atmosphere. You will notice a comma-shaped cloud pattern over Florida, the area over the Bahamas may be an area of low pressure forming. This should, and I say should, push most of the rain north over the Bahamas and into Central and Northern Florida. The wind should also not be as strong.

Regardless, any little rain that comes over us will be sure to cause street flooding.


So what is NHC saying about the area of disturbed weather over us?

They say that the pressure is slowly falling, and very little change in organization has taken place over the last 24 hours. It should move northwest over the next 2 days between 5-10 mph. NHC is giving it a 30% chance (up from 20% on Saturday) of becoming a tropical or subtropical system.

This means we could still see a chance of rain through Monday, by then most of the rainfall should aim for Georgia.

Saturday, October 8, 2011

Wet & Windy Weekend

Over the last few days the entire 7Weather team has been talking about the possibility of an area of low pressure developing near Florida.

The models were hinting at this happening but weren't clear as to where it may form. We showed a couple of scenarios on the air with the low tracking north on the West Coast, and another where it would organize over the Bahamas.

Our own in-house model agreed with the Bahamas development. On Saturday, NHC began to look closely at this area of clouds and rain and this is what they said.


  • A SURFACE TROUGH LOCATED FROM THE EXTREME NORTHWESTERN CARIBBEAN SEA ACROSS CENTRAL CUBA AND INTO THE CENTRAL BAHAMAS IS PRODUCING WIDESPREAD CLOUDINESS AND THUNDERSTORMS OVER MUCH OF CENTRAL ANDEASTERN CUBA...MOST OF THE FLORIDA PENINSULA AND THE FLORIDA KEYS...ALL OF THE BAHAMAS...AND ADJACENT ATLANTIC WATERS. 
  • THE TROUGH HAS BECOME A LITTLE BETTER DEFINED AND SURFACE PRESSURES ARE SLOWLY FALLING. GRADUAL DEVELOPMENT OF THIS LARGE AREA OF DISTURBED WEATHER IS POSSIBLE OVER THE NEXT FEW DAYS AS IT MOVES WESTWARD OR NORTHWESTWARD AT 5 TO 10 MPH. THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A TROPICAL OR SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS. 
  • REGARDLESS OF DEVELOPMENT...THIS DISTURBANCE WILL PRODUCE STRONG GUSTY WINDS AND LOCALLY HEAVY RAINFALL ACROSS PORTIONS OF THE BAHAMAS AND THE FLORIDA PENINSULA OVER THE NEXT COUPLE OF DAYS.



The big question is... where will it go? As of this writing there is no clear direction, but what we do know is that this area of clouds and rain will keep our weather unstable at least through Sunday and maybe into the early part of next week.

The radar loop gives you an idea of the rain over South Florida.

We can expect anywhere between 3-6 inches of rain over the next 48 hours. Most of this energy will be focused primarily over Miami-Dade and Broward Counties.


Plenty of advisories for all of South Florida, The following comes directly from NWS
  • FLOOD WATCH IN EFFECT PALM BEACH, BROWARD, MIAMI-DADE COUNTIES THROUGH SUNDAY EVENING
  • SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE AREA 
  • DANGEROUS RIP CURRENTS, STRONG WINDS, BEACH EROSION, AND ROUGH SURF ATLANTIC COAST
ASIDE FROM THE FLOODING RISK FROM HEAVY RAINFALL, THERE IS ALSO A
POTENTIAL FOR MINOR COASTAL FLOODING AND BEACH EROSION ALONG THE
ATLANTIC COAST, DUE TO STRONG ONSHORE WINDS AND A BUILDING
NORTHEAST SWELL. THIS POTENTIAL WILL BE GREATEST AT HIGH TIDE .

HAIL: PENNY SIZED HAIL MAY OCCUR WITH A FEW OF THE STRONGEST
THUNDERSTORMS TODAY AND TONIGHT.

TORNADOES: INCREASING LOW LEVEL WINDS THROUGHOUT THE DAY AND INTO
TONIGHT WILL CONTRIBUTE TO A SMALL POTENTIAL OF AN ISOLATED BRIEF
TORNADO DEVELOPING. 

WATERSPOUTS: THERE IS A SMALL POTENTIAL OF A WATERSPOUT DEVELOPING
TODAY AND TONIGHT.

RIP CURRENTS: DANGEROUS STRONG RIP CURRENTS WILL OCCUR AT THE
ATLANTIC BEACHES, SO SWIMMING IS NOT ADVISED.

WAVES: SEAS ACROSS THE ATLANTIC WILL BUILD INTO THE 7 TO 10 FOOT
RANGE, EVEN UPWARDS TO AROUND 12 FEET OFF THE NORTHERN PALM BEACH
COAST. BREAKING WAVE HEIGHTS IN THE SURF ZONE ARE FORECAST TO
REACH 10 FEET OR HIGHER ALONG THE PALM BEACH COAST TODAY AND
TONIGHT. FOR THIS REASON, A HIGH SURF ADVISORY IS IN EFFECT FOR
THE PALM BEACH COAST THROUGH SUNDAY.

Here is the info for the Keys:

A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL KEYS COASTAL WATERS
TODAY DUE TO SUSTAINED NORTHEAST TO EAST SURFACE WINDS AROUND 20
KNOTS...WITH GUSTS NEAR 25 KNOTS.

A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS LIKELY TONIGHT IN THE
ATLANTIC WATERS BEYOND THE REEF FOR RESIDUAL SEAS NEAR 7 FEET.

SCATTERED THUNDERSTORMS ARE EXPECTED ALONG THE FLORIDA KEYS AND
SURROUNDING WATERS TODAY AND TONIGHT. THE PRIMARY THUNDERSTORM HAZARDS WILL BE WIND GUSTS AROUND 35 KNOTS AND CLOUD TO SURFACE LIGHTNING STRIKES.



Friday, September 30, 2011

2 in the Atlantic

HURRICANE "OPHELIA"

Ophelia is a well organized hurricane aiming for Bermuda. Our friends there need to watch this one carefully as it could get a little stronger as it nears the island over the weekend.


This image clearly shows an eye with a well organized eyewall.

This is where you'll find the strongest winds and heaviest rainfall. It is a ring of destruction.

It should pass to your east, but none the less, you will feel Ophelia's fury.

Following is the official forecast cone for Ophelia.




TROPICAL STORM "PHILIPPE"

Tropical Storm Philippe is in the Eastern Atlantic and holding its own. The National Hurricane Center said it best.

THE RECENT EVOLUTION OF PHILIPPE IS A BIT OF A MYSTERY. 

This is why I love weather, just when you think you have things figured out, Mother Nature says "Oh no, I have plenty of secrets left!"


Here is what's interesting about Philippe:

  • NHC SAYS: A RECENT SATELLITE IMAGE SHOWS A WELL-DEFINED EYE SUGGESTING THAT IT HAS BECOME BETTER ORGANIZED, YET OTHER IMAGES SHOW MOST OF THE RAIN WELL TO THE  NORTHEAST OF THE CENTER, MORE TELLING OF A POORLY ORGANIZED STORM.
  • THE SHEAR HAS RELAXED OVER THE LAST 12-24 HOURS...YET PHILIPPE HAS NOT STRENGTHENED. ALTHOUGH IT MAY SOON. (Confused yet?)
Here is what should happen to Philippe:
  • NHC SAYS: IF IT REMAINS ORGANIZED, THE LOW-LEVEL STRUCTURE OF THE STORM WOULD SEEM TO BE CONDUCIVE FOR SOME INCREASE IN STRENGTH WHILE THE SHEAR REMAINS LOW. BUT....
  • WITHIN 24-36 HOURS...WEAKENING SEEMS LIKELY AS PHILIPPE SHOULD ENTER A REGION DOMINATED BY VERY STRONG UPPER-LEVEL NORTHWESTERLY WINDS ASSOCIATED WITH THE OUTFLOW OF OPHELIA.
  • ASSUMING THAT PHILIPPE CAN WITHSTAND WIND SHEAR OF THAT MAGNITUDE,THERE COULD BE AN OPPORTUNITY FOR SOME INTENSIFICATION TOWARD THE END OF THE FORECAST PERIOD.
The models suggest Philippe will move west until it runs into a wall of wind pushing off the Eastern Seaboard in about 5 days. It will also contend with Ophelia's upwelling (The movement of cold water to the surface by the storm. Ophelia is soaking up all the hot water right now as it gets stronger. As you know hot water is the fuel for tropical systems.) Once it hits this wall it should weaken and make a turn for the Western Atlantic, Bermuda may need to watch this one as well.




This is the official forecast cone from NHC.

Saturday, September 24, 2011

Low over the Bahamas

For my friends in the Central and Northwestern Bahamas, many of you have contacted me with worries regarding the area of disturbed weather over you. Right now, it is a stretched-out area of low pressure that extends from the Central Bahamas north to near the Carolinas.

The satellite imagery shows areas shaded in dark orange highlighting the heaviest areas of rain. All that is headed north and will continue to provide heavy rain for you for a few more days.



This is what NHC is saying:

  • AN ELONGATED LOW PRESSURE SYSTEM HAS DEVELOPED ABOUT 175 MILES EAST-SOUTHEAST OF CAPE CANAVERAL FLORIDA. 
  • SHOWERS AND THUNDERSTORMS HAVE BECOME A LITTLE BETTER ORGANIZED AND SOME SLOW DEVELOPMENT OF THIS DISTURBANCE IS POSSIBLE DURING THE NEXT DAY OR SO BEFORE UPPER-LEVEL WINDS BECOME UNFAVORABLE.
  • THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES GENERALLY NORTHWARD AT 10 TO 15 MPH. 
If it develops,  most models aim this system toward the Carolinas. We'll wait and see what develops, if anything as some strong upper winds are forecast to push off the East Coast that could destroy this tropical system.

Thursday, September 22, 2011

Ophelia is a fighter

Ophelia is up against the ropes with wind shear battering it in the mid to upper levels of the atmosphere.

In spite of this,  Ophelia has strengthened this Thursday.

Ophelia drifted over a NOAA buoy that detected stronger winds and thus as of Thursday morning, the intensity is up from 60 mph to 65 mph.



It is still a ragged looking system with much of the thunderstorm formation on the eastern semi-circle. The western side is being impacted by the shear and is almost all exposed to the elements. There are pockets of dry air ahead of it and if any works its way into the center, that could be its demise.

New satellite imagery also suggest the center is farther south than anticipated.

This strengthening should be temporary as the upper shear is expected to get stronger in the days ahead.


The latest suite of models show a more consistent track, not as fanned out as they were a mere 24 hours ago.

The Bermuda high should drift east and open a path for Ophelia to take.

This should happen in about three days.  By then , a front over the Southeast  accompanied by strong upper winds, will move offshore and protect us from Ophelia.



The official NHC forecast cone, keeps Ophelia as a Tropical Storm throughout its life cycle and moves it along the "Favored Route" this tropical season, between Bermuda and East Coast. Hopefully it won't bother anybody.




Wednesday, September 21, 2011

Ophelia



Tropical Storm Ophelia is a tad stronger this Wednesday with plenty of moisture on the Eastern Half, but the Western side remains mostly dry. This should keep it in check and prevent further intensification.

This is what NHC says about Ophelia's future:


THE UPPER-LEVEL WIND PATTERN AHEAD OF OPHELIA DOES NOT FAVOR
SIGNIFICANT STRENGTHENING.  MODERATE SOUTHWESTERLY SHEAR CURRENTLY
OVER THE CYCLONE IS EXPECTED TO BECOME MORE WESTERLY AND INCREASE
IN A FEW DAYS AS AN UPPER-LEVEL LOW FORMS NORTH OF PUERTO RICO. 
MOST OF THE INTENSITY GUIDANCE AGREES WITH THIS SCENARIO AND CALLS
FOR ONLY A LITTLE ADDITIONAL STRENGTHENING.  THE NHC FORECAST IS IN
GOOD AGREEMENT WITH THE SHIPS/LGEM GUIDANCE AND IS VERY SIMILAR TO
THE PREVIOUS ADVISORY.




NHC's  assessment is on track with the wind shear forecast map above. If you look at Friday's panel you will notice a yellow blob appearing east of the Lesser Antilles. This shear will make life miserable for Ophelia and should weaken it considerably.

But what about its track?  Only a few models take Ophelia into the Caribbean, while most curve it Northwestward into the Western Atlantic. This appears to be the favored route of systems this hurricane season.




This is the official forecast cone from NHC. The islands should keep their eyes on Ophelia as it may dump heavy rain.

Tuesday, September 20, 2011

Next Depression?

We are keeping an eye on a broad area of low pressure over 2,800 miles away from South Florida.  There is plenty of time to watch it and see what develops and where it may go.

From the satellite imagery one can see thunderstorm activity surrounding the area of low pressure.

It appears to be getting organized as it moves west toward the Lesser Antilles.

An upper low to its north has weakened and is no longer providing shear however, it still has to contend with a pocket of dry air ahead of it.

If it can overcome this obstacle it may become a depression over the next 48 hours.

If it stays on its westward track, it could be near the Lesser Antilles in about 5 days. As of this moment it's about 1500 miles east of the Windward Islands.

If it does develop, most models track it west for about 24-36 hours but then they fan out for the rest of the run. Some take it to Venezuela, others push it across the islands and into the Caribbean, while others keep it in the Atlantic. For now all we can do is watch and wait. By the way if it grows into a Tropical Storm it will be called, Phillipe. (Sorry, jumped the gun... it will be named Ophelia)


Wednesday, September 14, 2011

Maria aiming North

Maria is still headed near Bermuda, they remain under a Tropical storm warning. Bermuda may actually get winds of around 60 mph with plenty of rain.

Today, NHC was able to get a better fix on Maria's center by using some buoys that are in her path. While it shows that the system is still a tropical storm, most of the strong winds remain on the eastern half of Maria.

The image below shows the wind field of Maria in orange. If you extend this out over the next 24-48 hours, Bermuda may get a taste of this tropical storm.


Models do not hint at any further intensification. Hopefully this will only be a worry for the shipping lanes.





Tuesday, September 13, 2011

Maria's Rain

It's not Maria's future that's a menace, it's the present. It is moving painfully slow to the north and dumping rain over the same areas. One of those areas is Puerto Rico.

For our viewers with friends and family there, here is a great link to the NWS Puerto Rico site that keeps you up to date with the rain, and watches and warnings impacting the island.

NWS Puerto Rico Advisories Page

Meanwhile, once Maria gets going, it will ultimately head north threatening Bermuda before moving into the Hurricane Graveyard... the cold waters of the Northern Atlantic.  Models do not hint at any further intensification. Hopefully this will only be a worry for the shipping lanes.


Monday, September 12, 2011

Maria's ups and downs

This tropical system looks good one moment and poor the next.  As of this moment only Bermuda needs to watch it carefully.

Maria looks sheared this Monday, and its center of circulation is hard to find. You can barely see a swirl due North of Puerto Rico. Most of the strong winds, clouds, and rain are on the eastern semicircle since the western is completely exposed. This is due to shear from a persistent upper low just ahead of it. Even though some models had been forecasting this low to weaken, it hasn't , and it has kept Maria at bay.


Next for Maria is to get pushed away from the Bahamas and the Eastern Seaboard by strong upper level winds. This will act as a wall pushing Maria North.

Unfortunately this will keep the storm on a track toward Bermuda. By then, it could be as strong as a category one system.  This intensification remains doubtful since the shear may not relax throughout its duration. Maria will also be traveling almost the identical route as "Katia" and that system has already soaked up much of the heat energy from the ocean on that route. This means there is little fuel for Maria to use.

We hope this remains a worry only for shipping lanes and that Maria mercifully meets its end over the cold waters of the Northern Atlantic without incident.


Sunday, September 11, 2011

Maria

Oh Maria, you trouble maker you. In spite of strong upper winds battering you and keeping you looking ragged, you have persevered. This morning you are looking better.


Maria finally has the more familiar shape of a tropical storm and there is even a good outflow pattern developing in the upper levels.

Morning recon suggests that even though the strongest winds are in the northeastern quadrant, the center is better defined. This is confirmed by surface observations across the Leeward Islands.




Water vapor images still show the upper level low to Maria's Northwest.  This is causing the shear that has kept it in check, but today Maria is fighting back.  Even though there is plenty of dry air ahead of it, and models insist on the upper low hanging around a few more days...Maria is getting stronger.




So where is Maria headed? NHC says it best:

  • MARIA IS MOVING TOWARD THE NORTHWEST . THE CYCLONE IS EXPECTED TO BE TRAPPED BETWEEN THE ATLANTIC SUBTROPICAL HIGH AND A TROUGH ALONG THE EASTERN UNITED STATES.  

  • THIS IS THE SAME STEERING PATTERN THAT IN GENERAL HAS PREVAILED THIS SEASON... (this should take) MARIA WELL NORTH OF THE BAHAMAS...AND THEN RECURVING IT BETWEEN THE UNITED STATES EAST COAST AND BERMUDA.


The official forecast cone from NHC intensifies Maria into a hurricane by Wednesday, by then only Bermuda should be at risk. We hope this one too will follow in Katia's footsteps and not bother any land mass.

 

Saturday, September 10, 2011

Down to two

Of the three systems we are watching in the Tropics, Katia, is no longer being followed by NHC. Even though it's no longer a Tropical Cyclone, it will still pack gusty winds and rain as it aims for the British Isles. That now leaves us with Maria, and Nate. We begin with Maria.

Maria is looking extremely ill with an elongated shape to it.

It has a weak center of circulation exposed to the elements on the western semicircle and what gusty winds remain are far removed from it.

The only reason NHC is keeping it as a Tropical Storm is because, at least for now, there is still a weak circulation center.


This is what early recon had to say about Maria:


THE INITIAL INTENSITY IS GENEROUSLY
KEPT AT 35 KT...WITH THE ASSUMPTION THAT TROPICAL-STORM-FORCE WINDS
ARE OCCURRING IN THE CONVECTION WELL TO THE NORTHEAST OF THE
CENTER.  BECAUSE THESE WINDS ARE SO FAR REMOVED FROM THE
CENTER...AND NOT EXPECTED TO IMPACT THE LESSER ANTILLES...ALL
TROPICAL STORM WARNINGS HAVE BEEN DISCONTINUED.


That weak center of Maria is over Antigua. You can see Antigua highlighted in red on the map below on  center-right. Most of the rain and wind is to the Northeast of the Leeward Islands. About the only effects they may feel are breezy conditions and choppy seas, with an occasional t-storm.


So why is Maria so disorganized? For that answer we have to use the water vapor imagery. While a regular satellite image helps us see what is near the surface, this image gives us a view of what's happening in the upper levels of the atmosphere.

Here you can see the cloud cover over the Lesser Antilles belonging to Maria. You will also notice a dark inverted comma shape pattern just to its northwest. This is an upper low and it's responsible for shearing Maria apart.  This feature should remain for another 48 hours, if Maria can survive until then, it could restrengthen.



So if it survives, where is it headed?

Most models now keep Maria as Tropical Storm over the weekend as it moves North of the Leewards and Puerto Rico. It should then be pushed away from Florida and the Southeast by strong upper winds coming off the Continental US. After that, it may be a worry for Bermuda.




Now we check up on Nate:

This is a beautiful looking storm with plenty of banding and typical circular shape. It lacks however, a well organized inner core.

Models hint at slow intensification as it moves west toward Mexico. Even though the forecast cone shows Nate as a storm throughout its duration, it may have just enough punch to reach hurricane status before landfall.

The biggest threat will be rain as it could cause flash floods, land and mudslides from the coast to far inland locations.