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.