Katia Strengthening over the eastern Atlantic…

Posted on August 30, 2011 by James Proctor

The trend all afternoon for Katia is that she is strengthening at a decent rate. The 18z best track is now showing that Katia has winds reaching 50kts with the pressure down to 997mb. At this rate Katia could be nearing Hurricane Strength by later tonight.

18z Best Track:

AL, 12, 2011083018, , BEST, 0, 125N, 346W, 50, 997, TS

 

Ships RI probability Scale shows a 43% chance that Irene could go through a Period of 26kt RI.

Ships RI Output:

Prob of RI for 25 kt RI threshold=    43% is   3.3 times the sample mean(12.8%)
Prob of RI for 30 kt RI threshold=    26% is   3.1 times the sample mean( 8.4%)
Prob of RI for 35 kt RI threshold=    18% is   3.6 times the sample mean( 5.0%)
Prob of RI for 40 kt RI threshold=    10% is   2.9 times the sample mean( 3.4%)

All data available points to Katia entering or being in an area conducive to Strengthening. When looking at the data we must look at the following factors:

  • Shear over and ahead of the system
  • Sea surface Temps.
  • Temps of the water at depth
  • overall environment around the system (Is there dry air present or is the environment moist).

Let’s take a look at each of these elements now!

Shear – Developing Tropical Storms need to produce strong convection over the area of low pressure in order to keep on lowering the pressure and strengthen the low level circulation. If the winds aloft over the tropical storm are too strong then those developing thunderstorms will get blown off and won’t be able to build over the Low Level Circulation. Shear of under 20kts is generally acceptable for a Tropical system to strengthen or maintain it’s intensity. Anything above that can be disruptive to the circulation. Any amount under 10kts is normally conducive for Rapid Strengthen providing the other elements are in place.

Current Shear analysis shows around 10kts of shear right over Katia. The general tendency for shear during the last 24 hours is decreasing Shear in Katia’s path.

 

 

Sea Surface temps – The temperature of the Ocean is another vital component that allows Tropical systems to strengthen. Hurricanes must have sea surface temps. of greater then 82 degrees Fahrenheit for them to develop the deep convection.

Based on this map SSTs are in the 83 to 85 degree range and warmer along the forecast track.

 

Temps of the water at depth – Not only do Hurricanes need warm Ocean water at the surface but they need warm water at depth. The Deeper the water gets the cooler it gets. As the winds blow the water it mixes the cooler water from deep below the surface and cools off the surface water. If the water is warm below the surface then there is more heat energy for the Hurricane to tap into allowing it to strengthen more.

 

As you can see from this map Katia will be moving over pockets of higher heat content along her path. Even in the areas of lower heat content that she is currently in there is more then enough heat content for Katia to strengthen into a powerful Hurricane.

 

Overall Environment – Katia’s over all Environment looks to be fairly moist. There is some dry air to her northwest but over all it looks pretty ripe for further strengthening. Over all I believe we will be looking at a intense Hurricane with in the next 5 days.

Where will Katia go is still the main question we need to be watching and figuring out. All data points to Katia Strengthening but her future track will decide how she is remembered!

 

I will have more on Katia as we get new information!

Join us in discussing Katia in our Community Forum!

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Katia Model Breakdown – August 30th 2011

Posted on August 30, 2011 by James Proctor

A question on alot of people’s mind is “Is Katia headed for me?” At this point in time it is far to early to know for sure where Katia is headed but we can look at the models and see what they are forecasting. Alot can change over the coming days but let’s take a look at the models and see what they are saying.

Let’s start by taking a look at the NHC Forecast track for Katia:

The National Hurricane Center is forecasting Katia to travel on a general West-Northwest path and 5 days from now be north of the leeward Islands.

Here is what the National Hurricane Center has to say about the Forecast Track:

THE INITIAL MOTION IS A SLIGHTLY FASTER 285/16. NOT MUCH CHANGE HAS
BEEN MADE TO THE TRACK FORECAST.  KATIA IS EXPECTED TO CONTINUE
MOVING WEST-NORTHWESTWARD ON THE SOUTH SIDE OF THE SUBTROPICAL
RIDGE FOR THE NEXT COUPLE OF DAYS.  LATER IN THE FORECAST
PERIOD...THE TROPICAL CYCLONE IS EXPECTED TO BE APPROACHING A
WEAKNESS IN THE RIDGE CREATED BY A TROUGH OVER THE WESTERN
ATLANTIC.  THIS SHOULD CAUSE KATIA TO BEGIN TO TURN TOWARD THE
NORTHWEST WITH A DECREASE IN FORWARD SPEED.  THE OFFICIAL FORECAST
LIES A LITTLE NORTH OF THE DYNAMICAL MODEL CONSENSUS THROUGH 48
HOURS AND IS VERY CLOSE TO THE CONSENSUS FOR THE REMAINDER OF THE
FORECAST PERIOD.

Some of the Models after the 5 day forecast point are showing some sort of impact to the east coast. Others are showing Katia curving harmlessly out to sea. Bottom line is that the potential is there for Katia to impact the United States at this time it’s just to early to know for sure.

 

Q: Should I be concerned about Katia yet?

A: At this time there is no need to be Concerned about katia but everyone should be keeping an eye on her future forecast tracks.

If you have questions about Katia or Questions about Hurricanes in general please email them to admin@theweatherwatch.org

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…NEW TROPICAL STORM MOVING QUICKLY WEST-NORTHWESTWARD ACROSS THE TROPICAL ATLANTIC…

Posted on August 30, 2011 by James Proctor

The National Hurricane Center upgraded Tropical Depression 12 to Tropical Storm Katia. Maximum sustained winds are currently 40mph with a central pressure of 1006mb.

Here is the 5am update from the National Hurricane Center:

DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 AM AST...0900 UTC...THE CENTER OF TROPICAL STORM KATIA WAS
LOCATED NEAR LATITUDE 11.8 NORTH...LONGITUDE 31.7 WEST. KATIA IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 17 MPH...28 KM/H. THIS GENERAL
MOTION IS EXPECTED TO CONTINUE OVER THE NEXT 48 HOURS WITH A
GRADUAL INCREASE IN FORWARD SPEED. 

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 40 MPH...65 KM/H...
WITH HIGHER GUSTS. ADDITIONAL STRENGTHENING IS FORECAST DURING
THE NEXT 48 HOURS...AND KATIA IS EXPECTED TO BE NEAR HURRICANE
INTENSITY BY LATE WEDNESDAY OR EARLY THURSDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 35 MILES...55 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

and here is the projected forecast track:

I will have another update around 11am or sooner of needed!

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Severe Weather Outlook – Tuesday August 30th 2011

Posted on August 30, 2011 by James Proctor

Today there is a slight chance for Wind and Hail across the northern and central plains.

There is also a slight chance for wind across the High plains.

Here is what the SPC has to say about the threat for today:

SPC AC 300529

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 AM CDT TUE AUG 30 2011

VALID 301200Z – 311200Z

…NO SVR TSTM AREAS FORECAST…

…NRN AND CNTRL PLAINS…
A SHORTWAVE TROUGH WILL MOVE EWD ACROSS THE NRN PLAINS TODAY AS AN
UPPER-LEVEL RIDGE MOVES INTO THE CNTRL AND NRN HIGH PLAINS. AN AXIS
OF MODERATE INSTABILITY SHOULD BE IN PLACE BY AFTERNOON JUST TO THE
EAST OF THE RIDGE AXIS FROM THE CNTRL DAKOTAS SWD INTO THE CNTRL
NEB. MODEL FORECASTS INITIATE ISOLATED THUNDERSTORMS LATE THIS
AFTERNOON FROM THE INSTABILITY AXIS EWD NEAR A LOW-LEVEL JET MAX.
THE MOST CONVECTIVE COVERAGE SHOULD BE ACROSS ECNTRL ND AND ERN SD
WHERE THE NAM AND GFS BOTH INITIATE STORMS BUT IN DIFFERENT AREAS
WITH THE GFS FURTHER WEST. FORECAST SOUNDINGS FROM BISMARCK TO
ABERDEEN AT 00Z WED SHOW MLCAPE VALUES OF 1500 TO 2000 J/KG WITH 0-6
KM SHEAR VALUES OF 40 TO 45 KT. THIS ENVIRONMENT SHOULD SUPPORT AN
ISOLATED SEVERE THREAT WITH HAIL AND STRONG GUSTY WINDS POSSIBLE.
HOWEVER…THE THREAT SHOULD REMAIN VERY ISOLATED DUE TO LIMITED
LARGE-SCALE ASCENT. FOR THIS REASON…WILL MAINTAIN THE 5 PERCENT
WIND DAMAGE AND HAIL PROBABILITY IN SD AND EXTEND THIS AREA NWD
ACROSS CNTRL ND.

FURTHER TO THE WEST ACROSS NE WY AND SE MT…A NARROW AXIS OF
INSTABILITY SHOULD ALSO EXIST WHERE MODEL FORECASTS INITIATE
ISOLATED THUNDERSTORMS THIS AFTERNOON. ALTHOUGH INSTABILITY IS NOT
FORECAST TO BE AS STRONG AS TO THE EAST…MID-LEVEL LAPSE RATES IN
THE NRN HIGH PLAINS WILL BE QUITE STEEP SUGGESTING A MARGINAL SEVERE
THREAT WILL ALSO BE POSSIBLE.

TO THE SOUTH ACROSS THE CNTRL PLAINS…A CAPPING INVERSION AND WARM
AIR ALOFT IS EXPECTED TO LIMIT THE SEVERE THREAT THIS AFTERNOON.

…SRN HIGH PLAINS…
A VERY HOT AIRMASS IS FORECAST TO DEVELOP ACROSS THE SRN HIGH PLAINS
THIS AFTERNOON. IN SPITE OF THE RELATIVELY DRY AIRMASS…MODEL
FORECASTS INITIATE SOME THUNDERSTORMS ALONG THE NWRN EDGE OF THE
LOW-LEVEL JET LATE THIS AFTERNOON FROM SE NM NEWD ACROSS THE SERN TX
PANHANDLE INTO SW OK. DUE TO THE VERY STEEP LOW-LEVEL LAPSE RATES
AND STRENGTHENING LOW-LEVEL FLOW…A MARGINAL WIND DAMAGE THREAT
COULD EXIST.

..BROYLES/GARNER.. 08/30/2011

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
CURRENT UTC TIME: 0540Z (1:40AM), RELOAD THIS PAGE TO UPDATE THE TIME

I will have another update later this afternoon!

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…DEPRESSION COULD BECOME A TROPICAL STORM LATER TONIGHT OVER THE FAR EASTERN TROPICAL ATLANTIC…

Posted on August 30, 2011 by James Proctor

Well according to the National Hurricane Center we still don’t have Katia. They are now saying that Tropical Depression 12 could become a Tropical Storm later tonight.

 

Here is the 11pm update from the National Hurricane Center:

DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 PM AST...0300 UTC...THE CENTER OF TROPICAL DEPRESSION TWELVE
WAS LOCATED NEAR LATITUDE 11.0 NORTH...LONGITUDE 30.0 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 15 MPH...24
KM/H. THIS GENERAL MOTION ACCOMPANIED BY A GRADUAL INCREASE IN
FORWARD SPEED IS EXPECTED OVER THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS.  STRENGTHENING IS FORECAST DURING THE NEXT COUPLE OF
DAYS...AND THE DEPRESSION COULD BECOME A TROPICAL STORM EARLY
TUESDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.

The Forecast track from the National Hurricane Center:

 

I will have another update around 5am tomorrow morning or sooner if needed!

Click here to discuss this system with us on our forum!

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Tropical Depression 12 Forms over far Eastern Atlantic

Posted on August 29, 2011 by James Proctor

The National Hurricane Center upgraded the area we have been watching, Known as 92L, to the 12th Tropical Depression of the 2011 Hurricane Season. As of 5pm EST the Tropical Depression was located at 39.5°N 63.1°W or 670 KM SW OF THE SOUTHERNMOST CAPE VERDE ISLANDS. The Maximum sustained winds are near 35mph and strengthening is expected during the next 48 hours. Tropical Depression 12 could be near or at Tropical Storm strength by later tonight.

Here is what the National Hurricane Center has to say about Tropical Depression 12:

 

DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL DEPRESSION TWELVE
WAS LOCATED NEAR LATITUDE 10.2 NORTH...LONGITUDE 28.4 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST NEAR 14 MPH...22 KM/H.  A TURN
TOWARD THE WEST-NORTHWEST AT A FASTER FORWARD SPEED IS EXPECTED
OVER THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS.  SOME STRENGTHENING IS FORECAST DURING THE NEXT COUPLE OF
DAYS...AND THE DEPRESSION COULD BECOME A TROPICAL STORM TONIGHT.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.

I will have another update at 11pm or sooner if needed!

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92L Near 100% chance of Development

Posted on August 29, 2011 by James Proctor

As of the 8pm Tropical Weather outlook the National Hurricane Center is giving the area we are watching, Known as 92L, a near 100% chance of development during the next 48 hours. Should 92L develop into a Tropical Storm it’s name would be Katia. Katia replaces Katrina which was retired 6 years ago when it slammed into the northern Gulf coast killing hundreds and becoming the costliest Natural disaster in U.S. history.

 

Here is what the National Hurricane Center has to say about 92L as of 8pm EST August 28th 2011:

 

SHOWERS AND THUNDERSTORMS HAVE CONTINUED TO BECOME BETTER ORGANIZED
THIS EVENING IN ASSOCIATION WITH A LOW PRESSURE SYSTEM LOCATED
ABOUT 400 MILES SOUTH OF THE SOUTHERN CAPE VERDE ISLANDS.
ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR FURTHER DEVELOPMENT
OF THIS LARGE DISTURBANCE...AND A TROPICAL DEPRESSION COULD FORM
DURING THE NEXT DAY OR SO AS IT MOVES WESTWARD AT 10 T0 15 MPH.
THIS SYSTEM HAS A HIGH CHANCE...NEAR 100 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

The forecast Models have been trending back west today showing a strike to the East Coast. It is still very early to know for sure where 92L will go! We will continue to monitor the very latest on 92L as well as any other threats that might come. I will have another update on 92L at 2am or sooner if I get some new information.

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Irene downgraded to Tropical Storm

Posted on August 28, 2011 by James Proctor

As of 9am Irene was downgraded to a Tropical Storm as the Center of Irene made it’s final landfall near New York City. At least 2 million are with out power and Irene is responsible for at least 10 deaths as she tracked up the eastern seaboard. Here in Maine we are experiencing Tropical Storm conditions as the heavier Rain bands spiral through the area and these conditions will continue for much of today. Here is the latest from the NHC on Irene:

 

TROPICAL STORM IRENE TROPICAL CYCLONE UPDATE
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092011
900 AM EDT SUN AUG 28 2011

...CENTER OF IRENE MOVES OVER NEW YORK CITY...

REPORTS FROM AN AIR FORCE HURRICANE HUNTER AIRCRAFT AND NATIONAL
WEATHER SERVICE DOPPLER RADAR INDICATE THAT THE CENTER OF IRENE
MOVED OVER NEW YORK CITY AROUND 900 AM EDT...1300 UTC.  IRENE HAS
WEAKENED TO A TROPICAL STORM AND THE ESTIMATED INTENSITY AT
LANDFALL WAS 65 MPH...100 KM/H.

SUMMARY OF 900 AM EDT...1300 UTC...INFORMATION
--------------------------------------------------
LOCATION...40.7N 74.0W
ABOUT 0 MI...0 KM N OF NEW YORK CITY
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 26 MPH...43 KM/H
MINIMUM CENTRAL PRESSURE...965 MB...28.50 INCHES

$$
FORECASTER PASCH

I will have more on Irene as further updates are released!

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Tropical Storm Jose forms in the Atlantic

Posted on August 28, 2011 by James Proctor

This morning at 8am EST a well defined low level circulation formerly known as Invest 91L was upgraded to Tropical Storm Jose. As a result of it’s vicinity to Bermuda a Tropical Storm warning was issued.

 

THE BERMUDA WEATHER SERVICE HAS ISSUED A TROPICAL STORM WARNING FOR
BERMUDA.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* BERMUDA

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN 12
HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.

 

Here is the current Forecast Track:

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Season 2011 – Invest92L – August 27th

Posted on August 28, 2011 by James Proctor

The National Hurricane Center is highlighting a new area in the Atlantic this evening. They have designated the Tropical Wave that just emerged off the coast of Africa as Invest 92L. We will be keeping an eye on this area over the coming weeks for signs of development and for possible impacts to the Islands and/or the United States. At this early point it appears that should this area develop rather quickly that it could recurve harmlessly out to sea east of the islands. However there is still a-lot of time for things to change.

 

Latest from the NHC on this area:

A LARGE AREA OF SHOWERS AND THUNDERSTORMS JUST OFF THE WEST COAST OF
AFRICA IS ASSOCIATED WITH A TROPICAL WAVE.  THIS WAVE IS SHOWING
SOME SIGNS OF ORGANIZATION...AND ENVIRONMENTAL CONDITIONS APPEAR
CONDUCIVE FOR ADDITIONAL DEVELOPMENT OVER THE NEXT COUPLE OF DAYS.
THIS SYSTEM HAS A LOW CHANCE...20 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD AT ABOUT 10
MPH.
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