TD 2 struggling; new African wave bears watching
Tropical Depression Two is struggling. The depression still has a good chance of becoming the Atlantic hurricane season's first named storm this week, but the dry, Saharan air that surrounds the storm, combined with moderately high levels of wind shear, are interfering with the storm's organization. Satellite loops of the storm show that heavy thunderstorm activity is limited to the west side of the depression. This is due to strong winds out of the southeast that are creating a moderate 15 - 20 knots of wind shear. The intensity and coverage of these thunderstorms is meager, thanks to the large amount of dry air to TD 2's north that is getting wrapped into the circulation. This morning's QuikSCAT pass showed a well-formed surface circulation, with top winds of about 30 - 35 mph.
Wind shear over TD 2 is expected to remain in the moderate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures (SSTs) are a marginal 26 - 27°C, and will not change much over the next three days. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly. However, it does appear likely that TD 2 has enough going for it that it will eventually be able to become Tropical Storm Ana sometime in the next three days. Most of the computer models show some weak development, but none of them predict TD 2 will become a hurricane. It is unusual for storms forming this far north to make it all the way across the Atlantic to hit the Lesser Antilles Islands. For now, TD 2 doesn't concern me as much as the new tropical wave to its southeast, just off the coast of Africa.
Figure 1. Tropical Depression Two (left center of image) and a new tropical wave (right side of image), newly emerged from the coast of Africa.
Elsewhere in the Atlantic
A strong tropical wave with some rotation and plenty of heavy thunderstorm activity left the coast of Africa yesterday, and is located a few hundred miles south of the Cape Verdes Islands. The GFS and ECMWF models continue to predict the development of this wave late this week. Both of these models indicate that the wave would track further south than Tropical Depression Two, and could impact the Lesser Antilles Islands in about seven days. This storm bears close attention over the coming days.
Two other tropical waves, one that just passed through the Lesser Antilles Islands, and one about 300 miles east of the islands, are mentioned in NHC's Graphical Tropical Weather Outlook. Both of these waves have very limited heavy thunderstorm activity that is not increasing, and are not a threat to develop over the next two days. None of the computer models develop either of these waves.
Felicia moves through Hawaiian Islands as a tropical depression
Tropical Storm Felicia weakened to a tropical depression before passing through the Hawaiian Islands yesterday. The storm brought scattered heavy rains of 1 - 2 inches to the islands, and no damage was reported. Felicia is only the 10th tropical cyclone of tropical depression strength or higher to hit the islands since 1950. Four other tropical cyclones have passed within 75 miles of the islands during that time period.
Be careful clicking on external links in blog comments
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I'll have an update Thursday morning.
Jeff Masters
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TD2
AOI
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
152 PM EDT WED AUG 12 2009
VALID 12Z SAT AUG 15 2009 - 12Z WED AUG 19 2009
ATLANTIC TROPICS QUITE ACTIVE THIS PERIOD WITH T.D. TWO FORECAST
TO BECOME T.S. ANA. BY DAY SEVEN THIS SYSTEM MAY BE SOUTHEAST OF
THE SOUTH ATLANTIC SEABOARD WITH MOST GLOBAL MODELS SUPRESSING
INTENSITY AT THIS TIME BEYOND DAY 5. SECOND AFRICAN COASTAL WAVE
HAS AGITATED NEARLY ALL GLOBAL FORECAST MODELS WITH GFS LEADING
THE PACK IN ITS CYCLOGENESIS AND FORECAST SPEED. A WELL AGREED
UPON TRACK TOWARDS THE LESS ANTILLES AT T.S. STRENGTH OR GREATER
AS INDICATED BY A MODEL CONSENSUS BY DAY 7 WED. SEE NHC
DISCUSSIONS/ADVISORIES FOR THIS SYSTEMS. HPC PROGS REFLECT TPC AND
HPC COORDINATED POSITIONS.
ROTH/ROSENSTEIN
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
LIGHT TO GENTLE SOUTHEAST TO SOUTH WINDS DEVELOPED IN THE LOWEST 2
KFT OF THE ATMOSPHERE LATE THIS MORNING...RUINING THE POTENTIAL OF
ISLAND CUMULUS CLOUD LINES DEVELOPING ALONG THE FLORIDA KEYS. THESE
CLOUDS LINES WERE THE MECHANISM FOR SLIGHTLY HIGHER RAIN CHANCES
THIS EVENING COMPARED TO TONIGHT...SO POPS CAN BE DROPPED BY 10
PERCENT FOR TONIGHT. AN ATLANTIC RIDGE OF HIGH PRESSURE ACROSS
CENTRAL FLORIDA WILL STRENGTHEN THURSDAY THROUGH FRIDAY. ISLAND
CUMULUS CLOUD LINES DEVELOPING ALONG THE FLORIDA KEYS ARE UNLIKELY
FOR THURSDAY. LACK OF CONVECTIVE TRIGGER WILL LIMIT POPS TO SLIGHT
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY. A TROPICAL WAVE NEAR THE
LESSER ANTILLES SHOULD BE MOVING INTO THE FLORIDA STRAITS FRIDAY
NIGHT.
.LONG TERM (SATURDAY THROUGH WEDNESDAY)...
THE AFOREMENTIONED TROPICAL WAVE WILL CROSS THE FLORIDA KEYS
SATURDAY OR AT THE LATEST SATURDAY NIGHT. POPS WILL BE RAISED BY 10
PERCENT FOR SATURDAY. THE SUNDAY THROUGH WEDNESDAY FORECAST WILL BE
BASED ON CLIMATOLOGY.
I say 90L by 5, but it'll take a while before it develops.
Is there an official time that Invests get declared?
NOW you may laugh! But we were with out power for 3 weeks. We dusted off this ping pong table from the back of the garage and pulled it out. The first night 10 people, Second night 20 people. It was insane everybody was coming out, we barbaqued had a pit going. It was great. Did wonders for the moral in the neigborhood. Just remember you need tons of Ping pong balls.
Looks like:
AnaBill
anyone want to take a shot on what the models will show if we get 90l today
Okay...TD#3 at 5AM... :)
THE TROPICAL ATLANTIC HAS BECOME MORE FAVORABLE FOR TROPICAL
CYCLONE FORMATION. BUT THE LATEST RUN OF THE MODELS BREAKS
CONTINUITY...AND NOW SHOW MJO CONDITIONS PEAKING A LOT SOONER THAN
PREVIOUSLY ANTICIPATED...MID AUGUST RATHER THAN END OF THE
MONTH... THEN RAPIDLY WEAKEN THROUGH THE END OF AUGUST/EARLY
SEPTEMBER.
http://www.srh.noaa.gov/productview.php?pil=PMDCA&max=61
A long two weeks.
Invests are almost always declared when the model runs are initiated. Usually about an hour after the TWO or so.
No surface low...no TD
It still has allot to do before it can become a TD.
Press!!! Get the Thorazine!!!!!
RIDGE AXIS WILL CONTINUE IN PLACE OVER SOUTH FLORIDA TONIGHT AND
THURSDAY AS PATTERN BEGINS TO CHANGE OVER THE REGION. MODELS
CONTINUE THE UPWARD TREND IN THE POPS FOR THURSDAY AS PLENTY OF
MOISTURE WILL BE IN PLACE, ALONG WITH AN UPPER LOW OVER THE EASTERN
GULF WHICH SHOULD PROVIDE DECENT UPPER LEVEL DIVERGENCE OVER
FLORIDA. GFS MOS RESPONDED WITH POPS AS HIGH AS 60 PERCENT OVER
AREA, BUT COULD NOT SEE ANY JUSTIFICATION FOR RAISING POPS THAT
MUCH AS FORCING MECHANISMS STILL RATHER MODEST BEING THAT IT`S
AUGUST. NEVERTHELESS, WE EXPECT AN INCREASE IN SHOWERS AND TSTMS
THURSDAY VERSUS TODAY WITH POPS IN HIGH CHC CATEGORY.
HIGH PRES BEGINS TO REESTABLISH AND STRENGTHEN OVER THE WESTERN
ATLANTIC AND CENTRAL/NORTH FLORIDA THURSDAY NIGHT AND FRIDAY.
TROPICAL WAVE NEAR 63W EARLY THIS AFTERNOON CONTINUES TO MOVE
RAPIDLY WEST AND LOOKS INCREASINGLY LIKELY THAT IT WILL PLAY A
ROLE IN OUR WEEKEND WEATHER. BEFORE THE WAVE ARRIVAL LATE FRIDAY
NIGHT OR EARLY SATURDAY, AREA OF SUBSIDENCE AND DRIER AIR EXPECTED
TO MOVE THROUGH SOUTH FLORIDA ON FRIDAY, LEADING TO LOWER POPS AS
PRECIP WATER VALUES DROP TO ABOUT 1.6 INCHES.
THE GFS IS SHOWING THE TROPICAL WAVE MOVING THROUGH OVERNIGHT
FRIDAY NIGHT/SATURDAY MORNING WITH A WELL DEFINED LOW LEVEL WIND
SURGE (850 MB WINDS 30-35 KNOTS) ON ITS HEELS. THE MAIN AXIS OF
HIGHER MOISTURE VALUES IS PROGGED TO ARRIVE DURING DAY ON SATURDAY
WHICH IS WHEN WORST OF THE WEATHER MAY OCCUR. LATEST GFS RUN
ONLY EXTENDS THE HIGHER MOISTURE TO ABOUT A NAPLES/FORT LAUDERDALE
LINE, WITH DRIER AIR TO THE NORTH. THIS UNDERSCORES THE HIGH LEVEL
OF UNCERTAINTY WITH PRECIP PATTERNS ASSOCIATED WITH TROPICAL
WAVES. NEVERTHELESS, PRESENCE OF STRONG LOW LEVEL CONVERGENCE
BEHIND THE WAVE AND UPPER DIVERGENCE ASSOCIATED WITH A
SOUTHEASTERLY WIND MAX EXTENDING FROM THE CARIBBEAN ACROSS THE
FLORIDA STRAITS SHOULD PROVIDE ENOUGH SUPPORT FOR SCT TO NUMEROUS
SHOWERS AND TSTMS SPREADING WEST DURING SATURDAY. DRIER AIR THEN
FORECAST TO FOLLOW SATURDAY NIGHT INTO EARLY NEXT WEEK WITH RETURN
TO MORE TYPICAL AUGUST PATTERN AS EASTERLY FLOW BECOMES
ENTRENCHED OVER SOUTH FLORIDA FROM DEEP LAYERED HIGH EXPECTED TO
SIT OVER THE SE UNITED STATES.
Well its pretty obvious. Shows a Lesser Antilles threat in 7 days.
That's right, both times.
However, I've seen record-setting surface low development before.
So although I'm absolutely totally wrong...I could be right! :)
In simple terms?
DOOM! lol
I guess this could mean that this week and next week would be the most active weeks we'll see... before it peaks again in Sept for another round.
Lets just take this one day at a time. I say its needs a good 24-36 hours before we'll see a TD. The NHC will be more inclined to name this one since the press is already feeding on it. CNN just talked about it.
lol...I could use some right now...we have a NASTY line of uglies marching through the Lowcountry...thunder sounds like the battle of Charleston...
I think that our African wave comes together a bit faster than some others on the blog think... Very nice convergence and vorticity. All that moisture is streaming toward a center...and it's only a matter of time before convection gets focused there (instead of in these spokes currently)
I'll go out on a limb and say we will have a depression or storm probably by 11AM tomorrow or 5PM at the latest.
"In 1955, two hurricanes formed very near each other. Hurricanes Connie and Diane at one point seemed to be one huge hurricane. The vortices were moving around each other in a counterclockwise motion."
Looks like our some of our weather analog years!!
That would be me...
Ive been calling her Bill for 5 days.
Wow...
Big Blob in GOM
The ridge is more poleward oriented
It's ok, our local weathermen all act scared too when they talk about it. They keep referring to it as a monster on one station.
correct...you don't own it 'till you own it...
what does that all eman, adrian. you're scaring me.
It means that the wave behind TD 2 is likely to become a TS or better by the time it reaches the lesser Antilles, posing a possible threat later in the period to the lower eastern seaboard, CONUS.
Breathe, son...this isn't your first rodeo so please stop acting like a child...
It means stockpile the beer and ping pong balls!
Its very large and will take some time to develop a surface low. It wont pull a Gustav and develop one in 3 hours. Give it 24-36 hours.
Regarding?
The builder should have his own insurance on it. It's not yours until you take title.
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