Scott's Sep 2007

Mid-Atlantic Radar

Scott's September, 2007 Blog
(blog descends chronologically)

Lorenzo On Deck? East Coast (Hopefully) Gets Wet and Keep An Eye on Karen.
Wednesday, September 26

In order of significance to the US:

Invest 98L: This evening's 5:30PM NHC Outlook put Low Pressure "...just south of Key West, Florida" however a mid-level "swirl" is apparent over and just east of Broward-Miami-Dade County, Florida. These are actually two separate areas and add to an extremely complex setup. A trof of low pressure is diving down around Florida and comes up East coast...producing sufficient wind shear to keep the Invest "discombobulated" and not able to stack vertically. There will be no immediate organization but there IS a chance this could pull together off FL-GA-SC in the next day or so. Computer models are not bullish with good reason...they see the sharp Cold Front that will push across the Lakes and Mid-Atlantic on Thursday and then move offshore on Friday. If Low Pressure does organize tomorrow, we could have a Tropical Depression but as the front plows into the Atlantic, this has the looks of a considerable rainmaker for coastal locations from Norfolk/Virginia Beach to Georgetown, SC. Invest 98L and a brilliant Full Moon are also push up seas a half foot or more...and coastal (marsh) flooding is possible tonight and tomorrow. Crazier things have happened, but tropical named status is not expected. Perhaps beneficial rains make inland progress.

T.D. 13: Expected track is to drift W/WSW prior to yet another Mexico landfall. Yes, I do think this could reach Tropic Storm strength in the next 24 hours! No chance this shifts to the north northwest and takes a look at Texas. Steering currents are weak so the cyclone isn't in a hurry to zip inland. Currently online at our HurricaneCenter.

Invest 97L: located just NW of Puerto Rico is being blown to bits and has been dropped. This is another storm that I initially thought had a legitimate chance of cranking up near the Bahamas, but failed to do so. Our Premium Service model maps were still showing some potential at 18Z but we'll likewise drop the Invest at 0Z unless the models have a change of heart. Wind shear is rough and development is not expected.

Karen: Poor Karen...she is getting no respect. The tropical cyclone will become a hurricane and she still garners little attention. Out of sight, out of mind. But...that could change in a few days and I would urge the US East Coast to keep an eye on her! Hurricane Hunters out with her are sending in data that would indicate she'll be upgraded to a Cat-1 hurricane tonight. A look at our HurricaneCenter shows Karen's track should be Northwest, missing the Lesser Antilles. Current forecast also shows Karen will "miss" the benchmark I use in US landfall/near miss forecasts. That benchmark is 20° North, 60° West. Storms that cross 20° North EAST of 60° West "miss" the benchmark and are less likely to approach the US. In contrast, cyclones that are Southwest of this benchmark had a higher chance a US hit/near miss. Karen will miss the benchmark and despite High Pressure Ridging building in next week so after clearing the Lesser Antilles, Karen may increase a westward track. I certainly am not sold the storm ever gets into the Bahamas but interests there and along the East Coast should keep an eye on Karen at our HurricaneCenter. If I had to stake a claim tonight, I'd say Karen does not threaten the US and recurves north and away from land (this also is suggested by the current EURO model).

All Boss, All the Time! I'm a huge Bruce Springsteen fan...have been for over 30 years (first time I saw him live was in the mid-70's in Ithaca, NY. Price: 4 bucks!). I'm thrilled the All Springsteen channel has launched on AOL Radio featuring XM satellite! Unfortunately, it is an AOL only channel and not on the satellite :( But, The Boss is keeping my speakers bouncing here in the weather office!

UPDATE: 11:15PM:

A TWO AND A HALF HOUR HURRICANE. Very interesting development tonight. Hurricane Hunter's data indicated Karen had barely reached hurricane status. In fact, our Premium Service hurricane model maps picked up on this and were showing Karen as a hurricane. Then, the 11PM EDT Forecast/Advisory and Discussion come out and Karen is back to a tropical storm!

Snip from 11PM NHC Discussion:

...GIVEN THE DEGRADED SATELLITE APPEARANCE FROM EARLIER TODAY...KAREN WAS 
ALMOST CERTAINLY A HURRICANE THEN...AND THIS LIKELIHOOD MAY BE REFLECTED IN 
THE FINAL BEST TRACK FOR THE SYSTEM. AT THIS TIME...THE INITIAL INTENSITY IS 
HELD AT 60 KT FOR THIS ADVISORY.

Wind shear again is pestering the cyclone with the appearance of a mid-level center now northeast of the 
LLC (caused by brisk shear from the SW). It will be most interesting to see how this looks in the morning.

Have a good night.

Late September Smorgasbord of Storms.
Sunday, September 23

Recap: Invest 93L became Tropical Depression Ten and sloshed Florida with heavy rains and producing one confirmed damaging tornado.

Now...on with the show...have a scorecard handy!

INVEST 94L: Not tropical at this time but rather Low Pressure and a trof. The storm is currently exiting the Yucatan Peninsula and moving over the SW GOM. This is a complicated setup! Moisture will stream up toward the north-central Gulf Coast states and produce heavy rain with some storms. It is likely that the low level circulation (LLC) of Invest 94L will remain in the western GOM...at least into Monday. Models do not have a good drip on this complex scenario but the potential is there for a tropical depression to develop over the SW Gulf later today. Best hunch right now is eastern TX into LA could see heavy rains from the system, perhaps into late Wednesday and Thursday. Today's 11:30AM update from TPC/NHC:

A BROAD AREA OF LOW PRESSURE LOCATED JUST NORTH OF THE NORTHERN COAST OF THE NORTHERN YUCATAN PENINSULA IS PRODUCING A LARGE AREA OF SHOWERS AND THUNDERSTORMS EXTENDING FROM THE NORTHWESTERN CARIBBEAN SEA INTO THE SOUTHERN AND CENTRAL GULF OF MEXICO. THIS SYSTEM HAS NOT BECOME BETTER ORGANIZED THIS MORNING. HOWEVER THERE IS A POTENTIAL FOR DEVELOPMENT IN THE AREA...AND AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS ON STANDBY TO INVESTIGATE THIS SYSTEM LATER TODAY...IF NECESSARY.

With the LLC over water we'll know more this evening during and after today's Hurricane Hunter flight.

Subtropical Storm Jerry: Fish storm. Online and updating at our HurricaneCenter.

Invest 96L: Looks good this morning in the Eastern Atlantic at 6.4°N (but actually appears closer to 9° or 10°), 28.0°W. This has a long way to go and models are hinting a northwest turn on approach to the Windward and Lesser Antilles Islands. Wind shear is modest and conditions look favorable for development. Indeed, the Euro goes bonkers...ramping up to nearly a Cat-3, while the HWRF is a more modest tropical storm in 5 days. The bulk of the other models are progging a weak system. With little dry air to contend with, I think this will become a named storm. We wait and see.

Invest 97L: The second Invest of the day is closer to the Caribbean at 11.4°N, 55.0°W. Right out of the chute, I'm somewhat concerned about this system. It is a few days from the Lesser Antilles and Windwards, Satellite presentation is reasonable and more favorable conditions should prime the pump on Monday. There is a wide spray of computer model output, with the "hurricane models" taking the storm WNW/NW into the Caribbean and GFS/AVNI and the Euro getting up more toward Puerto Rico. High Pressure Ridging over the Atlantic and SEUS again will be key. This system will in all likelihood continue to organize and become a named storm...we need to monitor closely.

We're running model maps on all this mayhem in our Premium Service section. Click HERE for info.

I'll update the blog tonight after the Invest 94L Hurricane Hunter flight and add satellite links on Invest 97L.

UPDATE: 11:35PM:

lnvest 94L (SW GOM) is disorganized and has been dropped but remnants will bring rain to eastern TX and LA this week. I believe this could redevelop on Tuesday, so we'll keep an eye on the western Gulf of Mexico

Invest 97L continues to be the primary focal point of Atlantic tropical activity. It is satellite "floater 2" and you can get the latest images by clicking HERE. This appears to still be an open wave and convection is less impressive this evening but organization is still probable over the next two days. Models are tracking Invest 97 up toward Puerto Rico...harsher wind shear will develop later this week so I am not ready to begin honking over the possibilities. This system certainly should be closely monitored as rain and gusty winds bear down on the Lesser Antilles.

Invest 93L in GOM and a Better Blob.
Thursday, September 20

Invest 93L continues to do the rope-a-dope around Florida and in the west-central Gulf. Current enhanced view here (click graphic for more):

Several computer models bring the Invest up to a Tropical Depression or a minimal Subtropical Storm, however this isn't particularly impressive this evening. Tampa Radar shows clear rotation...click HERE...and there is a surface low in the Eastern GOM. Hurricane Hunters earlier today found no evidence of tropical characteristics but development is possible. While thunderstorms and strong winds continue tonight over the Florida Peninsula (an isolated tornadoes can't be ruled out), the north-central Gulf Coast will see rain, wind and rising surf as the storm approaches on Friday. This isn't a tightly wound low level center (LLC) but landfall is expected between NOLA and Mobile, perhaps on Saturday morning. Consensus of models bring this up to a TD or weak Tropical Storm (under 55MPH).We're running model maps on this event with our Premium Service .

Interesting "blob" in the SW Caribbean...click HERE...upper level wind flow does not support development, at least in the next 24 hours. Interesting feature to continue monitoring is in the Eastern GOM.

Ingrid Hangs Tough.
Sunday, September 16

Although downgraded to a depression, Ingrid is a tough cookie and persists despite ferocious shear. As opined below, there is a chance though the top is blown off surface circulation holds and the cyclone starts up again later this week. Indeed, the SHIPs/DSHP, GFDL, HWRFand NOGAPS all crank up anew to a tropical storm. Models diverge on a track...either out to sea or moving Northwest (not too specific, I know!). The Bahamas, Florida and the SEUS coast should continue to watch any developments with Ingrid over the next several days.

I will be away from the office through Wednesday (9/19). Next update here at the blog will be on Thursday.

"(still) Another One Bites The Dust" ...And...
Sweater Weather In The Northeast and Mid-Atlantic!
Friday, September 14

Well, in the four and a half days since my last blog, we've had an Invest drop, reorganize and become the fastest hurricane on record (sorta!)...another Invest become Ingrid, which should bite the dust with rapidity!

Humberto went from Invest to hurricane in less than 15 hours! The "sorta" reference is because Blanche '69 became a hurricane in less than 13 hours but was a TD for the better part of a day while Humberto went from Invest to TD to tropical storm in fewer than a dozen hours and becomes the "fastest" Atlantic Basin hurricane on record.

Ingrid most likely is a goner as she is tracking right into 30 knot westerly shear and is not expected to survive the weekend. Ingrid is disorganized (due in measure to current increasing shear) and messy little storms rarely survive 15 knots of wind shear...let alone 25-30 knots. This wind is courtesy of a trof of Low Pressure digging down into the Atlantic and will remain into next week. What's left of the tropical cyclone closer to the surface should be eaten away by dry air...so confidence builds the storm will no affect the Lesser Antilles, Bahamas or the US Mainland. One wrinkle in this tidy forecast is the possibility some circulation lingers at the surface and tracks to the Northwest. Next week, shear should abate, High Pressure build back down and *if* anything remains, it would shift more to the West. There is no computer modeling support for this to occur...but something to keep in mind next week.

The Big Chill! Today's rain and isolated storms actually are remnant moisture from Humberto being dragged out along a Cold Front crossing the region. Key word in that sentence is: cold. Freeze Watch tonight along the western Southern Tier of NYS and NW Pennsylvania. Yes: Freeze Watch! It's a Freeze Warning for the Upper Plains! Click here for maps. Behind this Cold Front, chilly High Pressure slides in with temps averaging at least 10 degrees below normal from the Upper Plains over to New England and south over much of the Mid-Atlantic. The Highlands and foothills of Virginia may drop well into the 40's on Saturday night. Cool (but boring) weather for the region next week with High Pressure ebbing out to sea (noted above with Ingrid) and a gradual increase in temps on return flow later in the week.

Next update here at the blog will be on Sunday. Have a football weather Saturday. Go Irish!

"Another One (or two) Bites The Dust"
Monday, September 10

Very rain totals of 7 inches at Morehead City as Gabrielle came in, swung around OBX and headed back out to sea. Cape Hatteras observed numerous 50+MPH gusts with a maximum of 53MPH. Twelve to fifteen foot seas also common as Gabby came inland for a brief visit. Not surprised but still disappointed how little progress inland the rain made and this tropical cyclone was of no help to those away from the shore.

Invest 91L: Tonight near 10.N/40.0W or 5 days east of the Windward Islands. A Tropical Depression is possible over the next day or so. Thunderstorms did "the big fizzle" again today however there certainly appears to be cyclonic rotation in the mid-levels. Very little wind shear at this time and so Invest 91L has a short window of a couple days to organize.

Invest 90L and 92L today were dropped.

Next update here on the blog will be Friday.

New Invest 90L in GOM...New Invest 91L in the Atlantic...and...
Gabby Goes to OBX.
Sunday, September 9

Gabrielle: Impressive banding of very strong thunderstorms on the south side of the storm this morning...Gabby has tried to intensify on approach to NC. No big changes to timing and location of track as the storm is due in this afternoon and expected to turn to the north and then northeast...heading back out to sea late tonight. Close-up of forecast track from our HurricaneCenter:

Great link for web cams along the NC coast HERE.

The tropical storm will not transport much tropical moisture inland. Precipitation will confine to coastal NC near landfall and SE Virginia. In fact, NWS offices are discounting any rain west of the I-95 Corridor or north of VA I-64. Total precip amounts along coastal areas south of VAB remain 1-2 inches.

INVEST 90L: popped up last night in south central GOM. A trof draped over the Gulf will produce 25-30 knot shear to the north of the disturbance. Last night's hurricane models trended toward the TX coast (except the CMC which went toward Houston then did an "about face" and went into LA). More on this system after Gabrielle makes landfall as immediate strengthening is not anticipated.

INVEST 91L: moments after originally publishing this discussion a new Invest went online. This is the wave that rolled off Africa and over the Atlantic a couple of days ago and now is Invest 91L. The disturbance is at 10° North...just south of 20 knot wind shear. The initial 12Z hurricane models bring the Low to the WNW over the next 72 hours. SHIPs and DSHP get this to a hurricane in 72 hours while several other models develop it into a T.D in the next 36 hours and then weaken or dissipate (shear and dry air). More on this Invest tonight.

UPDATE: 12:35PM:

ATTACK OF THE INVESTS! Three new Invests (areas of investigation) in 12 hours! Very brief update:

Invest 90L in Gulf of Mexico.
Invest 91L in central Atlantic
Invest 92L:east of the northern Windward Islands. This latest Invest is in a favorable environment and interests in the Bahamas...and Florida...must closely monitor. Approaching trof and High Pressure Ridging concern me as this could take aim at Florida and then ride around the Ridge closer to the SE US coast. VERY early ideas but continue to closely watch likely development.

Map of all systems as of 12 Noon today (this map will NOT update automatically):

More tonight. Stay tuned!

UPDATE: 10:35PM:

Gabrielle: Looks like immediate coastal areas around Morehead City have received 4-6 inches of rain from Gabrielle. Overall, not very beneficial as much of this will be runoff at the coast and very little rain made it inland. Winds have also been restricted near the disorganized center of circulation (my daughter attends college near Norfolk and we chatted on the phone...she reports it is "kinda sorta breezy" there). Gabby is behaving much as a trof running right down the I-81 corridor in advance of a weak front help to scoot the storm over cooler waters. Seas will be up but Gabrielle's departure will not bring stormy weather to the coastal Northeast on Monday.

GOM Invest 90L: Now located due south of NOLA in the southern Gulf, any development will be slow as conditions are not favorable for organization at this time.

Atlantic Invest 91L: Any development here should be slow. A Tropical Depression may form and the system bears watching, especially in the Windward and Lesser Antilles Islands.

Invest 92L: Hmmm...I took a few hours off this afternoon and returned to see virtually all thunderstorm activity with Invest 92L disappeared. Global models are not on it yet and there now is limited support from the hurricane models. Conditions actually are pretty good for development but for the moment: *poof*! There does appear to be circulation but until/unless storms refire this is a puff of wind. Should the storm organize, it will ride around the Ridge to its north and this would mean potential from PR and Hispaniola up into the Bahamas and possible Florida or the Southeast US coast. We will continue monitoring this and all other Invests at our HurricaneCenter.

Model maps on all storms available through our Premium Service hurricane model maps.

We'd love to share your storm photos from Gabrielle in our photo gallery and here on the blog! Photo Gallery: http://www.midatlanticwx.com/publicgallery/weather_gallery.htm
Send photos or video! Details HERE.

Subtropical Storm Gabrielle Update. SC/NC Tropical Storm Watches Now Up!
Saturday, September 8

This has probably been the world's most anticipated Invest and finally we have SUBtropical Storm Gabrielle. If you've been reading the past few day's blogs you'll recall the Invest was along a frontal boundary and began as "cold core"; therefore, the storm isn't truly tropical in origin. Subtropical means a storm that has traits of both a tropical and an "extratropical" system. Once in a while, subtropical storms become totally tropical and "sub" is dropped from their name. Another interesting feature of many subtropicals is their winds are not always the strongest near the center. But, like a true tropical cyclone, they can "bomb out" very rapidly!

That should not be the case with "Gabby" as the cut-off ULL to the southwest continues producing moderate shear shear that has diminished but remains present. Dry air further out in the Atlantic will also eat at the storm and should help minimize significant intensification. It is expected the storm will come inland between Wilmington and Morehead City, NC. Gabrielle may pass the OBX to the west (inland) as an advancing trof nudges High Pressure to the East and kicks the storm out to sea south of Virginia Beach.

An important caveat from the NHC:

IT SHOULD BE NOTED THAT THERE IS A POSSIBILITY OF CENTER REFORMATION DUE TO THE 
ELONGATED NATURE OF THE SYSTEM.  WHILE SUCH REFORMATION WOULD NOT CHANGE THE 
OVERALL STEERING PATTERN...IT COULD HAVE AN AFFECT ON IF AND WHERE THE CENTER 
MAKES LANDFALL.

This is why Tropical Storm Watches extend from Edisto Beach, SC up through much of OBX. 
Please visit our HurricaneCenter for real-time watch and warning information.

Still a bit too early to peg down rainfall totals and locations however a reasonable "gullywasher" would be welcomed 
here in the Mid-Atlantic. Given how quickly Gabby should recurve, it's reasonable to think moderate to heavy rain invades
NW South Carolina, eastern-central NC and SW Virginia. We'll monitor this and update again later on Saturday.

People along the coast from Savannah up to Norfolk/VAB should closely monitor developments and immediately begin 
necessary preparations for a moderate tropical storm. While a Cat-1 hurricane is not ruled out, only the SHIPs model brings
Gabrielle to a hurricane in the next 72 hours and this solution is discounted.

Next update will be around Noon today.

UPDATE: 12:05PM:

Gabby remains a subtropical storm this morning with winds and convective thunderstorm activity still removed from the center. She is trying to organize and if this gets pulled together around the center, Gabrielle will become a tropical cyclone. Current view (click graphic for more images):

Model trends are more to the east than was presented last night. A couple things seem to be developing. First, the (sorta) Center of Circulation (COC) appears to have shifted to the northeast...further away from land. Second, the frontal boundary with active storms from OK into the Tenn and Ohio valleys is not very strong and has gone Stationary; it probably has little effect on Gabrielle.

It appears ideas of a more westerly component closer to the SC/NC border will not verify and the storm may actually just clip OBX prior to the expected recurve to the NE or ENE on Monday. Gabrielle will still pull in decent rainfall totals but should not extend more than 100 miles inland. Intensity is always tricky but blending the models with what appears synoptically and I'll suggest a 60MPH Tropical Storm at approach to the OBX.

Hurricane Hunters will be back in around 2PM and I'll update the blog later tonight.

Please visit our HurricaneCenter for real-time information. Have a good day.

UPDATE: 11:25PM:

Tropical Storm Warning extended north by NHC at 11PM EDT to include Virginia Beach, VA. 11PM Forecast/Advisory package has shifted the track slightly west (thus VAB is issued a warning).

Gabrielle has completed the transition to a warm core tropical storm and "sub" was dropped this evening from the official name. Hurricane Hunters this afternoon found Gabby's winds actually dropped to 40MPH making it a marginal tropical storm. The storm should briefly landfall Sunday afternoon in the vicinity of Jacksonville, Morehead City, Cape Fear, NC. My previous idea of a 60MPH landfalling storm may be slightly high but there certainly is time for this to develop. I'm skeptical Gabrielle reaches hurricane strength but if there is one 75MPH gust some folks will say this was a hurricane!

Next issue is inland rainfall...and the news is not good for the parched Mid-Atlantic and Southeastern US. Current forecast map for 24 hour precipitation:|

As seen, we're only talking 1+ inches of rain for the immediate NC coast and islands with very little rain making it inland to I-95.This may be a little underdone but hopes of meaningful rain in the area will wait until a frontal boundary approaches later next week.

Cirrus clouds will stream in overnight and Sunday but it is unlikely the rain will make extensive westward progress even with NHC's 11PM nudge to the west. As I said, the above map is probably should extend more to the west...we'll watch Radar and see. Loop Wilmington, NC Radar HERE.

We'll get you some web cam links to OBX and update inland rain potential in my next update on Sunday morning.

Invest 99L: The Final Countdown Is Underway
Friday, September 7

As has been suggested here and elsewhere, conditions finally seem to begin being more favorable for the Invest to develop. Current enhanced satellite view shows a much better presentation with evidence of thunderstorms trying to wrap around the center (click graphic for more images):

To the North, an Upper Level Low spins over the North Atlantic while the High Pressure Ridge we've discussed is moving into position. You can see the ULL and also clouds rotating around the High at this loop from our HurricaneCenter. High Pressure blows clockwise and this should keep the storm on a NW track. One note of caution: if the Ridge drifts further to the South or expands faster than models predict, the storm could be steered more to the west or the WSW. I don't think that will happen as a trof will be crossing the Mid-Atlantic States, if anything, the storm approaches the coast and the recurves (fish storm). Models still are in good agreement regarding the general track: NW toward the coast from Myrtle Beach to Nags Head then recurving away from land southeast of the Delmarva Peninsula. Our Premium Service model maps continue to update progress with Invest 99L.

The system certainly can become a Tropical Depression today and there is time for intensification to a Tropical Storm...this may occur later on Saturday or perhaps Sunday. Computer guidance overall gets the Invest to Tropical Storm strength by Saturday evening. The Upper Low (TUTT) that has gnawed at the Invest for over two days is moving away. Wind shear is diminishing to around 15 knots ahead of the forecast track allowing the storm to wrap in and intensify. Looks like this will be: Game On!

Sunday and Monday we should expect gusty winds and rain to overspread NE South Carolina as well as eastern/central NC, VA as well as DE, E MD and southern NJ. I'll have an update here at the blog tonight.

Is the Clock STILL Ticking for Invest 99L?
Thursday, September 6

Snip from tonight's NHC Discussion:

SHOWER ACTIVITY ASSOCIATED WITH THE NON-TROPICAL AREA OF LOW PRESSURE ABOUT 350 MILES SOUTHWEST OF BERMUDA REMAINS DISORGANIZED. WHILE UPPER-LEVEL WINDS ARE UNFAVORABLE FOR DEVELOPMENT...THEY COULD BECOME MORE FAVORABLE OVER THE NEXT COUPLE OF DAYS...AND THERE IS STILL SOME POTENTIAL FOR THIS SYSTEM TO BECOME A TROPICAL CYCLONE.

What can I say? Invest 99L looks as disorganized tonight as it has all day. The most recent QuikSCAT pass shows circulation remains, so we'll keep at it and see what develops. Models continue to spin this up to a TD or Tropical Storm but the timing has been invalid since the Invest first went up. The system is without steering currents and is moving very little. Computer guidance is in excellent agreement the storm will track up to OBX then sharply recurve...almost tracking ENE early next week. Given this has not moved and has not developed, my "trof scooping" idea will probably not verify.

I saw on the S2K board AccuWeather forecast this to be a hurricane??? If so, ooops!

Shear abates and High Pressure to the north should get whatever is out there moving to the Northwest this weekend. If there actually IS a storm, it will push gusty winds and rain into NE South Carolina and central-eastern North Carolina on Sunday or Monday. Beyond that, we'll need to wait and see. With conditions actually becoming "somewhat more favorable", this is going to get going or get gone Friday and Saturday.

Tick...Tock...The Clock Is Ticking For Invest 99L.
Wednesday, September 5

Interesting day with very little specific information to pass along with Invest 99L...now located due East of Jacksonville at 70° West. I don't know what to call this thing and perhaps neither does the NHC which would explain why it remains Invest 99L. Hurricane Hunters were in today and found 33 knot winds with a center core 1 degree warmer in the center (such as it was). One might think that makes it a tropical depression, however, there appears to be a trof like boundary hanging off the Low to the SW (pictured below)

Tropical cyclones don't form on boundaries and sub tropical systems typically are not on a front, so it may be wait and see at the NHC. Either way, I am bullish this becomes a TD and probably Tropical Storm Gabrielle in the next 36 hours.

In terms of intensity, virtually all models bring this up to a Tropical Depression by Thursday evening. I dislike using models for intensity as they rarely are correct, but total agreement on making this T.D. 7 is logical. Next we consider potential track and in this, there is very little change to yesterday's ideas. The hurricane models (BAMS, BAMM, BAMD) all bring the system very close to OBX before recuriving. The 18Z Nogaps brought the satorm inland near Wrightsville Beach, NC and tracked west of OBX before coming out near Virginia Beach, although the 00Z run is off shore with the hurricane models. The GFS, GFDL and the HWRF follow suit...in fact, most models tonight gelled on the same track: NW toward Nags Head and then recurving sharply out to sea.

So, do we stick a fork in this and proclaim: "next"? I would not! As noted in yesterday's blog, High Pressure is sliding east into the Gulf of Maine. I'm not convinced the models have pegged the Ridge axis and strength...that has implications because as you know, Highs spin clockwise and that could steer the storm more to the west or NW.

We also can look to the west for possible input (click graphic for color and animation):

You can see in the Water Vapor image an area of Low Pressure over the Central Plains and a developing trof (darker colors). If that approaches the East Coast this weekend, it is possible it becomes the chute that allows "Gabrielle" to come right up along the coast...perhaps all the way to Southern New England. This, I believe is an option that needs to be monitored, especially if it indeed becomes negatively tilted (extending NW to SE). Models get very jumpy with developing systems close to land and above 25° North so while they are in agreement this is a near miss T.D or weak Tropical Storm for the OBX, this is not a done deal.

Rainfall could be moderate to heavy from NE South Carolina through central and eastern NC, VA as well as MD, DE and lower NJ. Let's keep an eagle eye on this and see what Thursday's recon flights show us.

Stay tuned!

Audacious, Absent and On Deck.
Tuesday, September 4

Very late post due to being on the road all day.

Felix: The hurricane quickly ramped up an made landfall as a Cat-5. Unlike other major storms (the 3 "5's of 2005" come to mind), this hurricane was actually strengthening as it came ashore. What utter audacity! How these storms can wrought such damage and death while being spectacularly beautiful to watch from a distance is perhaps the biggest fascination of hurricanes to me. Essentially, Felix went from a T.D to a Cat-5 in two days. The final slap in the face from Felix was the fact we have now had two landfalling Cat-5s in one season...this has never before been recorded.

A quick look at our Water Vapor Loop shows deep moisture pulling in over the Pacific, however the remnant circulation continues moving west and (so far) most of this additional precipitation is just off shore over the Pacific. Click HERE for the WVL.

Invest 98L: The Little Invest That Could...didn't. This system has been dropped and all that remains is a weak tropical wave approaching the Windward Islands. Swirling waves entering the Caribbean in September are never disregarded so we will monitor but noting brewing right now.

Invest 99L Sneak Attack: The "blob" previously referenced will not have an easy go of it...nor will forecasters! 20-30 knot wind shear near the Invest will keep this from quickly spinning up so there's no need to pack up the SUV at this time. We have an interesting set up at this time with High Pressure over the Southeast and a High that will slide down from Canada to center over the Gulf of Maine. In-between, a Cold Front will approach the Invest. Result: virtually no off shore steering currents and a frontal boundary to contend with. The models generallg loop the system around well east of Florida and then begin moving the system up toward NC and VA. The 00Z HWFI hugs the coast and aims directly at Nantucket! Model map subscription info here. I understand the loop off shore but am not sold on any of these scenarios as of now. Hurricane Hunters are scheduled to fly in tomorrow so we'll see what they sniff out (probably a Sunday drive after Felix!). High Pressure pushing down from the North will bring clockwise flow ahead of the Invest...suggesting perhaps a more westbound or WNW track. I would suggest the entire East Coast keeps an eye on this system as these systems are not like their Big Brothers and Sisters in the Caribbean that often take a fairly predictable straight course. Our Premium Service model maps for Invest 99L look like a pile-up of Daddy-Long-Legs!

Next Discussion after recon gets into Invest 99L tomorrow.

Fierce Felix...Invest 98L and SEUS "Sneak Attack"?
Monday, September 3

Brief update as I am hoping to enjoy some time with my kids (something that can be a bit of a challenge once school resumes in hurricane season!). I'll be back tonight with another discussion.

Felix: Heading toward even warmer water today, probably at about the same time an anticipated Eyewall Replacement Cycle (ERC) will occur. As of this morning, the eye continues to contract but no evidence on satellite or comments about an ERC from the hurricane hunters or the NHC. Slight nudge southward on the track...bringing it near or to Nicaragua. Honduras and Belize late Tuesday morning. NHC forecast track keeps the hurricane well south of Texas although the UKMET is bringing the tropical cyclone further NW than most models and the NHC forecast.

INVEST 98L: Disorganized "blob" of Low Pressure midway between the Lesser Antilles and Africa. This is the Little Invest That Could. No changes to yesterday's ideas: circulation remains and this could become a Tropical Depression if it holds together for another 24 hours. Shear and dry air continue to hamper development but conditions become slightly more favorable tomorrow.

SEUS: Low Pressure develops off the coast and will bear watching. I think it unlikely anything there zips off to the Northeast, given High Pressure Ridging. It may bop around off the coast or could get pulled inland so the question becomes what will develop? At this time, I don't know however it is possible moderate to heavy rain gets pulled in later this week from eastern Georgia up to Virginia and the Delmarva. Current view from our HurricaneCenter (click for more):

Back tonight!

UPDATE: 8:40PM:

Felix: Two scheduled hurricane hunter flights were cancelled today; one with the aircraft that bailed out of last night's flight (see update in yesterday's blog). From what I've gleaned through a couple emails, the NOAA craft was "stressed" by extreme turbulence yesterday but was given the "ok" to fly today. While the person I exchanged emails with didn't say so, I will: damn scary! The next and final flight into Felix should arrive at approximately 1AM EDT tomorrow...still time before landfall. Recon flights don't penetrate as a storm makes landfall nor do they fly into a storm over land due to unpredictable turbulence (caused by the wind's interaction with land producing insane updrafts and downbursts). It sounds as though they got a taste of that last night well away from land and we are most thankful there were no injuries...or worse. Incredibly, this is the same plane that nearly was lost in Hugo (also referenced in yesterday's blog update). Simply amazing to me.

Dvorak number currently is 6.1/133MPH winds. Dry air and a little shear has disrupted the hurricane, however, the anticipated Eyewall Replacement Cycle (ERC) did not happen earlier today but appears to be now underway. Felix, like a cat, is filled with mystery. At this time it doesn't appear the tropical cyclone will regain Cat-5 status (Katrina did, but that is somewhat unusual). No change to forecast track thinking and timing unless tonight's jogs slightly shift the track. Otherwise, all looks "go" for a high Cat-4 tomorrow morning. Current data at our HurricaneCenter.

INVEST 98L: No changes from this morning's thoughts. The system is barely moving and a few models still pull it WNW/NW in response to an advancing trof. On the other hand, this may do in the circulation. We watch and wait.

Sneak Attack now INVEST 99L: The "blob" is now Invest 99L located well east of Jacksonville, FL. Ridging and the eventual approach of a frontal boundary make this a tough call (most storms that spin up here are very problematic!). Our model maps show the UKMET getting the possible T.D into florida while the NOGAPS comes in closer to Wilmington, NC. The BAMM, BAMD and BAMS all swing the Invest around before getting into Florida. Certainly we'll watch this for possible development.

Model maps on each of these storms are available in our Premium Service weather section.

Felix The Cat...5! BOMBS AWAY!!!
Invest 98L in Atlantic Update.
Sunday, September 2

I've been away from the weather office and it seems every time I do so things start exploding! Perhaps my next day off should be in February!

Two weeks ago, Dean skimmed Jamaica and today Felix passed oh so close to the "A,B,C Islands". Tonight, we have FELIX THE CATegory Four hurricane moving well south of Jamaica and certainly destined to become the season's second Cat-5...possibly as soon as tonight.

Current enhanced view of Felix (click graphic for more):

The intense hurricane continues to strengthen...if fact I'm watching recon data coming in at this time (7:45PM) and it appears surface winds are 150MPH. It is rare that I or other forecasters will announce the expectation of Catagory-5 strength, but Fierce Felix will certainly become the season's second Cat-5 very soon and well before landfall on Wednesday. Tropical cyclones can not sustain this intensity indefinitely so perhaps this may be an encouraging sign that the cyclone will weaken somewhat on approach to land. The eye is down to 12 miles and an Eyewall Replacement Cycle (ERC) should be forthcoming on Monday.

Thus far, hurricane force winds extend out only 25 miles...an extremely compact wind field. Tropical storm force winds are also compact; currently extending 115 miles. Despite the compact area of storm winds, Felix will deliver a devastating hit where it makes landfall on the Central American coast...most likely the Yucatan Peninsula (again). With nothing to get in the way or alter this path, there is high confidence in the NHC forecast track for landfall #1:

Felix is an amazingly impressive hurricane tonight. This afternoon's final hurricane hunter flight VDM noted "stadium effect"; this is where the top of the eyewall arches out and gives the appearance of a football stadium and is a sign of a well organized and powerful tropical cyclone. At today's current pace, winds will have increased by nearly 90MPH today while minimum central pressure could drop by over 50 millibars in one day! "Bombing out" is slang for a storm that drops 24 millibars in 24 hours...Felix has already exceeded that benchmark, so it's MEGA Bombs Away for this storm. In fact, computer guidance is showing the hurricane to now (8:00PM) be at 921 millibars: 60+ millibar drop in less than one day. WOW!

So, it is interesting and a fascination to watch this tropical cyclone deepen and strengthen and we must watch and see if the "official" forecast track verifies (as I believe it will).

Next major question is where will Landfall #2 be? I am concerned the hurricane will be energizing anew over the Bay of Campeche just as a trof of Low Pressure crosses the Plains and digs into Texas. Timing is critical but sufficient weakness could affect the western periphery of the Ridge that the door *could* open for Felix to get pulled more to the NW or NNW. I am uncertain this will occur but Felix has a much higher potential than did Dean's chances of recurving. As such, interests along the northern coast of Mexico and those south of Houston/Galveston, TX must also carefully monitor future developments with this hurricane. We may not know until Wednesday or Thursday how Felix will track upon reemerging over water; therefore now is the time to firm up plans if you are in the potential "cone". We have a tremendous number of visitors on this sight from the Lone Star State and I urge you not to wait until late next week to see where Felix may be heading. Hurricane model maps are now updating at least 8 times daily in our Premium Service weather section.

INVEST 98L: The Invest over the Central Atlantic is currently a Low Pressure "blob". While extensive attention rightly is focused on Felix, I believe conditions are such that the Invest needs to hold together for another 24-36 hours before reaching more favorable conditions. Our Premium Service weather section is keeping an eagle eye on Invest 98L. Stubbornly, the UKMET model continues to see nothing at all with this disturbance...not a good sign for immediate development.

SOUTHEAST SNEAK ATTACK? A non-tropical Low should develop early in the week of the GA/SC coast (similar to last week's Invest 95L off Hilton Head Island). None of the models get this cranked up but this area needs to be monitored as well for possible development.

UPDATE: 10:15PM:

This evenings hurricane hunter flight was scrubbed in progress...extremely unusual! I do not recall a flight that bailed out due to grouple, turbulence and lightning. There was a frightening near crash incident as Hugo approached Charleston, SC with tremendous stress placed on the aircraft...thankfully there was nothing like that tonight. Still, this reminds us how dangerous these flights can be; flights we all consider "routine".

This hurricane reminds me of a "mini-Wilma" in terms of explosive, rapid intensification. Remarkable!

Current IR satellite shows some ragged edges (red inner area in image above). Earlier tonight it was near perfect symmetrically while now it is more jagged. Felix may have peaked for the night. Interaction with land is possible and while a second eyewall is not apparent, the hurricane may be beginning and ERC. I'm eager to read the 11PM Forecast/Advisory and Discussion.

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