Thomas is an avid weather enthusiast, landscaper and organic gardener. This blog is dedicated to Northeast and tropical weather forecasting. Enjoy!
By: sullivanweather , 8:14 AM GMT on September 25, 2007
Convection in association with a surface trough dubbed 94L quite a few days ago formed a surface low along the southern end of the trough axis yesterday, and has now become orgainized enough to quailify as a tropical cyclone.
TD-13 is located about 200 miles east of the Mexican coastline and in no hurry to get a move on. It has drifted towards the southwest over the last 24 hours and this meandering should continue for at least the next 24 hours, perhaps jogging a bit more towards the south. After the trough to the systems north over the US mainland passes the system by a ridge should build behind it and eventually push the cyclone west onto the Mexican coastline. South Texas is not out of the danger zone, but the most likely path for this storm is south, then west.
TD-13 is over very warm waters, around 29-30C. An upper level anti-cyclone is over the Bay of Campeche, but shearing winds from the trough to the north is still impacting TD-13. As this trough lifts the upper high should become better established. Given the cyclones' slow movement it should be able to wait around and take advantage of the favorable upper environment that will develop. The only inhibiting factor could be dry air over the Mexican mainland that could become incorporated into the circulation. Given the amount of time it has to spend over water and the favorable upper environment that will develop there's no reason why this cyclone could not attain hurricane status before coming ashore. Not to beat a dead drum, but we all saw what happened with Humberto just a few weeks ago.
I'll be adding to this a bit later when more time becomes available.
Very large, well-orgainized tropical wave traversing the Eastern Atlantic was named TD-12 last night and Tropical Storm Karen this morning. Karen's movement has been towards the west-northwest over the previous 24 hours. The cyclone remains very large and should therefore intensify slowly. Convection is somewhat limited and most of the cloud field associated with Karen is comprised of convective debris. The cyclone is also currently experiencing light to moderate northwesterly shearing winds.
Steady but gradual strengthening should occur over the next 48-72 hours and Karen should achive hurricane status. Thereafter, a digging trough should create a more hostile environment which should weaken Karen to a tropical storm by 96 hours time.
Karen's movement should continue towards the west-northwest for the next 24-48 hours before a turn towards the northwest and eventually north-northwest should ensue for the remainder on the next 5 days. Beyond the 5 day forecast period a bend back towards the west should occur as it is this forecasters belief that the trough responsible for the northerly turn should pass the cyclone by.
Sorry for the vagueness of this forecast but time is short and I wanted to get a forecast out on Karen on the blog. I'll have a more in-depth synopsis later when time becomes available. Below is my 5-day track forecast for Karen.
Karen 5 day forecast.
*Green dot = tropical storm
*Yellow dot = Category 1 hurricane.
9/26 - 2pm update
The NHC has gained enough interest in the disturbance in the Florida Straits to tag it with invest '98L'. There's a surface circulation evident on visible satellite imagery but it is displaced about 50 miles to the southwest of the main area of convection.
The disturbance has been stationary over the last 60-72 hours but should soon begin moving towards the north-northeast in the low level flow ahead of an approaching trough from the west. This trough should accelerate this system up the East Coast, just offshore. There's a chance that the Outer Banks and southern New England could get clipped with this system as it skirts by. As the trough and associated cold front push offshore on Friday it should absorb the disturbance and help to create a rather powerful extratropical cyclone for the Canadian Maritimes.
At this time, given the systems' lack of organization, an intensity forecast is hard to come by. There's an outside chance that enough organization can be aquired to upgrade this system into a tropical cyclone, but nothing stronger than a 40-50kt tropical storm.
9/26 - 3am
Possible tropical development in the Florida Straits?
An upper trough of low pressure has produced continued convective development over south Florida, the Keys, and Cuba for the last 48-72 hours. The NAM model develops a surface low in the region and brings it north-northeastward very quickly along the East Coast, perhaps close enough to Long Island and southern New England to have some level of impact on the area. Of course a surface low has yet to develop and until one does, if it does, details will be sketchy at best.
Updates will surely follow if something were to develop as this has the potential to impact the Northeast by the end of the week.
Record highs for selected cities - Tuesday, September 25th.
Binghamton, NY...81°F - 86°F*
Scranton, PA.........87°F - 86°F
Syracuse, NY........85°F - 91°F*
Central Park.........90°F - 85°F
Albany, NY............89°F - 82°F
Boston, MA............89°F - 88°F
Hartford, CT..........88°F - 90°F*
Pittsburgh, PA......92°F - 88°F
Burlington, VT......85°F - 84°F
(*) - Record tied or broken.
Nowcast. 9/26 215pm
Scattered showers and thunderstorms have developed over the northern and western sections of the region in broken line segments. Temperatures across the southeastern half of the region have risen into the 80's with record highs possible.
It'll be another warm summer-like day for most of the Northeast again on Wednesday with record highs possible from central New York into New England. The trough of low pressure approaching from the west and associated cold front will fire off some showers and thunderstorms across the western half of the region with isolated storms possible in the eastern half due to the heat and increasing levels of humidity. There's a small chance for severe weather tomorrow with the main threat being strong winds. High's tomorrow along the coastal plain could reach close to 90°F where clouds don't infiltrate. Elsewhere across most of the eastern half of the interior will reach into the 80's. Across the western half of the interior clouds and precipitation will tend to hold temperatures down so 70's should be expected here along with far northern New England.
Mostly cloudy skies in humid airmass along with anomalous warmth will make for a rather mild Wednesday night. Showers and thunderstorms moving acorss the Northeast will tend to wane as the night progresses. There could even be some leftover severe weather during the evening, but no later than 11pm. Lows should drop into the low 70's along the Jersey Coast and the big cities. Elsewhere lows should only drop into the 60's except for some 50's in the higher elevations of northern New England.
Current SST's off the Northeast Coast. SST's have returned to near to above normal levels for late September from southern New England south, with continued near normal SST's from Cape Cod northward along the coast of Maine.
Eastern Great Lakes water temperature as of August 26th.
Great Lakes SST's as of 9/24.
September daily weather statistics.
September 1st - 71°F/52°F....0.00"....90%
September 2nd - 73°F/43°F....0.00"....95%
September 3rd - 80°F/48°F....0.00"....95%
September 4th - 75°F/54°F....0.00"....85%
September 5th - 73°F/53°F....0.00"....40%
September 6th - 77°F/55°F....0.00"....40%
September 7th - 86°F/57°F....0.00"....95%
September 8th - 84°F/65°F....0.11"....50%
September 9th - 82°F/63°F....Trace....40%
September 10th - 77°F/63°F....0.00"....20%
September 11th - 66°F/56°F....0.68"....5%
September 12th - 65°F/47°F....0.02"....65%
September 13th - 70°F/42°F....0.00"....85%
September 14th - 69°F/51°F....Trace....10%
September 15th - 63°F/44°F....0.24"....40%
September 16th - 60°F/37°F....0.00"....40%
September 17th - 63°F/35°F....0.00"....90%
September 18th - 66°F/37°F....0.00"....90%
September 19th - 73°F/39°F....0.00"....95%
September 20th - 79°F/44°F....0.00"....100%
September 21st - 79°F/55°F....0.00"....90%
September 22nd - 79°F/54°F....0.00"....40%
September 23rd - 73°F/50°F....0.00"....80%
September 24th - 76°F/45°F....0.00"....95%
September 25th - 85°F/46°F....0.00"....95%
September 26th - 87°F/60°F....0.00"....70%
September 27th - 82°F/63°F....0.18"....60%
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