A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms that could produce damaging wind gusts and large hail. All interests in the Severe Thunderstorm Watch area should be alert for threatening weather. Additionally, please review your severe weather safety rules and know what to do should Severe Thunderstorm Warnings be issued for your location.

Supercell thunderstorms will continue to develop and affect southeastern Texas from Houston to Sabine Pass over the next few hours. Plenty of low level moisture will be lifted over a weak warm front and lead to rotating supercell thunderstorms. Vertical wind shear is favorable for rotation within these thunderstorms and tornadoes are a possibility.

Severe Thunderstorm Watch Graphic:

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Current Mesoscale Analysis:

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Radar Imagery:

Isolated to scattered showers and thunderstorms are forecast by the high resolution model guidance to develop across the Allagash region as early as midday today with other shower and thunderstorm activity forecast to develop across the Caribou-Presque Isle area, as well as the Saint John Valley by about the 2 to 3 pm timeframe and continue into late this afternoon. Some of these thunderstorms may be strong with gusty winds, very heavy rainfall and hail possible.

A line of showers and thunderstorms are forecast to develop along the cold front and will enter far western and northern Aroostook County, including the Saint John Valley and the Allagash region by early this evening. This line of showers and thunderstorms are then forecast to track across the Caribou-Presque Isle-Houlton corridor just before midnight and then continue well after midnight tonight. Heavy rainfall and lightning will be the main threat with this line of thunderstorms.

High temperatures today will be near 65 Degrees. Low temperatures tonight will be near 53 Degrees.

Sunrise this morning is at 4:55 am EDT. Sunset this evening is at 8:02 pm EDT.

Northern Maine Radar Image:

Northern Maine Satellite Image:

THURSDAY THROUGH FRIDAY: Thursday is expected to start out cloudy with scattered showers, however, skies will become sunny to partly sunny during Thursday afternoon. High temperatures Thursday will be near 58 Degrees. It is also expected to be kind of windy on Thursday with west winds of 10 to 20 mph with gusts to 30 mph.

Clear skies are forecast for Thursday night. Low temperatures Thursday night will be near 35 Degrees.

Friday will be sunny to partly sunny and windy with high temperatures near 66 Degrees. Winds on Friday will be west at 15 to 25 mph with gusts to 35 mph.

SATURDAY THROUGH MONDAY: High pressure will control our weather throughout this upcoming weekend. This means lots of sunshine on both Saturday and Sunday. High temperatures Saturday will be near 69 Degrees and high temperatures Sunday will be near 73 Degrees.

Plenty of sunshine is also expected on Monday with high temperatures near 78 Degrees.

Out ahead of this frontal system, the airmass is expected to become warm, humid and unstable throughout much of New England today. The current clouds and areas of fog are forecast to break, leading to partial sunshine by late this morning into this afternoon across eastern New York State, Vermont, southern New Hampshire, western Massachusetts and western Connecticut where high temperatures will make it to 75 to 80 degrees this afternoon with dew point temperatures somewhere between 60 and 65 degrees.

CAPE values are forecast to get up to between 1500 and 2000 j/kg with lifted index numbers between minus 3 and minus 5 across New Hampshire, Vermont, western Massachusetts and eastern New York State.

The latest high resolution mesoscale model guidance like the HRRR model is forecasting that isolated to scattered thunderstorms will develop well ahead of the cold front from eastern New York State, southern Vermont & southern New Hampshire into western Massachusetts by early this afternoon and then track eastward into central and eastern Massachusetts, southeastern New Hampshire and southern & western Maine by late this afternoon. Should these storms remain discrete and isolated enough, then development into supercell severe thunderstorms are quite possible with damaging wind gusts and large hail the primary threat.

A line of strong to possibly severe thunderstorms, associated with the cold front will first affect much of eastern New York State, Vermont and western Massachusetts by very late this afternoon and this evening and then track across the rest of New England during the overnight hours of tonight. Isolated reports of wind damage are possible with this line; other than that, very heavy rainfall and frequent lightning will be the main threat.

All interests across New England, especially across areas from central and western Massachusetts to much of New Hampshire, Vermont, western and northern Maine, as well as eastern New York state, should be alert for any severe weather watches or warnings. I will be doing my best to update all of our Crown Weather friends across New England today through Facebook and Twitter. So, go follow us on Twitter (LINK) and Facebook (LINK).

Additionally, you may want to bookmark our New England weather page for the latest weather information. The link is http://www.crownweather.com/?page_id=46 .

Today & Tonight’s Severe Weather Outlook:

Today & Tonight’s Tornado Outlook:

Chance Of A Tornado Within 25 Miles Of Your Location

Today & Tonight’s Damaging Wind Outlook:

The Chance Of Damaging Thunderstorm Winds Within 25 Miles Of Your Location

Today & Tonight’s Large Hail Outlook:

The Chance Of One Inch Diameter Or Larger Hail Within 25 Miles Of Your Location

Current Severe Thunderstorm/Tornado Watches:

Current Mesoscale Convective Discussions:

Sunrise this morning is at 4:58 am EDT. Sunset this evening is at 8:00 pm EDT.

Northern Maine Radar Image:

Northern Maine Satellite Image:

TONIGHT: A weak area of low pressure will track northward across downeast Maine tonight; so, I expect skies to become mostly cloudy this evening with scattered showers expected after midnight tonight. Low temperatures tonight will be near 52 Degrees.

TUESDAY THROUGH WEDNESDAY: A weather disturbance will start to cross the area on Tuesday. I expect generally cloudy skies with a good deal of showers in the morning. It appears that the overall coverage of showers should diminish during Tuesday afternoon. High temperatures Tuesday will be near 65 Degrees.

Rain is expected on Tuesday night and Wednesday as a cold front crosses the area. Low temperatures Tuesday night will be near 48 Degrees. High temperatures Wednesday will be near 65 Degrees.

THURSDAY THROUGH SUNDAY: A secondary cold front will track across northern Maine on Thursday, so I am expecting mostly cloudy skies with scattered showers Thursday morning to be followed by partly sunny skies on Thursday afternoon. High temperatures Thursday will be near 62 Degrees.

Sunny to partly sunny skies is expected on Friday with high temperatures near 63 Degrees.

Sunny to partly sunny skies are expected on both Saturday and Sunday. High temperatures Saturday will be near 64 Degrees and high temperatures Sunday will be near 66 Degrees.

At the very least, this storm system will likely bring rough surf and gusty winds to much of the coastal sections of the southeastern United States from eastern North Carolina to northeastern Florida from late this week into this upcoming weekend. It should be pointed out that there are indications from the model guidance that this system may acquire sub-tropical characteristics as it tracks near the Gulf Stream by Sunday into next Monday and this will be something that will be watched for closely.

Will There Be Tropical Development In The Southwestern Caribbean This Weekend Into Next Week??:
Model guidance members such as the GFS operational model continue to insist that some sort of tropical system will develop in the southwestern Caribbean between Saturday and Monday. The latest GFS operational guidance forecasts that this tropical system will end up tracking northeastward into the northwestern Bahamas by next Friday. Now, other model guidance members like the Canadian and European model are showing that the development will be in the eastern Pacific and this is something that I am leaning towards.

The reason why I am leaning strongly towards the idea of an eastern Pacific tropical cyclone rather than a tropical system in the southwestern Caribbean is because one it is climatologically favored and two the statistical forecast are pointing towards tropical cyclone development in the eastern Pacific in late May.

So, I suspect by late this weekend and early next week, we may have a sub-tropical storm about 200 miles to the southeast of the outer banks of North Carolina and a tropical storm in the eastern Pacific about 350 miles south-southeast of Acapulco, Mexico.

One particularly strong cell is located offshore to the southwest of Panama City. This particularly strong cell concerns me as it will track onshore between Port Saint George and Apalachicola sometime between 12 & 1 pm CDT this afternoon. Already, this storm is exhibiting signs of rotation and contains hail of 1 to 2 inches in diameter. Those of you from Port Saint George to Apalachicola should monitor this thunderstorm cell extremely closely.

Another thunderstorm cell located due south of Seagrove Beach is also showing signs of rotation and will track onshore between Seagrove Beach and Panama City Beach between 10 & 11 am CDT this morning. Tornadoes, damaging winds and large hail are possible with this storm cell. Those of you along coast between Seagrove Beach & Panama City Beach need to monitor this storm cell very closely.

Mariners should stay off of the waters between Navarre and Apalachicola today. Thunderstorm cells tracking northeastward across the coastal and offshore waters will likely produce waterspouts, squalls, frequent lightning and hail.

I will be doing my best to update all of our Crown Weather friends in the Florida Panhandle today through Facebook and Twitter. So, go follow us on Twitter (LINK) and Facebook (LINK).

Current Weather Advisories:

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Current Mesoscale Analysis:

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Satellite Imagery:

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The latest GFS model is forecasting that development will occur in the western Caribbean near the north coast of Honduras as early as next Saturday and forecasts it to slowly track northward into the southeastern Gulf of Mexico by about May 25th before tracking across south Florida during the Memorial Day weekend.

GFS Operational Model Guidance Forecast:
May 19th:

May 25th:

May 27th:

The European model guidance has a completely different solution and forecasts the development of a sub-tropical storm near Great Abaco Island in the northwestern Bahamas on Friday and forecasts this sub-tropical storm to track northward just off of the east coast of Florida next Saturday before coming inland in southeastern and eastern North Carolina next Sunday and next Monday.

European Model Guidance Forecast:
May 18th:

May 19th:

May 20th:

May 21st:

The Canadian model seems to agree with the GFS model and forecasts the development of a tropical system in the western Caribbean between May 19th and May 21st. It should be pointed out that the European ensemble guidance seems to hint at lowering pressures in the southwestern and western Caribbean right around May 20th and 21st supporting the GFS operational model idea.

Canadian Model Forecast For May 21st:

My thoughts are really no different than what they were a couple of days ago: The overall weather pattern that is forecast to set up for the second half of May is one that can lead to early season tropical development in either the western Caribbean or somewhere near the Bahamas much like what all of the model guidance is hinting at. Many of the analog years that I have been looking at for this upcoming hurricane season have had early season tropical development. These years include 1951, 1957 and 1976; in fact, 1951 and 1976 had tropical development in May with Category 3 Hurricane Able developing just off of the US Southeast Coast in Mid-May of 1951.

So, I do think that the GFS, European and Canadian models are pointing out what could happen with the pattern that is forecast to set up. I think we really need to start watching the corridor between the northwestern Bahamas and the western Caribbean starting around next Saturday and then right through the following week (Week of May 21st) .

Obviously this is something that is not a guarantee, but it is a distinct possibility and it will be something that I will be keeping close tabs on and I will post another discussion on this potential first thing Monday morning.

Strong to severe thunderstorms are expected to keep reforming this afternoon across much of south Texas with the environment supportive of intense supercells which will produce very large hail, tornadoes and damaging winds across much of south Texas, including coastal locations like Brownsville and Corpus Christi.

Late breaking as I was typing this: Tornado Watch now in effect for south Texas, including Brownsville and Corpus Christi until 8 pm CDT.

Elsewhere, isolated severe thunderstorms which will be capable of producing locally damaging wind gusts, hail and isolated tornadoes are possible from about Vero Beach southward through Miami-Dade County in southeastern Florida. Enhanced convergence along the eastern sea breeze front will lead to scattered thunderstorms. The environment across southeastern Florida is such that multicell and even supercell thunderstorms are possible.

Today & Tonight’s Severe Weather Outlook:

Today & Tonight’s Tornado Outlook:

Chance Of A Tornado Within 25 Miles Of Your Location

Today & Tonight’s Damaging Wind Outlook:

The Chance Of Damaging Thunderstorm Winds Within 25 Miles Of Your Location

Today & Tonight’s Large Hail Outlook:

The Chance Of One Inch Diameter Or Larger Hail Within 25 Miles Of Your Location

Current Severe Thunderstorm/Tornado Watches:

Current Mesoscale Convective Discussions:

To upgrade to the full version would cost us approximately $250. Any financial help you can provide to help us pay for this software would be greatly appreciated. Go to http://www.crownweather.com/?page_id=6892 for more information on how to donate.

I have posted some screenshots of what this software can do:

Radar Imagery Of Mobile Bay, Alabama at 12:50 pm CDT Wednesday, May 9, 2012:

Volume Slice Of The Thunderstorm Moving Through Mobile Bay:

Finally, I wanted to let all of you know that I greatly and sincerely appreicate all of the support everyone gives us. As a way of thanking you, I have decided to issue these discussions year round, meaning you will receive my thoughts and analysis of breaking weather throughout the year and not just during the Hurricane season. During the winter and spring months we plan on focusing on any severe weather that may be impacting the United States or any significant weather that may be impacting the Caribbean. Obviously during the Hurricane season our focus will be on any potential development in the tropics, however, we will also keep an eye on potential severe weather setups during the summer and fall and warn you of this.

This morning’s forecast guidance is no different and in fact seems to be consistent in forecasting this development around the timeframe of the 20th of this month rather than the “normal” GFS model bias of forecasting a tropical storm 16 days out and keeping it out at that range. This consistency is important and thus I have sat up a little more and have taken more notice and thus the reason why I am posting this.

So, the latest GFS model guidance is forecasting that a tropical system may develop very near the coast of Honduras and Nicaragua around May 20th and track northeastward to near the Cayman Islands by about May 22nd before tracking across central and western Cuba and into the northwestern Bahamas by May 23rd. The GFS model ultimately forecasts that this tropical cyclone will track to just off of Cape Hatteras by May 24th, which is the end of its model run.

GFS Operational Model Guidance Forecast:
May 20th:

May 22nd:

May 23rd:

May 24th:

It should be noted that the GFS operational model is supported by its ensemble members with both the mean position and the timing around the potential development. The European model, which only goes out ten days, forecasts a small area of low pressure located near the southern coast of Nicaragua on May 18th. What is intriguing is that the operational GFS model has an area of low pressure in just about the same location, so my question is whether the GFS model may be on to something. Now, the Navy NOGAPS model guidance forecasts tropical development in the southwestern Caribbean as soon as next Wednesday.

GFS Ensemble Means Forecast:
May 20th:

May 22nd:

May 23rd:

May 24th:

So, here are my thoughts: The overall weather pattern that is forecast to set up for the second half of May is one that can lead to early season tropical development in either the western Caribbean or somewhere near the Bahamas. Many of the analog years that I have been looking at for this upcoming hurricane season have had early season tropical development. These years include 1951, 1957 and 1976; in fact, 1951 and 1976 had tropical development in May with Category 3 Hurricane Able developing just off of the US Southeast Coast in Mid-May of 1951.

So, I do think that the GFS operational and the GFS ensemble guidance are hinting at what could occur with the pattern that is forecast to set up. I think the NOGAPS model is too quick with its forecast development and feel that the GFS model may be closer to a potential reality. Obviously this is something that is not a guarantee, however, it is a strong possibility and it will be something that I will be keeping very close tabs on and will update these discussions as conditions warrant.