ATL: INVEST 95L - Discussion

[chaser1]

wonder why NHC is going with the southern Gulf solution. Looking more like a more northerly track now

Well, in deference to Wxman's thoughts on 95L being unlikely to impact the Texas coast as a hurricane, I took another look at the maps and have to admit that in all likelyhood a Westbound system located near the Belize/Yucatan border...would appear likely to more or less continue slowly in that direction.

Although doubtful, a stationary 95L "could" strengthen and organize along the coast for perhaps 24 hours and if then moving 290 over a flatter terrain could strengthen further in the S. Gulf (but not quite "buried" in the BOC); Such might be in place late Thursday to be far north enough to start moving NW through the eroding western flank of the ridge, towards the S. Texas coast. But to be realistic, do I really think that even a developing storm that were buried in the BOC would respond to the weakened ridge? Probably not....just doesnt look like that deep of a 500mb trough that would cause such a dramatic shift in the steering flow. Would likely really take some unexpected reformation a bit further north in the near term. Other than the oft chance of this developing in a COL, just no reason at the moment to assume that any forward motion could be anything more than west or WNW.

[chaser1]

....and the 2013 Bay of Campeche Hurricane Season slugs on.....

[gatorcane]

wonder why NHC is going with the southern Gulf solution. Looking more like a more northerly track now

Yes I noticed they used "Southern Gulf of Mexico." As I have been saying this won't be the same as Ingrid as far as track. Folks along the Northern Gulf and Florida should monitor this situation. Right now looks like just a big rainmaker as it merges with the front but there is so much uncertainty on this as far as how consolidated and how intense this system can get. Stay tuned.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[cycloneye]

18z Best Track.

AL, 95, 2013091718, , BEST, 0, 181N, 883W, 25, 1006, LO, 34, NEQ, 0, 0, 0, 0, 1008, 120, 60, 0, 0, L, 0, , 0, 0, INVEST, M

[trave2]

South west winds in San Pedro Belize and falling pressure (Observation site below)
http://sanpedroweather.com/

On visible sat image earlier today you could see two large storms ( lobes) form nw and se of the estimated center. than the llc formed and began to spin, pretty neat to see

[cycloneye]

Couple of tweets by Levi Cowan.

Levi Cowan ‏@TropicalTidbits 36m
@qcbigbody Dissimilar to Ingrid - likely to be weak for a while, then potential baroclinic interaction to the northeast in 5+ days.

Levi Cowan ‏@TropicalTidbits 47m
Bay of Campeche is tropical hot spot this year. Lack of upper diffluence should limit 95L for first few days.

This post is NOT AN OFFICIAL FORECAST and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

[trave2]

I have a feeling this will be Jerry, it will fester in the B.O.C for a couple days, then get pulled east into Florida on Monday/Tuesday as a moderate Hurricane. Just my opinion based on sat imagery and models



The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[trave2]

Belize Radar Loop

http://hydromet.gov.bz/250-km-radar-loop

[ROCK]

wonder why NHC is going with the southern Gulf solution. Looking more like a more northerly track now

Yes I noticed they used "Southern Gulf of Mexico." As I have been saying this won't be the same as Ingrid as far as track. Folks along the Northern Gulf and Florida should monitor this situation. Right now looks like just a big rainmaker as it merges with the front but there is so much uncertainty on this as far as how consolidated and how intense this system can get. Stay tuned.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

thats a BIG "IF" it merges with the front....the 12Z EURO didnt think so as it misses it....

[cycloneye]

From this afternoon's Tampa AFD:

.LONG TERM (FRIDAY THROUGH NEXT MONDAY)...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT THROUGH THE REMAINDER OF
THE WORK WEEK...WITH SOLUTIONS THEN DIVERGING OVER THE UPCOMING
WEEKEND AND INTO EARLY NEXT WEEK. THE 00Z CANADIAN MODEL COMPARED
WITH THE GFS/ECMWF IS DEVELOPING A TROPICAL CYCLONE IN THE GULF OF
MEXICO BY SATURDAY EVENING. ALTHOUGH NOT IMPOSSIBLE GIVEN THE
GENERALLY FAVORABLE CONDITIONS OVER THE GULF...ONE OF THE BIASES OF
THE CANADIAN MODEL IS TO OVERDEVELOP TROPICAL CYCLONES DUE TO
INTERACTION WITH LARGE SCALE SYNOPTIC FEATURES. AS A RESULT...WILL
FOLLOW A BLEND OF THE 00Z GFS AND 00Z ECMWF FOR FORECAST DETAILS
THROUGH THE LONG TERM PERIODS.

HIGH PRESSURE WILL REMAIN NORTH OF THE FORECAST AREA FOR THE TAIL
END OF THE WORK WEEK AND INTO THE UPCOMING WEEKEND...RESULTING IN
PREVAILING EASTERLY FLOW WITH ISOLATED TO WIDELY SCATTERED SEA
BREEZE DRIVEN CONVECTION EACH AFTERNOON/EVENING THROUGH SATURDAY.
HIGH PRESSURE NORTH OF THE STATE WILL WEAKEN AS A FRONTAL BOUNDARY
PUSHES SOUTHWARD TOWARD THE NORTHERN GULF COAST AND STALLS OUT BY
SUNDAY. THIS WILL RESULT IN AN INCREASE IN DEEP LAYER MOISTURE
ACROSS THE ENTIRE FORECAST AREA...SUNDAY THROUGH NEXT TUESDAY. THE
GFS AND ECMWF MODELS TO DIFFERING DEGREES CONTINUE TO SHOW A BROAD
AREA OF LOW PRESSURE WITH PLENTY OF DEEP LAYER MOISTURE IN PLACE
OVER THE GULF OF MEXICO. THE CANADIAN ON THE OTHER HAND AS
MENTIONED ABOVE...HAS A FAIRLY IMPRESSIVE TROPICAL CYCLONE MAKING
LANDFALL ALONG THE NORTHERN GULF COAST ON SUNDAY. GIVEN THE TIME
OF YEAR AND SOME INDICATIONS OF POTENTIAL DEVELOPMENT IN THE
NUMERICAL MODEL GUIDANCE...WILL NEED TO CLOSELY MONITOR TRENDS AS
THE WEEK PROGRESSES FOR THE POTENTIAL FOR TROPICAL CYCLONE
DEVELOPMENT.

[Aric Dunn]

There is clearly a closed circ now, showing up on radar , satellite and surface obs just offshore belize. though the convection minimal and its about to move onshore..

[Rgv20]

NWS in Brownsville afternoon discussion on 95L..

A LOW PRESSURE AREA IS DUE
TO CONTINUE ACROSS THE YUCATAN PENINSULA AND MOVE INTO THE BAY OF
CAMPECHE TONIGHT AND TOMORROW...TRACKING WEST...WITH A 40 PERCENT
CHANCE OF FURTHER DEVELOPMENT TOWARD A TROPICAL CYCLONE IN THE NEXT
48 HOURS.

.LONG TERM /THURSDAY THROUGH TUESDAY/...
A FAIRLY WET START TO THE LONG TERM ENDS WITH THE FIRST REAL PERIOD
OF DRIER WEATHER IN SEVERAL WEEKS.

THURSDAY THERE IS GOOD GENERAL SYNOPTIC AGREEMENT AMONGST THE
DETERMINISTIC AND ENSEMBLE GUIDANCE REGARDING AN APPROACHING PLAINS
TROUGH...RIDGING OVER THE NORTH CENTRAL GULF OF MEXICO...AND AN AREA
OF LOW PRESSURE...QUITE POSSIBLY A TROPICAL CYCLONE...IN THE SOUTH
CENTRAL GULF OF MEXICO. WITH GOOD DEEP LAYER MOISTURE INCREASING BUT
NO REAL LARGE SCALE LIFT EXPECTING DAYTIME THUNDERSTORM DEVELOPMENT
FROM EAST TO WEST THROUGH THE LATE MORNING AND AFTERNOON. A LITTLE
LOW LEVEL CURVATURE FLOW AROUND THE LOW IN THE SOUTH CENTRAL GULF
SHOULD HELP LOW LEVEL CONVERGENCE AND SHOWER/STORM COVERAGE A LITTLE.

BY FRIDAY THE UPPER TROUGH GETS CLOSER AND BEGINS TO DEVELOP WHAT
LOOKS LIKE A BAROCLINIC LOW OVER THE WESTERN GULF OF MEXICO. WITH
THE ECMWF LOOKING A LITTLE MORE LIKE A WEAK LOW OFF OUR COAST...AND
SOME FORM OF TROPICAL CYCLONE TO OUR SOUTH...WITH THE NHC/WPC
COLLABORATIVE POINT ABOUT 200 MILES SOUTH OF BROWNSVILLE. BY FRIDAY
AFTERNOON UPPER DIFFLUENCE/DIVERGENCE INCREASES MARKEDLY AND WE
SHOULD HAVE STRONG LARGE SCALE FORCING OVER A VERY SATURATED LOW
LAYER AIRMASS WITH 1000-500MB RH VALUES OVER 70 PCT AND PWAT VALUES
AROUND 2.2 TO 2.4 INCHES. WITH GOOD MODEL AGREEMENT BUMPED THE RAIN
CHANCES IN THE AFTERNOON TO 60 PCT AND INCREASED QPF VALUES WITH
NUMEROUS STRONGLY POSITIVE RAINFALL INDICATORS.

SATURDAY SHOULD SEE SOME CONTINUED SHOWER ACTIVITY BUT OUR LOWER
LAYER FLOW BECOMES MORE NORTHEASTERLY AS THE BAROCLINIC LOW
STRENGTHENS IN THE GULF AND OUR TEMPERATURES COOL JUST A LITTLE.
STILL EXPECTING SHRA/ISO TSRA BUT LESS PRECIP THAN FRIDAY. BY
SATURDAY NIGHT THE UPPER TROUGH AXIS MOVES THROUGH AND CLEARS THE
REGION AND DRIER MID AND LOWER LAYER AIR WORKS IN AS THE TROUGH
POOCH KICKS THE BAROCLINIC AND APPARENTLY TROPICAL LOWS OUT OF THE
WESTERN GULF...OR AT LEAST EAST AND SOUTH OF OUR CWA/MAOR. BY SUNDAY
SHOWER CHANCES SHOULD BE CONFINED TO THE COAST WITH PRECIP PROSPECTS
ALL BUT ZERO TO START THE WORK WEEK ON MONDAY AS MUCH DRIER AIR
BECOMES ESTABLISHED OVER THE REGION. THE AIRMASS CHANGE MAY BE
FAIRLY GRADUAL AND THE TEMPERATURE CHANGE SHOULD BE NEGLIGIBLE...BUT
THE CHANGE IN HUMIDITY WILL DEFINITELY NOT BE. /68-JGG/

&&

[gatorcane]

Latest saved VIS loop GIF shows little, if any movement. Latest model guidance as of 18Z shows it is moving a little more North of west (290 degrees) at 3 Knots with center at 18.1°N and 88.3°W:

[cycloneye]

From Tallahassee afternoon AFD:

.LONG TERM [Friday through Tuesday]...

Things start to get more interesting this weekend with possible
tropical development in the Gulf of Mexico and an approaching
mid-latitude trough. Several models do show some sort of low
pressure in the Gulf with a wide range of solutions in terms of how
it interacts with the approaching mid-latitude system. Rain chances
look to be increasing for the weekend, and the main reason PoPs are
not even higher than currently depicted is due to some timing
differences in the guidance. Whenever tropical moisture is involved,
we always have to watch out for the potential of some heavy
rainfall amounts, but forecast confidence in heavy rain is
currently lower than average with a wide range of possibilities
still on the table this far out.

[SeminoleWind]

Anyone think it may not even survive the trip across the Yucatan?

[Stormcenter]

I don't think it will have any problem surviving the trip. IMO

Anyone think it may not even survive the trip across the Yucatan?

[wxman57]

might not be hurricane but could see this affect texas coast though..

I'm not seeing a TX coast threat, hurricane or TS. That trof digging down into the NW Gulf would not steer anything toward Texas. We'll be in NW flow aloft.

By the way, surface obs indicate the low is inland over northern Belize. The rotation on satellite and radar may be a mid-level center displaced east of the LLC.

And the 12Z high-res Euro does indicate it is associated with the front all the way through 10 days.

This storm is going to be a pain, but all indications so far are that a combination of increasing shear associated with the front along with dry air entrainment would limit strengthening.

[cycloneye]

Melbourne afternoon AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
401 PM EDT TUE SEP 17 2013

.DISCUSSION...

SAT-TUES...THE 00Z GFS CHANGED ITS TUNE DRAMATICALLY EARLIER THIS MORNING IN THE EVOLUTION OF THE BROAD AREA OF LOW PRESSURE OVER THE GULF OF MEXICO OVER THE WEEKEND INTO EARLY NEXT WEEK. IT NOW DEPICTS A CONSIDERABLY STRONGER UPPER LEVEL TROUGH/LOW SWINGING THROUGH THE MISSISSIPPI AND TENNESSEE VALLEYS...ALONG WITH STRONG BAROCLINIC CYCLOGENESIS ALONG THE NORTHERN GULF AND EAST COAST. THIS SWINGS THROUGH A DECENT COLD FRONT THROUGH MOST OF THE STATE LEAVING BEHIND A VERY UNORGANIZED AREA OF LOWER PRESSURE ALONG THE FRONT IN THE BAY OF CAMPECHE. THE 12Z GFS SUBSEQUENTLY BACKED OFF ON SUCH A BULLISH EVOLUTION...DEPICTING A WEAKER LOW PRESSURE SYSTEM AND KEEPING A COLD FRONT FURTHER TO OUR NORTH.

THE 00Z ECMWF REMAINS CLOSE TO THE PREVIOUS MODEL SOLUTIONS WITH A WEAKER TROUGH AND BROADER DOUBLE BARRELED (BAROCLINIC NORTH/TROPICAL SOUTH) AREA OF LOW PRESSURE OVER THE GULF ON SUN WHICH THEN LIFTS OUT IN THE GENERAL VICINITY OF FLORIDA AND THE BAHAMAS INTO MID NEXT WEEK.

BOTH SCENARIOS LOOK COMPLEX...AND THE UNCERTAINTIES IN INTENSITY AND STRUCTURE OF ANY LOW THAT WOULD POTENTIALLY IMPACT THE AREA ARE QUITE LARGE. BUT REGARDLESS OF HOW THIS FEATURE DEVELOPS...IT APPEARS WE ARE HEADED TOWARD A WETTER PERIOD FOR AT LEAST THE FIRST HALF OF NEXT WEEK.

[TropicalAnalystwx13]

Invest 95L is a bit different than other systems we've seen take a similar track into the Bay of Campeche this season, simply because it actually has the possibility of reaching United States soil. It's complicated, though. Most models agree that the well-defined area of low pressure will track west-northwestward into the Bay of Campeche and slowly organize there. After that time, we have some taking the system straight west into Mexico while others curve it northeast into the United States. You can split this further into the ECMWF showing a fully tropical cyclone hitting Louisiana to the GFS showing a baroclinically-enhanced low affecting Florida. It depends on timing, really. If it heads quickly west-northwest, of course it's headed into Mexico. However, if it tracks slowly as forecast and stalls in the western Gulf, it has the possibility of being drawn towards the USA. How long this stall takes place should determine its structure as well. If it shoots northeast ahead of the trough, it should transition into an extratropical low and deepen baroclinically given the strong west-southwesterly shear dipping into the Gulf (weird to say that about a system in the Gulf in September). If by some chance it slips behind the trough and feels the weakness then, it wouldn't have the unfavorable environment nor interaction with a front to deal with, and would be tropical accordingly.

The environment in the BOC is not bad, at all. Shear is light and there is little dry air. Hurricane Ingrid did upwell the waters, but not to the point of it being unfavorable for tropical cyclogenesis. That stall might cause some issues for it though. A lack of upper-level divergence may limit quick intensification as well.

I have two analogues that are nearly opposite to one another...TS Josephine 1996 and Hurricane Opal 1995.

[wxman57]

...snip...
I have two analogues that are nearly opposite to one another...TS Josephine 1996 and Hurricane Opal 1995.

Or Edith, 1971. Went right over me in Lafayette after bouncing off the MX coast near Tampico. Pathetic as hurricanes go, but we had some TS winds with it. I don't think this system would be a hurricane heading for LA (or FL), though: