Global model runs discussion

[Dean4Storms]

Funny last week the GFS was cranking up a strong storm into the Panhandle of Florida around the 3rd of July much like what the CMC is now predicting.

[gatorcane]

CaneFreak, the key word with WxMan's post there is "weak" which would mean a more westward path. Plus a system in the SW Caribbean would be too far south to feel any kind of weakness in the ridge the models are showing. Have to admit, the GFS trough seems way overdone for this time of year. The 500MB pattern the ECMWF is showing a week from now looks more likely.

['CaneFreak]

Weak does not always mean west. Even at 850 mb on the 12Z EURO, the steering flow in the western GOM is from south to north from hours 144 all the way through hour 240.

http://www.meteo.psu.edu/~fxg1/ECMWF0.5 ... floop.html

Edit: I don't think WxMan57 wants to have to work overtime. That's what I think his problem is...LOL...clouds his ability to reason

CaneFreak, the key word with WxMan's post there is "weak" which would mean a more westward path. Plus a system in the SW Caribbean would be too far south to feel any kind of weakness in the ridge the models are showing. Have to admit, the GFS trough seems way overdone for this time of year. The 500MB pattern the ECMWF is showing a week from now looks more likely.

[Hurricane Andrew]

I don't see a Barry either. CMC starts development in 5 days, so...

[gatorcane]

NWS Miami mentioning the trough that the global models are showing for this coming weekend which will finally break the stubborn ridge over the Southeastern U.S. and northern Gulf of Mexico:

LOW PRESSURE IS EXPECTED TO DEVELOP AND DEEPEN OVER OHIO AND THE
LOWER GREAT LAKES. HOWEVER...THE AREA OF LOW PRESSURE WILL GET
BLOCKED FROM PROGRESSING EASTWARD...AND A SERIES OF SHORTWAVES
WILL HELP PUSH AN UPPER LEVEL TROUGH INTO THE DEEP SOUTH THIS
WEEKEND. SO UPPER LEVEL HEIGHTS ARE FORECAST TO DECREASE FRIDAY
THROUGH THE WEEKEND. LOW LEVEL FLOW WILL SLOWLY SHIFT TO THE SOUTH
FRIDAY...AND TOWARDS THE SOUTHWEST SATURDAY AND SUNDAY. SO RAIN
CHANCES MAY BE SLIGHTLY LOWER FOR THE GULF COAST...WITH THE
HIGHEST CHANCES NORTH AND EAST

http://forecast.weather.gov/product.php ... glossary=1

Should something develop in the NW Carib, it could conceivably get pulled northward as the CMC is showing.

[wxman57]

I don't buy the Canadian. Even though some parts of the Canadian were changed, the microphysics were not changed. I think the best chance of development will be in the southern BoC next Mon-Wed while the ridge is building off the Texas coast into the NW Gulf. This would mean a west track is most likely, should something develop down there.

[wxman57]

NWS Miami mentioning the trough that the global models are showing for this coming weekend which will finally break the stubborn ridge over the Southeastern U.S. and northern Gulf of Mexico:

LOW PRESSURE IS EXPECTED TO DEVELOP AND DEEPEN OVER OHIO AND THE
LOWER GREAT LAKES. HOWEVER...THE AREA OF LOW PRESSURE WILL GET
BLOCKED FROM PROGRESSING EASTWARD...AND A SERIES OF SHORTWAVES
WILL HELP PUSH AN UPPER LEVEL TROUGH INTO THE DEEP SOUTH THIS
WEEKEND. SO UPPER LEVEL HEIGHTS ARE FORECAST TO DECREASE FRIDAY
THROUGH THE WEEKEND. LOW LEVEL FLOW WILL SLOWLY SHIFT TO THE SOUTH
FRIDAY...AND TOWARDS THE SOUTHWEST SATURDAY AND SUNDAY. SO RAIN
CHANCES MAY BE SLIGHTLY LOWER FOR THE GULF COAST...WITH THE
HIGHEST CHANCES NORTH AND EAST

http://forecast.weather.gov/product.php ... glossary=1

Should something develop in the NW Carib, it could conceivably get pulled northward as the CMC is showing.

I'd agree with that last statement about NW Caribbean development. Any development there would certainly have a good shot at moving north rather than west.

[Ntxw]

I think specific landfalls at this time is anyone guess, a baby with a dart could do just as well. We're talking about ridging and troughing that's far from where they are currently. Key to take from the models is there is very good indication to believe something will spin up in the NW Carib and likely head N or NW. The Bay of Campache is a good area to start once that does happen. Beyond that what we do know is that the pattern allows for a more North track towards the US vs ram it straight into Mexico as compared to Barry and most storms that form in the BOC.

[floridasun78]

wxman57 vs cmc and rest of forum let see who right

[cycloneye]

Here is the weekly Global Hazard update for 6/25/13 that is valid until July 9. I think we have some clues here about future developments in the North Atlantic basin. I highlighted in blue a portion that will be key.


Last Updated: 06.25.13 Valid: 06.26.13 - 07.09.13


The MJO propagated across the Maritime Continent, maintaining amplitude similar to last week, according to the Wheeler-Hendon MJO Index. The CPC index indicates a slightly weaker MJO signal with eastward propagation. Both indices indicate a convectively active phase over the western North Pacific and show influence from others modes of tropical variability (atmospheric Kelvin Waves and tropical cyclones).

Dynamical model outputs generally indicate continued propagation of the MJO signal during the next two weeks, with the convectively active phase moving across the Central Pacific to the Americas and Africa, with some models depicting a resurgent signal over the Indian Ocean by late in week 2. Statistical model forecasts align with the dynamical model forecasts, although the signals in those are less amplified, so the current outlook reflects a stronger and more coherent MJO, aligned with the dynamical models.

The tropics were active with Tropical Storm Bebinca forming over the South China Sea on 20 Jun, and Tropical Storm Cosme developing over the eastern Pacific on 23 Jun. Tropical Storm Bebinca made landfall twice, first in Hainan and second in Vietnam. Tropical Storm Cosme is not predicted to impact any major land mass. The chancers for tropical cyclogenesis are enhanced over the eastern Pacific during the end of week 1 and during week 2. Tropical cyclogenesis odds are also slightly elevated over the western Caribbean, during latter portions of week 1, although the confidence in that is low, so no hazard is depicted. Additionally, the threat of tropical cyclogenesis near the Most MJO associated tropical cyclone formations over the tropical Atlantic in July occur when the MJO is transitioning from phase 1 to phase 2, which likely to occur near the end of week 2 and during week 3.

The week 1 outlook is based on a continued, significant MJO signal, with enhanced convection likely over the northeast India, northern Thailand, and across the southern China, as a residual, northward movement from the prior phase of the MJO. The core convection associated with the MJO is likely to be over Mexico, Central America, the Caribbean, and portions of the southeast US. Local enhancement of the West African Monsoon is likely to bring enhanced rainfall to western Africa and the Gulf of Guinea region, with drier than average conditions likely over central Africa. Enhanced odds for below-average rainfall are anticipated from Southern India to the Philippines and across much of Indonesia.

During week 2, the odds for above-average rainfall are enhanced over Central America, the Caribbean, southeast US, and northern South America. Additionally, the MJO is likely to emerge over the Indian Ocean during late week 2, yielding an area of above-average rainfall over the Central Indian Ocean. Enhanced odds for below-normal.




http://www.cpc.ncep.noaa.gov/products/p ... /ghazards/

[Alyono]

EC ensembles now showing about a 50 percent chance of genesis in either the WC or the BOC from days 6-8

[TropicalAnalystwx13]

EC ensembles now showing about a 50 percent chance of genesis in either the WC or the BOC from days 6-8

Link please?

[catskillfire51]

i may be crazy but looking at the 12z and 16z gfs runs it looks like the first storm from the boc gets pushed into mexico but the storm coming from the islands is the one that hits tx.

['CaneFreak]

I think we are looking at two different areas of concern. The one you are talking about...yes...I agree it will move west into MX but the one further east will have to go north later in the period when the trough is over the eastern US. I was confused. My bad.

I don't buy the Canadian. Even though some parts of the Canadian were changed, the microphysics were not changed. I think the best chance of development will be in the southern BoC next Mon-Wed while the ridge is building off the Texas coast into the NW Gulf. This would mean a west track is most likely, should something develop down there.

[TropicalAnalystwx13]

I think we are looking at two different areas of concern. The one you are talking about...yes...I agree it will move west into MX but the one further east will have to go north later in the period when the trough is over the eastern US. I was confused. My bad.

I don't buy the Canadian. Even though some parts of the Canadian were changed, the microphysics were not changed. I think the best chance of development will be in the southern BoC next Mon-Wed while the ridge is building off the Texas coast into the NW Gulf. This would mean a west track is most likely, should something develop down there.

Huh?

There's only one area of interest in the models as far as I can tell. The GFS takes it into the Bay of Campeche and develops it there while the CMC takes it into the NW Caribbean develops it there, and sends it to Florida. Key issue is where it develops.

[catskillfire51]

I think we are looking at two different areas of concern. The one you are talking about...yes...I agree it will move west into MX but the one further east will have to go north later in the period when the trough is over the eastern US. I was confused. My bad.

I don't buy the Canadian. Even though some parts of the Canadian were changed, the microphysics were not changed. I think the best chance of development will be in the southern BoC next Mon-Wed while the ridge is building off the Texas coast into the NW Gulf. This would mean a west track is most likely, should something develop down there.

Huh?

There's only one area of interest in the models as far as I can tell. The GFS takes it into the Bay of Campeche and develops it there while the CMC takes it into the NW Caribbean develops it there, and sends it to Florida. Key issue is where it develops.

If you watch around 204hrs it looks like the high pressure system pushes the storm from the boc into mexico, but another storm wave coming from the caribbean is the one that makes it to the gulf of mexico up to tx or la

[Alyono]

EC ensembles now showing about a 50 percent chance of genesis in either the WC or the BOC from days 6-8

Link please?

pay the ecmwf and you can get the data yourself. Just be warned... they are EXPENSIVE

[ozonepete]

MJO positive phase moving over the western Atlantic basin now.

[tropicwatch]

Unless the wind shear across the Caribbean lessens considerably during the next week, we wont see anything getting organized until it reaches the GOM or BOC. At that point it wont have much time to develop much into anything unless it has the opportunity to sit there, no matter what direction it goes in.

Personal Forecast Disclaimer:
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. For official information, please refer to the NHC and NWS products.

[NDG]

During the last few minutes I spent some time dissecting the ECMWF and GFS models, something that I had not done since Sunday night. I have had a couple of long days of work so far this week.
I came to the conclussion that there is a fairly good possibility of tropical development in the BOC/southern GOM early next week. While it starts developing it should start feeling the deep trough to its north across the Plains/MS River valley, so unlike what happened with Barry it should start moving northward along with the trough as it also lifts northward as a narrow east to west ridging across the GOM will not be present this time, as I mentioned a couple of days ago.
I am not buying the Euro's forecast of the Atlantic Ridge building westward across the GOM so quickly later next week, it tends to over-build ridging across the GOM thus why it tends to push tropical systems more westward than other models.
So if indeed we get development in the southern GOM/BOC it should move northward to some degree towards the TX coast, maybe SW LA at the most, possibly putting LA on the wet side.
As far as intensity probably it will not have the best UL conditions initially but it could change as the UL trough starts lifting and an UL anticyclone builds over the GOM later next week, so is too early for me to say what kind of intensity it will have.




The post above is made by me, NDG, just the opinion of myself and may or may not be backed by sound meteorological data. NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.