BOC system

[Ivanhater]

Almost all the big models are sniffing out development in the SW Caribbean later this week. Something that needs to be looked at in the coming days..

12z Euro sniffing it out as well



12z Para GFS





12z Canadian



12z Nogaps

[Vortmax1]

Thanks for posting Ivan.
I just ran through the models and saw this.

[rockyman]

Unless this is truly a "homegrown" system, the spark should be a tropical wave coming in from the east...Based on a wave moving an average of 20 miles per hour, the wave would travel about 2400-3400 miles in the next 5-7 days. Since a degree of longitude is around 67 miles long at this latitude, the wave should be about 35 to 50 degrees of longitude away from 80W, which would put the system now between 30 and 45 degrees west, give or take

Right now, there are 2 waves in the Atlantic that might qualify...one around 45W and one around 25W:



TROPICAL WAVE EXTENDS FROM 10N25W TO 19N24W MOVING W AT 15-20
KT. THE WAVE AXIS IS POSITIONED BETWEEN A WEAKENING NORTHERN
VORTEX NW OF THE CAPE VERDE ISLANDS NEAR 18N27W AND A MAXIMUM IN
DEEP LAYER MOISTURE TO THE EAST BETWEEN 18W-24W. BROAD CYCLONIC
TURNING OF THE LOW-LEVEL CLOUD FIELD IS ALSO NOTED ON SATELLITE
BETWEEN 21W-30W IN THE VICINITY OF THE WAVE AXIS. SCATTERED
MODERATE CONVECTION IS FROM 06N-15N BETWEEN 17W-26W.

TROPICAL WAVE EXTENDS FROM 07N-18N ALONG 45W MOVING W AT 20 KT.
THE WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN
TOTAL PRECIPITABLE WATER IMAGERY BETWEEN 40W-50W. HOWEVER...DUE
TO A DRY SAHARAN AIR LAYER AND ASSOCIATED DUST IN PLACE N OF 11N
ACROSS MUCH OF THE ATLC...CONVECTION IS LIMITED NEAR THE WAVE
AND MOSTLY CONFINED TO THE ITCZ. SCATTERED MODERATE CONVECTION
IS FROM 06N-11N BETWEEN 43W-48W.

[N2Storms]

I think this snippet from the Tallahassee NWS might be alluding to this wave in their Long Range AFD:


MAINTAINING A LOW LEVEL SOUTH TO SOUTHEAST FLOW ACROSS
THE AREA...WITH SOME HINTS OF ADDITIONAL TROPICAL MOISTURE BEING
DRAWN NORTHWARD. NO SIGNIFICANT CHANGES TO PREVIOUS FORECAST
TRENDS...WITH POPS REFLECTING SEABREEZE CLIMATOLOGY...AND
TEMPERATURES A LITTLE ABOVE CLIMO THROUGH THE PERIOD.

[Vortmax1]

The HPC extended came out before benefit of the 12Z runs:



EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
201 PM EDT MON JUL 12 2010

THE 00Z ECMWF ENSEMBLE MEAN WAS
GIVEN THE GREATEST WEIGHTING SAT/SUN/MON 17-19 JUL. THE 00Z
CANADIAN GLOBAL WAS NOT USED DAY SEVEN MON 19 JUL AS IT DEVELOPS A
CLOSED LOW IN THE NORTHWEST CARIBBEAN AND ANOTHER OVER THE FL
PENINSULA WHICH TRACKS TO THE PANHANDLE. THE OTHER MODELS DO NOT
SHOW THIS DEVELOPMENT.

[wxman57]

It appears that the models are picking up on the energy associated with the wave currently approaching 50W. Speed of movement of the waves this year is a lot lower than last season, due to the weaker easterly trades (weaker Bermuda High). This wave doesn't look like much on satellite or TPW loops, but it may just add instability to the SW Caribbean by this coming weekend. Something to keep an eye on, but chances are the models are overdoing it.

Here's the TPW image. You need to look at the full loop to see its origins 3 days before. Now it's barely visible as a small rotation in the ITCZ:


TPW Loop:
http://cimss.ssec.wisc.edu/tropic/real- ... /main.html

[lonelymike]

The HPC extended came out before benefit of the 12Z runs:



EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
201 PM EDT MON JUL 12 2010

THE 00Z ECMWF ENSEMBLE MEAN WAS
GIVEN THE GREATEST WEIGHTING SAT/SUN/MON 17-19 JUL. THE 00Z
CANADIAN GLOBAL WAS NOT USED DAY SEVEN MON 19 JUL AS IT DEVELOPS A
CLOSED LOW IN THE NORTHWEST CARIBBEAN AND ANOTHER OVER THE FL
PENINSULA WHICH TRACKS TO THE PANHANDLE. THE OTHER MODELS DO NOT
SHOW THIS DEVELOPMENT.

I'm pretty sure HPC has access to the 12z model runs before the public does.

[wxman57]

We get the 12Z model data as it's generated, but it's only a minute or two ahead of when it's public on NCEP's server. The HPC gets it the same time as we do, and not more than a few minutes ahead of the public. Their statement at 2PM EDT was about the 00Z runs, not the 12Z. Though they did have the 12Z GFS at that time.

[KWT]

There do seem to be hints of development, thats about it for now but the area the models are keying into is somewhere that has helped to develop Alex and strengthen pre-TD2.

[Ivanhater]

18z Nogaps

[KWT]

I still want to see a couple more sets of runs from the models before getting too interested in this region, but I have to admit if there is one region that looks like it could be condusive enough for development, its the SW caribbean.

[srainhoutx]

What has caught my eye is the fact that the para GFS has been suggesting weak development from the SW Caribbean to the W GOM since late last week. MJO pulse as well as an active WPAC and development suggested in the EPAC certainly bears watching IMHO.

[Aquawind]

Ohh how weather can change so quickly...a couple more runs would be convincing alright. The climatology is right.

[rockyman]

The wave approaching 50W (possibly the one the models develop in the SW Carib) is really struggling:

TROPICAL WAVE IS ALONG 47W S OF 16N MOVING W 20 KT. WAVE IS
EMBEDDED WITHIN DRY SAHARAN AIR AND DUST MASKING ANY SATELLITE
SIGNATURE AND SUPPRESSING ANY SHOWER ACTIVITY/CONVECTION.

[Ivanhater]

00z GFS Para still tries to develop this system and bring it into the Gulf

[Ivanhater]

Long range Canadian still develops this wave

[ROCK]

Looks to me the CMC has backed off from its earlier run. Still looks like a closed low at 144hr maybe a depression. I dont have access to the long range CMC...Ivan do you have a link to that? care to share for a buddy down the coast...

[Wx_Warrior]

tue 0z EURO run is clear

[Ivanhater]

12z Canadian



yeah rock, the post above you had the long range...showed it hitting south Texas

[funster]

South Texas... that region has had just about enough