Ominious synoptics as we head into mid August

[Vortex]

The GFS and other models have been very consistent the last week in forecasting an overall pattern change. The persistant trough this summer will be replaced with ridging over the western Atlantic and SE. Should a storm develop and traverse the Atlantic this is a set-up the SE and gulf coast wish not 2 see with the parametersexpected to be in place.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_384l.gif

[flwxwatcher]

This teleconnects also with whats been happening in the WPAC.

[skysummit]

The GFS this morning continues to show a big time ridge setting up.

[Sanibel]

Perhaps that pattern will flush out the SAL and allow those persistant waves to moisten.

[Stormcenter]

Perhaps that pattern will flush out the SAL and allow those persistant waves to moisten.

I sure hope not. Don't get me wrong I like tracking storms when they are headed anywhere but the GOM.

[N2FSU]

From this morning's Tallahassee NWS discussion:

.SHORT TERM...LARGE SCALE PATTERN IS IN A STATE OF TRANSITION WITH
PERSISTENT EAST COAST TROUGH GIVING WAY TO STRONG RIDGE OVER THE
NEXT SEVERAL DAYS. SFC TROUGH WHICH PROVIDED FOCUS FOR SHOWERS AND
STORMS OVER LAST TWO DAYS HAS MOVED WELL INLAND AND RAPIDLY
DISSIPATED. SATELLITE AND RADAR DATA SHOW THAT THE MOISTURE AND
ASSOCIATED SHOWER ACTIVITY WITH THIS TROUGH HAS RAPIDLY DIMINISHED
AS WELL. 00Z NAM APPEARS TOO AGRESSIVE HOLDING ONTO THE MOISTURE
TODAY SO HAVE GENERALLY FOLLOWED 00Z GFS FOR SHORT TERM FCST.

RISING HEIGHTS...DRYING...AND SUBSIDENCE WILL ALL COMBINE TO LIMIT
POPS OVER THE NEXT FEW DAYS. HAVE GONE ABOVE THE VIRTUALLY NIL POPS
IN GFS MOS TODAY THROUGH MONDAY...BUT ONLY ALLOWING FOR ISOLATED
ACTIVITY IN DEFERENCE TO CLIMATOLOGY. WITH LACK OF AFTERNOON
CONVECTION...TEMPS WILL BE ABLE TO RISE INTO THE MID AND UPPER
90S THROUGH MONDAY.

.LONG TERM...STRONG UPPER RIDGE WILL REMAIN ENTRENCHED OVER
THE SOUTHEASTERN STATES THROUGH MUCH OF NEXT WEEK. MAY SEE AN
OCCASIONAL DISTURBANCE ROTATE AROUND THE PERIPHERY AND SPARK SOME
CONVECTION...BUT OVERALL EXPECT THE WEEK TO BE VERY HOT WITH TEMPS
RISING TO NEAR 100 DEGREES AND BELOW CLIMO

[canegrl04]

Strong ridginh over the east does not bode well for those living in Florida or the coastal regions of the GOM.Looks like we will see a storm track pattern similar to 2005

[windstorm99]

The GFS has been back and forth with this output and honestly i would put to much stock on that patten until i see real evidence. So far troughs of low pressure have been in control.Adrian

[Blown Away]

Unless something home grown happens, there is nothing that is within 7 days of the CONUS.

[wzrgirl1]

Just shows how timing is everything....if this verifies and anything should spark up....

[Sanibel]

The SAL layer has plunged back in front of that dry system that exited Africa.

CONUS still has a stationary trough parked over the east coast - so the Bermuda High pattern isn't quite in place yet as predicted by Masters weeks ago.

Africa is pumping out dry waves into a hostile Atlantic ITCZ

An Atlantic ridge appears to be attempting to set up. Its first burp held 99L on a low track and into Honduras. But the west Atlantic is still a jumble of weakening ULL's and pockets of high pressure. The SAL dominating regime in the Atlantic is still in place keeping the weak waves that exit Africa in check. Very much like 2006 - but with more waves taking a shot.

Just a few weeks more I guess...

[Extremeweatherguy]

The GFS has been back and forth with this output and honestly i would put to much stock on that patten until i see real evidence. So far troughs of low pressure have been in control.Adrian

It hasn't really been that back and forth at all recently. For the last several days it has shown virtually the same scenario evolving...a ridge setting up and barely moving for at least 10-15 days. As for evidence, it is already showing up too. High pressure is currently building over the SE and GOM and this will lead to a heat wave in the mid Atlantic by early next week. Also, 99L moved westward due to the building ridge north of it in the Atlantic and was not able to find a way to get too far north. It looks like the pattern shift is likely already starting..

Let's just hope that beyond a week or two something does change and we can be saved by another troughy pattern. That would be great for many of us! However, I would not count on it based on what the models are showing and what I am hearing from the mets (including JB and Jeff Masters).

[Sanibel]

But a Gulf High is meaningless if the east Atlantic still has a hostile SAL regime keeping the ITCZ dry.

[Frank2]

I'd tend to disagree - the long-term (though wishy-washy) GFS shows serious troughiness in the Western Atlantic towards the middle of the month - very different from what was forecast by many only a week or two ago...

[Extremeweatherguy]

But a Gulf High is meaningless if the east Atlantic still has a hostile SAL regime keeping the ITCZ dry.

I don't think there is a hostile SAL regime in place ATM. It looks pretty normal out there for this time of the year with most of the SAL staying north of the ITCZ.

[hurricanetrack]

12Z GFS shows a serious trough, a deep one, after 10 days out....we'll see.

[Aquawind]

12Z GFS shows a serious trough, a deep one, after 10 days out....we'll see.

Tis an impressive run showing a system following the weakness as well..


http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/carib/gfs/12/model_m.shtml

[wxmann_91]

The GFS and other models have been very consistent the last week in forecasting an overall pattern change. The persistant trough this summer will be replaced with ridging over the western Atlantic and SE. Should a storm develop and traverse the Atlantic this is a set-up the SE and gulf coast wish not 2 see with the parametersexpected to be in place.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_384l.gif

I doubt that will verify. It's the 384 hr GFS... pretty unreliable.

This teleconnects also with whats been happening in the WPAC.

Recurving TY Usagi teleconnects to East Coast troughing, although upcoming TY's might not recurve.

But a Gulf High is meaningless if the east Atlantic still has a hostile SAL regime keeping the ITCZ dry.

I don't think there is a hostile SAL regime in place ATM. It looks pretty normal out there for this time of the year with most of the SAL staying north of the ITCZ.

[img][/img]

[img][/img]

There is a hostile SAL right now. The SAL and the associated low-level easterly wind surge killed 99L.

[Steve]

>>Recurving TY Usagi teleconnects to East Coast troughing, although upcoming TY's might not recurve.

Interesting point. I thought the signals were somewhat neutral if the storm recurved after hitting Japan, and if it was weak. Might still indicate a 7-10 day trough though (transient? shallow?). We'll have to see - it would be around the 11th-15th . JTWC has TD 6W hitting Vietnam, also as a weak system. 98W is unknown. Maybe it will give a stronger signal?

Steve

[Extremeweatherguy]

According to one of JBs videos from a day or two back, the teleconnection for Usagi would be a storm hitting south FL, recurving into the Panhandle and then moving up through Tennessee before turning back NE.

As for the SAL..I just posted two maps showing that it really was not that bad in the eastern Atlantic. Yes, the dry air in the caribbean did help to kill 99L, but it was mostly the strong pressure gradient causing a fast east to west motion of the wave that did it in. If that hadn't been there, then 99L would have likely had a better chance at development (regardless of the dry air in place). Since that time the dry air has also modified quite a bit too..though I do admit it is still there ( http://www.ssd.noaa.gov/goes/east/tatl/wv-l.jpg ). It looks fairly normal for this time of the year though and much less hostile than in 2006.

current SAL = http://cimss.ssec.wisc.edu/tropic/real-time/wavetrak/winds/m8g10split.html

SAL on July 29th, 2006 = http://www.wunderground.com/hurricane/history/sal_jul29.png