Gulf of Mexico (Is Invest 91L)

[Ptarmigan]

Large Blow-up of convection over the eastern
gulf associated with a trough has been producing
squalls that contain gusty winds of 30-45 mph
and torrential tropical rains all day today
across Florida:
http://www.goes.noaa.gov/ECIR3.html

This is a different area of convection
from the one near Texas, but this new
area of convection is producing squall activity
over the peninsula of Florida, and will
impact Florida tomorrow with heavy squalls.

A ridge builds in by Sunday pushing whatever
becomes of this convective blow-up
westward. I'm going to check some model runs.

I don't expect tropical development yet, but I do expect
the squalls to continue to develop and roll in across Florida
tomorrow, with gusty winds and heavy rain.

Bears watching if it persists.

[KatDaddy]

Excerpt from the Dallas AFD:

GFS AND ECMWF ARE BRINGING A TROPICAL SYSTEM TOWARD TEXAS TUESDAY
INTO WEDNESDAY. ALTHOUGH UNCERTAINTY IS HIGH AT THIS TIME...WILL
OPT TO INTRODUCE SLIGHT CHANCE POPS ON WED. THIS MAY ALSO BRING
SLIGHTLY COOLER TEMPS TO THE AREA BY MID WEEK.


Joe B is concerned about the trough split next as well.

[Stormcenter]

Excerpt from the Dallas AFD:

GFS AND ECMWF ARE BRINGING A TROPICAL SYSTEM TOWARD TEXAS TUESDAY
INTO WEDNESDAY. ALTHOUGH UNCERTAINTY IS HIGH AT THIS TIME...WILL
OPT TO INTRODUCE SLIGHT CHANCE POPS ON WED. THIS MAY ALSO BRING
SLIGHTLY COOLER TEMPS TO THE AREA BY MID WEEK.


Joe B is concerned about the trough split next as well.

The weather service out of N.O. mentions it too.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
329 AM CDT THU JUL 31 2008

.DISCUSSION...

THE TROUGH IS EXPECTED TO BECOME
NEARLY STATIONARY AND DISSIPATE NORTH OF OUR AREA AS AN UPPER-
LEVEL HIGH BUILDS INTO THE MID AND LOWER MISSISSIPPI VALLEY THIS
WEEKEND. THIS WILL LOWER RAIN CHANCES AND ALLOW FOR TEMPS TO RISE
FARTHER INTO THE 90S ACROSS THE AREA. BOTH THE GFS AND ECMWF STILL
SHOW A WAVE DEVELOPING OVER THE NORTHWESTERN GULF OF MEXICO AND
PUSHING WESTWARD TOWARD THE LOUISIANA COAST MONDAY AND TUESDAY.
THIS WAVE MAY PUSH ONSHORE ON TUESDAY...AND INCREASE RAIN CHANCES.

[Sanibel]

They must have meant "NORTHEASTERN".

[Ed Mahmoud]

Just looked at the 0Z GFS. Real stretch to call what is predicted a 'tropical system'. A piece of the trough pinches off, retrogrades back under the ridge with a weak surface reflection right on the coast, and the rain basically falls apart before Houston.

Euro has a similar pinch off, and a retrograding inverted trough, no surface development, but the inverted trough is a bit more impressive, and at least hope for some showers for SE Texas.

[Tampa Bay Hurricane]

Excerpt from the Dallas AFD:

GFS AND ECMWF ARE BRINGING A TROPICAL SYSTEM TOWARD TEXAS TUESDAY
INTO WEDNESDAY. ALTHOUGH UNCERTAINTY IS HIGH AT THIS TIME...WILL
OPT TO INTRODUCE SLIGHT CHANCE POPS ON WED. THIS MAY ALSO BRING
SLIGHTLY COOLER TEMPS TO THE AREA BY MID WEEK.


Joe B is concerned about the trough split next as well.

I agree with these forecasts. The area in the Eastern
Gulf has moderate convection, and will push west
towards Texas under the influence of a ridge.
What those models are developing
is the area currently in the Eastern
Gulf, so it bears close watching:
http://www.goes.noaa.gov/ECIR3.html

Convection will increase significantly today
with day time heating and likely persist
with water temperatures in the 87+ Fahrenheit
range over the area.

[srainhoutx]

Mobile WFO thoughts on this senerio...snipet...

.LONG TERM [FRIDAY THROUGH WEDNESDAY]...EXPECT TO SEE A MID LEVEL
SHEAR AXIS DROP SOUTHWARD ACROSS THE GULF COAST FRIDAY AS BREAK IN
THE UPPER RIDGE SETS UP OVER THE REGION. ENHANCED SYNOPTIC SCALE LIFT
ATOP A WEAK SURFACE TROF OF LOW PRESSURE ALSO TO SLIP IN FROM THE
NORTH...SHOULD INTERACT WITH PLENTIFUL DEEP LAYER MOISTURE AND
DAYTIME INSTABILITY FOR THUNDERSTORMS TO FORM. THIS IS THE BEST
SIGNAL WE HAVE SEEN OVER THE PAST SEVERAL DAYS THAT SUGGESTS A BUSY
RADAR SCOPE FOR FRIDAY. THE FLOW SUGGESTS STORMS WILL HEAD SOUTHWARD
TOWARD THE COAST THROUGH THE COURSE OF THE DAY AND THEN OFFSHORE LATE
AFTERNOON/EVENING. UPPER RIDGE EXPANDS EASTWARD OUT OF THE PLAINS
THIS WEEKEND WITH A PIECE OF THE MID LEVEL SHEAR AXIS...DISCUSSED
EARLIER...TO BREAK OFF THE UPPER TROF OVER THE EAST COAST AND
RETROGRADE WESTWARD ACROSS THE NORTHERN/NORTHWEST GULF EARLY IN THE
WEEK. A WEAK SURFACE LOW/TROF REFLECTION MAY FORM OVER THE GULF COAST IN
RESPONSE TO THE MID LEVEL FEATURE LATE THIS WEEKEND...TRACKING
WESTWARD ACROSS THE COAST OF LOUISIANA AND INTO EAST TEXAS EARLY HALF
OF NEXT WEEK.

http://www.srh.noaa.gov/mob/productview ... &version=0

[Kludge]

[quote="Tampa Bay Hurricane]The area in the Eastern
Gulf has moderate convection, and will push west
towards Texas under the influence of a ridge.
[/quote]

Sure hope you're right, TBH. I'm just afraid that the same scenario will reoccur as it did with the blob in the same area that crept across the gulf this week, and then ran into our 'shield' (aka ridge) and suffered a 'poof-ation'. Not being a pessimist...just not getting my hopes up this time.

[N2Storms]

[quote="srainhoutx"]Mobile WFO thoughts on this senerio...snipet...

.LONG TERM [FRIDAY THROUGH WEDNESDAY]...EXPECT TO SEE A MID LEVEL
SHEAR AXIS DROP SOUTHWARD ACROSS THE GULF COAST FRIDAY AS BREAK IN
THE UPPER RIDGE SETS UP OVER THE REGION. ENHANCED SYNOPTIC SCALE LIFT
ATOP A WEAK SURFACE TROF OF LOW PRESSURE ALSO TO SLIP IN FROM THE
NORTH...SHOULD INTERACT WITH PLENTIFUL DEEP LAYER MOISTURE AND
DAYTIME INSTABILITY FOR THUNDERSTORMS TO FORM. THIS IS THE BEST
SIGNAL WE HAVE SEEN OVER THE PAST SEVERAL DAYS THAT SUGGESTS A BUSY
RADAR SCOPE FOR FRIDAY. [u]THE FLOW SUGGESTS STORMS WILL HEAD SOUTHWARD
TOWARD THE COAST THROUGH THE COURSE OF THE DAY AND THEN OFFSHORE LATE
AFTERNOON/EVENING.[/u] [b]UPPER RIDGE EXPANDS EASTWARD OUT OF THE PLAINS
THIS WEEKEND WITH A PIECE OF THE MID LEVEL SHEAR AXIS...DISCUSSED
EARLIER...TO BREAK OFF THE UPPER TROF OVER THE EAST COAST AND
RETROGRADE WESTWARD ACROSS THE NORTHERN/NORTHWEST GULF EARLY IN THE
WEEK. A WEAK SURFACE LOW/TROF REFLECTION MAY FORM OVER THE GULF COAST IN
RESPONSE TO THE MID LEVEL FEATURE LATE THIS WEEKEND...[u]TRACKING
WESTWARD ACROSS THE COAST OF LOUISIANA AND INTO EAST TEXAS EARLY HALF
OF NEXT WEEK.[/u] [/b]

http://www.srh.noaa.gov/mob/productview ... &version=0[/quote]



the Tallahassee NWS AFD mentions this also...both mention that it will essentially hug the coast as it drifts wwd...if it does this it most likely won't become anything but a shower producer, but isn't that just what the DR. ordered for the Texans

[Tampa Bay Hurricane]

Sure hope you're right, TBH. I'm just afraid that the same scenario will reoccur as it did with the blob in the same area that crept across the gulf this week, and then ran into our 'shield' (aka ridge) and suffered a 'poof-ation'. Not being a pessimist...just not getting my hopes up this time.

We will have to watch the water vapor imagery over Texas to make sure
no dry air kills the convection; that is once this moves west towards
TX, in 3-4 days.

[cheezyWXguy]

Dallas AFD:
GFS and European model (ecmwf) are bringing a tropical system toward Texas Tuesday
into Wednesday. Although uncertainty is high at this time...will
opt to introduce slight chance probability of precipitation on Wednesday. This may also bring
slightly cooler temperatures to the area by middle week.

is there any other model support than gfs and euro?

[Ed Mahmoud]

Dallas AFD:
GFS and European model (ecmwf) are bringing a tropical system toward Texas Tuesday
into Wednesday. Although uncertainty is high at this time...will
opt to introduce slight chance probability of precipitation on Wednesday. This may also bring
slightly cooler temperatures to the area by middle week.

is there any other model support than gfs and euro?

See my comment above- Euro and GFS 'tropical system' mentioned by NWS FWD isn't all that impressive. GFS has weak surface reflection of a bit of troughiness that pinches off and retrogrades, that hugs the coast, but doesn't quite make it to Houston with rain, Euro has better looking pinched off trough that eventually cuts off, that does make it to Texas, with suggestion of enhanced relative humidity fields, but no apparent surface reflection.


Of course, whether using Penn State e-Wall or ecmwf.int web sites, Euro is shown with poor resolution. The model itself, per NHC, has the finest resolution of the global models, but the Europeans don't seem to like to make good model data available for free, even though I'm sure they are supported by EU taxpayers.

I like the availability of US models. I've seen complaints that spurious tropical cyclones predicted on long range models could lead to hysteria, but I haven't seen that happen, and as a taxpayer, military veteran, voter, and a guy that actually shows up for jury duty, and has sat through deadly dull civil cases, I feel somewhat entitled to view highly detailed model data.

[Stormcenter]

We do have an area of disturbed weather in the NE GOM.
I'm not sure if this is what the NWS discussions are referring to.

http://www.ssd.noaa.gov/goes/east/gmex/loop-avn.html

[Stormcenter]

Dallas AFD:
GFS and European model (ecmwf) are bringing a tropical system toward Texas Tuesday
into Wednesday. Although uncertainty is high at this time...will
opt to introduce slight chance probability of precipitation on Wednesday. This may also bring
slightly cooler temperatures to the area by middle week.

is there any other model support than gfs and euro?

See my comment above- Euro and GFS 'tropical system' mentioned by NWS FWD isn't all that impressive. GFS has weak surface reflection of a bit of troughiness that pinches off and retrogrades, that hugs the coast, but doesn't quite make it to Houston with rain, Euro has better looking pinched off trough that eventually cuts off, that does make it to Texas, with suggestion of enhanced relative humidity fields, but no apparent surface reflection.


Of course, whether using Penn State e-Wall or ecmwf.int web sites, Euro is shown with poor resolution. The model itself, per NHC, has the finest resolution of the global models, but the Europeans don't seem to like to make good model data available for free, even though I'm sure they are supported by EU taxpayers.

I like the availability of US models. I've seen complaints that spurious tropical cyclones predicted on long range models could lead to hysteria, but I haven't seen that happen, and as a taxpayer, military veteran, voter, and a guy that actually shows up for jury duty, and has sat through deadly dull civil cases, I feel somewhat entitled to view highly detailed model data.

So what your saying is you don't buy it.

[Dean4Storms]

If the feature hugs the Gulf Coast and moves WNW as they mention it could miss the TX. coast altogether.

[Ed Mahmoud]

If the feature hugs the Gulf Coast and moves WNW as they mention it could miss the TX. coast altogether.

Per 0Z GFS, indeed.



I think JB will discuss this on his videos which should post anytime now. He loves this kind of thing, "home brew" development that starts with a "trough split", or a longwave trough lifting out, with a piece at the base of the trough pinched off between the ridge, that starts retrograding underneath the ridge.

Sometimes the trough fires up enough storm action to induce a weak surface reflection, than retrogrades faster than the surface feature, so it slowly changes from shearing the weak low apart to providing upward motion and ventilation without shear, even inducing a short wave ridge over the surface low.


Doesn't happen quickly, and usually, doesn't happen at all. But it is the kind of tropical development JB prides himself on spotting before most other meteorologists.

[Tampa_God]

I just had a squall go through with a gust of 32 mph. Winds in this squall is around 16 mph.

[stevetampa33614]

We do have an area of disturbed weather in the NE GOM.
I'm not sure if this is what the NWS discussions are referring to.

http://www.ssd.noaa.gov/goes/east/gmex/loop-avn.html

Thats just afternoon T-storms.

[Kludge]

I think JB will discuss this on his videos which should post anytime now.

He says he'll be here in Houston next week. Any clues? Is he meeting with clients? Are you one of them?

[HouTXmetro]

Not buying it...... The drought continues