September 2015: Pleasant Weather To End The Month

[Paul Robison]

From HGX:

IN THE EXTENDED...THINGS GET A BIT MORE COMPLICATED AS WE LOOK
INTO NEXT WEEK AS BOTH ECMWF AND GFS CONTINUE TO DEVELOP A WEAK
LOW PRESSURE AREA OVER THE CENTRAL GULF. CONSIDERABLE UNCERTAINTY
EXISTS WITH THIS POTENTIAL...ALTHOUGH OVERNIGHT MODELS SEEM TO
WOBBLE THIS LOW N-NEWD AND THEN BACK TO THE SW NEXT WEEK. UPPER
LEVEL SHEAR DOES NOT APPEAR OVERLY CONDUCIVE AT THIS TIME FOR TOO
MUCH ORGANIZATION...BUT GIVEN THE TIME OF YEAR AND WARM GULF WATER
IT IS SOMETHING TO WATCH. 48

Why watch, if this is an EGOMEX problem? I'd think it'd be more of an issue from New Orleans to Pensacola. Besides, don't the chances for a storm strike on the Upper Texas Coast go down after Sept. 20?

[Katdaddy]

A low chance of isolated showers and thunderstorms mainly along the coastal areas for the next 7 days and will be watching the GOM. A few isolated showers in the offshore waters this morning. Currently the development of low pressure looks to effect areas from the Central GOM, as well as, areas to the E rather than the WGOM. The NHC has a 20% chance for tropical development over the next 5 days in the S Central GOM which moves N.

[sambucol]

Any idea when we will get a good cold front?

[srainhoutx]

Any idea when we will get a good cold front?

No sign of a good cold front through at least mid October at this time. Remember we really did not see a strong cold front last Fall until the entire pattern across the Northern Hemisphere was reshuffled with a Category 5 Typhoon that transitioned to a big extra tropical storm in the Bering Sea in early November that finally ushered in a big pattern change that lasted into March of this year.

[srainhoutx]

Upper level wind shear via the GFS at 90 hours certainly does not support tropical development across the Gulf of Mexico next week.

[texoz]

Any idea when we will get a good cold front?

No sign of a good cold front through at least mid October at this time. Remember we really did not see a strong cold front last Fall until the entire pattern across the Northern Hemisphere was reshuffled with a Category 5 Typhoon that transitioned to a big extra tropical storm in the Bering Sea in early November that finally ushered in a big pattern change that lasted into March of this year.

Would think that this winter might play out differently with El Nino coming on strong???

[Kludge]

It's getting awfully 2011-ish up here guys...

Please pray for us.

[Paul Robison]

It's getting awfully 2011-ish up here guys...

Please pray for us.

I'm afraid of a repeat of 2011's Tropical Storm Lee happening next week.
True, Lee made landfall in LA, but we felt some of his high winds in the Houston/Galveston area. It wasn't pretty, trust me.

Anybody think that's going to happen?

[Texaspirate11]

It's getting awfully 2011-ish up here guys...

Please pray for us.

I'm afraid of a repeat of 2011's Tropical Storm Lee happening next week.
True, Lee made landfall in LA, but we felt some of his high winds in the Houston/Galveston area. It wasn't pretty, trust me.

Anybody think that's going to happen?

Nope. Not gonna happen.

[Paul Robison]

It's getting awfully 2011-ish up here guys...

Please pray for us.

I'm afraid of a repeat of 2011's Tropical Storm Lee happening next week.
True, Lee made landfall in LA, but we felt some of his high winds in the Houston/Galveston area. It wasn't pretty, trust me.

Anybody think that's going to happen?

Nope. Not gonna happen.

Lee was a pretty weird storm. As I recall, it was really a subtropical low before it reached the LA coast and stayed that way at landfall. It had a huge windfield that developed because of the stall offshore prior to landfall. Until it actually develops, I suppose it's possible. Do any of the models show an offshore stall prior to landfall?

[Katdaddy]

Partly sunny skies with a slight chance of afternoon thunderstorms across SE TX this weekend. The coastal areas will see increasing thunderstorm chances late this weekend and into next as low pressure develops across the Central GOM and drifts N. The NHC has low chances for tropical development in the Central GOM during the next 5 days which will remain E of TX.

[srainhoutx]

Moisture levels at the mid and upper levels have slowly increased as the pesky upper ridge continues to move West away from Texas. The guidance suggests a slight chance of showers and thunderstorms increasing today into the weekend as an upper low organizes over S Texas and pulls moisture from the NW Caribbean Sea into the Gulf and potentially develops a surface low near the Yucatan Peninsula by Sunday. The GFS keeps the bulk of the heavy rainfall to our East while the European suggests the upper low may linger a bit longer and a Coastal low develops early next week with increasing rain chances mainly along and S of the I-10 Corridor Monday into Tuesday.

ENE winds may increase as well as tide levels along the Middle and Upper Texas Coast if the area of distributed weather organizes more than currently expected. Temperatures should be a bit cooler with increasing cloud cover as the weekend progresses. There is a slight chance that the area of distributed weather expected to develop in the Southern Gulf of Mexico may end up being a bit stronger than currently expected, so we will continue to monitor throughout the weekend into early next week.



EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1254 AM EDT FRI SEP 25 2015

VALID 12Z MON SEP 28 2015 - 12Z FRI OCT 02 2015

OVERVIEW...

AN UPPER HIGH OVER THE SOUTHERN ROCKIES AND A BROAD UPPER LOW OVER
THE GULF OF MEXICO WILL LIKELY PERSIST THROUGH ABOUT DAY
5/WED...BEFORE SOME WEAKENING AND EASTWARD MOVEMENT BEGIN. THE
CHANGES OCCUR AS THE WESTERLIES INCREASE AND AMPLIFY ACROSS CANADA
RESULTING IN A BROAD UPPER TROUGH FORMING ALONG THE EAST
COAST...AS WELL AS INCREASING WESTERLIES FORMING ACROSS THE
NORTHERN PACIFIC WHICH MAY HELP TO THE MOVE INLAND THE CLOSED LOW
OFFSHORE OF THE WEST COAST.

MODEL EVALUATION...

THE PATTERN CHANGE ACROSS CANADA FROM AN UPPER RIDGE TO AN UPPER
TROUGH EARLY TO MIDWAY THROUGH THE FORECAST PERIOD...WHICH
EVENTUALLY LEADS TO SPLIT FLOW...AS WELL AS THE COMPLEXITY OF THE
UPPER LOW OVER THE GULF OF MEXICO CREATE DIFFICULT CIRCUMSTANCES
FOR THE DETERMINISTIC SOLUTIONS TO PERFORM WELL. THE ENSEMBLE
MEMBER SPREAD SHOWS ABOVE AVERAGE SIZE THROUGH THE ENTIRE
PERIOD...WITH THE ECMWF ENSEMBLES MOSTLY FASTER ACROSS CANADA AND
EARLIER TO EJECT THE UPPER LOW FROM THE NEAR THE WEST COAST
COMPARED TO THE GEFS AND NAEFS MEMBERS. GIVEN THE DEVELOPING
SPLIT FLOW...A SLOWER EJECTION TIME IS GENERALLY
PREFERRED...ALBEIT WITH LOW CONFIDENCE. RUN-TO-RUN CONTINUITY IS
ABOUT AVERAGE...THUS NOT REALLY SUPPORTING NOR NEGATING THE
PREFERENCE. ALONG THE GULF COAST...ALMOST ANY OUTCOME SEEMS
POSSIBLE...WITH THE GEFS MEMBERS MORE AGGRESSIVE WITH LOW
DEVELOPMENT JUST OFFSHORE THE EAST COAST COMPARED TO THE ECMWF
ENSEMBLE MEMBERS WHICH ARE WEAKER AND FLATTER. THUS...HAVE SPLIT
THE DIFFERENCE WITH AN INTERMEDIATE POSITION AND INTENSITY CHOSEN
UNTIL MORE INFORMATION BECOMES AVAILABLE. REGARDING MEDIUM RANGE
GRIDS...THE PREFERENCE WAS 50/30/20 18Z GEFS MEAN/12Z NAEFS/12Z
ECMWF ENSEMBLE MEAN...WHICH IS CLOSE TO THE BLEND USED TO CREATE
THE 500 MB/PMSL FIELDS.

SENSIBLE WEATHER HIGHLIGHTS...

HEAVY RAIN IS A DISTINCT POSSIBILITY ACROSS THE GULF COAST
ANYWHERE FROM EASTERN TEXAS TO FLORIDA DAYS 3 THROUGH 5...WITH THE
GEFS SUPPORTING A CONTINUATION THROUGH DAY 7 ACROSS THE SOUTHEAST
WHILE THE ECMWF ENSEMBLE MEMBERS DIMINISH THE THREAT. THE FRONTAL
PLACEMENT EXTENDING FROM THE PLAINS EASTWARD WILL BE TRICKY. NOT
ONLY IS THE SPREAD QUITE HIGH...THE FRONT WILL ALSO LIE ON THE
WEAKER SIDE OF FRONTAL SYSTEMS AND MAY WEAKEN AND/OR STRENGTHEN
QUITE EASILY DUE TO DIFFERENTIAL HEATING AND MIXING. THE SENSIBLE
WEATHER WITH THE FRONT WILL MAINLY INVOLVE TEMPERATURE CHANGES
WITH LITTLE OR NO PRECIPITATION. THE SLOWER TIMING FOR THE CLOSED
LOW ALONG THE WEST COAST WHICH IS CLOSEST TO THE 18Z GEFS MEAN OR
12Z NAEFS...FAVORS PERSISTENCE OF WARMER TEMPERATURES ACROSS THE
INTERMOUNTAIN WEST AND SOUTHWEST BEFORE THE LOW MOVES INLAND MORE
THAN INDICATED BY THE ECMWF ENSEMBLES.

JAMES

[Paul Robison]

If the area of distributed weather expected to develop in the Southern Gulf of Mexico is stronger than currently expected, will this lead to a huge wind-field covering the Houston/Galveston area similar to what happened with TS Lee in 2011?

As I've mentioned before, the failure of Lee to make immediate landfall is what led to the heavy winds we experienced back then.

Here's the Wiki link, for those of you who may not be familiar with what I'm talking about:

https://en.wikipedia.org/wiki/Tropical_Storm_Lee_(2011)

[srainhoutx]

If the area of distributed weather expected to develop in the Southern Gulf of Mexico is stronger than currently expected, will this lead to a huge wind-field covering the Houston/Galveston area similar to what happened with TS Lee in 2011?

As I've mentioned before, the failure of Lee to make immediate landfall is what led to the heavy winds we experienced back then.

Here's the Wiki link, for those of you who may not be familiar with what I'm talking about:

https://en.wikipedia.org/wiki/Tropical_Storm_Lee_(2011)

This is not a similar situation at all to what we saw with TS Lee, Paul. The upper low and its affect on our sensible weather is the main player. The upper level winds associated with that upper low is not conducive for a strong tropical system. What we are most likely looking at is a baroclinic low or several baroclinic lows rotating around and East of the main closed upper low in S Texas.

[srainhoutx]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT FRI SEP 25 2015

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Depression Ida, located a little more than 1000 miles east-northeast
of the northern Leeward Islands.

1. A trough of low pressure is producing a large area of disorganized
showers and thunderstorms over the northwestern Caribbean Sea and
portions of Central America. Development is not expected during the
next couple of days while this system moves northwestward across the
Yucatan Peninsula. A surface low could form once the disturbance
reaches the southern Gulf of Mexico in a few days, but environmental
conditions are not particularly favorable for significant
development early next week while the system moves northward over
the Gulf of Mexico.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...20 percent

Forecaster Avila

[srainhoutx]

Complicated forecast to say the least. The afternoon Updated surface charts suggest at least a couple areas of potential low pressure and troughs making for an unsettled late weekend into at least mid next week across the Gulf Coast.

[wxman57]

Models are trying to develop a surface low west of the jet core beneath the upper low (TX coast). That looks unlikely. Main low should be east of the jet in the central Gulf, moving inland between East LA and FL Panhandle on Tuesday. No impact here from that low. There's a chance the NHC could classify the sheared, broad weak low as a TD but the impacts in its path would be the same (mostly rain east of the track).

[Paul Robison]

Moisture levels at the mid and upper levels have slowly increased as the pesky upper ridge continues to move West away from Texas. The guidance suggests a slight chance of showers and thunderstorms increasing today into the weekend as an upper low organizes over S Texas and pulls moisture from the NW Caribbean Sea into the Gulf and potentially develops a surface low near the Yucatan Peninsula by Sunday. The GFS keeps the bulk of the heavy rainfall to our East while the European suggests the upper low may linger a bit longer and a Coastal low develops early next week with increasing rain chances mainly along and S of the I-10 Corridor Monday into Tuesday.

Joe Bastardi seems to think this coastal low you mentioned might become a TC itself, srainhoutex.

[Katdaddy]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1050 PM CDT FRI SEP 25 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM...
GALVESTON BAY...

* UNTIL 1130 PM CDT

* AT 1050 PM CDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM...
CAPABLE OF PRODUCING WINDS TO 40 KNOTS...LOCATED OVER GALVESTON
BAY...MOVING SOUTHWEST AT 20 KNOTS.

* LOCATIONS IMPACTED INCLUDE...
GALVESTON BAY...TABBS BAY...BURNET BAY...TRINITY BAY...EAST
GALVESTON BAY...EAGLE POINT...THE TEXAS CITY DIKE...BLACK DUCK
BAY...SCOTT BAY...GALVESTON CAUSEWAY AND NORTHEASTERN WEST BAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MARINERS CAN EXPECT GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...
AND HEAVY RAINS. BOATERS SHOULD SEEK SAFE HARBOR IMMEDIATELY...UNTIL
THIS STORM PASSES.

[Paul Robison]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1050 PM CDT FRI SEP 25 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM...
GALVESTON BAY...

* UNTIL 1130 PM CDT

* AT 1050 PM CDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM...
CAPABLE OF PRODUCING WINDS TO 40 KNOTS...LOCATED OVER GALVESTON
BAY...MOVING SOUTHWEST AT 20 KNOTS.

* LOCATIONS IMPACTED INCLUDE...
GALVESTON BAY...TABBS BAY...BURNET BAY...TRINITY BAY...EAST
GALVESTON BAY...EAGLE POINT...THE TEXAS CITY DIKE...BLACK DUCK
BAY...SCOTT BAY...GALVESTON CAUSEWAY AND NORTHEASTERN WEST BAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MARINERS CAN EXPECT GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...
AND HEAVY RAINS. BOATERS SHOULD SEEK SAFE HARBOR IMMEDIATELY...UNTIL
THIS STORM PASSES.

So the "good times" have already begun, eh?