September 2014: Seasonably Warm & Dry To End The Month

[BlueJay]

It seems the wind has picked up a bit this afternoon.

[srainhoutx]

TROPICAL DEPRESSION FIVE DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052014
400 PM CDT MON SEP 01 2014

An Air Force Reserve Unit reconnaissance aircraft investigating the
low pressure area over the southwest Gulf of Mexico found a
well-defined center of circulation. The system has a curved band of
deep convection that wraps around the southern and eastern portions
of the circulation. Thus the system is being designated as a
tropical depression at this time. The maximum winds reported by the
aircraft so far support an intensity of 25 kt. Although the
cyclone is situated over very warm waters of near 30 deg C, the
atmospheric environment is not ideal for strengthening. Dynamical
models indicate that significant northerly to northwesterly
vertical shear should affect the tropical cyclone for the next 36
hours and this is likely to limit intensification up to landfall.
After landfall, dissipation should be quick due to the mountainous
terrain of Mexico. The official wind speed forecast is a little
above the intensity model consensus.

The initial motion is west-northwestward or around 295/11. The
steering scenario appears to be fairly straightforward. The flow
to the south of a mid-level ridge along the northern Gulf of Mexico
coast should maintain a west-northwestward track for the next 36
hours, i.e. through the expected time of landfall. The official
track forecast is very close to the latest dynamical model
consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 20.1N 93.6W 25 KT 30 MPH
12H 02/0600Z 21.1N 94.8W 30 KT 35 MPH
24H 02/1800Z 21.9N 96.3W 35 KT 40 MPH
36H 03/0600Z 22.4N 97.9W 40 KT 45 MPH...INLAND
48H 03/1800Z...DISSIPATED INLAND

$$
Forecaster Pasch

[skidog40]

i think its a little northeast of of 4pm model.

[BlueJay]

We are receiving a nice little shower with a dab of thunder right now. How nice for the first day of September!

0.07 inches for the first day of September. Pretty good!

[srainhoutx]

i think its a little northeast of of 4pm model.

It is possible that this could come inland near or just S of La Pesca in the State of Tamaulipas.

[tireman4]

On a Fall discussion, could we ( Texas or Houston) be having a cold (cool) front coming next week?


From our friend Ntxw on Storm 2K...( any mets wanna chime in here... )

As in my post earlier today, the EURO and other longterm guidance looks a little better today. Still within the 7 day period not much but 7-10 there is a massing (seasonal shift) of colder air pooling in NA (Hello there MR -EPO). Some kind of front will likely make it down here next week. With 93E in the EPAC getting it's act together (should be in the Baja vicinity) we have a tropical connection. Will need to wait a few more days to see if the two features interact and fine tune.

[srainhoutx]

TROPICAL STORM DOLLY DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052014
400 AM CDT TUE SEP 02 2014

An Air Force Reserve reconnaissance aircraft investigating the
cyclone early this morning found 925 mb flight-level winds of 50-53
kt in the northeast quadrant and adjusted SFMR winds of at least 40
kt. In addition, two ASCAT overpasses at 0313 UTC and 0406 UTC
indicated surface winds of 40-41 kt in the eastern quadrant. Based
on these wind data, the intensity has been increased to 40 kt,
making the cyclone the fourth tropical storm of the 2014 Atlantic
hurricane season. These wind data also required the initial
position to be relocated about 60 nmi north of the previous track.

The initial motion estimate is northwestward or 305/12 kt, which is
based on a blend of passive microwave, scatterometer, and
conventional satellite fix data. Other than the northward relocation
of the center position, the forecast track reasoning remains
unchanged from the previous advisories. The tropical storm is
expected to gradually turn more toward the west-northwest as Dolly
skirts along the southern periphery of a strong mid-level ridge that
is located across most of the Gulf of Mexico and the southeastern
United States. Landfall along the northeastern coast of Mexico is
expected in about 24 hours, followed by dissipation in 48 hours
over the rugged terrain of the Sierra Madre Oriental mountains. The
NHC forecast track is similar to the consensus model TVCA, and lies
roughly in the middle of the guidance envelope.

About 20 kt of north-northwesterly vertical shear is affecting
Dolly, which has resulted in most of the convection being displaced
well to the south and east of the exposed low-level circulation.
However, new convection has recently developed near and just to the
southeast of the center, and with the shear forecast to decrease to
about 15 kt during the next 12 hours, some additional slight
strengthening is possible before Dolly makes landfall.

The surface wind data from the reconnaissance aircraft and the
two scatterometer passes indicate that the tropical-storm-force wind
field has expanded significantly in the eastern semicircle. Since
the pressure gradient between Dolly and the large high over the
Gulf of Mexico is expected to remain quite strong for the next 36
hours or so, the Government of Mexico has extended the tropical
storm warning area northward to Barra El Mezquital. However, no
additional northward extension of the warning area appears likely
at this time.

The primary threat from this system is expected to be heavy
rainfall, which is likely to cause flash flooding and mud slides
over portions of eastern Mexico.

FORECAST POSITIONS AND MAX WINDS

INIT 02/0900Z 22.6N 94.8W 40 KT 45 MPH
12H 02/1800Z 23.1N 95.9W 45 KT 50 MPH
24H 03/0600Z 23.7N 97.5W 45 KT 50 MPH
36H 03/1800Z 24.1N 98.9W 35 KT 40 MPH...INLAND
48H 04/0600Z...DISSIPATED INLAND

$$
Forecaster Stewart

[srainhoutx]

Morning Update from Jeff:

TD # 5 becomes the 4th tropical storm of the 2014 hurricane season….Dolly.

Discussion:
Data from the latest USAF plane indicates the center of circulation has reformed about 60 miles northward overnight. The aircraft also recorded 925mb flight level winds of 50-53kts and a satellite overpass indicated surface winds of around 40kts…thus the system is upgraded to a tropical storm with 45mph winds. The aircraft also indicates that the wind field has greatly expanded to the northeast and east of the center with tropical storm force winds extending outward to 115 miles from the center. This wind field expansion is a result of the increasing pressure gradient between the deepening surface low with Dolly and high pressure over the southern US.

Track:
Besides the center re-location which requires a northward shift in the forecast track there has been no change in the forecast reasoning and Dolly should gradually turn toward the WNW and W and cross the eastern coast of Mexico within the next 24 hours. Dolly will move generally along the southern edge of an increasingly strong mid level ridge building along the US Gulf coast. There is a fairly tight model track consensus and the forecast track forecast is above average.

Intensity:
Dolly is under about 20kts of NNW wind shear on the eastern side of an upper level ridge along the eastern Mexican coast. This wind shear should continue through landfall with only some slight additional increase in intensity. Rapid weakening and dissipation is expected within the first 12-24 hours of landfall.

Impacts:
The center re-location overnight and the expanding wind field required the tropical storm warning to be shifted northward to about 100 miles south of the TX border. The larger wind field will help to increase large long period swells across the central and western Gulf of Mexico for the next 48 hours. Not expecting any significant water level rise on the upper coast associated with the fetch or wave action, but could get close to 2.0 ft total water level rise on the lower TX coast south of Rockport which could place water near the base of the dune on Padre Island.

Deep moisture will be flowing into the region today on the northeast side of the circulation with scattered to numerous showers and thunderstorms likely. Brief heavy rainfall is likely, but fairly quick storm motions should prevent any significant accumulations or flooding.

[srainhoutx]

A quick look at the medium to longer range suggests once we get beyond this weeks mini heat wave, things may begin to change as the zonal flow across North America becomes much more amplified. A rather deep trough is suggested by the ensembles to dig S into the Plains and that tends to suggest a stalling boundary somewhere across Texas. The other fly in the ointment is unusually lower pressures developing across the Western Caribbean and the Western Gulf. That pattern in the Western Atlantic Basin has persisted for a week now via the ensembles. When we see a pattern persist beyond a week, it raises an eyebrow. Something to watch as the week unfolds.

[srainhoutx]

As mentioned this morning, the pattern in the medium to longer range is getting a bit interesting. The ensembles continue to suggest very low pressures across the Western Caribbean and the Western Gulf and a deep trough continues to be indicated by the ensembles across Central North America. The Analog dates in the afternoon Update from the CPC Day 8+ Analogs raise an eyebrow and with the potential of a very unsettled pattern across the SW Caribbean to the Western Gulf. We may need to follow things a bit more closely in the coming days. We will see.

[jasons2k]

Rain seems to like me when it's supposedly all over. I got a quick .12" in a late PM shower. I'm glad to have it, but it's not enough to do much....

[skidog40]

was that a u-turn

[srainhoutx]

The ensembles continue to advertise well below normal pressures across the Western Gulf and Western Caribbean in the 9 to 15 day period. The afternoon Update from the Climate Prediction Center also is suggesting a deep trough across Central North America and normal to above normal rainfall across all of our Region into Mid September. The longer range beyond day 9 is very insistent of potential tropical mischief brewing in the Western Caribbean into the Western Gulf. It appears a monsoonal gyre may develop and has some support from the MJO. This is day 8 that I have counted that the ensembles have had an unsettled pattern potential setting up. We will see.

[jasons2k]

Happy for the folks on the NW side getting some rain. Sure wish it was a little more to the east, though. I can hear the thunder. So close...yet so far away.

[BlueJay]

Maybe it's coming your way Jasons. We just received 0.27 inches. I feel lucky indeed!

[jasons2k]

Nada. Just went for a walk by the office, which is in the Waterway district. There are still a couple of undeveloped plats with native trees and plants. I noticed virtually all the vines and most of the shrubs and smaller trees are wilting. They could really use a drink, and something more than a 5-minute passing shower.

[BlueJay]

Nada. Just went for a walk by the office, which is in the Waterway district. There are still a couple of undeveloped plats with native trees and plants. I noticed virtually all the vines and most of the shrubs and smaller trees are wilting. They could really use a drink, and something more than a 5-minute passing shower.

very sad

[srainhoutx]

As has been mentioned over the last several days, the ensembles have been suggesting unusually low pressures developing across the Western Caribbean and the Western Gulf in the medium to long range. There is now growing indications that a Convectively Couple Kelvin Wave may develop (cckw) as well as a favorable MJO (Madden Julian Oscillation) pattern that tends to increase rising air in the Tropics allowing for potential enhanced tropical development is moving E across the Pacific Ocean. It is also noteworthy that a deep trough is expect across the Central United States later next week and that would suggest a stalled frontal boundary across our Region (Southern Plains and possibly into Texas/Louisiana). It is a bit too soon to expect a strong Fall front to make it this far S in Mid September, but conditions may well develop for enhance Tropical development from the SW Caribbean Sea into the Gulf of Mexico. It is too soon to know with any certainty exactly how things may develop in the Day 7+ Range, but the ensembles have remained very insistent that a pattern somewhat conducive for Tropical development may increase. Peak Season for Tropical Development in nearing, so we will continue to closely watch the pattern carefully over the next several days.

The attachment 09042014 00Z GEFS 192 gfs-ens_mslpa_sd_watl_33.png is no longer available

[texoz]

Numerous showers already showing up on radar along and east/south of I-35 from Austin down to Brownsville. I think today's rain chances look a lot better than yesterday for C. Tex.

[tireman4]

Back to teasing us again, look at the snippet from the DFW NWS. This was their AFD. It seems the Euro is latching onto this and will not let go....

**
WE ARE STILL WATCHING THE MIDDLE AND
LATER PART OF NEXT WEEK FOR A POTENTIAL PATTERN SHIFT THAT WOULD
ALLOW A COLD FRONT TO ARRIVE IN THE REGION. BOTH THE GFS AND ECMWF
DEVELOP A STRONG UPPER LEVEL VORTEX OVER THE NORTHERN PLAINS OR
SOUTHERN CANADA DURING THE LATTER HALF OF NEXT WEEK. AS A
RESPONSE...TROUGHING ACROSS THE PLAINS RESULTS IN WEAKENING THE
UPPER LEVEL RIDGE. THE ECMWF IS MUCH MORE AGGRESSIVE WITH THE
STRENGTH AND DEPTH OF THE UPPER LEVEL TROUGH THAN THE GFS.
HOWEVER...BOTH MODELS DO BRING A FRONT INTO THE REGION BY THE END
OF NEXT WEEK. WE WILL BE WATCHING THIS SCENARIO CLOSELY AS THIS
COULD BE THE FIRST SIGNIFICANT FRONT OF THE FALL METEOROLOGICAL
SEASON.

We shall see. I would love to quote Sraintx and say, "Stepping down"