Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 4

[DoctorMu]

Waiting for Recon, but estimated sustained winds for Ernesto per NHC 5 pm EDT advisory are up to 60 mph

[Ed Lizard]

I wasn't in love w/ 12Z GFS, but 6Z and 18Z seem, IMHO, to be most likely option, and I think second Mexican landfall will be big one.

BTW, even down there, HOU are on the edge of GFS 500 mb and 700 mb 70% RH line, with deep East flow, we might get something out of Ernesto.

[DoctorMu]

Ugh. Ernesto is not stacked at all..possibly heading to Honduras as an open wave - all flash

Hoping for local action Monday with the ghostly disturbance sliding from the east.

[Ed Lizard]

Always interesting to see an exposed LLC. It does have at least a storm relative closed LLC, as fast as it is moving, West winds might be hard to find.

One tiny spot of convection may be forming on the East side of the LLC.

Not super-optimistic on Ernesto in the short term, but maybe that first little microblob is the beginning of the center getting covered again. Or maybe not. Longer term, CMC/Euro is probably best case scenario, and I am seriously doubting rain for my lawn from Ernesto.

GFDL has been horrible, but always entertaining.

In more likely weather news, radar is rather active offshore today, and I am glass full optimistic of 30-ish % coverage of afternoon showers and storms.

[msp]

cool shot today of a waterspout off kemah:

https://twitter.com/NWSHouston/status/232156854376099840/photo/1

[DoctorMu]

A very nice sea breeze kicking in related to the low on the coast. Will the AggieDome yet again block this about 5 miles from my lawn?

[DoctorMu]

missed it by that much. I could literally smell the rain

[My Weather Today]

missed it by that much. I could literally smell the rain

Been there, done that. Just hang it in there, your rains will come in due time. You're due for a big payday sometime in the near future.

[Ed Lizard]

missed it by that much. I could literally smell the rain

An hour of frequent thunder for a 10 minute sprinkle. Better than nothing...

[Srain]

Morning e-mail from Jeff:

Upper level trough/weakness over the region today will provide another shot at rainfall.

Fairly widespread rainfall coverage on Sunday especially west of I-45. With the upper level ridge that has been anchored over NW TX retreating toward the WNW, a weakness has developed over the area and deeper moisture has pushed westward from LA and the central Gulf of Mexico. Expect to see another round of thunderstorms this afternoon as trigger temperatures are exceeded by midday. May see a slightly later start compared to yesterday and better coverage north of I-10 today. Models really peg the areas north of I-10 between about 4-8pm possibly with the help of a weak short wave dropping southward on the eastern edge of the upper ridge.

Gradually lowering rain chances through the rest of the week as upper level northerly flow results in drier air mass pushing southward. This will also limit the inland movement of the seabreeze front and help focus rain chances mainly south of I-10 Tues-Fri. Would not discount a couple of weak short waves rotating down the eastern edge of the ridge and across our area helping to produce more thunderstorms than currently shown, but when this happens is nearly impossible to determine.

Ernesto may briefly move into the far southern Bay of Campeche on Thursday-Friday. The system will be far enough south that moisture will remain south of our area. Broad wind field across the central Gulf may bring 2-4 foot swells into the NW Gulf by late this week/weekend, but this should have little to no impact on tide levels. Overall little to no impact is expected from Ernesto.

[DoctorMu]

An hour of frequent thunder for a 10 minute sprinkle. Better than nothing...

I think we're going to be dealt a good hand today. We've got outflow instability and easterly movement...

[Srain]

Morning e-mail from Jeff:

Slightly better chance of thunderstorms this afternoon compared to yesterday.

Early this morning a blow up of deep convection has occurred over C LA likely in response to a southward moving weak short wave on the eastern side of large scale high pressure over the western US. These storms or their outflow boundaries along with the impulse aloft will move in a general SSW to SW direction today and will be in our area toward peak heating this afternoon. This combined with the slow northward movement of the seabreeze boundary may result in low level boundary collision near/along I-10 late this afternoon and a possible enhancement of storms chances in that area.

Will continue with the 20-30% rain chances each day as along the seabreeze boundary and for any weak disturbances that approach from the NE. Thursday-Friday a weak boundary (front) will approach the area from the NNE and storms along this feature may push southward both late Thursday and again late Friday to affect at least the northern and eastern parts of the region. Weak boundary may make it down toward I-10 by Saturday…not expecting any cold air advection, but increased clouds may knock 1-2 degrees off the daytime highs.

As for Ernesto, the forecast track remains unchanged with the system only briefly emerging into the Bay of Campeche well south of TX and then moving inland over mainland MX. This track and the forecasted intensity will result in little to no impact along the TX coast. A slight increase in swells is possible over the weekend on the beaches, but this is not expected to result in any tidal issues

[Ed Lizard]

Severe weather approaching Metroplex and everyone looking at a hurricane far, far away...

Radar has the cluttery look I sometimes see when there is an inversion. Interesting.

[nrgjeff]

Good day for microbursts in North Texas at 100/60. Little evaporation goes a long way, toward microburst.

[Srain]

Morning e-mail from Jeff:

Ernesto:

Ernesto made landfall yesterday round 1015pm on the southern coast of the Yucatan near Mahahual, MX. Just prior to landfall weather station on Banco Chinchorro IS just off the coast recorded a surface pressure reading of 979.4mb. The inner core and eye of Ernesto was tracked by Belize Radar and the eye diameter was about 15 miles across at the time of landfall. Since landfall the system has moved inland over the southern Yucatan and begun to weaken. While deep convection remains over the center the cloud tops are warming and Ernesto will continue to weaken until it emerges over the warm waters of the Bay of Campeche later today. The structure of the storm looks well on satellite images with a core of convection over the center and large curved bands extending outward in all directions. Conditions over the Bay of Campeche will be very favorable for intensification with good 200mb outflow aloft. The main question is how far offshore will Ernesto move before its second landfall along the eastern coast of MX. Based on the most recent satellite trends, the center may only briefly be over water.

92L:

An area of low pressure is located over the east-central Atlantic about 700 miles WSW of the Cape Verde Islands. While there is a defined elongated circulation at the surface, there is little convection and the system has large amounts of dry air to the north and west. Any development will be slow and similar to Ernesto most of the global models keep the system fairly weak as it moves generally westward.

A much stronger wave will be moving off the African coast in the next day or two and this system looks to have some development potential also.

[Ed Lizard]

Mesoscale convective discussion for NE to North Central Texas for isolated severe/microburst, watch unlikely.

[DoctorMu]

Mesoscale convective discussion for NE to North Central Texas for isolated severe/microburst, watch unlikely.

Bring it. The AggieDome has been officially constricted down just to our neighborhood as of yesterday. A mini-deluge on campus and nary a drop just east of Hwy6. The line of storms should make it past Hearne moving South. Fingers crossed the outflow has enough steam to water lawns in CLL.

[msp]

Bring it. The AggieDome has been officially constricted down just to our neighborhood as of yesterday. A mini-deluge on campus and nary a drop just east of Hwy6. The line of storms should make it past Hearne moving South. Fingers crossed the outflow has enough steam to water lawns in CLL.

i'll be back down there shortly, so that dome will expand to cover the area around rock prairie and wellborn... i promise.

and texas could sure use a nice tropical system to bust that drought in the valley and west of 35. i'm hoping 92L can do it.

[Quixotic1]

108 today. I'm having flashbacks to last year.

[Ed Lizard]

NE Texas in a Slight Risk this morning. SETX well outside that, but AOA 5% on severe winds w/i 25 miles. Will water if it isn't raining when I get home, as GFS suggests today is the best chance in several days.

I had hopes for 07L as a potential rainmaker in ~10 days, but I seriously doubt it will survive the Caribbean. Too bad, steering looks like it would have taken it Northwest or Northward, and besides my lawn liking rain, places inland like Arkansas and Oklahoma could certainly use the rain. But I'm not seeing it happen.

Hope I am wrong.

[Srain]

Morning e-mail from Jeff:

Weak frontal boundary over N TX this morning will sag southward today while aloft a short wave moves southward over the region on the eastern edge of the high pressure cell to our west. Front and short wave will reach our northern counties around early afternoon as surface temperatures reach the upper 90’s (the trigger temperatures for today). Expect thunderstorms to develop as the air mass becomes very unstable (CAPE of 2500-4500 J/kg) by early to midafternoon.

Forecast soundings show dry air in the mid layers of the atmosphere which will help support strong downburst winds and strong outflow boundaries. Strong damaging winds will be the main threat with these storms. Storms should move S to SSW toward the I-10 corridor by late afternoon and may collide with the inland moving seabreeze front helping to enhance coverage near I-10. With the loss of heating, the activity should begin to die off around 7-8pm.

Weak front/outflow boundary from today will be located across the southern regions on Saturday and this may help foster additional storms especially as the seabreeze begins to move inland south of I-10. Boundary washes out and begins to lift back northward on Sunday with rain chances returning to isolated.

Will discuss TD # 7 later today.

[Srain]

Nice to see some storms firing for a change...

[Ed Lizard]

Will that warned cell entering Harris County reach my lawn???

[DoctorMu]

Nice to see some storms firing for a change...

That's one sweet photo. Our lawn is located about 5 mi north of that line. High and dry again at 103° last hour.

[Ed Lizard]

Dark skies, lightning, thunder, nary a drop...

[DoctorMu]

The dry line cruised on through, but no real lift and moisture for any action. Dew point settling from around 70° to upper 50s. At least 100°F+ is more comfortable now.

Still hoping for any tropical action. TTCFKA TD7 now open wave would be nice if it splits the difference on model projections. BAMM places in the BoC...

http://www.wundergro...1207_model.html

[Srain]

Heat Advisories have been issued for our southern zones and a lucky few may see a sea breeze storm pulse up late in the day mainly S of I-10. This pattern should continue until Thursday when things become a bit more interesting and rain chances increase. A stalling strong front near the Red River Valley and remnants of what was TD 7 enter the picture from the Gulf if the GFS and Euro are correct. That increasing deep tropical moisture along with a stalled boundary may set the stage for a prolonged rain event with heavy rains possible. The GFS is suggesting a broad surface wave developing with the tropical remnants meandering along the S Texas Coast while the Euro suggests a tad further S to the N of Tampico. Both models do suggest that broad surface wave to linger and the frontal boundary to begin to wash out across the N Texas region with daily storms and copious tropical moisture across Texas. Perhaps we just may see a return of the very wet pattern we experienced in mid July and with a favorable MJO pulse heading E, the days on little to no rainfall may become a distant memory. We will see.

[DoctorMu]

Heat Advisories have been issued for our southern zones and a lucky few may see a sea breeze storm pulse up late in the day mainly S of I-10. This pattern should continue until Thursday when things become a bit more interesting and rain chances increase. A stalling strong front near the Red River Valley and remnants of what was TD 7 enter the picture from the Gulf if the GFS and Euro are correct. That increasing deep tropical moisture along with a stalled boundary may set the stage for a prolonged rain event with heavy rains possible. The GFS is suggesting a broad surface wave developing with the tropical remnants meandering along the S Texas Coast while the Euro suggests a tad further S to the N of Tampico. Both models do suggest that broad surface wave to linger and the frontal boundary to begin to wash out across the N Texas region with daily storms and copious tropical moisture across Texas. Perhaps we just may see a return of the very wet pattern we experienced in mid July and with a favorable MJO pulse heading E, the days on little to no rainfall may become a distant memory. We will see.

Really hoping to shut down the sprinklers in the next 10 days due to our high Na+ (alkaline) water as we move from brown grass season to brown patch season.

[Ed Lizard]

Dallas might get some fun today...

[Srain]

Morning e-mail from Jeff:

Hot and mostly dry for the first part of this week.

A large dome of high pressure over NM ridging SE into TX will continue to produce hot and mainly dry weather for the next day or so. Cannot rule out an isolated thunderstorms along the seabreeze during peak heating or along any boundaries drifting down from the N and NNE. Slow storm motions under weak steering currents indicate if you do get a storm a good dump of rainfall is likely.

Changes appear toward the end of the week into the weekend as the ridge over NM move westward allowing a downstream trough to develop over the central US. Models continue to show a rare August cold front dropping southward down the plains an into TX by late this week and this weekend. Feel the models are likely fairly robust showing the front and cold air advection making it deep into TX, but the upper air pattern does favor the boundary making decent progress under N flow aloft. While a boundary or outflow boundaries from the north come into play by Friday a tropical wave (ex TD #7) looks to arrive into the western Gulf near the same time and make landfall along the TX coast Saturday. This feature will spread a highly tropical air mass into the state from the western Gulf and will work with the stalling frontal boundary to produce a good chance of showers and thunderstorms. Yesterday, some of the models tried to spin the wave up into a closed surface low, but they have backed away from that thinking overnight. With that said there is already a surface trough in the SW Gulf and Bay of Campeche and the models keep this feature in that region for the next several days…so we will have to keep an eye on it to see if presentat convection can develop lower surface pressures. May also see a connection from the EPAC TS Hector and this could help enhance rainfall totals. Overall it is looking fairly wet toward the end of the week into next weekend with several rain making features. Highs will peak in the upper 90’s today-Wednesday and then begin to cool under increasing clouds and rainfall.