June 2014: WET & WILD OR HIGH & DRY?

[Andrew]

Also keep an eye on things around the San Antonio/Corpus area. Possible meso development could be developing if precip can stay organized.

[jeff]

Band from NNE of Corpus to NW of Victoria looks impressive. Likely going to get some storm totals of 6-8 inches or more in that area this evening.

[Paul Robison]

Dear Jeff:

Could we see any major mesoscale events evolve on Thursday?

[srainhoutx]

Evening Update from Jeff:


After a round of morning thunderstorms the air mass inland stabilized while a large convective complex exploded just offshore. This complex helped to “rob” incoming Gulf moisture to inland areas today and held back surface heating with its mid and high level cloud canopy thus keeping the heavy rainfall focused offshore.

 

Clearing to the SW has resulted in another complex of thunderstorms stretching from Victoria to north of Corpus Christi. 88D indicates upwards of 6 inches of rainfall in the past few hours over Aransas and Refugio Counties. A circulation is clearly noted in the radar loops from San Antonio and Corpus suggesting some sort of mid level vort may be centered somewhere in all the activity between San Antonio and Corpus. Offshore complex over the NW Gulf has weakened considerably in the last few hours and expect air mass over our coastal waters to begin to destabilize with an influx of deep tropical moisture over the western Gulf. Meso models not supporting much development tonight, but given the “vort” off to our WSW and increasing nocturnal speed convergence over the nearshore waters expect activity to begin to fire off in the 100am-400am time period and at least spread toward the coast. This tends to be fairly common with these types of air masses and setups.

 

Main question becomes if and how far inland any coastal convection will penetrate on Thursday morning. Think main trough axis over SC TX will be closer to SE TX on Thursday morning and this will support a little better inland movement of activity however events in the past tend to favor convection anchoring near the coast or offshore and little inland development (ie today). Meso models are not really handling the potential for development very well and will trend more toward experience in these situations over short term model guidance and go with nearshore development late tonight moving into at least the coastal counties and possibly reaching US 59.

 

With the trough axis closer tomorrow storm motions may be slower than the last few days. Even with 15-25mph movement we have still been able to see 1-2 inch per hour rainfall rates with the stronger cells. Think motions on Thursday will be in the 10-15mph range and the air mass remains extremely moist so high hourly rainfall rates will be common. Flash Flood Guidance has shown only modest decreases as rains so far have been spotty and not overly concentrated and for the most part think we should be able to handle an additional 2-3 inches without major problems. Some concern for urban areas where tropical rainfall rates can easily overwhelm drainage systems even if the storm total is a couple of inches, but it all falls in 30-45 minutes.

 

Friday-weekend:

Upper ridging will at least attempt to gain a foothold across the region, but I have my doubts if it will be able to cut off rain chances. GFS drops rain chances from 61% Friday to 25% Saturday which seems a little aggressive with the drying. Models have been struggling with how fast and how strong the sub-tropical ridge builds over the region. Think the ridge will have a harder time gaining a foothold with fairly moist grounds and green vegetation compared to the past several summers and allow at least scattered seabreeze storms each day.

 

Ridge looks to finally overtake the area early next week, but again looks short lived as a westward moving tropical wave/TUTT low works is way from FL toward TX by the middle to end of next week. This may result in another surge of deep tropical moisture toward the July 3-4 time period with increasing rain chances again.

[Paul Robison]

TUTT low, Jeff?

Any chance of that developing into a TC?

[Ptarmigan]

A stormy morning gives way to calm days. Tonight could be interesting.

[Paul Robison]

Is this Jeff's TUTT low?

000
ABNT20 KNHC 252321
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED JUN 25 2014

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

A low pressure area could form off of the southeastern coast of
the United States by early next week. Some development of this
system is possible if it remains over water while it drifts
southward or southwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

Note 20% probability development. What'll it be by the time it crosses Florida and reaches TX?

[Ptarmigan]

Is this Jeff's TUTT low?

000
ABNT20 KNHC 252321
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED JUN 25 2014

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

A low pressure area could form off of the southeastern coast of
the United States by early next week. Some development of this
system is possible if it remains over water while it drifts
southward or southwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

Note 20% probability development. What'll it be by the time it crosses Florida and reaches TX?

That one is off the coast of Florida.

[Paul Robison]

Is this Jeff's TUTT low?

000
ABNT20 KNHC 252321
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED JUN 25 2014

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

A low pressure area could form off of the southeastern coast of
the United States by early next week. Some development of this
system is possible if it remains over water while it drifts
southward or southwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

Note 20% probability development. What'll it be by the time it crosses Florida and reaches TX?

That one is off the coast of Florida.

My Question is: Would it likely it cross Florida and develop by the time it reaches Texas?

Seriously, I want the rain but I don't want the wind and lightning.

[Ptarmigan]

My Question is: Would it likely it cross Florida and develop by the time it reaches Texas?

Seriously, I want the rain but I don't want the wind and lightning.

Evening Update from Jeff:


After a round of morning thunderstorms the air mass inland stabilized while a large convective complex exploded just offshore. This complex helped to “rob” incoming Gulf moisture to inland areas today and held back surface heating with its mid and high level cloud canopy thus keeping the heavy rainfall focused offshore.



Clearing to the SW has resulted in another complex of thunderstorms stretching from Victoria to north of Corpus Christi. 88D indicates upwards of 6 inches of rainfall in the past few hours over Aransas and Refugio Counties. A circulation is clearly noted in the radar loops from San Antonio and Corpus suggesting some sort of mid level vort may be centered somewhere in all the activity between San Antonio and Corpus. Offshore complex over the NW Gulf has weakened considerably in the last few hours and expect air mass over our coastal waters to begin to destabilize with an influx of deep tropical moisture over the western Gulf. Meso models not supporting much development tonight, but given the “vort” off to our WSW and increasing nocturnal speed convergence over the nearshore waters expect activity to begin to fire off in the 100am-400am time period and at least spread toward the coast. This tends to be fairly common with these types of air masses and setups.



Main question becomes if and how far inland any coastal convection will penetrate on Thursday morning. Think main trough axis over SC TX will be closer to SE TX on Thursday morning and this will support a little better inland movement of activity however events in the past tend to favor convection anchoring near the coast or offshore and little inland development (ie today). Meso models are not really handling the potential for development very well and will trend more toward experience in these situations over short term model guidance and go with nearshore development late tonight moving into at least the coastal counties and possibly reaching US 59.



With the trough axis closer tomorrow storm motions may be slower than the last few days. Even with 15-25mph movement we have still been able to see 1-2 inch per hour rainfall rates with the stronger cells. Think motions on Thursday will be in the 10-15mph range and the air mass remains extremely moist so high hourly rainfall rates will be common. Flash Flood Guidance has shown only modest decreases as rains so far have been spotty and not overly concentrated and for the most part think we should be able to handle an additional 2-3 inches without major problems. Some concern for urban areas where tropical rainfall rates can easily overwhelm drainage systems even if the storm total is a couple of inches, but it all falls in 30-45 minutes.



Friday-weekend:

Upper ridging will at least attempt to gain a foothold across the region, but I have my doubts if it will be able to cut off rain chances. GFS drops rain chances from 61% Friday to 25% Saturday which seems a little aggressive with the drying. Models have been struggling with how fast and how strong the sub-tropical ridge builds over the region. Think the ridge will have a harder time gaining a foothold with fairly moist grounds and green vegetation compared to the past several summers and allow at least scattered seabreeze storms each day.



Ridge looks to finally overtake the area early next week, but again looks short lived as a westward moving tropical wave/TUTT low works is way from FL toward TX by the middle to end of next week. This may result in another surge of deep tropical moisture toward the July 3-4 time period with increasing rain chances again.

According of Jeff, he thinks that tropical wave you mentioned could end up here by next week.

[Paul Robison]

Ring any bells?

[Rip76]

Everything seems really worked over.

[Andrew]

Still seeing some high PW values out there. Gulf is still very moist with PW ranging from 2-2.2 inches. Any type of meso low that was trying to develop around the Corpus area has dissipated from the amount of work-over the atmosphere experienced earlier today. Looking into the overnight hours, I suspect things will remain relatively quite until the morning hours. The coast is relatively stable and I suspect we will need to reach convective temps to see widespread precip. 850mb-surface wind prorogation suggests we should see plenty of moisture advecting from the central and western parts of the gulf. The NAM hi res has been doing a very poor job at accurately initializing storms across the area so it is hard to put much trust in it. The HRRR on the other hand, has done a much better job at this and suggests that around noon tomorrow we should see another large surge of moisture cross the area. Storm motion is predicted to be under 10kts tomorrow which really supports a flooding threat. Today was a good example of that across parts of central Texas and the coast as storms didn't move much at all. This will only be amplified by any outflow boundaries that are produced. Similar to today, places that receive rain could receive a lot in a short period of time. Keep in mind that radar underestimates rain estimates in these type of tropical air masses.

[Paul Robison]

Still seeing some high PW values out there. Gulf is still very moist with PW ranging from 2-2.2 inches. Any type of meso low that was trying to develop around the Corpus area has dissipated from the amount of work-over the atmosphere experienced earlier today. Looking into the overnight hours, I suspect things will remain relatively quite until the morning hours. The coast is relatively stable and I suspect we will need to reach convective temps to see widespread precip. 850mb-surface wind prorogation suggests we should see plenty of moisture advecting from the central and western parts of the gulf. The NAM hi res has been doing a very poor job at accurately initializing storms across the area so it is hard to put much trust in it. The HRRR on the other hand, has done a much better job at this and suggests that around noon tomorrow we should see another large surge of moisture cross the area. Storm motion is predicted to be under 10kts tomorrow which really supports a flooding threat. Today was a good example of that across parts of central Texas and the coast as storms didn't move much at all. This will only be amplified by any outflow boundaries that are produced. Similar to today, places that receive rain could receive a lot in a short period of time. Keep in mind that radar underestimates rain estimates in these type of tropical air masses.

This HRRR graphic come close to what you're talking about, Andrew?

[Andrew]

Still seeing some high PW values out there. Gulf is still very moist with PW ranging from 2-2.2 inches. Any type of meso low that was trying to develop around the Corpus area has dissipated from the amount of work-over the atmosphere experienced earlier today. Looking into the overnight hours, I suspect things will remain relatively quite until the morning hours. The coast is relatively stable and I suspect we will need to reach convective temps to see widespread precip. 850mb-surface wind prorogation suggests we should see plenty of moisture advecting from the central and western parts of the gulf. The NAM hi res has been doing a very poor job at accurately initializing storms across the area so it is hard to put much trust in it. The HRRR on the other hand, has done a much better job at this and suggests that around noon tomorrow we should see another large surge of moisture cross the area. Storm motion is predicted to be under 10kts tomorrow which really supports a flooding threat. Today was a good example of that across parts of central Texas and the coast as storms didn't move much at all. This will only be amplified by any outflow boundaries that are produced. Similar to today, places that receive rain could receive a lot in a short period of time. Keep in mind that radar underestimates rain estimates in these type of tropical air masses.

This HRRR graphic come close to what you're talking about, Andrew?

Yea it is. I was mainly noticing the moisture stream from the western part of the gulf streaming north. I think there will also be other activity along the coast too as convective temps are reached.

[Paul Robison]

Andrew, I don't seem to see very much happening in the Houston region on the HRRR. It looks more like the absolute worst will be to the east and southwest of the metro. But that's me.

[Andrew]

Andrew, I don't seem to see very much happening in the Houston region on the HRRR. It looks more like the absolute worst will be to the east and southwest of the metro. But that's me.

HRRR only goes out 15hrs.

[unome]

I like when they do video updates

https://www.youtube.com/watch?v=2v2-qWgEjaU

[djmike]

Wow, QPF and current radar seems to be way off...

[ticka1]

What does the you tube update show? Can't play youtube here at work.