Tuesday, June 29, 2010

3pm NOAA Update on Alex Impact


I'm devoting my blog to the latest update from our local NOAA office in regard to the impacts from Alex:

Alex continues to slowly strengthen and is making a path toward deep South Texas and extreme northern Mexico. Ahead of this tropical system...easterly and northeasterly flow to its north is pulling in copeous amounts of moisture from the northern Gulf. This moisture, combined with a weakness aloft and daytime heating will continue to trigger scattered showers and thunderstorms over the next 24 hours ahead of Alex. This activity has the potential to create locally heavy rain with some isolated Flash Flooding concerns. Some of these storms may have rain rates on the order of 1-2 inches of rain per hour...enough to cause problems in low lying areas as well as urban areas.

As Alex makes landfall to our south by late Wednesday...even more moisture will push onshore and make it into South Central Texas. It appears that the main threat from this system will be locally heavy rain and possible flooding. I have attached the latest graphic showing the rainfall estimates that are forecast by our meteorologists. 3 to 4 inches with some isolated totals of 6 inches or more are generally forecast for southern areas of South Central Texas. As the center of Alex is forecast to be well south of the area, we do not expect to have sustained tropical storm force winds...Breezy conditions of 15-30 mph may occur generally south of line from Del Rio to San Antonio to Cuero. The strongest winds 20-30 mph will likely occur Wednesday night with some slightly higher gusts. These forecast wind speeds can also be found on the graphic. However, with any thunderstorm, there is a threat for gusty winds of 30-40, maybe as high as 50 mph.

Any sort of Tornado threat appears to be small. If we do get a threat for small tropical tornadoes, this threat would likely occur Wed night or Thursday as rain bands from Alex rotate west and northwest into the area. This would mainly impact southern areas of South Central Texas.

If the remnants of Alex head west as forecast, we will continue to see a threat of heavy rainfall through Friday. The threat may in fact then turn into a river flood threat for areas along the Rio Grande River near Eagle Pass and Del Rio. I have attached a 2nd graphic showing this threat as well.

Overall, the threat for South Central Texas appears to be mainly heavy rain...with some southern areas getting isololated totals of 6 inches or more over the next several days. Stay informed by going to the National Weather Service webpage www.srh.noaa.gov/ewx and monitoring the latest forecasts and tracks of Alex.

Paul Yura
National Weather Service Austin-San Antonio TX

Monday, June 28, 2010

The Latest on Alex...


The Hurricane Center has just released their 4pm update...they are shifting Alex to the south of where they were this morning, putting its landfall about 60 miles to the south of Brownsville. That would lower our rainfall chances, but since we will be in the right hand quadrant as it moves inland, it should give us some decent rainfall. There are still some models taking it to the north of that track...we shall see.

Meanwhile, the rare summer cool front is just to the NW of San Antonio, on a San Angelo to Abilene line. Along and to the south of the front isolated storms are forming this afternoon, but as of now, none have wound up in my backyard...just dry and hot in Helotes. Between the dying front and tropical storm Alex, I still think our chances for several inches of rain this week look good.

One of my favorite sites for tracking hurricanes is Stormpulse. Nice graphics!

Sunday, June 27, 2010

Where oh where will Alex go?

Late this afternoon, tropical depression Alex was almost finished traveling through the Yucatan peninsula and is about to move into the SW Gulf of Mexico. According to the latest forecast from the National Hurricane Center, Alex should redevelop into a tropical storm, then a category one hurricane, before moving NW into near Tampico,Mexico on Thursday. If that occurs, San Antonio will have to rely on a very rare "summer cool front" to move close enough to us to deliver some much needed rainfall. Even with a wet Spring, highs in the 90's tend to bake our vegetation around here and it does not take long to quickly move into a dry and brown landscape.

Here's where it all gets interesting...most of the time, by now, the "spaghetti" computer plots as they are known, start combining into a pretty narrow field of where a tropical system is going. With Alex, because of the rare cool front moving toward Texas and a fairly strong trough to our NE, several major computer models continue to bring Alex much closer to San Antonio. The GFS takes it into Houston, the HWRF into Corpus and the GFDL and NAM take it into Brownsville, which would all lead to some potentially big rains for south Texas. I'm leaning toward the models that take Alex near Brownsville...we shall see.

No matter what happens, it should be an exciting weather week around here...especially for this time in the summer, when it is normally pretty boring. Another positive sign this afternoon is the extended forecasts. Both the 6-10 and 8-14 forecasts are showing near normal temperatures and above normal rainfall.

Friday, June 25, 2010

Tropical "Something" Update....


Sorry I haven't updated this blog for a while, but I've been busy doing my "photo thing" and not much has been happening, weather wise.

Latest computer models are indicating a trough to form in the NE part of the country next week, changing our upper air flow from the tropical SE, to the NW. If this happens, the potential tropical "something" will stay to the south of Texas but our rain chances may increase from afternoon thunderstorms moving in from the NW...a more fall like pattern instead of summer. We may even see a cool front make a run for our area.

Meanwhile, the Hurricane Center wants to take the "depression" and possible tropical storm "Alex" into the Gulf by Wednesday. If Alex were to stay on the course of the Hurricane Center, we could see some big rains as it moves into Texas instead of Mexico. Either scenario looks promising for potential rain next week.

I'll be updating the storm this weekend.

Monday, June 14, 2010

A possible tropical system in Atlantic


A tropical low, almost off the coast of Africa, is being investigated by the Hurricane Center (Invest 92) for possible development. If it does turn into something it would not be a threat to the US until the end of this month. That's also our next chance of rain for San Antonio according to the latest models. Meanwhile, big storms with heavy rains are falling to the NW of us in north central Texas. The line of storms appears to be heading toward Dallas.

Here's what the National Hurricane Center has to say:

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUN 14 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. AN AREA OF LOW PRESSURE LOCATED ABOUT 1250 MILES EAST OF THE LESSER
ANTILLES HAS CHANGED LITTLE TODAY...BUT CONTINUES TO SHOW SIGNS OF
ORGANIZATION. ENVIRONMENTAL CONDITIONS ARE FORECAST TO REMAIN
SOMEWHAT CONDUCIVE FOR DEVELOPMENT OF THIS LOW FOR THE NEXT DAY OR
SO...BUT ARE EXPECTED TO BECOME LESS FAVORABLE AFTER THAT. THERE
REMAINS A MEDIUM CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES
WEST-NORTHWESTWARD TO NORTHWESTWARD AT ABOUT 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

Saturday, June 5, 2010

Hell High not as big as advertised

Although it will be getting pretty toasty in the San Antonio area for the next couple of days, the worst of the "Hell High" appears to be missing us. Because of that, look for increasing chances of rain, starting on Tuesday, and lasting for the rest of the week.

With the Atlantic, Caribbean and Gulf much warmer than average, I think we will see an early tropic season this summer. Hopefully there will be only tropical depressions in the Gulf instead of major hurricanes, but with El Nino leaving, major storms are possible.

In Helotes, our yearly rainfall now stands at 25.39 inches, with almost 6 more months to come.

Thursday, June 3, 2010

Storm Reports from NOAA

Below are some storm reports from last night's fast moving, big storm. At my place in Helotes, I witnessed a couple of large limbs fall from my neighbor's home around 8:30 last night as I was outside. Unfortunately, the computer that controls my weather station needed to be re-booted, so I did not record the high wind gusts of over 60 mph that were reported within a mile of my home, but seeing the damage done to trees in the neighborhood and being outside when the gusts occurred, I feel confident that we had similar winds. Rainfall total at my place was 0.61 inches.


06/02/2010 0815 PM

N Leon Springs, Bexar County.

Thunderstorm wind damage, reported by public.


Winds gusting to 50 mph and numerous power lines down.




06/02/2010 0825 PM

N sea world, Bexar County.

Thunderstorm wind gust e50 mph, reported by park service.


Winds gusting over 50 mph.




06/02/2010 0830 PM

3 miles SW of San Antonio, Bexar County.

Thunderstorm wind gust e50 mph, reported by NWS employee.





06/02/2010 0830 PM

N Castle Hills, Bexar County.

Thunderstorm wind damage, reported by amateur radio.


Numerous power outages.




06/02/2010 0830 PM

8 miles NNE of San Antonio, Bexar County.

Thunderstorm wind damage, reported by public.


Numerous trees blown down around the San Antonio
Airport.




06/02/2010 0830 PM

4 miles NNE of Alamo height Antonio, Bexar County.

Thunderstorm wind damage, reported by public.


EST 60 mph. Large tree limbs down




06/02/2010 0832 PM

San Antonio, Bexar County.

Thunderstorm wind gust m64 mph, reported by ASOS.





06/02/2010 0839 PM

7 miles W of San Antonio, Bexar County.

Thunderstorm wind gust e60 mph, reported by amateur radio.


Winds over 60 mph and nea loop 1604 and Bandera.
Several lines blown down.




06/02/2010 0840 PM

2 miles N of Alamo Heights, Bexar County.

Thunderstorm wind damage, reported by public.


Several tree limbs down and shingles blown from roofs




06/02/2010 0859 PM

N Alamo Heights, Bexar County.

Thunderstorm wind damage, reported by amateur radio.


Several tree Downs.




06/02/2010 0905 PM

10 miles S of San Antonio, Bexar County.

Hail e0.50 inch, reported by amateur radio.


Pea to Marble size hail report south of downtown San
Antonio.




06/02/2010 0840 PM

2 miles N of Alamo Heights, Bexar County.

Thunderstorm wind damage, reported by public.


Several tree limbs down and shingles blown from roofs





06/02/2010 0830 PM

4 miles NNE of Alamo height, Bexar County.

Thunderstorm wind damage, reported by public.


EST 60 mph. Large tree limbs down





06/02/2010 0905 PM

10 miles S of San Antonio, Bexar County.

Hail e0.50 inch, reported by amateur radio.


Pea to Marble size hail report south of downtown San
Antonio.





06/02/2010 0859 PM

N Alamo Heights, Bexar County.

Thunderstorm wind damage, reported by amateur radio.


Several tree Downs.





06/02/2010 0839 PM

7 miles W of San Antonio, Bexar County.

Thunderstorm wind gust e60 mph, reported by amateur radio.


Winds over 60 mph and nea loop 1604 and Bandera.
Several lines blown down.





06/02/2010 0830 PM

8 miles NNE of San Antonio, Bexar County.

Thunderstorm wind damage, reported by public.


Numerous trees blown down around the San Antonio
Airport.





06/02/2010 0830 PM

N Castle Hills, Bexar County.

Thunderstorm wind damage, reported by amateur radio.


Numerous power outages.





06/02/2010 0825 PM

N sea world, Bexar County.

Thunderstorm wind gust e50 mph, reported by park service.


Winds gusting over 50 mph.





06/02/2010 0832 PM

San Antonio, Bexar County.

Thunderstorm wind gust m64 mph, reported by ASOS.






06/02/2010 0830 PM

3 miles SW of San Antonio, Bexar County.

Thunderstorm wind gust e50 mph, reported by NWS employee.






06/02/2010 0815 PM

N Leon Springs, Bexar County.

Thunderstorm wind damage, reported by public.


Winds gusting to 50 mph and numerous power lines down.

Wednesday, June 2, 2010

Latest GFS looks promising


Latest computer runs are looking more optimistic for rain chances and rain amounts for late this afternoon or evening as an upper low moves this way from NW of us. We need every drop we can get before the "Hell High" moves in by later this week. Once the Hell High moves in, we could have 1-2 weeks of above normal temps and below normal precipitation.