Alex Slowly Gains Strength

By: Dr. Jeff Masters , 6:35 AM GMT on June 29, 2010

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Hello, it's Dr. Rob Carver substituting for Jeff on the late shift.

As of the 0100 EDT advisory, Alex is 475 miles SE of Brownsville TX moving NNW at 8 mph. The advisory wind speed is 65 mph with a minimum central pressure of 985 mb. The most recent vortex fix was at 1225EDT with an unchanged pressure reading. Alex is expected to take a turn to the NW and make landfall just south of Brownsville late Wednesday night/early Thursday morning. The government of Mexico has issued a hurricane warning from the mouth of the Rio Grande south to La Cruz. NHC has hoisted the hurricane warning flag from the Rio Grande north to Baffin Bay. A tropical storm warning extends from Baffin Bay to Port O'Connor. Alex is expected to expand in size so it will be much larger than Hurricane Dolly, which was the last storm to affect the region in 2008.

Hurricane Local Statements are now being issued by the Brownsville and Corpus Christi NWS offices. These statements provide a detailed look at how Alex will affect the region and summarize how local emergency management is responding to the situation.

Alex has three different ways to negatively impact the Rio Grande Valley: storm surge, heavy rains, and strong winds.

Risk of Storm Surge
NHC is forecasting a storm surge of 3-5 feet along the coast north of where Alex makes landfall. The exact details of the surge's extent depend on where Alex makes landfall and how big it gets while it is over the open water. I've include a plot of the statistical storm surge forecast product. Unless Alex refuses to make it's left turn, I don't think there's a chance of storm surge north of Port O'Connor.

Plot of experimental storm surge forecast.

Threat from Rain
NHC thinks 5 to 10 inches of rain over southern Texas/northern Mexico is possible when Alex makes landfall. This is why the Brownsville office thinks the primary threat from Alex will be inland flooding in areas with poor drainage.

Alex has a history of producing torrential amounts of rain as shown by this estimate of rainfall during Alex's passage over the Yucatan Peninsula.

Satellite-derived rainfall estimates for June 27, 2010 using data from the Climate Prediction Center.

Threat from Wind
Alex is currently forecast to reach hurricane status. There will likely be hurricane force winds along the coast where Alex makes landfall. The current hurricane wind probabilities show that Brownsville has a 77% chance of experiencing tropical storm force winds and a 18% chance of experiencing hurricane force winds. Corpus Christi has a 44 % chance of tropical storm winds and a 4% chance of hurricane force winds. There is also the possibility of tornadoes forming in outer rainbands as Alex makes landfall.

The Curious Incident of the Hurricane Dynamical Models
One thing that strikes me as odd about Alex is that neither the GFDL nor the HWRF have been intensifying the storm into a hurricane in the past few model runs. This is intriguing because Alex is already a strong tropical storm. It will bear watching to see if GFDL/HWRF continue this pattern for future storms.

Next Update
Jeff will post an entry sometime this morning, and I'll have another entry late Tuesday night.

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162. IKE
Quoting southtxweather:
Good morning~

I am in McAllen TX, inland from Brownsville. Should we board the windows?

Thanks for your help!!


I'd be doing something if it were me. NHC states that intensity is hardest to forecast. He looks on his way to a cane. NHC has the path about zeroed in.

Good luck!
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting southtxweather:
Good morning~

I am in McAllen TX, inland from Brownsville. Should we board the windows?

Thanks for your help!!
if dolly was bad for you in mcallen then yes. Alex should be worse..
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My parents live in Harlingen, and during Dolly they had trees down and also water damage from loss of shingles. Were glad they boarded, but thyen again Harlingen is also under that inland hurricane warning. Never hurts to board.
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Quoting hurricanehanna:
morning gang. I thought for sure this AM we'd see watches going up further to the TX/LA coast based on the stearing map from last night. Guessing Alex isn't "feeling" the opening


yah, im from galveston, and don't trust alex.

Good morning~

I am in McAllen TX, inland from Brownsville. Should we board the windows?

Thanks for your help!!
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Link
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isn't it kinda of weird that every storm that hits the U.S now just goes to texas?

erin
Humberto
dolly
edward
ike
and now alex

exept for fay and claudette the rest been hitting Texas.

morning gang. I thought for sure this AM we'd see watches going up further to the TX/LA coast based on the stearing map from last night. Guessing Alex isn't "feeling" the opening
Member Since: September 5, 2007 Posts: 0 Comments: 3480
Good to luck to everyone in the RGV. We're outta here in about an hour before the roads get busy.

Gennys were going like mad yesterday at Home Depot--people 'cane shy after the power outages we had with Dolly, I believe. Be interesteing to see how this thing finally plays out.
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152. IKE
Isn't there someone on here from Brownsville,TX. that's been wishing for a hit? Looks like he's getting what he asked for. I wonder if his parents feel the same way? Looks like 2 days worth of Alex....

Wednesday
Very windy. Showers and thunderstorms likely. Some thunderstorms may produce gusty winds. Locally heavy rainfall possible. Highs in the upper 80s. North winds 20 to 25 mph increasing to 40 to 50 mph with gusts to around 60 mph in the afternoon. Chance of rain 70 percent.

Wednesday Night
Very windy. Rain and thunderstorms. Rain may be heavy at times. Lows in the upper 70s. Northeast winds 35 to 45 mph. Gusts up to 75 mph. Chance of rain near 100 percent.
rain
Thursday
Strong winds. Rain and thunderstorms. Rain may be heavy at times. Highs in the upper 80s. East winds 55 to 65 mph with gusts to around 70 mph becoming southeast and decreasing to 45 to 55 mph with gusts to around 60 mph in the afternoon. Chance of rain near 100 percent. Heat index readings around 105.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
80 mph flight level winds
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Quoting allhailme36:
yes....Finally starting to see some closed circulation around TS Alexes' eyewall.....too bad its headed right for me....!!!


Where do you live? I'm in Port Isabel.
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latest NHC track ya'll stay classy weatherunderground posters


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148. IKE
It is very close to Dolly.....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
147. IKE
Buoy 42055 @ 22.1N and 94.2W....

Wind Direction (WDIR): NNW ( 330 deg true )
5-day plot - Wind Speed Wind Speed (WSPD): 19.4 kts
5-day plot - Wind Gust Wind Gust (GST): 21.4 kts
5-day plot - Wave Height Wave Height (WVHT): 6.9 ft
5-day plot - Dominant Wave Period Dominant Wave Period (DPD): 8 sec
5-day plot - Average Period Average Period (APD): 5.9 sec
5-day plot - Mean Wave Direction Mean Wave Direction (MWD): ENE ( 73 deg true )
5-day plot - Atmospheric Pressure Atmospheric Pressure (PRES): 29.49 in
5-day plot - Pressure Tendency Pressure Tendency (PTDY): -0.06 in ( Falling )
5-day plot - Air Temperature Air Temperature (ATMP): 82.2 °F
5-day plot - Water Temperature Water Temperature (WTMP): 84.9 °F
5-day plot - Dew Point Dew Point (DEWP): 76.3 °F
5-day plot - Heat Index Heat Index (HEAT): 90.0 °F
Member Since: June 9, 2005 Posts: 23 Comments: 37858
dolly 2.0 he is
Alex will not hit mexico, he will hit mid texas coast. my weather men are treating alex like a cat 5. One even said y'all need to leave this is deadly and can be worse then Ike.
144. IKE
From the Birmingham,AL. discussion....

"A LOT OF UNCERTAINTY WITH THE FORECAST DURING THIS PERIOD. MANY
OF THE MODELS ARE HINTING AT A SURFACE LOW DEVELOPING ALONG STALLED
OUT SURFACE FRONT ON FRIDAY. PREVIOUS MODEL RUNS HAVE BEEN
SHOWING THE SURFACE LOW SHIFTING EASTWARD AND HELPING BRING IN
DRIER AIR FROM THE NORTH. HOWEVER...THE MODELS ARE NOW SHOWING THE
SURFACE LOW MOVING WESTWARD TOWARDS LOUISIANA. THIS WOULD PULL
MOISTURE BACK NORTHWARD INTO ALABAMA FRIDAY AND SATURDAY...AND
RAISED POPS ACROSS AREA FOR FRIDAY."


From Mobile,AL. discussion...

"COMPUTER MODELS ARE IN GOOD AGREEMENT THROUGH AT LEAST FRIDAY WITH
THIS SOLUTION. OVER THE WEEKEND...THINGS BEGIN TO DIVERGE. THE GFS
AND GEM WANT TO DEVELOP A SURFACE LOW PRESSURE SYSTEM ALONG THE
FRONTAL BOUNDARY ON FRIDAY AND REMAIN NEARLY STATIONARY OVER THE AREA
THROUGH THE WEEKEND. THE ECMWF ON THE OTHER HAND HAS NO SUCH FEATURE.
IT PUSHES THE FRONT THROUGH AND SETS UP A MUCH DRIER PATTERN BY
SUNDAY AND THROUGH EARLY NEXT WEEK WITH A RIDGE OF HIGH PRESSURE IN
PLACE.

BEING THIS FAR OUT AND WITH SO MANY DIFFERENT UNKNOWN VARIABLES WILL
RESULT IN A VERY LOW CONFIDENCE IN THE LONG TERM PORTION OF THE
FORECAST. TOOK A BLEND OF ALL 3 MODELS FOR NOW AS A COMPROMISE FOR
BOTH RAIN CHANCES AND TEMPERATURES."


NO,LA discussion.....

"LONG TERM...
AS ALEX MAKES LANDFALL AND MOVES INLAND OVER THE WESTERN GULF
COAST...A FRONTAL BOUNDARY IS EXPECTED TO LINGER EITHER OVER OR
JUST NORTH OF THE FORECAST AREA ON THURSDAY AND FRIDAY...BUT AM
DISCOUNTING THE SURFACE LOW ALONG THE FRONT THAT THE GFS MOVES
WEST ALONG THE CENTRAL GULF COAST.
STILL...NUMEROUS SHOWERS AND
THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL ARE EXPECTED AGAIN ON
THURSDAY. THE SHOWERS AND STORMS SHOULD BECOME MORE SCATTERED ON
FRIDAY AS A WEAK HIGH PRESSURE AREA ALOFT TRIES TO BUILD IN AS THE
FRONTAL BOUNDARY DISSIPATES.

THE ECMWF AND GFS MODELS DIFFER GOING INTO THE WEEKEND AND EARLY
NEXT WEEK WITH THE ECMWF ADVERTISING A DRIER SOLUTION DUE TO A
STRONGER 500 MB RIDGE BUILDING IN FROM THE NORTH. THE GFS KEEPS
SUBTLE WEAKNESSES ALOFT AND DEEPER MOISTURE OVER THE FORECAST
AREA. HAVE FOLLOWED CLOSER TO THE GFS WHICH MAINTAINS AS BIT
BETTER CONTINUITY WITH THE PREVIOUS FORECAST WITH A CHANCE OF
MOSTLY DAYTIME SHOWERS AND THUNDERSTORMS."

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Hurricane Force flight level winds
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Good morning...
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Good Morning...
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lots of 50+ knt flight level winds
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BBL all. (prolly around 8a.m. local time....)
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alex not look good imo
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Quick update from ACCUWEATHER:




Alex Nearly a Hurricane


As of 4:00 a.m. CDT, Alex is located near 21.7 north and 91.9 west, or about 460 miles southeast of Brownsville, Texas. The storm has increased its speed slightly to 8 mph and maximum-sustained winds have increased to 70 mph. Minimum central pressure has lowered to 984 millibars, or 29.06 inches.



A hurricane warning continues from the coast of Texas, south of Baffin Bay to La Cruz, Mexico. Hurricane-force conditions are possible in these areas within the next 36 to 48 hours. The tropical storm warning for the Texas coast from Baffin Bay to Port O'Connor remains in effect.

.

Areas of deep convection have continued to blossom around the central circulation of Alex through the night. This trend of thunderstorm development around the center of the storm should continue to increase leading to strengthening of the system. A gradual strengthening trend in expected from Alex until landfall as the storm passes over very warm water, which is in the middle 80s. Any limiting factors to the strengthening of Alex will be minor. The storm is moving through an area where there is very little wind shear, and it is expected to remain that way.



With the current motion of the storm to the north-northwest, one of the biggest questions will be when Alex makes the turn to west. The longer the storm takes to turn to the west, the greater the threat will be to South Texas and the lower Rio Grande Valley region. Also, the slower the storm moves, the longer it will spend over water and therefore be able to gain strength. The westerly turn that the storm is expected to make will likely occur later today as a ridge to the north begins to build. This will, in effect, keep the storm from moving north as it turns the steering flow more to the west. At this point, it appears most likely that Alex will reach hurricane strength, even to Category 2 intensity, before making landfall just south of the mouth of the Rio Grande.



Alex has a fairly large circulation however, so it will have far-reaching effects. The outer most rain bands from Alex could be impacting coastal South Texas as early as the wee morning hours of Wednesday. Coastal South Texas will likely experience tropical storm conditions late on Wednesday and Wednesday night into Thursday as Alex's center makes landfall just south of the Rio Grande. If the current forecast track works out, hurricane conditions could also be felt for a time along coastal Cameron County and perhaps Willacy County in Texas. There will also be a storm surge of at least a few feet in this area. However, the greatest concern at this point is the potential for excessive rainfall over a large area of South and even southeastern Texas. Not only will excessive rain fall over Deep South Texas and the lower Rio Grande Valley region on Wednesday night into Thursday, drenching thunderstorms are likely well to the north, perhaps even into coastal Louisiana. This will likely result in flooding problems well to the north of the storm track.



Elsewhere in the tropics, there are a few tropical waves, but any development through the Atlantic is not expected. There is an upper-level low east of the Bahamas, which absorbed a tropical wave over the last couple of days. While this feature will not likely develop further however, it could bring some drenching thunderstorms to Florida by Thursday.



By AccuWeather.com Meteorologist Adam Douty

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Blog Update

Alex nearing hurricane strength

BBL
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Quoting miguel617:
I live in Brownsville and work in Matamoros. I wish this storm had already become hurricane. I can't decide if I should board up the windows or not. It seems that the big threat will be flooding as opposed to high winds.

Miguel, people in Corpus are boarding up as a precautionary measure--I'd do the same if I were in Brownsville--you can always take them down when the rain stops, but once the winds start, it will be very difficult to board up. Happened to us during Bret--was out of town and had to board up during the storm once we got home-not fun.
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The 00z GEM and the GFS are harmoniously developing a system in the eastern GOM.
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...WATER VAPOR IMAGERY INDICATES
THE UPPER-LEVEL OUTFLOW PATTERN IS STRONGLY ELONGATED IN A
NORTH-SOUTH ORIENTATION. THIS IS A GOOD SHORT-TERM MOTION INDICATOR
...WHICH WOULD SUGGEST THAT ALEX SHOULD MAINTAIN ITS CURRENT
NORTH-NORTHWESTWARD MOTION FOR ANOTHER 6-12 HOURS BEFORE TURNING
TOWARD THE NORTHWEST.

This is interesting too. Without the NW / WNW turn, Alex would end up somewhere near Port O'Connor, right?
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Quoting IKE:
If the GFS verifies with the northern GOM low, which seems unlikely, it's a washout all week in the eastern GOM coast.

IKE see my post below, GFDL and CMC are now on board
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Should Alex become a hurricane before the 11pm advisory on Wednesday night, it would be recorded as a June hurricane. We have not had one in a very long time, not even in 2005. The date for the first hurricane is Aug 10. We would surpass 2005 by a few days - Cindy.
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55 knt surface winds already in Alex per recon... no where near the center
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good morning all, just checking in on the slooooow progress of alex, north? north west? still a little disorganized, none the less a rain maker & high tide/ surge in coastal areas, key west is cloudy overcast with winds 15-20 no rain yet & humidity in the tolerable range, check back later
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Quoting Levi32:
Great forecast by Stewart....as every one of his has been so far on this storm. Great reasoning on the models possibly being still a bit too far south based on Alex's behavior and cloud pattern.

I'm out as well, till tomorrow everyone.
I was about to say how much I'm enjoying Stewart's discussions. Clear, concise, and focused on the "salient" points....
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According to a local met, Alex will stay on current path and then about 12 hrs from now will shift off towards the west.
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Quoting DestinJeff:


thanks. my concern is that the rockies high is shifting ene / ne and will be centered too far north as a weak high to really induce the westward motion of Alex that is forecasted.

if he doesn't make landfall as a result the the ridge, then that leaves a chance for a sw flow from the advancing trof out west to then influence his steering to the n / ne.



I think the Rockies high would have a tendency to propagate either east or southeast to replace the trof. A landfall in SE Texas is not out of the question tho.

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Quoting MahFL:
Alex seems to be north of the official track.


he's been north of the projected track(okay, in the northern portion of the projected path) since midday yesterday, really, and the "official" track has changed very little; seems odd that he's expected to make a relatively drastic turn like that...am I that far wrong on this?
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Morning all.

Thanks for the update, Dr. Carver. We do appreciate the unique way u guys have figured out to help deal with the blogomania we suffer from here ... .

I note at 4 a.m. CDT Alex is up to 70 mph. I expect we will see Hurricane Alex at the next update. I haven't looked at any maps yet, but I can really buy that Baffin Bay solution a lot more this a.m. Alex is still gaining latitude without much of a westward component to the movement.

Didn't I mention yesterday there was a reason the CLIP was included? I guess we have a while to go before Alex intercepts storm tracks that point to western TX / N Mexico....
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I agree I think he is North of the forecast track. I also dont think he will turn west till tommorow sometime but thats just me I think by late tonight if he still at this pace and going NNW than people in corpus might need to watch it. But im not a expert jsut my thinking
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I live in Brownsville and work in Matamoros. I wish this storm had already become hurricane. I can't decide if I should board up the windows or not. It seems that the big threat will be flooding as opposed to high winds.
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119. IKE
If the GFS verifies with the northern GOM low, which seems unlikely, it's a washout all week in the eastern GOM coast.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
118. MahFL
Alex seems to be north of the official track.
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Mornin' Buda et al from SPI.

One more day in paradise before we move inland I suppose.
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116. IKE
Quoting DestinJeff:
please let the GFS be wrong on the new low.


Spurious low?

Quoting redux:
I am a novice at this....

is that subtropican ridge a sure thing to develop?

from a statistical standpoint, you would think at least one of the runs of the model would show it not developing.


It's usually there all summer.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Looks like Mother Nature will decide what to do with the oil!
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Quoting DestinJeff:


hey 456, I have been wondering about the ULL off the east coast ... is that a player at all with regards to Alex? thanks


Its a player in Alex's intensity more than track by providing an upper outflow channel for the storm. however, even though the ull isnt deep enough to largely affect the deep layer steering of the storm; it has weakened the effects of the subtropical ridge over the W ATL resulting in the slow motion of Alex. This along with the weakness of the mid-lat trough.
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Good Morning from hot and humid Buda Texas
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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.