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Alex Becomes a Hurricane

By: Dr. Jeff Masters, 2:57 AM GMT on June 30, 2010

Hi, Dr. Rob Carver filling in for Jeff on the late shift.

430AM EDT Update
The 400AM EDT advisory package has hit the wires. Alex' center of circulation is located at 23.3N, 95.1W, which is 175 miles east of La Pesca, MX and 235 miles southeast of Brownsville, TX. Alex is responding to a weakness in the ridge to it's north, the storm motion has shifted to WNW at 7 mph. The winds are unchanged from the 100AM advisory, they are still 80 mph. However, Alex continues to deepen it's pressure, the minimum central pressure is 961 mb. Hurricane force winds now extend to 30 miles away from the center, and tropical force winds extend to 200 miles from the center. Alex is currently over warm ocean waters and under weak vertical shear, so the winds are forecast to increase. However, given the strength of Alex's central pressure, there is a small possibility of a rapid intensification of an additional 35 mph.

I haven't changed my risk assessment with this advisory. Flooding from rain still remains the greatest hazard posed by Alex. Tropical storm force winds are expected to reach the coast later this morning. People should plan on finishing their outdoor preparations by this time.

150 AM Update As of the 100AM EDT advisory, Alex is at 23.1N, 94.8W. The minimum central pressure is 972 mb, and the winds have increased to 80 mph. Alex is slowly moving westwards at 5 mph in an "erratic" fashion.

As of the 11PM EDT advisory, NHC has upgraded Alex to a hurricane with maximum winds of 75 mph and a minimum central pressure of 973 mb. Alex's center is at 23.1N, 94.8W, which is 255 miles south of Brownsville, TX and 195 miles east-southeast of La Pesca, MX. Alex is moving westwards at 9 mph. Alex is expected to slightly alter it's course to the WNW before making landfall south of the Rio Grande. The winds are also forecast to pick up to 90 mph before landfall. In any event, mandatory evacuation orders have been issued for recreational vehicles and other high-profile vehicles in county parks on South Padre Island. A voluntary evacuation is in place for residents of South Padre Island and Port Isabel.

Threat from storm surge
NHC is forecasting a 3-5 foot storm surge north of the eye as Alex makes landfall.

Threat from wind
NWS forecasters expect that damage from Alex's winds will be limited to the southern counties of Cameron, Willacy, and Hidalgo. Hurricane force winds extend 15 miles from the storm center, but tropical storm force winds extend 175 miles from the center. This is a rather large circulation. The Storm Prediction Center is monitoring southern Texas for the threat of tornadoes in the outer rainbands as Alex makes landfall. I'd expect a tornado watch to be issued around noon CDT.

Threat from rain
This is the most significant impact from Alex. Rainfall totals of 6 to 12 inches are expected over northern Mexico/southern Texas with 20 inches possible in some locations. There will be flooding from this storm. If more than 5 inches fall in 6 hours, there will likely be flash flooding. The NWS office in Brownsville is advising people who were flooded out by Dolly in 2008 to evacuate to higher ground now.


Satellite-derived rainfall estimates for Alex's passage over the Yucatan peninsula on June 28, 2010. Data provided by the Climate Prediction Center.

Alex is the first Atlantic June hurricane since 1995's Allison. The storm tally for that season was 19 named storms, 11 hurricanes, and 5 major hurricanes. It will be interesting to see how this season compares to 1995.

Next update
I'll have an update Wednesday evening/night. Jeff will have an update sometime tomorrow morning.

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

1502. Squid28
If it were a hundred years ago, and i was on the upper Texas coast, I would be freaking out, swearing that a storm was coming in on my door step. I know it is going south but the sky sure has that look, as does the water up here.

Also here is the Trinity river authority gauges/flow data, see if I can find the rest to many bookmarks...

TRA LINK
1480:

Wow.

That radar shows very nearly true N motion...



eye clearing up on vis... maybe we will get a clear eye here soon
1505. hercj
Quoting Skyepony:


Just about to fix center..

Sky, have you noticed the last two fixes have been NW and if im looking at the flight path right this one is going to be NW as well?
Thanks StormW - I'm on & off the blog this morning & just saw your reply to my question.
Quoting StormW:


For right now, until I look at things later today, my benchmark is at least a possible border hit.


Thank you so much. Always appreciate your insight. Will look for your update later today.
1508. IMA
Quoting Patrap:
Areal Flood Watch, Coastal Flood Advisory

Good morning, {{{Pat}}}! I think y'all have gotten more rain than we have - but I'm afraid that's going to change, maybe greatly. This has sure been a "fun" one to watch, I tell ya!
1510. Max1023
1505 - The eye seems to be oscillating between 300deg and 340deg motion for an average of maybe 315-325deg.
1511. Squid28
Lower colorado river authority link, discharges into the west bay of Matagorda

L.C.R.A. LINK
1512. Patrap
13:45:00Z 24.533N 96.300W 843.7 mb

(~ 24.91 inHg) 1,379 meters

(~ 4,524 feet) 988.0 mb

(~ 29.18 inHg)
Quoting RecordSeason:
1480:

Wow.

That radar shows very nearly true N motion...

more like nw/nnw
1514. Patrap
Quoting IMA:
Good morning, {{{Pat}}}! I think y'all have gotten more rain than we have - but I'm afraid that's going to change, maybe greatly. This has sure been a "fun" one to watch, I tell ya!


G'morn IMA ..
Quoting MiamiHurricanes09:
Wow pretty slow motion there. I'm starting to think more towards a landfall tomorrow morning/afternoon opposed to a landfall late tonight.


TWC just showed early Thursday morning, 1AM as landfall...was going to be tonight.
1516. 7544
wait is that a wobble now in the frame to the nne could he want to do this before reaching at least 25n hmmmmm
Quoting Patrap:


Great loop! Seems to be returning to the wnw motion
Quoting Squid28:
If it were a hundred years ago, and i was on the upper Texas coast, I would be freaking out, swearing that a storm was coming in on my door step. I know it is going south but the sky sure has that look, as does the water up here.

Also here is the Trinity river authority gauges/flow data, see if I can find the rest to many bookmarks...

TRA LINK


I'm on the East Fork of the Trinity--be interesting to see if it floods with all that water being pushed up.
7544 this is more probable there are lots of factors that come into play here..alex is huge in size already his circulation is over mexico ..in that part of the gulf when a storm the size of alex starts to feel the friction from the mexican coast it tends to back off stall like its doing now..another thing not in alex favor is the high that was steering it wnw or w can't anymore it has moved to far north..the last thing is alex has deepening trough at the 750mb level over the sw that will be the main player for alex in the next 36-48 hours..so for now alex movement will be erratic and maybe a slow n drift at the most..all upper texas and la should not let there guard down here ...
Quoting CyclonicVoyage:


Thanks Skye. How are things?


Good.. Alex isn't here, need rain though.

LRandyB's blog has some recon pics from lastnight. Looked a little tense coming back early with the broken radar.

Hunters are still headed in..down to 959.3 mb
(~ 28.33 inHg) a few minimal hurricane flight winds.
1521. Patrap
Quoting TeachOnTheEdge:


TWC just showed early Thursday morning, 1AM as landfall...was going to be tonight.
Well with the slow motion I'm still thinking tomorrow morning (around 10 AM EDT) opposed to 1 AM.
Uh-oh. Pressure down to 959.3mb and they're still away from the eye.

000
URNT15 KNHC 301405
AF306 1101A ALEX HDOB 48 20100630
135530 2410N 09552W 8429 01362 9839 +203 +203 060041 042 033 003 00
135600 2409N 09551W 8426 01361 9837 +201 +201 059043 044 034 004 00
135630 2408N 09550W 8430 01354 9834 +199 +199 060046 046 035 003 00
135700 2407N 09549W 8429 01351 9832 +196 +196 060047 047 036 005 00
135730 2406N 09547W 8428 01346 9825 +195 +195 060046 046 039 004 00
135800 2404N 09546W 8430 01338 9820 +195 +195 060047 048 038 005 00
135830 2403N 09545W 8430 01333 9810 +197 +197 059049 050 040 005 00
135900 2402N 09544W 8426 01328 9802 +197 +197 055051 053 041 005 00
135930 2401N 09543W 8425 01321 9793 +196 +196 054054 055 044 005 00
140000 2400N 09541W 8432 01305 9783 +200 +200 052057 058 045 004 00
140030 2359N 09540W 8430 01296 9775 +190 +190 052059 061 048 005 00
140100 2358N 09539W 8428 01284 9756 +193 +193 053059 062 050 006 00
140130 2357N 09538W 8428 01271 9739 +202 +200 049056 057 051 004 00
140200 2356N 09537W 8428 01257 9724 +205 +198 043058 060 053 005 00
140230 2355N 09535W 8431 01240 9704 +208 +197 041055 056 054 005 00
140300 2353N 09534W 8421 01231 9682 +215 +197 036051 052 049 006 00
140330 2352N 09533W 8425 01211 9664 +218 +199 027049 050 044 004 00
140400 2351N 09531W 8425 01193 9639 +226 +202 019047 047 037 004 03
140430 2351N 09530W 8436 01156 9608 +236 +206 016037 043 038 003 00
140500 2350N 09528W 8426 01151 9593 +229 +211 021023 027 024 004 03
$$
;
940's anyone???
rita alex has very little motion now maybe inching his way north..
1528. Jynni99
Honetly right now I think there is going to be some horrible flooding from Alex... not pretty at all!
1529. Bayside
Morning all, been on here a long time, but rarely post unless something headed toward the Chesapeake Bay area. I just wanted to thank ncforcaster for his well explained post on the winds and correlation with the pressure gradient. Now that I am logged on, I guess I can use the ignore feature that I shoulda been using yesterday ;)

Stay safe all in Alex's path!

Jon
1530. JDSmith
Quoting Max1023:
1505 - The eye seems to be oscillating between 300deg and 340deg motion for an average of maybe 315-325deg.


Meaning...? NW-NNW?
1531. Patrap
When ya focus on Landfall of the CoC or Eye..one has to realize Half the Storm is on shore and so is most of the surge...at that time and point.

Landfall is just a Point in time.

The effects are beginning now and will only degrade and worsen today in the Warned areas
Have to see the next center fix but Alex is running away again to the NW

One thing I have learned on here - these systems will wobble back and forth before landfall. A wobble to the north does not mean it's moving to the north...you'de have to wait a while to see a change in it's direction.
recon has changed direction somewhat to more of a NNW fix
1535. Max1023
1530- It is going NW when you average it out, but quite slowly. 20-25 hours until landfall at this speed.
Quoting Thundercloud01221991:
940's anyone???
Unlikely. They are only a couple miles from the eye. I'm thinking more towards 953mb-958mb.
SPC DEEP S TX...

BASED ON LATEST NHC GUIDANCE...HURRICANE ALEX IS FORECAST TO
CONTINUE A WNWWD TRACK...MAKING LANDFALL ALONG THE NERN COAST OF
MEXICO TONIGHT. TIME TRENDS FROM BRO VWP INDICATE THAT LOW-LEVEL
SHEAR HAS STRENGTHENED CONSIDERABLY THIS MORNING WITH THE APPROACH
OF THE TROPICAL CYCLONE...AND THIS TREND WILL LIKELY CONTINUE
THROUGH THE REMAINDER OF THE DAY. AS WOULD BE EXPECTED...AMBIENT
AIR MASS IS VERY MOIST WITH PW VALUES APPROACHING 2.80 INCHES. AND
WHILE WIDESPREAD CLOUDINESS WILL LIMIT THE DEGREE OF DIABATIC
HEATING...THE HIGH MOISTURE CONTENT WILL MAINTAIN MODERATE
INSTABILITY WITH MLCAPE OF 1000-1500 J/KG.

CURRENT THINKING IS THAT THE THREAT FOR A FEW TORNADOES WILL
INCREASE THROUGH THE DAY...PEAKING THIS AFTERNOON INTO EVENING...IN
ASSOCIATION WITH ANY MORE PERSISTENT...ROTATING STORMS EMBEDDED
WITHIN LANDFALLING RAINBANDS.
Quoting Skyepony:


Good.. Alex isn't here, need rain though.

LRandyB's blog has some recon pics from lastnight. Looked a little tense coming back early with the broken radar.

Hunters are still headed in..down to 959.3 mb
(~ 28.33 inHg) a few minimal hurricane flight winds.


How far are they from the eye?
Blog sure is slow now, good, now I can go back and read what I missed..
1540. Patrap
RECON fly's a Pre planned Pattern over the Storm.\






Galveston/Clear Lake area will be pounded soon by some of Alex. (not sure I know how to post radar)
Quoting MiamiHurricanes09:
Unlikely. They are only a couple miles from the eye. I'm thinking more towards 953mb-958mb.


I'm thinking 957. just a guess :)
Quoting MiamiHurricanes09:
Unlikely. They are only a couple miles from the eye. I'm thinking more towards 953mb-958mb.



Im sorry I was referring to peak strength
1544. jpsb
Quoting hurricanehanna:
One thing I have learned on here - these systems will wobble back and forth before landfall. A wobble to the north does not mean it's moving to the north...you'de have to wait a while to see a change in it's direction.
Very true, a wobble or two does not mean a change in direction. (I hope)
Quoting hercj:

Sky, have you noticed the last two fixes have been NW and if im looking at the flight path right this one is going to be NW as well?


This next one may show a little wobble south..they are already south of the last fix..
1546. beell
12Z NAM would suggest that the general track forecast for Alex is still valid as ridging slowly builds to the S over TX.

2 frames from the 500mb 12Z NAM. Note the position of the 588 isohyte at 12Z (7AM CDT) and 00Z Thur (7PM tonight CDT). Certainly not a killer ridge but enough to suggest Alex will take a very gentle curve towards the beach. I'll guess landfall approx 50 miles S of Brownsville.

12Z soundings across the TX coast (and inland some) place the current weakness along the Rio Grand Valley.


Link


Link
i doubt this is going to mexico, either lousianna or texas.
000
URNT15 KNHC 301415
AF306 1101A ALEX HDOB 49 20100630
140530 2350N 09526W 8432 01134 9589 +216 +216 036005 011 002 004 03
140600 2349N 09525W 8426 01137 9583 +224 +218 229006 009 999 999 03
140630 2350N 09523W 8436 01131 9588 +219 +219 163012 015 004 004 03
140700 2350N 09522W 8429 01138 9588 +217 +217 180019 021 999 999 03
140730 2349N 09520W 8436 01142 9601 +212 +212 190036 047 038 007 03
140800 2348N 09519W 8430 01161 9619 +209 +209 195059 061 052 008 03
140830 2348N 09517W 8436 01178 9644 +209 +209 196064 066 055 010 03
140900 2347N 09516W 8425 01201 9655 +209 +209 198064 065 999 999 03
140930 2347N 09516W 8425 01201 9650 +207 +207 203059 060 053 013 03
141000 2347N 09519W 8420 01184 9631 +208 +208 208054 059 052 010 03
141030 2347N 09521W 8428 01161 9616 +210 +210 216037 041 044 010 03
141100 2348N 09522W 8430 01151 9607 +211 +211 216024 027 029 005 03
141130 2349N 09524W 8428 01148 9600 +213 +213 196012 016 012 005 03
141200 2349N 09526W 8438 01137 9601 +211 +211 052003 007 010 005 03
141230 2350N 09527W 8425 01151 9599 +216 +215 025013 014 999 999 03
141300 2351N 09527W 8425 01153 9600 +220 +217 053012 013 007 005 03
141330 2352N 09526W 8435 01141 9600 +215 +215 095018 020 013 005 00
141400 2353N 09525W 8424 01153 9601 +214 +214 116030 039 030 006 00
141430 2355N 09524W 8434 01150 9608 +217 +217 119051 055 047 006 00
141500 2356N 09522W 8440 01158 9625 +213 +213 122062 065 056 008 00
$$
;


958.3 I was close
1549. Patrap




Quoting Thundercloud01221991:



Im sorry I was referring to peak strength
When it peaks prior to landfall you will likely see some 949-940mb readings, you might even see some 930s.
1551. FLdewey
Geez the Northwishing won't stop until landfall in Mexico... heck maybe even after landfall.
Quoting MiamiHurricanes09:
When it peaks prior to landfall you will likely see some 949-940mb readings, you might even see some 930s.


if we get into 930's that usually is equal to cat 4/5 right
958.3 mb
(~ 28.30 inHg)

23.817N 95.417W


That's more N than W of the last fix
turned into NE quadrant meaning we will see how high these winds are... before 11 AM
958.3mb pressure reading was located at: 23.4°N 95.2°W. The 8AM intermediate advisory center fix was at: 23.4°N 95.3°W.

Alex is obviously stationary, and believe it or not drifting slowly eastward.
its goin to mexico accept it and move on
If I lived close to Brownsville Texas.. this northern shift would bother me... a lot



AOI
7am CDT Intermediate Advisory
Information via the National Hurricane Center







Always good to remember that a few degrees of variation or wobble, as a storm is approching landfall, can mean a difference of a few hundred miles in terms of the eyewall...But, to my eyes, the current "drift" appears to be towards the North a bit but still within the cone.....Agree with Storm that we might see a general "border" area landfall give or take a hundred miles on either side (more impacts felt in Texas).
1562. Max1023
1556 - No, it is still moving NW-NNW, the intermediate position was based on satellite estimates and was off a couple tenths of a degree. It is moving slowly however.
miami thats going to be alex drifting erratic for the next 24-36 hours..
Quoting Thundercloud01221991:


if we get into 930's that usually is equal to cat 4/5 right


900mb is not out of the question..
Quoting FLdewey:
Geez the Northwishing won't stop until landfall in Mexico... heck maybe even after landfall.


LOL! True! ;)
Quoting MiamiHurricanes09:
958.3mb pressure reading was located at: 23.4°N 95.2°W. The 8AM intermediate advisory center fix was at: 23.4°N 95.3°W.

Alex is obviously stationary, and believe it or not drifting slowly eastward.



That should put a kinck in the NHC projected path. This could get real interesting.
NEW BLOG
Just woke up, pointed my curser at the center of the storm of the floater from last night, refreshed it, and it has moved an inch! Not just that, but a NW movement, Amazing storm.
from radar view, the eye from an Xtrap point of view would take it north of Brownsville
1570. jpsb
Quoting MiamiHurricanes09:
958.3mb pressure reading was located at: 23.4°N 95.2°W. The 8AM intermediate advisory center fix was at: 23.4°N 95.3°W.

Alex is obviously stationary, and believe it or not drifting slowly eastward.
Looking at Pat's radar, motion appears to be NW. Are you seeing something different?
Quoting Max1023:
1556 - No, it is still moving NW-NNW, the intermediate position was based on satellite estimates and was off a couple tenths of a degree. It is moving slowly however.
Just pointing out the coordinates between center fixes, and I believe that the 8AM advisory position was from Recon and not satellite. Either way Alex seems to be moving very slowly.
1572. FLdewey
Quoting JamesSA:

We might as well start evacuating Chicago NOW. ;-)


LOL! Well I can see it now... as Alex makes landfall in Mexico somebody on here will start posting "look... you can see on radar it's backing up and heading to LA" LOL.
new blog
NEW BLOG!


definitely a shift...still going to Mexico...
No northwishing here... Some would just like to know how much weather we will get from this storm. The further north it goes the more severe/weather some of us will get. 100 miles can make a difference
1577. LaCoast
Hey STORMW
Could you give us your thoughts on this supposed weakness in the ridge. Even if it exists does it really have a major influence on the steering of Alex. I don't see a stall and I don't see a true NW. I still see a WNW. Just a reminder to all picking apart the SAT's frame by frame is very deceiving. The earth is round and huge.
1578. Asta
WATER VAPOR
1579. Asta
IR
With the steering bieng so weak, is there a chance this storm could possibly ride up the coast. Just curious
Quoting mcluvincane:



That should put a kinck in the NHC projected path This could get real interesting.

If that is true should New Orleans Start Evac? Way to soon to say east movement.
1585. snotly
I wonder if the storm can wobble if most of the convection gets forced to one side because of dry air.
Quoting watchingnva:


definitely a shift...still going to Mexico...


You'd best be putting up a big disclaimer and cropping out their logo you go coloring on government maps.
1587. Asta
Quoting watchingnva:


definitely a shift...still going to Mexico...


Probably a decent wobble. It;s going to continue to wobble too.
To follow the NHC forecast path Alex is going to have to slam on it's brakes and make a sharp left, after speeding up a little to the NW.
Saved as favorite - Thank You!
01L/H/A/C2
MARK(APPROACHING LANDFALL)
24.6N/97.1W