Tuesday, November 24, 2015

Will Holiday Weather Be A Turkey?


It's looking a little soggy for Southeast Texas toward the end of this week. That could mean wet weather for the annual Thanksgiving Day parade in downtown Houston and depending on where you're traveling in the Lone Star a new taste of winter.

A vigorous winter storm hitting the Pacific Northwest Tuesday will being to move through the Rockies and then take a dive into Texas by Wednesday. High pressure east of the Mississippi will force Gulf moisture inland as a cold front approaches. Along the collision line is where rain will develop in Texas along with stronger storms in Oklahoma:


The system then deepens by Black Friday with icy conditions for the Texas and Oklahoma panhandles:


Don't worry though, the cold air doesn't seep much further than west Texas. Whatever your travel plans, have a safe holiday!





Tuesday, November 17, 2015

Cooler Weather Behind The Storms


Fortunately, most of southeast Texas missed seeing the kind of storms that roared across the panhandle Monday night. In the wake of Tuesday's drenching rains that did move through the region, colder air is poised to move in. Shown above are the expected morning low temperatures, mainly in the upper 40s and low 50s.

High pressure moving in the next few days should help dry things up a bit but freezing cold temperatures are not expected. The core of that colder air stays north of the region. That means only about two crisp fall mornings before the next change moves in this weekend. Here is a look at Thursday morning's low temperatures:


Notice they're not that much colder. A new front Saturday may bring some spotty rain, but behind it - the chilliest weather so far this fall moves in. Look at the lows Sunday morning:


Probably too early to talk about freeze warnings, but if the cold air descends further south, it is possible. At the very least some frost advisories are possible. Right on time for the holidays!



Friday, November 13, 2015

Another Round of Storms On The Horizon



Southeast Texas is bracing for another round of possible flooding and severe storms early next week. Depicted above is the expected rainfall totals through Tuesday. Note the +3" amounts from east Texas into eastern Oklahoma. One way to always know when an imminent severe storm threat is looming is by subscribing to WeatherCall: try.weathercall.net/signupnow.

It's becoming an all-too familiar pattern which began the weekend before Halloween. This time, low pressure will emerge from southwest Texas and interact with a vigorous upper-level low pressure and cold front coming out of the Rockies. 

The surface low will be able to tap into abundant Gulf moisture while the upper-level low and front will provide sufficient lift and wind shear to allow strong, slow-moving and possibly severe thunderstorms to develop. Here is the depiction for late Monday:


Notice how the rain area expands by Tuesday:



This system doesn't move out until late Tuesday. Even this far out, the Storm Prediction Center is indicating that Southeast Texas and southwest Louisiana could have a risk for severe weather; first late Monday going into Tuesday morning:



And then from late Tuesday into early Wednesday:



This will definitely be a system to watch as it evolves, so stay aware and alert. 

Monday, November 2, 2015

Dry For Election Day



The memories of the Halloween storms may be fresh in the minds of some, but there are no weather worries for Election Day. Expect some early morning cloudiness, but by mid-morning, there should be a mix of sun and clouds. Southeast winds replace Monday's milder north breezes, bringing back the humidity as well. That increased moisture will interact with an approaching cool front that signals a return of now unwelcome rains.

Here is a depiction of conditions by Wednesday afternoon:


The last thing people in the Hill country want to see is more rain headed in their direction. However, that's what today's models are showing. Here is the depiction for Thursday afternoon:


The red splotches indicate the possibility of stronger storms stretching from the Austin/San Antonio area into Dallas and Tulsa. It's a little too early to tell how severe these storms could become, but its a situation that needs to be watched. Eventually, those rains move eastward into east Texas and Louisiana.




 

Friday, October 30, 2015

More Trick Than Treat For Halloween


Early morning tornadoes did some damage to parts of Texas. There are numerous reports coming out of the towns of Floresville (seen above) and D'Hanis, just outside San Antonio. A vigorous upper-level disturbance moving through the area is packing quite a punch, providing sufficient lift in a moist atmosphere spawning the storms. 

The threat is far from over for the rest of the day across south-central Texas. Shaded in yellow are areas that the Storm Prediction Center believes have the highest risk of seeing potentially more of this kind of weather through the day Friday:


Not only is the upper-low vigorous, but also slow-moving. It won't be until late Saturday night that the threat exits eastward. Here is the current threat risk for Saturday, mainly emphasizing extreme southeast Texas and southern Louisiana:


If things work out correctly, you may be able to salvage the heart of trick-or-treat time in Southeast Texas. However, it will be soggy for most of the day Saturday and there could be some spots dealing with high water. Remember, it was just last weekend that the remnants of former hurricane Patricia soaked some of the same areas. Here is a projection of where rain will fall for Saturday in Texas:


After its all over, some places could pick up anywhere from 2 to 6 inches as indicated by this forecast for rainfall totals:


Stay safe on the roads and especially with so many potentially headed out for holiday activities.




Tuesday, October 27, 2015

Sunshine Returns - But For How Long?


After days of rain, the Lone Star state will get a chance to dry out a bit. Depicted above is the forecast for clouds Wednesday. The white are the clouds and the dark areas, cloud-free, should be mostly sunny. 

The remnants of former hurricane Patricia will move into the eastern third of the U.S. A weak trough of upper-level low pressure behind the surface low Patricia has become will move across the central plains. However, with little moisture to work with, there won't be much in the way of cloud cover. 

The dry spell won't last too long as a new disturbance emerges from west Texas by early Friday. This one moves through fairly quickly, so while there won't be a repeat of the flooding brought on by Patricia, there will be significant rainfall. Here's a depiction of conditions by Friday evening:


Unfortunately, the rain may linger for the trick-or-treaters headed out Saturday.


Friday, October 23, 2015

Major Flood Threat This Weekend


Nearly two-thirds of the state of Texas along with almost the lower half of Louisiana could see some astonishing rainfall this weekend. The green-shaded areas depicted above are under flash flood watches. 

It is possible that over a foot of rain could fall, bringing dangerous conditions to locations that have been very dry for weeks. Remnants of record-setting hurricane Patricia will combine with a cold front progressing across the central Plains, setting the stage for widespread misery.

When I first saw the blaring headlines that the Pacific hurricane named Patricia was the "strongest on record", I thought it was more media hyperbole. However, this time, it's fact. The two main measures of hurricane potency are maximum winds and central pressure. The lower the pressure, the stronger the storm. Here's what it looked like. when it made landfall Friday evening:



This is different than impact, because a storm could strengthen over warm water, far from harming anyone. However, when that danger looms, it certainly gets our attention.

Here's an idea of how strong Patricia is compared to its predecessors:

STORM         YEAR        MAX WINDS  (mph)       CENTRAL PRESSURE (mb)
Patricia        2015               200                              879
Wilma          2005               185                              882
Gilbert        1988                185                              888
Labor Day    1935                185                             892
Rita             2005                180                             895
Allen           1980                190                             899

The storm will weaken with regard to those two parameters as it encounters the mountains of central Mexico, but the moisture from the storm will be drawn into southern and central Texas by Saturday. Here's what computer models show for Saturday afternoon:


By late Sunday, here's the projection for accumulated rainfall. The purple shading indicates amounts that could easily exceed one foot:


Residents in the watch areas should stay alert to rapidly changing conditions as rain will fall repeatedly over the same areas, leading to the flash flood threat. Remember the live-saving adage - turn around, don't drown. The majority of the fatalities from the catastrophic South Carolina flooding earlier this month occurred in cars. People either got trapped in rapidly rising water or they ignored "road closed" signs and drove around barricades.






Tuesday, October 20, 2015

Much-needed Rain Later This Week



As of this writing, 147 counties in Texas are under a burn ban due to dry conditions. Much-needed rain is in the forecast for later week as low pressure develops in the western Gulf. That, in combination with a strong high pressure cell in the southeast U.S. will allow for extensive periods of rain to move into some of the driest areas in the Lone Star State.

Already, a few spotty showers have developed off the upper Texas coast, a sign that the lower atmosphere is much more saturated than recent days. By Friday, the picture changes dramatically to this:


The low pressure develops by late Sunday and could linger in the Gulf for a while:


Once the rain begins late Thursday, it could deposit over half a foot in the Hill Country, which could lead to flood concerns:



The pattern will be periods of repeated rains over some of the same areas. In situations like this, dry soil actually increases the flood threat because runoff is stifled. 

The best thing to do is to monitor weather conditions and if you know you are in a flood-prone area, you should have a plan to get to higher ground. Continue to monitor this blog for updates heading toward the weekend.



 

Friday, October 16, 2015

Cool Fall Weekend Ahead!


Believe it or not, a cool front slipped through Southeast Texas late Friday night. The only way you'd know is because of a wind shift as there wasn't any rain and just a few high clouds. You'll definitely feel the difference as drier and cooler air descends down to the coast. Shown above are the forecast low temperatures by Sunday morning.

High pressure filling in behind the front dominates the weather for much of the up-coming week. Gradually, by the end of next week, the high will slide off to the east. Then, a return of southeast winds pushes temperatures higher, increases the humidity and eventually brings rain back to the region.

For the past few days, the long-range GFS model has been hinting that low pressure will develop in the Gulf. Where it ends up and how intense it becomes is still a bit uncertain. However, there is a good chance that widespread, heavy rain will spread from Corpus Christi through Houston and into East Texas. Here's a depiction for the last Sunday of the month:


This will need to be monitored to see exactly where the low forms and more importantly, how much rain falls and where. Until then, enjoy the crisp mornings and warm afternoons!
 

Thursday, October 1, 2015

Joaquin's Journey



The third hurricane of the 2015 has become the strongest. Today, Joaquin was found to be packing 130 mph winds, making it a dangerous category 4 hurricane. Very warm water and weak upper-level steering conditions are creating the perfect environment for growth. Residents in the southern Bahamas are reporting widespread flooding and wind damage Thursday afternoon. So the question now is, where will Joaquin head next? Here's the latest forecast from the National Hurricane Center:


It still shows the storm remaining just off shore and not making landfall. For the past few days, models that forecast movement have been waffling between sending the storm out to sea and taking aim at some point of the east coast. Not surprisingly, the official track from the National Hurricane Center has been quite wide, nearly paralleling the east coast. This is intended to demonstrate the uncertainty of the forecast.

There are two major complicating factors steering this storm. The first is a stalled cold front, which is draped along the east coast. This has brought some heavy flooding rains from parts of Maine down to South Carolina:


At the same time, there is an upper-level low pressure cell in the southeast that may draw Joaquin northward over the weekend as well as enhance moist conditions from the mid-Atlantic to the southeast:


Computer projections have varied because the location and strength of the upper-low in the Southeast is uncertain. It seems that each day's computer model runs makes a different determination of where the upper-level low will end up.

This afternoon, the so-called spaghetti model plots have a split decision, with roughly half of them trending toward a mid-Atlantic landfall by Sunday and the other half sending the storm toward Bermuda:


There is virtually no chance of Joaquin heading into the Gulf of Mexico, so this will largely be an East Coast concern. It is also interesting to note that in the last 10 years, there have been fourteen Category Four hurricanes, most of them occurring in late September or October. Most have impacted the Caribbean or meandered in the middle of the Atlantic. The last Category Four hurricane to hit the U.S. was Charley in 2004.

Continue to watch for my blog updates on this dangerous storm to see where it ends up. If you know folks along the East Coast, encourage them to remain watchful and to be prepared. Even if the hurricane doesn't make a landfall, the stalled out front could bring more heavy rain that may lead to flooding.


Monday, September 14, 2015

Showers Make A Comeback


Keep the umbrella handy Tuesday as a weak disturbance in the Gulf sends showers toward the upper-Texas coast. The last few days featuring warm, but not overly humid weather, and pleasant mornings is about to change.

High pressure in the Southeast U.S. will allow for southeast winds to develop, which always means a return of muggy weather to Houston. Additionally, there are signs of low pressure in the western Gulf of Mexico.

Typically, a low in the Gulf might raise a few eyebrows, even though we've reached the peak of hurricane season. However, the low is very weak and very disorganized. Also, there isn't high pressure aloft. The latter would make tropical development a bit more favorable.

Expect showers today to develop as those southeast winds send Gulf showers inland. The afternoon could be especially soggy and even in the morning, there may be considerable cloudiness. 

Once Tuesday's rain threat diminishes, the rest of the week looks rain free, although the southeast winds will make the days warm and muggy and the mornings not quite as pleasant as they have been recently. Lows should range in the mid to upper 60s.

Tuesday, September 8, 2015

Change On The Horizon



No sign of summer's end today as the heat beat wears on across the Lone Star. Nothing really unusual about that after Labor Day. However, there are signs of change later in the week. It is very likely that a cold front, currently dragging through the middle of the country is headed toward Texas.

Along the front, showers and in some cases, stronger thunderstorms are likely to develop. The front should make it through Dallas by Wednesday and then arrives along the Upper Texas coast by Thursday. Here is a projection for rain and the front then:


The slow-moving nature of this front means rain chances could linger well into the weekend. It's still a little early for THE cold front that puts and end to the seemingly endless summer, but it will be a welcome sign.

Tuesday, September 1, 2015

Soggy Start To September


Even though rainfall in August was .66" below normal, there were only five days with rain in Houston. So the forecast for wet weather over the next few days is a good thing. The image above shows the water vapor imagery for Texas. The bright white indicates moisture, the red area indicates dry sections. 

An upper-level disturbance near Corpus drifts slowly northward, spreading rain chances upward and inward today and tomorrow. With little steering it, showers could linger through late in the week. Here are projections for Tuesday and Wednesday:





There are no concerns as of yet for flash flooding as there should be decent breaks between rainfall episodes. Best advice: keep the rain gear handy.


Thursday, August 27, 2015

Erika Emerges As A Potential Threat



Tropical Storm Erika drenched and damaged parts of the Leeward Islands Thursday with Puerto Rico and Hispanola in its sights for Friday. Unlike its predecessor Danny, which barely brought much rain to the Caribbean earlier this week, Erika may make more of an impact.

Already four lives were lost in Dominica as torrential rain sparked mudslides and several homes and buildings were damaged. Even though the storm only has 45 mph winds, weak construction often leads to quicken ruin.

The latest track from the National Hurricane Center has Erika becoming a Category 1 hurricane threatening the Florida peninsula early next week:


Danny was no match for a strong shear zone as it approached the eastern Caribbean. That storm was torn apart by the stronger winds aloft. Erika is moving into a somewhat weaker shear zone, which should slow its growth. However, it will still likely bring some substantial rains to drought-stricken Puerto Rico.

Once Erika crosses Hispanola, things get more interesting as there is less shear and water temperatures are extremely warm. Take a look at the pool of water warmer than 30° C (85° F) degrees in the Bahamas, eastern Gulf and around Florida's Atlantic coast:




As Erika emerges from Haiti and the Dominican Republic this weekend, it could experience explosive growth as it moves over that water. The majority of computer models have the storm heading toward Florida with only a few keeping it away from the U.S. and a handful nudging it into the Gulf:



One of the challenges for this storm is that once it moves toward the Bahamas, there isn't much in the way of upper-level winds to steer it. Based on the so-called spaghetti plots of the various computer models, Erika could linger off the Georgia and South Carolina coasts for several days. 

It's not quite deja vu as the 10 year anniversary of Katrina's landfall approaches this weekend, but it doesn't help allay fears. If indeed Erika does become a hurricane and strikes Florida, it would be the first time in ten years that the Sunshine State has been hit by a hurricane. The last one was Wilma in 2005.

As with all storms, this one needs to be monitored as it continues to move and develop and forecasts change (and they will). As I am fond of saying - stay tuned...and be prepared.