Heavy rain and areas of flash flooding continue in Southeast Texas

Brief update. Parts of Southeast Texas continue to face locally heavy rain this evening. Things should begin to improve tomorrow, but more of the same through tonight unfortunately. Hidalgo County, TX along the border with Mexico (in the Rio Grande Valley) suffered significant flooding in multiple communities, including Weslaco and Mercedes. The Weather Channel showed live footage this afternoon of people wading in the water and cars driving through flooded roads (please do not ever do that!). See their news story on the events in Texas HERE. Rainfall is currently impacting portions of far south Texas and near Houston and Galveston which have yet to receive significant heavy rainfall.

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Flash flood warnings along US-281 west of Corpus Christi this evening.
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Training rainfall over Galveston Island and inland east of Houston this evening. Some flooding possible from the rainfall if this persists.
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Graphic by the National Weather Service – Weather Prediction Center indicating likelihood for training rain bands and elevated flash flooding potential this evening.
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Thermal infrared image showing coldest (and therefore tallest) cloud tops over South Texas and the southeast Texas coast, where the strongest thunderstorms and heaviest rainfall is currently located (as of 7:30 pm CDT).

 

–Meteorologist Nick Humphrey

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Flooding Rains Impacting Coastal Texas

Heavy rainfall and flash flooding continue to impact parts of Southeast Texas and the far northeast region of Mexico as tropical moisture sourced from the Caribbean shifts over the area.

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Lower atmospheric water vapor image showing deep tropical moisture streaming into Southeast Texas and northeast Mexico around a broad mid-level circulation (located over South Texas) Tuesday night. White to green is higher moisture content.
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Flash flood warnings in and north of Corpus Christi, TX Tuesday night as rainfall “trains” over the same areas for hours.
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Storm total rainfall (likely in the past 36 hrs) over the same region. Some areas have received up to an estimated 4-8 inches of rainfall.
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Storm Total Rainfall over the Houston Metro and surrounding areas. A core of heavy rainfall occurred today over far southeast Texas and southwest Louisiana. The Lake Charles radar (not shown) which is closer to this core and provides are more accurate estimate shows isolated 5-6 inches of rainfall in the area.

Corpus Christi International Airport has seen over 4.5 inches of rain since Monday night. Endinburg, TX has also seen about 4.5 niches since Monday morning where the heavy rain began earlier. Victoria, TX has seen close to 2 inches since Monday morning. More locally heavy rainfall and possible flash flooding is possible through Wednesday as further tropical moisture spreads over the region.

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One model forecast for precipitable water over much of Southeast Texas and western Louisiana during the day Wednesday. This is total of amount of liquid in the water column if all the water was precipitated out of the atmosphere. High values with available lift in the atmosphere to form precipitation indicates a high heavy rainfall potential.
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One model forecast showing total rainfall through midnight CDT Thursday. It indicates areas of heavy rainfall along the south-central Texas Coast. Where the heaviest bands of rain set up ultimately is unknown because of very fine scale variability, although areas near Corpus Christi appear to be the most favored, risking further flash flooding. Some areas could receive an additional 3-5+ inches of rain Tues night-Thursday.

Please avoid flooded roads as fast moving currents in unexpectedly deep water can sweep a vehicle away easily and roads may be washed out and unseen under the water. Keep track of the latest weather in your area prior to and while traveling as well.

–Meteorologist Nick Humphrey

Major ocean cyclone pummeling the British Isles with strong winds/rainfall; Remnants of Bud to bring rain to US Southwest

An unusually potent (for the time of year) North Atlantic frontal system impacted British Isles and Ireland this morning and afternoon (local time) with intense winds and locally heavy rainfall. Ireland and Scotland were particularly hard hit with gusts to 80-90 mph (isolated gusts to 100 mph) during the morning and early afternoon hours Thursday.

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Powerful Atlantic cyclone…known officially by the UK Met Office as “Storm Hector”, advancing over the British Islands and France at 7 am CDT/1 pm British Standard Time (BST) Thursday. Intense wind wind gusts were behind the cold front and just south of the northeast advancing surface low.
The BBC reported that the highest wind gust ever recorded in the month of June in Northern Ireland occurred this morning; a hurricane-force wind gust of 74 mph at Orlock HeadEdinburgh, Scotland reported a gusts near 60 mph, as did Leeming Royal Air Force Base in northern England. Great Dun Fell, a 2,782 ft mountain in northern England reported a gust at its peak of 95 mph. With trees fully bloomed with leaves in mid-June (especially thanks to the recent very abnormally warm weather in Britain), large trees act as sails to the wind and are more easily toppled, posing life-threatening hazards from falling trees or branches onto roads. And this was much the case today with trees falling in the strong winds and heavy rain spreading over the north.

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Visible satellite image of powerful cyclone moving through the United Kingdom and Ireland. Image at 9 am BST.
Some photos:

Branches down in Glasgow. Also HERE

Tree down in North Bangor, England.

News Story on ‘Hector’ by The Telegraph


The Eastern Pacific tropical cyclone Bud has, as expected, continued its rapid weakening is now a dying tropical storm with maximum sustained winds of 45 mph. It has lost much of its deep convection, but still has a prominent circulation with gusty winds and locally heavy rain bands with scattered thunderstorms.

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Visible satellite image of Tropical Storm Bud approaching the southern Baja California Peninsula this afternoon.

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Thermal infrared image of Bud this afternoon. Infrared allow us to differentiate clouds of similar optical brightness (see previous visible image) and determine cloud top warmth and therefore height into the atmosphere. The “deep convection” or intense thunderstorm activity is associated with the coldest (brighter white) tops in this image. Much of the rest of the circulation is made up of low clouds with far less precipitation.
Bud is expected to make landfall near Cabo San Lucas late tonight as a very minimal tropical storm or depression (likely 35-40 mph winds) as it continues to track of waters with little heat to support heavy thunderstorm activity. It will then move over the southern Peninsula and into the Gulf of California for mainland Northwest Mexico Friday as a weakening depression.

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As the systems enters the Gulf, its moisture, plus additional low-level moisture will rapidly surge northward from the Gulf, leading to increasing showers and thunderstorms in parts of Arizona, New Mexico and farther northward. Flash flooding is possible from these storms.

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Slight Risk (2 out 4 scale) of flash flooding within 25 miles of a point over southeast AZ on Friday morning – Saturday morning and over much of NM and southwest CO Saturday morning – Sunday morning.

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Total rainfall expected today through Sunday morning according to one model. General agreement of 3-5 inches possible in northern Mexico into far southern Arizona, with some variability based on where the heaviest showers and thunderstorms are. Widespread 1-2+ inches with locally heavier amounts are possible during the day Saturday farther north. Although the rain will be beneficial for the extreme to exceptional drought, flash flooding is a risk.
I would also mention, given the very dry soils and very dry air ahead of the system, more isolated storms may produce intense downbursts of cooler strong winds which may induce dust storms, so be mindful of this if they develop.

I will also give special mention to the surge of tropical moisture expected into Texas and Louisiana Sunday into early next week. Heavy rainfall and flash flooding will be possible in parts of Southeast Texas and Southwest Louisiana.

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Total precipitation accumulation forecast by one model (much beginning Sunday) associated with tropical moisture surge sourced from the Caribbean Sea. Forecast details will change, but this poses a significant flash flood risk.
I’ll have more on this event this weekend, as it’s associated with a marginal risk of tropical development in the Bay of Campeche tomorrow or Saturday. But regardless, heavy rainfall will be the biggest issue with this event.

-Meteorologist Nick Humphrey

Bud in the Eastern Pacific becomes a major hurricane well-offshore Pacific Mexico; threat to Baja late-week.

Hurricane Bud has continued its robust intensification, as expected, now a Category 3 hurricane (at 8 am PDT) based on satellite intensity estimates with maximum sustained winds of 120 mph and gusts to 150 mph.

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The hurricane continues to show strong blow ups of thunderstorms with very cold cloud tops in its inner core region known as the “central dense overcast” or CDO Region indicating that it is continuing or organize and additional strengthening may occur during the day today into this evening.

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As mentioned last night, given the thermodynamic environment (abnormally warm waters below unstable air above for air to rise), low wind shear (winds not increasing in speed with height so the low pressure system remains “vertically stacked”) and favorable poleward outflow (air from the surface low being sent up upper atmosphere and blown off generally northward and away, allowing surface low to intensify further), there’s little to stop Bud from strengthening further, except for the system itself. Unpredictable structural changes in its eyewall could inhibit further strengthening, but for now that doesn’t appear to be imminent. However, by tomorrow, the steering currents are forecast to slow down somewhat and its own powerful inner core may act as a “negative feedback” and cool the waters under it as a result of upwelling of colder water from greater depths not as well heated by sunlight. This will likely result in a gradual weakening. After this, it will also begin to traverse somewhat lower temperature waters already on the surface itself, limiting any opportunity for re-intensification as it approaches the Baja California Peninsula late-week. So an overall weakening trend should begin after Tuesday.144123_5day_cone_no_line_and_wind

It appears the hurricane’s tropical storm-force wind field will largely stay offshore the Pacific coast of mainland Mexico, although gusts of 40+ mph are certainly possible in gusts as the rain bands hug the coast line near Manzanillo and points with a couple hundred miles north and south over the next 48 hrs. The system should pull away from land the tropical storm watch area after Tuesday and the threat of locally heavy rain and gusty winds will diminish (rip currents and heavy surf will continue) and the threats will shift and increase for the Baja CA Peninsula. There has been a trend in some numerical models to track the to system more toward the southern tip of Baja or slightly towards the Gulf of California. Any track farther away from the open Pacific waters would mean more of its circulation over warmer waters (compared to the more open Pacific) for more thunderstorm activity to keep the system stronger in terms of winds, wave action and heavy rain. So far, given the decrease in ocean heat content and increasing wind shear, this still looks far more like a tropical storm event than a hurricane event for Baja and the possibly the southern Gulf waters. But this would still mean areas of heavy rain, flash flooding and landslides over mountainous terrain and wave hazards along coastal areas. In addition, if Bud moves more toward the Gulf, this may induce a stronger moisture surge up into the Southwest US, enhancing the monsoon flow pattern change and increasing thunderstorm activity.

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One model depiction of the total precipitation over the Southwest US between Sunday evening (6/10) and next Sunday evening (6/17) local time. Much can change and will depend on the track of Bud, but if the system approaches the southern tip of Baja or moves into the Gulf of California a strong low-level moisture surge would result, bringing an unstable air mass for abundant thunderstorms to much of the Four Corners States over the weekend. Virtually all the US rain on this map and much of northern Mexico is forecast to fall beginning Friday night from the south.

While *again*, amounts will change depending on the track of Bud, some monsoon-related switch in air flow pattern is expected and if the moisture is as abundant as possible with a very abnormally warm Gulf + remnant moisture from Bud, folks living in the Four Corners region should watch forecasts specifics related to possible thunderstorms and locally heavy rainfall this weekend. Given the extreme to exceptional drought conditions in this region, the soils are likely very dry and hard and heavy rain which falls will not be absorbed as quickly as it would be otherwise (rainfall will help, but too much too soon is bad for rapid runoff). So details can only be found in future forecasts, but it’s something to keep in mind at the moment.

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Follow updates as I get them on my Twitter and Facebook!

–Meteorologist Nick Humphrey

PS: I was just asked a question about the Eastern Pacific Hurricane Climatology compared to how things are going thus far in 2018. Numbers of systems thus far are listed with days, late or normal listed in parentheses). The normal values are based on 1971-2009 baseline. Still very early in the season and early season activity doesn’t necessarily provide clues to future activity.

Tropical Storms: 2 (2nd storm formed 16 days earlier than normal).

Hurricanes: 2 (2nd hurricane formed 34 days earlier than normal).

Major Hurricanes: 2 (2nd major hurricane formed 69 days earlier than normal).


For the North Atlantic, which is quiet at the moment (based on 1966-2009 baseline):

Tropical Storms: 1 (1st storm formed 45 days earlier than normal).

Hurricanes: 0 (normal until August 10th)

Major Hurricanes: 0 (normal until September 4th)

 

Bud Now a Hurricane and a Threat To Pacific Coast of Mexico

Bud is now a hurricane (Category 1 on the Saffir-Simpson wind scale as of this post) and expected to intensify as it moves over waters in the mid-80 F (28-29 C). With these very warm waters and weak vertical wind shear, I expect robust intensification during the next day or two. Steering currents will take take the system much closer to Mexico, making direct impacts by wind, wave action and rainfall likely vs. Aletta which stayed completely offshore. As a result, the government of Mexico has issued a tropical storm watch for a portion of the mainland Pacific coast from Manzanillo to Cabo Corrientes.

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Hurricane Bud with its eye offshore Mexico rapidly intensifying at the 8 pm PDT hour.

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The tropical storm watch covers the possibility that the tropical storm force wind field…with sustained winds of 39 mph or greater…may graze the coastal communities late-Monday through late-Tuesday. Based on the as the track suggests, the system could also threaten Baja California by the end of the week. The system will likely go through its period of robust intensification through the next 24-36 hrs. Based on satellite trends tonight and the upper-level environment, I think it becoming a Category 4 hurricane (130 mph+) is not out of the question. Satellite estimates suggests the system may be approaching Category 2 (96-110 mph) status already. A stronger hurricane could mean a larger wind field and higher waves threatening more of the Pacific coast.

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Model Forecast Total Precipitation through 5 am PDT Wednesday. One depiction showing potentially 10+ inches of rain impacting the tropical storm watch area the first half of the week.

While it is still too early to determine the full impact that Bud will have on the Baja Peninsula, given the abnormally warm waters, it will likely be an organized cyclone with rain bands and some wind, but yet likely to weaken thanks to increasing vertical wind shear farther north. Although there’s a likelihood Bud will become a major hurricane, its slow forward motion over the next few days may induce cold upwelling, inducing earlier weakening than would otherwise occur. I think the likelihood of a Bud bringing hurricane-force winds to the Peninsula as low at this time.

So anyone traveling to the mainland areas, be mindful of locally heavy rainfall, rip currents and strong winds in the tropical storm watch area Monday-Tuesday. The southern tip of Baja California will know more about their threats by Tuesday.

–Meteorologist Nick Humphrey