It's Not Over: Tropical Storm Harvey Rainfall Sets Preliminary All-Time Lower 48 States Record, Still Soaking Texas, Louisiana

Tropical Storm Harvey has set a preliminary Lower 48 U.S. rainfall record for any tropical storm or hurricane as it continues to soak the upper Texas coast and Louisiana, worsening record-breaking, catastrophic flooding.

(FULL COVERAGE ON HARVEY: Hurricane Central)

The Cedar Bayou gauge near Highlands, Texas, has reported a preliminary 51.88 inches through 3 p.m. CDT Tuesday. This total will likely climb higher as Harvey's rainfall continues.

A Harris County Flood Warning System rain gauge near Friendswood, Texas, reported a four-day storm total of 49.32 inches through 9 a.m. CDT Tuesday. 

If either of these are confirmed, it would be the heaviest storm-total rainfall from any tropical cyclone in the continental U.S. in records dating to 1950, topping the 48-inch storm total in Medina, Texas, from Tropical Storm Amelia in 1978, according to research by NOAA/WPC meteorologist David Roth.

Suffice to say, this is one of the worst flood disasters in U.S. history, with record-smashing river flooding lasting well into next week.

(FULL DETAILS: River Flooding May Last For Weeks In Some Areas)

Through Tuesday morning, parts of southeast Texas have received more than 40 inches of rain since Friday. The top official rainfall total is 43 inches in South Houston, 

The average rainfall within the Harris County Emergency Management network has exceeded that of Tropical Storm Allison (2001) in almost half of the time (2 to 3 days versus 5 days).

(MORE: How You Can Help Victims)

Houston's Bush Intercontinental Airport crushed its record-wettest calendar day Sunday by over 5 inches, picking up 16.07 inches of rain, just under the five-day total of 16.48 inches from Tropical Storm Allison in 2001. Houston's Hobby Airport also crushed a two-day rainfall record by almost 8 inches, picking up 23.06 inches of rain Aug. 26-27.

Still a named storm over 72 hours after landfall, Harvey is the longest a Texas landfalling hurricane has remained a named storm after landfall on record, according to Colorado State University tropical scientist Dr. Phil Klotzbach.

Harvey made landfall Friday night near Rockport, Texas, north of Corpus Christi, as the first Category 4 hurricane to landfall in the U.S. since Charley in August 2004.

Harvey's center is currently in the far northern Gulf of Mexico accelerating toward the east and eventually northeast. On this track, Harvey's center will make a third and final landfall along the southwestern Louisiana coast early Wednesday.  Here's our latest forecast.

STILL DAYS OF HEAVY RAIN AHEAD

The heaviest rain is now targeting areas near the upper Texas coast east of Houston, and parts of Louisiana. Beaumont, Texas, picked up 1 inch of rain in just 26 minutes early Tuesday morning.

Harvey's center of circulation is now just offshore, triggering tropical storm warnings from Port O'Connor, Texas, to Morgan City, Louisiana. A tropical storm watch is in effect from east of Morgan City, Louisiana, to Grand Isle, Louisiana.

(MORE: Harvey Louisiana-Specific Forecast)

The tropical storm had been stuck between two areas of high pressure and, but will finally make a concerted move northeast later in the week, as high pressure over the western U.S. finally weakens and Harvey is steered by high pressure centered near the Bahamas and Florida.

The National Hurricane Center is not expecting a significant strengthening of Harvey while it's briefly off the Gulf Coast, so the main concern should remain additional heavy rainfall.

A tropical cyclone's rainfall potential is a function of its forward speed, not its intensity. Therefore, several more days of torrential rain are expected in many of the already flood-ravaged areas, but Harvey is accelerating which should bring the end of the rain from west to east by midweek in much of Texas.

Areas of heavy rain may persist in parts of Texas or the adjacent lower Mississippi Valley into Friday or Saturday, though the heavy rain threat will be gradually lessening in the most flooded areas by late this week.

(MORE: Harvey By the Numbers)

Here are the latest additional rainfall forecasts through Thursday from the National Hurricane Center and NOAA's Weather Prediction Center:

• Upper Texas coast into southwest Louisiana: an additional 6 to 12 inches, bringing isolated storm totals up to 55 inches over the upper Texas coast, including the Galveston metro area
• South-central Louisiana: storm totals of 5 to 10 inches
• Southeast Louisiana: storm totals of 4 to 8 inches
• Part of Arkansas and the Tennessee Valley: storm totals of 4 to 8 inches

Persistent onshore winds are still keeping water levels higher than normal along the upper Texas and southern Louisiana coasts, including Galveston Bay. This coastal flooding may continue through multiple high-tide cycles the next few days, only slowly subsiding with time.

The NHC says storm surge flooding of 1 to 4 feet is possible at high tide along the immediate coast from Port Bolivar, Texas to Morgan City, Louisiana.

(MORE: Water, Not Wind, the Deadliest Factor in U.S. Tropical Storms, Hurricanes)

These surge-choked bays and inlets won't allow rain-swollen rivers to drain fast enough, backing up these rivers and worsening flooding upstream, just as the floodwater upstream arrives.

It will be an arduously slow process to first get coastal water levels down, then drain the massive volume of floodwater upstream. This process will likely continue past Labor Day, in some areas.

(MORE: Three Reasons Slow-Moving Tropical Storms and Hurricanes Are the Worst)

RECAP: A TRULY HISTORIC HURRICANE

Harvey made landfall Friday night near Rockport, a town of less than 10,000 people and about 30 miles up the Texas coast from Corpus Christi.

Harvey is this nation's first major (Category 3 or stronger) hurricane landfall since Hurricane Wilma struck South Florida in October 2005, an almost 12-year run. A multi-day deluge of the Texas Gulf Coast with catastrophic and life-threatening flooding and destructive winds could leave areas uninhabitable for an extended period of time, the National Weather Service has warned.

Harvey went from a tropical depression to a major hurricane in 56 hours. It intensified rapidly to a Category 4 hurricane with winds up to 130 mph after moving over a pocket of hot water in the Gulf. 

Harvey is also the strongest landfall in this area, known as the Texas Coastal Bend, since Hurricane Carla, in September 1961, produced catastrophic damage from storm surge and high winds in Port O'Connor and Palacios, Texas, among other locations.

The only other Category 4 landfall of record near the Texas Coastal Bend was the infamous Indianola hurricane of August 1886, which devastated the town of Indianola just 11 years after another Category 3 hurricane, eventually turning the former bustling port into a ghost town.

A storm surge of more than 6.6 feet was recorded at Port Lavaca, Texas, with destructive surge reported in other locations along the Texas Coastal Bend.

There have been over a dozen tornadoes so far, with the total number of tornadoes still yet to be determined.

One apparent tornado crossed Interstate 10 and hit a storage facility in the western Houston metro suburb of Katy around 5:30-6 a.m. CDT Saturday morning.

At least one tornado was confirmed in northwestern Harris County, Texas. 

In the southwest suburb of Missouri City, more than 50 homes were damaged in the Sienna Plantation neighborhood.

Following landfall, Hurricane Harvey slowed down and stalled over western Texas Hill Country, turning the Gulf of Mexico firehose on southeast Texas and southwest Louisiana for three days. 

Harvey steadily weakened to a tropical storm as it sat and spun north of Victoria, Texas from the early morning hours on Aug. 26 through late on Aug. 27. 

Rainfall totals pushed more than a half foot higher than totals seen in Houston's previous worst disaster, Tropical Storm Allison, and breaking Lower 48 tropical cyclone rainfall records. 

Numerous flash flood emergencies were issued for the Houston and Beaumont, Texas metropolitan areas, and for Bastrop County and nearby communities. 

Harvey, as a tropical storm, began to drift southeastward toward the Gulf of Mexico on Aug. 28, re-entering the Gulf of Mexico mid-afternoon near Matagorda, Texas. 

Strong wind shear and Harvey-cooled waters in the Gulf of Mexico have so far prohibited Harvey from re-strengthening as of late morning on Aug. 29.

RAINFALL TOTALS

Here are the latest rainfall totals through 11 p.m. CDT Tuesday, all in Texas unless otherwise specified:

• 5.188 inches on Cedar Bayou near Highlands, Texas (Preliminary Lower 48 tropical cyclone record)
• 49.32 inches on Mary's Creek near Friendswood (Preliminary Lower 48 tropical cyclone record)
• 46.08 inches in Dayton
• 43.00 inches in South Houston
• 42.58 inches in Pasadena
• 41.66 inches in League City
• 41.52 inches in Clear Lake City
• 37.40 inches in Baytown
• 33.88 inches at Houston Hobby Airport
• 31.18 inches at Houston Bush Intercontinental Airport
• 21.94 inches in Galveston
• 21.88 inches in Smithville
• 19.64 inches in College Station
• 13.25 inches near Lake Charles, Louisiana
• 12.33 inches near Hackberry, Louisiana
• 10.07 inches at Austin's Robert Mueller Municipal Airport
• 9.37 inches near Victoria
• 6.50 inches in Lafayette, Louisiana
• 6.23 inches near Corpus Christi
• 3.65 inches at New Orleans/Lakefront

STRONGEST WIND GUSTS

Here are the highest wind gusts we've seen from Harvey:

• Port Aransas: 132 mph, sustained to 110 mph
• Near Copano Village: 125 mph
• Near Lamar: 110 mph
• Rockport: 108 mph
• Near Taft: 90 mph
• Near Magnolia Beach: 79 mph
• Palacios: 69 mph
• Corpus Christi Int'l Airport: 63 mph
• Austin Bergstrom Int'l Airport: 52 mph

RAINFALL PERSPECTIVE

Really, how much rainfall this week in southeast Texas?? 

In some spots of the West, it can take more than a decade to accumulate 50 inches of rainfall.