Updraft® - Minnesota Weather News

Catastrophic flooding in Houston; Minnesota shower chance

Harvey's torrential rains continue.

Tropical Storm Harvey is bringing flooding rains to much of the southeastern part of Texas.

This was how the floodwaters looked on the Interstate 610 highway in Houston Sunday morning:

Many areas in southeast Texas have already seen over a foot and a half of rain, based on radar estimates through early Sunday morning:

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NWS Houston/Galveston

There's the potential for significant additional rain today through Wednesday:

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NWS Houston/Galveston

Houston could see record flooding:

This chilling message was sent by Houston's Emergency Management Department Sunday morning:

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NWS

It'll take a long time to recover from Harvey:

There have been some fatalities related to Hurricane/Tropical Storm Harvey.

According to the Houston Chronicle:

The unconfirmed death toll by the National Weather Service reached five, but authorities expected that to climb as the waters recede.

Harvey update

The Sunday morning update from the National Hurricane Center shows that Tropical Storm Harvey's maximum sustained winds are now down to 40 mph:

BULLETIN

Tropical Storm Harvey Advisory Number 29

NWS National Hurricane Center Miami FL AL092017

1000 AM CDT Sun Aug 27 2017

...FLASH FLOOD EMERGENCIES IN PARTS OF SOUTHEASTERN TEXAS INCLUDING

GREATER HOUSTON...

...DO NOT ATTEMPT TO TRAVEL IN THE AFFECTED AREA IF YOU ARE IN A

SAFE PLACE...

...DO NOT DRIVE INTO FLOODED ROADWAYS...

 

SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION

-----------------------------------------------

LOCATION...29.0N 97.4W

ABOUT 35 MI...55 KM WNW OF VICTORIA TEXAS

ABOUT 70 MI...115 KM ESE OF SAN ANTONIO TEXAS

MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H

PRESENT MOVEMENT...SSE OR 160 DEGREES AT 2 MPH...4 KM/H

MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES

 

WATCHES AND WARNINGS

--------------------

CHANGES WITH THIS ADVISORY:

The Storm Surge Warning for the coast of Texas has been

discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...

* Port O'Connor to Sargent Texas

Catastrophic and life-threatening flooding is occurring in

southeastern Texas, and flash flood emergencies are in effect

for portions of this area. Please see warnings and other products

issued by your local National Weather Service office for additional

information on this life-threatening situation.

For storm information specific to your area, including possible

inland watches and warnings, please monitor products issued by your

local National Weather Service forecast office.

 

DISCUSSION AND 48-HOUR OUTLOOK

------------------------------

At 1000 AM CDT (1500 UTC), the center of Tropical Storm Harvey was

located near latitude 29.0 North, longitude 97.4 West. Harvey is

moving toward the south-southeast near 2 mph (4 km/h), and a

slow southeastward to east-southeastward motion is expected over the

next couple of days. On the forecast track, the center will move

very near the coast of southeastern Texas.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.

Little change in strength is forecast during the next 48 hours.

Tropical-storm-force winds extend outward up to 175 miles (280 km)

primarily over water to the east and northeast of the center.

The estimated minimum central pressure is 1000 mb (29.53 inches).

 

HAZARDS AFFECTING LAND

----------------------

RAINFALL: Harvey is expected to produce additional rainfall

accumulations of 15 to 25 inches through Friday over the middle and

upper Texas coast, including the Houston/Galveston metropolitan

area. Isolated storm totals may reach 50 inches in this region.

These rains are currently producing catastrophic and life-

threatening flooding, and flash flood emergencies are in effect

for portions of southeastern Texas. DO NOT ATTEMPT TO TRAVEL IN THE

AFFECTED AREA IF YOU ARE IN A SAFE PLACE. DO NOT DRIVE INTO FLOODED

ROADWAYS. Please see warnings and other products issued by your

local National Weather Service office for additional information on

this dire and life-threatening situation.

Elsewhere, Harvey is expected to produce total rain accumulations of

5 to 15 inches farther south toward the lower Texas coast, farther

west toward the Texas Hill Country, and farther east through

southwest and central Louisiana.

A list of rainfall observations compiled by the NOAA Weather

Prediction Center can be found at:

www.wpc.ncep.noaa.gov/discussions/nfdscc1.html

STORM SURGE: The combination of a dangerous storm surge and the

tide will cause normally dry areas near the coast to be flooded by

rising waters moving inland from the shoreline. The water is

expected to reach the following heights above ground if the peak

surge occurs at the time of high tide...

Port Aransas to High Island including Galveston Bay...1 to 3 ft

High Island to Morgan City...1 to 2 ft

The deepest water will occur along the immediate coast near the

area of onshore winds, where the surge will be accompanied by large

and destructive waves. Surge-related flooding depends on the

relative timing of the surge and the tidal cycle, and can vary

greatly over short distances. For information specific to your

area, please see products issued by your local National Weather

Service forecast office.

WIND: Tropical storm conditions are occurring in an area near the

center and over portions of the tropical storm warning area along

the coast. Tropical storm conditions are likely to persist in

areas of onshore flow within the warning area during the next day

or so.

SURF: Swells generated by Harvey are affecting the coasts of Texas

and Louisiana. These swells are likely to cause life-threatening

surf and rip current conditions. Please consult products from your

local weather office.

TORNADOES: A few tornadoes are possible today and tonight near

the middle and upper Texas coast into southwest Louisiana.

Even if Harvey's weaken below tropical storm strength later today, the bands of rain are expected to linger over southeastern Texas for several days.

Minnesota rain chances

Northeastern and north-central Minnesota will see periods of showers Sunday and Sunday evening.

Scattered showers and an isolated thunderstorm will be possible over the remainder of eastern Minnesota, including the Twin Cities metro area, later Sunday afternoon and Sunday evening.

The National Oceanic and Atmospheric Administration's North American Mesoscale forecast model shows the potential rain pattern:

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NOAA NAM simulated radar for Sunday and Sunday evening, via tropicaltidbits

It could rain in some spots that look dry in the simulated radar loop, but the loop illustrates the scattered nature of the showers/isolated t-storm that could pop up.

Temperature trends

Sunday afternoon highs are expected to reach the lower 70s in many areas, with 60s over north-central and northeastern Minnesota.

On Monday, most areas should see highs in the 70s:

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The Twin Cities metro area should see highs in the upper 70s Tuesday, with lower 80s Wednesday.

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:49 a.m. Thursdays and Fridays, and at 7:35 a.m., 9:35 a.m. and 4:35 p.m. each Saturday and Sunday.