Severe Weather 101: Floods

Flooding is the overflow of water onto land that is normally dry. Floods can happen during heavy rains, when ocean waves come on shore, when snow melts too fast, or when dams or levees break. Flooding may happen with only a few inches of water, or it may cover a house to the rooftop. They can occur quickly or over a long period and may last days, weeks, or longer. Floods are the most common and widespread of all weather-related natural disasters. Flooding occurs in every U.S. state and territory, and is a threat experienced anywhere in the world that receives rain. If your home has been affected by floods it might be a good idea to consider consulting Water Damage Austin US (https://water-damage-austin.us/restoration-companies/) to start restoring your home.

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Flash floods are the most dangerous kind of floods, because they combine the destructive power of a flood with incredible speed and unpredictability. Flash floods occur when excessive water fills normally dry creeks or river beds along with currently flowing creeks and rivers, causing rapid rises of water in a short amount of time. They can happen with little or no warning. These flash floods can cause significant damage to houses. If your home ever experiences flash flooding, it’s important to try and find a company that can remove this water from your home before it begins to cause structural damage. By searching the internet for emergency water damage restoration near me, homeowners will be able to find a restoration company that can help them to get their house back to normal. It’s so important to keep an eye on your home throughout these flash floods, the water can cause significant damage.

In 1993, many levees failed along the Mississippi River, resulting in devastating flash floods. The city of New Orleans experienced massive devastating flooding days after Hurricane Katrina came onshore in 2005 due to the failure of levees designed to protect the city. Dam failures can send a sudden destructive wall of water downstream. In 1889 a dam break upstream from Johnstown, Pennsylvania, released a 30-40 foot wall of water that killed 2200 people within minutes.

Here in the U.S., floods kill more people each year than tornadoes, hurricanes or lightning. These tragic incidences happen too often and ironically, the people who are rescued from the vehicles reported the reason they drove into the water was to get to the safety of their home.

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Where does the idea that a heavy vehicle will keep you safe come from? Many automobile commercials advertise the ability to drive through water. This may lead to the false sense of security at best and tragic consequences at worst.

Many believe that a 3000 lb vehicle will remain in contact with the ground and won’t float. But if you really think about that, a 97,000 ton aircraft carrier floats, why wouldn’t your car?

Vehicles can be swept away in as little as 2 feet of moving water. Trucks and SUV’s don’t fare much better with only an extra 6 to 12 inches of clearance. In moving water, all that needs to happen if for the vehicle to become buoyant enough for the force of the water to push it sideways. Once swept downstream, vehicles frequently flip over, leaving the driver only a few seconds to escape.

The solution is simple. Turn around, Don’t drown. Stay out of flooded roadways. Not only may the water be much deeper than it appears due to washed out roads, but as little as 6 inches of rapidly moving water is enough to sweep a person off their feet. You must be especially cautious at night, as flooded conditions can be hard to see.

The best thing to do is know when you’re at risk. Consider carefully when you camp or park alongside a river, especially during threatening conditions. Keep alert for the latest watches and warnings and pay attention to local weather conditions. Also plan a safe route. Find a hill near the river that you can go to should flash flood conditions occur.

Robert Millette

NHC Monitoring Two Areas For Tropical Development

Just wanted to give you all a quick update on the tropical waves discussed earlier this week. The National Hurricane Center (NHC) is still monitoring these two areas for possible further development in the tropical Atlantic; Invest 97 and Invest 96.
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Two Invests Being Monitored By The NHC

These two tropical waves are moving towards the east and have a 60% (Invest 97) and 20% (Invest 96) chance of development into tropical depressions over the next five days. (The NHC has given a 30% and 20% chance for development during the next two days, respectively). Invest 97, which has the greatest chance of short-term development, is located about 500 miles east of the Lesser Antilles. As this tropical wave moves towards the west, it should begin to encounter favorable environmental conditions for further strengthening–by the time it enters the Caribbean around Tuesday.

The shear is relatively low in this area and the ocean waters are very warm. These tropical waves gain their energy from warm ocean waters, and the ocean heat content is ‘impressive’ in the western and central Caribbean (where Invest 97 appears to track). This means if Invest 97 moves into this region, which looks probable, abundant energy is available for storm intensification.

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Ocean Heat Content

Invest 96, located off of the African Coast, does not appear as organized as it was earlier in the week. Environment conditions, at this time, do not appear to favor further or quick strengthening. We will still keep an eye on this system as it moves towards the WNW.

Please note, Invest 97 is a couple days from land, so there’s time to observe the system to determine the extent of impacts for the Lesser Antilles. We will need to keep a close eye on this system to see if it enters the Gulf of Mexico. Any direct impact to the Gulf of Mexico Here is several days out, and a lot can change, so we will continue to update as needed. Here’s the latest (18Z) model track guidance for the invests.
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18Z Model Track Guidance (Invest 96)
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18Z Model Track Guidance (Invest 97)

We will have updates on development and potential tracks as needed.

Localized Flash Flood Threat Increasing

Rain chances continue to look likely for parts of southern Oklahoma and northern Texas this afternoon. Isolated storms have developed late this morning near the Red River, and this trend will continue once convective temperatures are met in the region. It does appear the flash flood threat is increasing for northern Texas and southern Oklahoma. Current analysis shows a deformation region extending across the Red River. This, along with unusually high moisture levels, and slow storm movement will aid in the flash flood threat. The HRRR is concurring with the idea of widespread storms developing within this deformation region. Most areas will see less than 1″ of rainfall; however, some areas will see 2-3″, which will lead to isolated flash flooding.
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HRRR Simulated Radar (This Afternoon)
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HRRR Rainfall Totals (Today–the greatest flash flood threat is in the yellow-outlined areas)

Along with a flash flood threat, frequent lighting, and strong winds are possible with thunderstorms. Temperatures will be held in the low 90s in this region (much warmer temperatures are expected outside of the clouds/rain).

More Summer Storms

Scattered thunderstorms have been ongoing across much of the Southern Plains over the past two days; expect this trend to continue on Wednesday. The upper-level ridge (that caused the 100+ temperatures across Oklahoma and Texas) continues to remain west of the region. This has allowed for an inverted trough to influence the region.

This trough, coupled with a weak boundary (located along the Red River this evening), will aid in fairly good thunderstorm coverage Wednesday afternoon. There may be isolated storms Wednesday morning, but once convective temperatures are met (around 1:00-2:00PM), storms will become more widespread. The heaviest storms will dump 1-3″ of rainfall due to the high moisture and slow storm motion. Be alert for frequent lighting and gusty winds associated with any thunderstorm that develops. Temperatures will top out in the low to mid 90s.
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HRRR Simulated Radar (Wednesday Afternoon)
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HRRR Rainfall Totals (Through Thursday Evening)

More rain chances will continue Thursday through Saturday. I’ll have an update tomorrow afternoon.

Severe weather to strike again in Northeast

The severe weather simply refuses to quite down in the Northeast as we move into what we expect to be our third day of severe weather in 4 days.  The past week has seen New England experience 4 Tornadoes in New Hampshire and Maine, though all were thankfully weak and In mostly uninhabited regions.

Currently, a shortwave trough moving through Ontario is expected to move into Southern Quebec by Monday.  A mid-level disturbance is moving around the bottom of this shortwave and the disturbance will induce height falls at the 500 millibar level through Monday afternoon into Monday night, increasing the overall instability of the region.  A cold front associated with the trough will move through the Great Lakes region into New England with the trailing southern portion extending through the Ohio River Valley back into Arkansas and Oklahoma.

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Severe Summary

Southwesterly flow ahead of the trough and cold front has been working to moisten the air across Pennsylvania and New York.  This moist air is spreading into the Hudson River Valley and will expand across much of Western and Southern New England through Monday afternoon.  Dew points are expected to climb well into the 60s at the surface with some locations approaching 70 degrees.  There will be an elevated mixed layer between 700 and 500 millibars that should spread east atop this moist air which should allow for cumulonimbus clouds to build to very high heights for this area, especially across Central and Eastern New York, Northeast Pennsylvania and Western areas of New England.

There may be some limiting factors to overall destabilization if some early period convection and cloudiness occurs to limit day time heating, but moderate to high mid to upper-level cape (convective available potential energy) and strong forcing from the cold front is expected to help overcome any deficiencies that may occur from areas of limited heating.  Strengthening deep layer shear is also going to be a factor and the increasing shear conditions over New York and Northern Pennsylvania as well as Western and Central New England should bring higher severe weather risks.

Strengthening westerly winds with height suggest organized storms will be possible, with some splitting of storms occurring.  Damaging winds will be the primary threat though some hail cannot be ruled out.

 

Robert Millette

Staff Meteorologist

Firsthand Weather

 

Rain Chances!

Hot, hot, HOT! These three words sum up the weather across the Southern Plains thanks to an intense upper-level ridge. No changes are in store for the next 36 hours, but then there’s a slight glimmer of hope shortly after.

By Sunday afternoon this ridge will begin to shift towards the west. The westward shift of this ridge will allow for a couple pieces of energy to move into Oklahoma/Texas, and guidance is also hinting at a low (which has provided rainfall for parts of the Southeast) to move towards eastern Texas. These features will increase rain chances by Sunday afternoon through Tuesday for the Southern Plains.

Sunday’s thunderstorm activity will be more isolated (mainly across Kansas/northern Oklahoma and far eastern Texas), but coverage will increase by Monday and Tuesday. There will be two areas where the greatest thunderstorm coverage will occur: locations along and east of I-35 in Texas and far southeastern Oklahoma (due to the low), and locations along the Oklahoma/Kansas state line (due to a frontal boundary).
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NAM Simulated Radar Monday Morning
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NAM Simulated Radar Monday Afternoon

Rainfall totals may exceed 2″ in some areas due to the slow moving nature of storms, but most areas will see less than 1″ of rain. We will take what we can get during the summer!
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NAM Rainfall Totals Through Tuesday Morning

Temperatures will be slightly cooler due to the ridge shifting westward, and an increase in cloud cover/storms. High temperatures will fall about 5 degrees into the mid-90s. Some areas in southeastern Texas may stay in the upper-80s due to more widespread thunderstorm activity.
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NAM Temperatures Monday Afternoon

As always, if you have any outdoor plans, please remain alert. Any storm can produce cloud-to-ground lighting and damaging downburst winds. It appears a decent northwesterly flow may setup for the Southern Plains in about 7-days, which would increase rain chances, but I’ll have more on that in a few days.

Severe weather comes to the Northeast

Severe weather threat for the Northeast

Severe weather is expected today in the Northeast and the Storm Prediction Center has out most of the region under a slight risk from eastern New York and northeast Pennsylvania up trough all but the south coast of New England   Remaining locations in the aforementioned region are under a marginal risk for severe weather.

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Summary

Damaging winds and hail are the primary threats as a cold front moves through the region.   Dry conditions are impacting some areas to the north but southerly flow is moistening some areas through the day.

A shortwave trough, now evident in moisture channel imagery, is shifting east through Canada.  This system is bringing a cold front southeast, stretching across New England into the Great Lakes.

This frontal boundary, along with a wind shift from Maine down to the mid-Atlantic will be the primary focus areas for thunderstorm development from mid afternoon into the early overnight hours.

Deep shear is expected to strengthen this afternoon along with upper level height falls as the system approaches this afternoon.   These factors should occur at the same time as the maximum heating and boundary layer destabilization and could lead to supercell and multicellular cluster development.  Early cloudiness was not a major factor as temperatures are climbing into the low 90s to upper 80s in the majority of locations.

Should storms occur in your area, please remember than dangers that thunderstorms and flooding conditions can bring.  If you can hear thunder, you can be struck by lightning and even a small amount of water can float even heavy vehicles.

Stay here with firsthand weather for updates on this developing situation and also keep advised of your NOAA radio or local media sources for instant coverage of warnings in your localities.

Robert Millette

Staff Meterorologist

Firsthand Weather

Severe weather threatens the Northeast

Severe weather threatens as a long lived linear mesoscale convective system continues eastward across Lower Michigan, strong heating ahead of the system should result in re-intensification of storms along the leading edge this afternoon.  This system should hold together to cross Lake Erie into Ohio and Pennsylvania before spreading into New England overnight.

By Friday, a belt of moderately strong mid-level flow will move into the northeast ahead of an advancing cold front.  This cold front should reach eastern New England by Friday evening into Friday night and extend westward into the southern Great Lakes region.

Severe weather summary

Scattered severe storms are forecast Friday into Friday night across Eastern New York and New England.  Isolated strong to severe storms are expected through parts of central and western New York, New Jersey, and Pennsylvania into the southern Great Lakes region.

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Considerable uncertainty exists regarding the impact of the ongoing mesoscale convective system as it moves east.  This system is expected to weaken overnight but considerable cloudiness will exist with the systems remnants and those may prevent destabilization in certain areas ahead of the front.  The areas where these clouds are most prevalent are the areas that will see less destabilization.    Models do indicate low level moistening ahead of the cold front with strong southerly flow contributing to the amount of buoyancy that develops in the region.   Strong westerly flow aloft, which will increase with height, will support organized storms.  These may include supercell and a muticellular clusters primarily during the late afternoon and early evening hours.   Wind and hail appear to be the primary threats but a tornado like the one this past week in New Hampshire cannot be ruled out in the most intense storms.  Another article should be out Friday morning to bring you all the latest information.

 

Robert Millette

Staff Meteorologist

Firsthand Weather

Expect Severe Weather in the Northeast today.

Northeast and Mid-Atlantic Forecast

A cold front extending from the Great Lakes southwestward into the Plains will move east today and be just off the coast of New England and the Mid-Atlantic by Tuesday morning.  Showers and Thunderstorms will develop along and ahead of the boundary layer Monday into Monday nightAfter the front moves off shore and departs, conditions will clear and the heat will return throughout the region with another chance of showers and storms on Friday.

northeast severe outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 162,009 21,120,119 Pittsburgh, PA…Rochester, NY…Syracuse, NY…Manchester, NH…
MARGINAL 523,786 76,969,862 New York, NY…Philadelphia, PA…Boston, MA…

 

Scattered showers and thunderstorms that have brought wind damage and hail to the Ohio Valley will move east today into New England and the Mid-Atlantic region as an upper level trough and its associated cold front shifts east this afternoon.  Ahead of the front, a corridor of surface dewpoints in the mid to upper 60s is in place with an axis of instability developing from Central Ohio across Pennsylvania, New York and into New England.  Scattered  storms will initiate along this axis around mid-day and several squall lines will move East Southeast across the area this afternoon into tonight.  Forecast soundings from overnight from Pittsburgh northeast toward Burlington Vermont show midlevel cape values near 1000 J/KG with high 3 kilometer lapse rates and good low level wind shear profiles.

The wind profile favors the development of persistent line segments with wind damage potential and the potential for some hail.  Model forecasts suggest the area of greatest large scale ascent and mid-level flow will be from Northern Pennsylvania into New England.  For this reason, the wind damage potential is higher in this area.

 

Robert Millette

Staff Meteorologist

Firsthand Weather

Southern Oklahoma/Northern Texas Overnight Storms

A large thunderstorm complex has developed across southwestern Oklahoma down through northwestern Texas. This complex is propagating towards the ESE, and is expected to continue to advance towards the ESE overnight. A well-defined outflow boundary, from thunderstorms earlier in Oklahoma, lies across the Red River Valley. This outflow boundary will sustain (coupled with the low-level jet) and will guide the thunderstorm complex into the I-35 corridor during the early morning hours on Friday. The highest rain chances are along and west of I-35, but locations east of I-35 will see scattered thunderstorms too. Heavy rainfall and isolated damaging winds are the main threats.
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HRRR Simulated Radar Friday Morning
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HRRR Rainfall Forecast
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SPC Thunderstorm Forecast