Southeast Flooding

The flood risk is high across the Southeast to wrap up February. The storm track, which has been just north of the Southeast, will shift south allowing for several wet storms to move from the Mississippi Valley towards the east and north. As the storm track moves south this upcoming week, several disturbances will move across the Southeast. Each one creating enough lift to generate rain. Periodically, stalled frontal boundaries will be located across this region, which will act to enhance rainfall–increasing the flood threat.

It is difficult to pinpoint exactly which area will see the heaviest rainfall but at this time it appears widespread 3-6″ will fall from Louisiana east through Mississippi, Alabama, Georgia and north into parts of Tennessee and Kentucky this week with isolated 5-10″ amounts (see Fig. 1). The heavy rain axis will also extend farther east in north into Virginia and the Carolinas.

Fig. 1: Rainfall forecast through next week

The soil is saturated in this region from above average precipitation during the cool season. This, paired with a lack of foliage due to the cold season, will allow for quick runoff into area streams, creeks and rivers this upcoming week. Please remain alert of your surroundings. And, as always, TURN AROUND, DON’T DROWN!

Tropical Update: Harvey and Hurricane Safety

Hurricane Harvey, now 115 miles southeast of Corpus Christi Texas, has seen the maximum sustained winds increase to 110 this morning, just shy of major hurricane status. The minimum central pressure has dropped 947 Millibars. Harvey is expected to become a major hurricane today with winds increasing further to 120 mph. As of this 11 AM EDT, the following watches and warnings are in effect.

A Hurricane Warning is in effect from Port Mansfield to Sargent Texas. Hurricane conditions will be occurring in these areas within the next 12-24 hours.

A Tropical Storm Warning is in effect from south of Port Mansfield to the Mouth of the Rio Grande River and from North of Sargent to High Island Texas

A Tropical Storm Watch is in effect for South of the mouth of the Rio Grande to Boca de Catan Mexico

A Storm Surge Warning is in effect from Port Mansfield to High Island Texas. A Storm Surge Warning means there is a danger of life-threatening inundation from rising water moving inland from the coastline in the indicated locations. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials.

A Storm Surge Watch is in effect from south of Port Mansfield to the Mouth of the Rio Grande. A Storm Surge watch means there is a possibility of life-threatening inundation from rising water moving inland. Persons located within these areas should take all necessary actions to protect life and property and be on the look out for rising seas.

Forecast Information

Harvey

Hurricane Harvey continues to increase in strength this morning and is now approaching major hurricane status. Harvey is expected to be a category 3 storm when he moves ashore in Texas. Sustained winds are expected to be between 120 and 130 miles per hour with higher gusts. Harvey will be bringing life-threatening storm surge, rainfall, and wind hazards to portions of the Texas coast. Preparations to protect life and property should be completed this morning, as tropical storm force winds will first arrive in the hurricane and storm surge warning areas later today.

Life-threatening storm surge flooding could reach heights of 6 to 12 feet above ground level at the coast between the north entrance of the Padre Island National Seashore and Sargent. Devastating and life-threatening flooding is expected across the middle and upper Texas coast from heavy rainfall of 15 to 25 inches, with isolated amounts as high as 35 inches, from today through next
Wednesday.

Harvey will hug the coast after he moves inland, which could help prevent the quick weakening associated with land falling hurricanes. While Harvey will still weaken, it may be a slower process and he could maintain Tropical Storm strength longer than usual. Harvey is forecast to impact this area for several days.

Hurricane Harvey Hazards

Storm Surge and Storm Tide

Storm Surge and large waves are the greatest threats to life and property along the coast. A storm surge is an abnormal rise of water generated by a storm’s winds. Many will remember the surge from Hurrican Ike is 2008. Storm Surge with Harvey is expected to be as high as 12 feet in some locations (was 20 feet in Ike). Please check your local media sources for the exact surge totals expected for your area. Surge related flooding will be dependent on the exact timing and the tide and can vary greatly over short distances. Large waves will also be a factor at the coast. Based on the tide charts, Harvey should hit as tides are moving out and close to low tide, but onshore winds are possible during several tidal cycles.

Tornadoes

Hurricanes frequently produce tornadoes, usually in the embedded thunderstorms in the rain bands now beginning to hit the Texas coast line. They can also be associated with the eye wall. Tornadoes produced by these systems are usually weak and short lived, but they can be a threat to where they hit. A Tornado watch is expected to be posted for coastal areas of Texas and Louisiana later today.

Winds

It goes without saying that winds are a major issue with Hurricanes. Sustained winds with Harvey are expected to reach up to 120 mph with gusts reaching as high as 150 mph with some locally higher gusts. Harvey is forecast to be a major Hurricane at landfall.

Rainfall

Forecasts for Harvey have indicated significant rainfall is possible, with some models showing over 30 inches of rain. This will be a very long duration event and flooding and flash flooding will bea major issue for many areas.

Hurricane Safety

Evacuations

Many areas in Texas have had evacuation orders given, for those who are evacuating, you will need to determine a safe evacuation route inland. While evacuating, you’ll want to monitor the latest information to ensure that you will be evacuating to a location that is not also under a risk. Public services in these areas will already be strained and adding many evacuees will only cause more strain for everyone. Learning the location of official shelters will be helpful both in the event that you evacuate as well as for those who do not evacuate. Areas that are not under evacuation orders should also have shelters for the residents who end up in trouble due to hurricane hazards. Tornadoes, lightning, power outages, and property damage due to falling trees can force residents from their homes, even if a mass evacuation isn’t needed. The good news is that a quick check of traffic in this region doesn’t show any, so many heeded these orders in advance.

When evacuating, put together a go-bag. Include a disaster supply kit, including a flashlight, batteries, cash, first aid supplies, medications, and copies of your critical information if you need to evacuate. Snacks and stuff to drink will also be good for longer evacuations, especially with children. While you may stop for gas, many others are also evacuating with you so its possible that many supplies will be sold out along your route. If you haven’t already, fill up your gas tank in your local area, gas supplies may also be strained along your route. Cell phones should be charged before you leave. Have one member of your family turn their phone off while travelling together. This will ensure that if one phone does run out of battery, you will have another phone to turn on and use. All family members should have all numbers for your phones and know to call multiple numbers if they can’t get a hold of you.

You should also inform someone of your plans. If you fail to arrive at your destination due to a car accident, your contact can alert the authorities. Having them know the route you planned to take is essential in locating you.

Stay tuned to local news outlets as you travel. Conditions may change and areas you were heading to that were going to be safe may not be anymore. Harvey is brining a large area of rain to Texas and the location you were heading for may end up under a flood warning when it wasn’t before. Always ensure that the safety of your location is the top priority.

Staying at home

For those of you who are not leaving home, I would first implore you to heed local evacuations if you are under them. Evacuation orders are given for a reason. If you are under those orders it is absolutely not safe where you are. While I do realize that some properties remain even in massively damaged areas, you only put yourself and those who would need to rescue you in the event of an emergency in danger by taking that gamble. It is never just your survival on the line.

If you have not been ordered to evacuate, there are several things you should plan for. First, as I mentioned above, have a plan to be able to evacuate to a local shelter if your house if one of the unfortunate locations that falls victim to one of the more local hurricane hazards. Lighting occurs frequently within a hurricane and can strike even in areas where hurricane conditions are not occurring. You should also have a plan for any pets you may have. Not all shelters accept pets so ensure the one you may go to does.

What to bring to the shelter

You will need to make sure that you have everything you need at the shelter. While the shelter will have supplies, they don’t usually carry specific medications or your specific brand of baby food. Ensure that you have a first aid kit with all the medications taken by your family. If you are running low, see if your local pharmacy can give you more. Baby food and diapers will be needed. Your baby should be prepared for a multiple day stay at the shelter. Bring things to do as well. Books, games for children, headphones and a source of music (we all know some of you still have a Walkman) will all be desired. The shelter is not exactly a fun place to be. Bring your toiletries and blankets. The shelter will have some but we all prefer our own. Flashlights and batteries are good to have in case the power goes out at the shelter as well. Also ensure you bring identification, cash and credit cards as well as copies of your essential documentation like proof of insurance.

Protecting your home

Be aware that Hurricane winds can cause trees and branches to fall, so before a hurricane trim or remove damaged trees and limbs to keep you and your property safe.
Secure loose rain gutters and downspouts and clear any clogged areas or debris to prevent water damage to your property. When it comes to repairing your rain gutters, it’s as easy as checking out sites such as https://www.aluminiumwarehouse.co.uk/, finding the right materials and replacing your damaged/old gutters. This will help protect your property, which is what you need to consider, especially after weather conditions like thunderstorms and heavy rain. This can also help keep them lighter and not fall under the weight of all the rain. Reduce property damage by retrofitting to secure and reinforce the roof, windows and doors, including the garage doors. Plywood over windows or close storm shutters if your house has them, this can protect them from wind and debris. If you are construction inclined, hurricane clips can be installed in your attic to help secure your roof to the house. You may also want to get in touch with a home improvement service similar to Mastershield Atl that may be able to provide support for homeowners who are looking for a way to protect their roof from water damage. While it is certainly too late to hire a contractor to do this for Harvey, other storms will come along and this can be done for future storms. You can also brace your garage door and doors that lead outside with planks to keep it from blowing in. You should also close all interior doors to compartmentalize the house. This way, if a window does break in one area, the remaining areas will have protection against the elements coming in. Purchasing a portable generator or installing a generator for use during power outages is also a good idea. Remember to keep generators and other alternate power/heat sources outside, at least 20 feet away from windows and doors and protected from moisture. You should never try to power the house wiring by plugging a generator into a wall outlet. If power does go out, use a flashlight. Candles are a fire hazard.

Keeping food and water safe

The most important thing when it comes to food is to buy nonperishable goods and to store water. You do not need to buy multiple gallons of water for activities like brushing your teeth. Simply refill an old milk or water bottle with tap water and use it. You can do the same thing for bath water, pre-filling your tub is also recommended. Tap water storage can be done with any container from large pots used for cooking to old bottles and even any large plastic container. Always remember to keep using the tap water until it goes out, you don’t want to needlessly use up your supply and not be able to replenish it. For any cold food you do have, turn your refrigerator and freezer to their maximum cold settings and open them as little as possible. This will help keep things cold. Try to use up any chilled foods first so that keeping things cold becomes unnecessary and have a supply of ice on hand to keep things cold longer. While you can buy ice at the store, you can also just use ice cubes. Simply dump your tray into a plastic bag and refill the trays. Dump new ice cubes as they form and keep refilling the trays. You will be able to continue this process for as long as you have power or tap water. This also creates an emergency water supply should you run out of water. Simply melt the ice. You can also use rain water if you have a safe way to get a bucket outside to collect some. You should always try to keep a lid on your water supply. This will keep dust and bugs out of it.

After the Storm

It will be tempting to go outside after the storm has passed or during the calm period in the eye. This should be avoided. The eye is only temporary and hurricane conditions can start very quickly. After the storm, there will be a lot of damage in the region. Floods could still be occurring and the water could be contaminated. You also can’t see what’s in the water. Animals and hazards in the water could be potentially dangerous to your health. The water could even be electrically charged from downed power lines.

We here at Firsthand will do our utmost to keep you up to date with the latest information. Our thoughts go out to those in the areas affected by Harvey. Stay safe everyone.

Robert Millette

Incident Meteorologist

Braintree Emergency Management Agency

Severe weather risk continues for the next few days

After yesterday’s severe weather across parts of Oklahoma and Texas, storms have spread to the east.  Severe Thunderstorm watches are in effect across several states from now until tonight.

Severe Risk

A trough across Missouri this morning moved eastward to the middle Ohio River Valley and will arrive by late tonight. A belt of 40-50 kt west-southwesterly mid level winds will continue to overspread an increasingly moist warm sector. A cold front has moved across the Ozarks and Ark-La-Tex region and continues east through Kentucky and Tennessee down to the Gulf Coast.  Organized convection across far northeast Arkansas far southeast Missouri from late this morning has spread east-northeastward and increased in coverage and intensity into Tennessee and Kentucky. This activity will pose a damaging wind and severe hail risk, although a tornado cannot be ruled out.

Farther south, more discrete storms have developed within the warm sector this afternoon across additional portions of Tennessee, northern Mississippi and northwest Alabama.  A supercell-favorable wind profile and steep mid-level lapse rates will support large hail potential. A few tornadoes also appear possible,  particularly into early evening across middle portions of Tennessee and northern Mississippi and northwest Alabama.   In this corridor, a modest westerly component of the mid-level winds  and modestly strong low-level shear coincide.

Severe

Tornado Risk

Hail Risk

Wind Risk

Current Watches

A Convective line stretching from near Huntingburg Indiana southward across central Kentucky and middle Tennessee and into northwest Alabama is expected to continue moving eastward over the next few hours. The downstream airmass is generally cooler and has less overall instability. However, the line is well-organized and the bulk shear
is expected to remain relatively constant for the next several hours. Near-severe gusts have been measured at several sites as the line moved through. The ongoing severe threat will persist for the next few hours.  A threat is possible downstream in eastern Kentucky, Tennessee and far northwest Georgia and a watch has been issued for this region.  Additionally, the cluster of storms ahead of the line in eastern Kentucky pose an isolated hail and damaging wind threat.

Current warnings

 

 

Robert Millette

 

Southern Plains Storms

As expected this time of the year, it has been hot and oppressive across the Southern Plains this week. Luckily, changes are in store beginning tomorrow (Friday). An approaching upper-level trough will push a cool front into northern Oklahoma late tonight into Friday. This cool front will provide adequate lift to generate scattered thunderstorm activity along and north of I-40 in Oklahoma, southern Kansas, and parts of the Texas Panhandle. Any thunderstorm that develops tomorrow has the chance to become severe. The main threats are damaging winds and large hail.
Slide02
SPC Thunderstorm Forecast (Friday)

Heavy rainfall is possible with the thunderstorm activity on Friday, too, and the rain chances will continue through Sunday. These rain chances will continue throughout the weekend due to a couple upper-level disturbances moving across the area. 1-2″ is possible north of I-40, and for parts of the Texas Panhandle; with isolated higher amounts.
Slide03
NAM Rainfall Forecast Through The Weekend

While most of southern Oklahoma and northern Texas wont see widespread rain chances. A few thunderstorms are possible for these areas; however, the more widespread activity will remain further north. Areas that do not see rainfall/cloud-cover can expect temperatures and humidity levels to remain uncomfortably high.

Sunday Severe Storms

Showers and thunderstorms are ongoing across parts of Oklahoma and northern Texas this morning. This activity will continue to progress towards the east throughout the morning hours before new activity ignites. A cool front is slowly pushing into central Oklahoma this morning, coupled with a shortwave trough rapidly approaching the area; this will be the focus for new thunderstorm development this afternoon.
Slide02
HRRR Simulated Radar For This Afternoon

Some of these storms will likely be strong to severe and the Storm Prediction Center has a slight risk for severe thunderstorms for most of eastern Oklahoma. Damaging winds, large hail, very heavy rainfall, and frequent lighting will be possible with any thunderstorm.
Slide04
SPC Thunderstorm Forecast (Yellow Area: Slight Risk)

The heaviest rainfall will be along and east of I-35. These areas will see .5-1″ of rainfall with amounts as high as 2-4″ towards northeastern Oklahoma.
Slide03
HRRR Rainfall Forecast

If you’re on area lakes today, please remain on high alert in case a thunderstorm approaches your area. Regardless of thunderstorm chances, temperatures will be extremely hot. Heat indices will exceed 100, so stay hydrated out there. Another chance for thunderstorms exists for you 4th of July across parts of Texas and Oklahoma. I’ll have an update on this later this evening.

Forecast and Severe Outlook: Wednesday, May 11th

Additional severe weather is in the forecast as the last several days have brought 67 tornadoes from Colorado to Kentucky.  Strong low pressure moving into Canada will continue to move a strong warm front North ahead of a weaker cold front.   This clash of frontal boundaries is responsible for the weather the Plains and river valleys have been dealing with.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

The main weather feature across the nation will be a strong low pressure system over the north-central U.S. that will have a trailing cold front extending southward to Texas and the Desert Southwest. An occluded surface low over North Dakota will slowly lift northeastward to southern Canada, with rainy weather over eastern Montana and western North Dakota for the first half of Wednesday. Farther to the south, another surface low along the trailing cold front will also produce widespread showers and thunderstorms extending from Texas to the Ohio Valley. Some of these storms could be severe at times, and also produce localized flash flooding.

Temperatures are expected to be below normal across much of the Intermountain West with an upper level trough in place, and also for the Northeast U.S. which will be under the influence of a Canadian surface high. It will continue to be warm and humid south of a stationary frontal boundary, which will extend from the Ohio Valley eastward to the Mid-Atlantic coast. Highs in the 80s to near 90 along with noticeable humidity will be commonplace across the Deep South and the Southeast states.

West of the Rocky Mountains, a quiet weather pattern should prevail through the end of the week with no Pacific storm systems imminent. Inland temperatures should slowly return closer to average after the recent cool weather.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

No critical Fire areas to report.

Severe Weather Analysis

Summary

Scattered severe storms are forecast from parts of North Texas into Oklahoma and the Missouri and Mississippi River Valleys. Large hail and damaging winds will be the main concern by late in the day but a brief tornado or 2 are possible for this region.  For the Ohio Valley into the Mid-Atlantic, isolated severe hail or wind is possible during the day.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 47,289 2,762,058 Norman, OK…Wichita Falls, TX…Lawton, OK…Broken Arrow, OK…Muskogee, OK…
SLIGHT 218,024 19,885,612 Dallas, TX…Fort Worth, TX…Oklahoma City, OK…Kansas City, MO…Tulsa, OK…
MARGINAL 378,142 52,006,921 Chicago, IL…Indianapolis, IN…Columbus, OH…Charlotte, NC…Milwaukee, WI…

Analysis

Low pressure will move across Iowa during the day today and bring a warm front across Missouri into Central Illinois and across the remainder of the Ohio Valley. A very moist air mass exists behind this front supporting scattered storms during the day from Iowa into the Ohio Valley.  Warm advection will allow for development of storms across Virginia and North Carolina under the influence of the disturbance currently causing thunderstorms in Kentucky.

Moderate to strong mid-level flow will spread into the Oklahoma and Far Northern Texas area as a weak cold front extends from Missouri down into Northwestern Texas by late this afternoon. A very warm and moist air mass is already in place though current storms in the area will play a pivotal role in destabilization during the day.  Strong instability will lead to intense clusters of thunderstorms with the primary threats of wind and large hail across the enhanced risk area.  A couple of tornadoes cannot be ruled out for this region.

Substantial moisture and instability is currently developing over Eastern Kansas and Western Missouri causing cluster of thunderstorms to form during the overnight hours. This activity is expected to continue during the morning hours with a threat of large hail.  Further development of stronger storms during the early afternoon will present a risk of damaging winds as a mesoscale convective system develops.

Dewpoints in the 60s across Iowa are forecast to result in a small corridor of supercell activity. Some heating is expected during the day as shear profiles are locally enhanced by the presence of the low pressure system.  Hail will be the primary threat with these storms but there is a risk of tornadoes later in the afternoon.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather

Forecast and Severe Outlook: Monday, May 9th

Southerly winds ahead of an upper system moving out of the central Rockies into the Great Plains are forecast to draw warm, moist air from the Gulf of Mexico supporting widespread showers and thunderstorms across the lower and central Great Plains into the lower and mid Mississippi valley Monday into Monday night. Some of these storms may be strong to severe, particularly from northeast Texas, southeast Oklahoma into Arkansas and northwest Louisiana, where the air mass is expected to become highly unstable as well.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

Moisture spreading further to the north is likely to focus along a slow moving frontal band supporting widespread moderate to locally heavy rainfall accumulations across portions of the lower Missouri and mid Mississippi valleys.

On Tuesday into early Wednesday, the previously noted upper system is forecast to weaken as it continues to track to the east. Organized showers and thunderstorms are expected to focus along the frontal boundary that will continue to extend from the mid Mississippi into the Ohio valley and Mid-Atlantic states.

Back to the west, a well-defined cold front is forecast to drop through the western U.S. this period, with below-average temperatures spreading south and east from the northern Rockies and High Plains. Moderate to heavy precipitation is likely to develop west of an organizing area of low pressure over the northern High Plains. Heavy rain accumulations are expected to center over eastern Montana, with heavy mountain snows over the ranges of southwestern Montana and northwestern Wyoming.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
Critical 35,626 780,783 Las Cruces, NM…Roswell, NM…Hobbs, NM…Carlsbad, NM…Artesia, NM…

Critical Fire Weather area for portions of Eastern New Mexico and Far West Texas.

Severe Weather Analysis

Summary

Severe storms are forecast Monday into Monday night from parts of the Southern and Central Plains eastward into the Lower to Mid Missouri Valley, the Ozarks, and ArkLaTex region. Tornadoes and very large hail are possible across the region under the enhanced risk from Eastern Oklahoma and Northeastern Texas into Central Arkansas and Northern Louisiana.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 67,531 4,070,056 Shreveport, LA…Little Rock, AR…Tyler, TX…Fort Smith, AR…Longview, TX…
SLIGHT 228,723 20,439,696 Dallas, TX…Oklahoma City, OK…Kansas City, MO…Omaha, NE…Tulsa, OK…
MARGINAL 203,583 16,544,671 Houston, TX…Memphis, TN…Fort Worth, TX…Arlington, TX…Pasadena, TX…

 

tornado risk

Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
10 % 45,082 2,815,545 Shreveport, LA…Little Rock, AR…Tyler, TX…Fort Smith, AR…Longview, TX…
5 % 56,517 4,200,601 Tulsa, OK…Mesquite, TX…Broken Arrow, OK…Fayetteville, AR…Springdale, AR…
2 % 135,312 14,700,662 Dallas, TX…Fort Worth, TX…Oklahoma City, OK…Arlington, TX…Wichita, KS…

hail risk

Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 73,480 8,648,809 Dallas, TX…Tulsa, OK…Plano, TX…Garland, TX…Shreveport, LA…
30 % 67,798 4,097,285 Shreveport, LA…Little Rock, AR…Tyler, TX…Fort Smith, AR…Longview, TX…
15 % 229,629 20,571,862 Dallas, TX…Oklahoma City, OK…Kansas City, MO…Omaha, NE…Tulsa, OK…
5 % 202,489 16,100,321 Houston, TX…Memphis, TN…Fort Worth, TX…Arlington, TX…Pasadena, TX…

Analysis

Strong heating over much of the region will combine with steep lapse rates aloft to result in strong instability from Eastern Texas into Eastern Oklahoma and Kansas as well as Western Arkansas. Southerly low-level flow will continue to bring moisture into the region as it did with yesterdays storms.  Dewpoints are forecast to reach the mid to upper 60s across the region.  Thunderstorms currently near the Red River will shift into Arkansas by this afternoon.  There is a risk of damaging winds and hail with these storms.

The outflow from the aforementioned storms should help to focus the areas of severe weather development later this afternoon when instability reaches its maximum. Wind Shear profiles will clearly favor the development of discrete supercells and support conditions for tornadoes.  The most likely area for tornadic development will be Eastern Oklahoma into West Central Arkansas southward across the ArkLaTex region.  Supercells may also develop farther south within the moist regions near Shreveport.  Convergence in this area will be weak but rapid moistening and weakening outflow boundaries may be enough to initiate discrete storms.

Further west, from Central Oklahoma into Central Kansas, severe storm chances are more conditional along the Dryline but some storms should develop in this area and large hail is the primary risk.

Further north along the weakening warm front, strong warm advection pushing north will result in destabilization from Missouri into Western Illinois. A few severe storms capable of large hail and possibly a tornado or 2 cannot be ruled out.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather

Forecast and Severe Outlook: Sunday, May 8th

After yesterday’s tornadoes in Colorado, Severe weather is forecast to continue on the Plains today.  A few tornadoes, very large hail and damaging winds will be the primary threats.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

A broad upper low currently centered over the Great Basin and southwestern U.S. is expected to slowly lift northeastward this period. Scattered showers and thunderstorms are forecast to continue today from the Sierra eastward to the central and southern Rockies, with precipitation expected to end by early Monday across California and much of the Great Basin as the aforementioned low reaches the central Great Plains.

Further to the east, southerly winds are expected to draw moist, unstable air from the Gulf of Mexico northward increasing the threat for strong to severe thunderstorms across portions of the southern and central Great Plains. On Monday, the threat is forecast to shift further east, extending into portions of the lower and mid Mississippi valley.

The greatest potential for heavy rainfall accumulations is expected center across the lower Missouri and mid Mississippi valleys. Moisture advecting from the south is forecast to focus along a slow moving frontal boundary, supporting heavy rains across the region.

Across the Northeast, a strong low moving across southeastern Canada is expected to usher in cooler temperatures and another chance for showers and thunderstorms early Sunday. Further to the south, scattered showers and thunderstorms are forecast to focus near a frontal boundary dropping into the region. Meanwhile, high pressure and dry conditions are likely to prevail across the Southeast.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
Critical 50,750 896,717 Las Cruces, NM…Roswell, NM…Clovis, NM…Carlsbad, NM…Portales, NM…

A Critical Fire Weather area has been issued for portions of Eastern New Mexico and Far West Texas.

Severe Weather Analysis

Summary

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 51,455 1,370,679 Wichita, KS…Enid, OK…Salina, KS…Hutchinson, KS…Dodge City, KS…
SLIGHT 163,105 8,307,061 Oklahoma City, OK…Kansas City, MO…Omaha, NE…Tulsa, OK…Lincoln, NE…
MARGINAL 109,930 5,511,073 Fort Worth, TX…Arlington, TX…Des Moines, IA…Grand Prairie, TX…Denton, TX…

Severe thunderstorms are forecast across much of the Central and Southern Plains Sunday afternoon into evening. Very large hail and a few tornadoes are anticipated with the primary threat area from Central Kansas into Northwestern Oklahoma beginning in the late afternoon.

Tornado Risk

tornado risk

Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 38,306 907,149 Wichita, KS…Enid, OK…Hutchinson, KS…Dodge City, KS…Hays, KS…
10 % 37,880 807,808 Wichita, KS…Enid, OK…Hutchinson, KS…Dodge City, KS…Hays, KS…
5 % 57,931 1,772,470 Edmond, OK…Salina, KS…Manhattan, KS…Stillwater, OK…Kearney, NE…
2 % 35,823 1,715,349 Oklahoma City, OK…Lincoln, NE…Topeka, KS…Norman, OK…Lawton, OK…

Hail Risk

hail risk

Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 50,943 1,364,854 Wichita, KS…Enid, OK…Salina, KS…Hutchinson, KS…Dodge City, KS…
30 % 51,776 1,381,121 Wichita, KS…Enid, OK…Salina, KS…Hutchinson, KS…Dodge City, KS…
15 % 163,586 8,317,521 Oklahoma City, OK…Kansas City, MO…Omaha, NE…Tulsa, OK…Lincoln, NE…
5 % 112,522 5,439,040 Fort Worth, TX…Arlington, TX…Killeen, TX…Denton, TX…Lewisville, TX…

Analysis

Low pressure will quickly deepen across Southwest Kansas today as strong moisture advection takes place across the Southern Plains. A well-developed Dryline should be in place by this afternoon from Southwest Kansas into Western Oklahoma and Northwest Texas with Dewpoints at the surface getting into the 60s.  Widely spaced thunderstorms are expected to develop along and east of the Dryline during the mid to late afternoon.

The model forecast soundings for the day are impressive with high levels of CAPE and shear. These conditions are very favorable to supercell development.  Tornadoes, very large hail and wind damage are likely with any cell that develops east of the Dryline.  The Storm Prediction Center has removed the moderate risk they issued yesterday for this region due to some uncertainty in the levels of moisture available to the storms, but a wider area of enhanced risk has been created overnight and I will not be surprised if an area of moderate risk is reintroduced as observations create more certainty for moisture levels.

Further south along the Dryline, from Northwest Texas down to the Rio Grande, moderate instability will form when daytime heating combines with a retreating Dryline and the arrival of moisture advection this afternoon. Widely spaced thunderstorms should form along the Dryline.  This activity will move eastward into an area of increasing low level flow.  Supercells with large hail and damaging wind will be likely.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather

Forecast and Severe Outlook: Friday, May 7th

As severe weather returns to the Plains, Fire Weather remains Critical in Eastern New Mexico after yesterday’s dry thunderstorms.  Today’s forecast and severe weather analysis follows below.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

An omega block pattern aloft at the beginning of the period is forecast to slowly break down over the weekend. Well defined upper level lows are evident over the Desert Southwest and near the Mid-Atlantic coast Saturday morning, and a weakening upper level ridge over the Plains.  By Sunday afternoon, the pattern should not be quite as amplified with the upper low lifting northward towards Canada and the ridge becoming more suppressed to the south.

In terms of sensible weather, temperatures are expected to begin moderating across the eastern U.S. after several days of unseasonably cool weather and persistent cloudy skies. The same also holds true across much of the Intermountain West region with below normal temperatures likely to continue through the weekend, along with numerous showers and high elevation snow.  The heaviest snow is expected for the highest mountains of Wyoming, Utah, and Colorado.

Across the south-central U.S., it will become increasingly warm and humid as moisture returns northward from the Gulf of Mexico ahead of the upper low near the Rockies. Strong to severe thunderstorms will be possible from Texas to Nebraska on Sunday, and general thunderstorm activity is possible along a frontal boundary that will extend eastward to the Southeast U.S. coast.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
Critical 36,742 239,972 Roswell, NM…Clovis, NM…Carlsbad, NM…Portales, NM…Artesia, NM…

Critical Fire Weather area for portions of Eastern New Mexico and Far West Texas.

Severe Weather Analysis

Summary

Severe Thunderstorms are forecast to occur this afternoon and evening across the Central and Southern High Plains and the Ohio River Valley.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 95,499 9,079,542 Denver, CO…Cincinnati, OH…Aurora, CO…Lexington-Fayette, KY…Louisville, KY…
MARGINAL 347,529 20,467,273 Indianapolis, IN…Columbus, OH…St. Louis, MO…Pittsburgh, PA…Lincoln, NE…

Analysis

A southeastward moving trough over the Great Lakes will impact the high amplitude pattern in place and allow the closed low over Southern California to finally begin to move east. Surface cyclogenesis will occur over Northeast Colorado and the adjacent Central Plains as a southward moving front extends across the Middle and Lower Missouri Valley into the Ohio River Valley.

In the High Plains, Moist Southeasterly upslope flow will establish itself this afternoon and evening along the Front Range in Northern Colorado and Southern Wyoming. Storms are expected to develop and steadily increase by mid-day over the higher terrain and then move into the foothills and then over the High Plains.  Severe hail is expected and a coup-le of Tornadoes could occur particularly over Northeastern Colorado.

Further east, a cold front associated with a deepening low near the Great Lakes will amplify over the Ohio Valley. Persistent strong west southwesterly winds will feed moisture just above the surface and raise surface Dewpoints into the 60’s by late afternoon.  With near surface based storms expected to form this afternoon and evening, severe hail and winds should be the primary hazards.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather

Forecast and Severe Outlook: Monday, May 2nd

Severe Weather is forecast in the Piedmont of the Carolina’s to the Mid-Atlantic as the system that brought a few tornadoes to Indiana yesterday moves east.  Meanwhile in Texas, showers and thunderstorms will continue to exacerbate the flooding problems across that region.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

A quasi-stationary front extending from the Mid-Atlantic and Central Appalachians southwestward to the Lower Mississippi Valley will slowly sag south and eastward to the Southern Mid-Atlantic to the Southeast and parts of the Eastern Gulf Coast by Tuesday evening. Showers and thunderstorms will develop along and ahead of the boundary from the Mid-Atlantic to the Southern Plains that will extend from the Northern Mid-Atlantic Coast to the Central Gulf Coast by Tuesday.  Rain will also develop over parts of the Great Lakes to the Northeast that will slowly move into Southeastern Canada by Tuesday afternoon.

Meanwhile, upper-level energy over Southern California will move slowly eastward to the Southern Plains by Tuesday. The energy will produce rain with embedded thunderstorms that will have a diurnal component to the areal coverage over parts of Central California to the Central and Southern Rockies that will end over the Region by Tuesday morning.  Another area of upper-level energy will move southward from the Northern Plains to the Southern Plains by Tuesday evening.  The energy will trigger rain over parts of the Northern Plains on Monday morning that will move southward to the Central High Plains by Tuesday morning.

Furthermore, a front moving southward out of Central Canada on Tuesday morning will move to parts of the Upper Great Lakes and Upper Mississippi Valley and Northern Plains by Tuesday evening.

Current Model Analysis

6 hour model

On Monday, one batch of rain moves out of the Northeast as another prepares to move in. Rain should stop for a time in New York and New England as the second batch comes through the Ohio Valley.  This system did produce a couple of Tornadoes on Sunday and brought several instances of severe weather across the Ohio Valley.  This risk will continue from Virginia down through the Gulf Coast along the cold front.

Showers and storms will continue to exacerbate the flooding issues down in Texas throughout the day though conditions will begin to dry out later in the forecast period.

High pressure will dominate the western half of the country but a couple of weak disturbances will be enough to generate some rain  and snow showers from the Pacific Coast into the 4 Corners region.

18 hour model

 

Monday afternoon, the rain shifts east and is now impacting the East coast from Florida to Maine within this broad circulation and along the cold front.  Areas near Dallas should begin to dry out as the front pulls east toward the coastline.  Rain and thunderstorms should be expected along the entire Gulf Coast and Eastern Seaboard at some point during the day.

High pressure will completely dominate the western half of the ountry Monday afternoon with only a few spot showers and a small batch of rain showers in the Dakotas associated with a weak low in Canada.

36 hour model

By early Tuesday, High pressure dominates the West with only the remnants of a cold front draped across the Country from Massachusetts to Coastal Louisiana. Low pressure in the Mid-Atlantic will continue to bring rain to nearly the entire East Coast.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

No critical fire weather expected

Severe Weather Analysis

Summary

A few severe storms are forecast today across the Appalachian Mountains and Piedmont of the Carolinas into the Mid-Atlantic region.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 70,267 19,724,039 Baltimore, MD…Charlotte, NC…Washington, DC…Greensboro, NC…Durham, NC…
MARGINAL 155,209 27,778,806 Philadelphia, PA…New Orleans, LA…Virginia Beach, VA…Atlanta, GA…Raleigh, NC…

Analysis

Weak to moderate boundary layer destabilization is expected by this afternoon near and east of the lee surface trough from the Piedmont region of the Carolinas to the Mid-Atlantic. Moderate instability and strong southwesterly low and mid tropospheric winds are forecast to be sufficient for convective development.  These thunderstorms will be capable of producing damaging wind gusts and some hail.  Storm coverage east of the Appalachians is expected to become more widespread this afternoon with the approach of a upper level disturbance emerging from the west.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather