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

 

Severe weather threatens the Northeast

Severe

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.

Severe

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

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.

Southern Plains Storms

Shower and thunderstorm chances will continue across much of Kansas, northern Oklahoma, and the Texas Panhandle over the next few days. Isolated thunderstorms are ongoing across parts of the Southern Plains this evening, but more widespread activity is expected to develop in eastern Colorado/western Kansas and propagate towards northern Oklahoma tonight into early Thursday.

By Thursday evening a weak cool front will advance into Kansas and north of I-40 (in Oklahoma) by Friday morning. This boundary will be the focus for several rounds of showers and storms for Kansas as well as northern and central Oklahoma. Heavy rainfall is likely during this setup; most areas north of I-40 will see 1-2″ with isolated 3-6″ possible. This could create flash flooding for localized areas during the day on Friday. Isolated damaging winds and large hail is possible with any storm over the next few days, and lightning will be a major concern for those who have outdoor plans.
Slide02
Potential Rainfall Totals (Next 5 Days)

It is important to note that the area will see a northerly flow aloft, so some of the thunderstorms that develop in northern/central Oklahoma may move further south than the models indicate. This will keep scattered rain chances in the forecast for southern Oklahoma as well as northern Texas, but the greatest coverage will be north of I-40.

Rain chances will subside for northern Texas and much of Oklahoma on Saturday, but appear to return later in the weekend. These rain chances will be bumped up a few notches on Sunday into Monday due to the upper-level ridge weakening. Temperatures will top out in the 80’s and 90’s the rest of this week so make sure you’re staying hydrated! I’ll have more details on the Monday (4th of July) forecast in the next day or two.

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

Forecast and Severe Outlook: Sunday, May 1st

Today’s forecast brings rain to the East Coast and another risk of severe weather to the Gulf Coast.  Heavy rain will bring several Texas waterways back into moderate to major flood stage for a short time with the risk for flooding now spreading into Louisiana.

The current Surface Analysis

Surface map us

 

Today’s National Forecast

Weather Forecast map

A front extending from the Lower Great Lakes to the Western Gulf Coast will become quasi-stationary with the boundary inching to New England Coast southwestward to the Lower Mississippi Valley by Monday evening. The system will develop showers and thunderstorms from the Ohio Valley to the Lower Mississippi Valley that will move to the Northern Mid-Atlantic Coast to the Lower Mississippi Valley and Western Gulf Coast by Monday evening.  Rain will develop over parts of the Central Plains eastward to the Great Lakes and parts of the Northeast as well as parts of the Northern Mid-Atlantic.  The rain will come to an end over the Central Plains and Middle Mississippi Valley by Monday morning and over the Great Lakes by Monday evening.  The rain will move into Northern New England by Sunday evening.

 

Current Model Analysis

6 hour model

On Sunday, thunderstorms will continue across the Appalachian region. Storms will not be as severe as they have been over the past several days but severe weather will continue to be a threat.  The low bringing this risk to the mountains is very broad, and continues to have rain and snow across Nebraska, Wyoming and Colorado this morning.

Dual disturbances in the Southeast continue to bring showers and some storms to the 4 corners region.

While rain won’t be a big factor in the Northeast early this morning, it will be by this afternoon and most of the East Coast, from Northern Florida up through Pennsylvania and New Jersey will begin to see rain by this morning.

18 hour model

Sunday afternoon, the rain shifts east and is now impacting the East coast from Florida to Maine within this broad circulation.

Rain and snow will begin to let up during the afternoon over the Rockies of Colorado, Wyoming and Nebraska.

A low over Arizona will begin to bring rain and snow to the 4 Corners region as a weak and moisture starved low moves into California with nothin to show for it.

36 hour model

By early Monday, High pressure dominates the West with only the remnants of a cold front draped across the Country from Massachusetts to Texas. A weakening low pressure system will set the stage for what looks to be a very wet week along the East coast.

 

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

No Critical Fire Weather areas

Severe Weather Analysis

Summary

Scattered Strong to severe thunderstorms are possible across Southern and Central Texas and the Central Gulf Coast Region as well as in the Ohio Valley and Central Appalachians.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 309,811 43,672,165 Houston, TX…San Antonio, TX…Indianapolis, IN…Columbus, OH…Austin, TX…

Analysis

With moderate destabilization forecast from the Ohio Valley to the Central Appalachians, strengthening mid to upper level wind fields will allow for marginally conducive conditions for severe storms.  Deep layer sheer will be strong and supportive of supercells, but lower level wind shear is forecast to me weak.  This will minimize tornadic potential in this area but severe hail and strong surface gusts are forecast in the strongest storms.  These storms are expected to be widely scattered this afternoon and evening.

Along the Gulf Coast, Upper level flow is forecast to be moderately strong between the divergent jet streams. Instability will be high ahead of the advancing frontal boundary which could lead to severe weather development.  While some storms are forecast near Upper Texas and Louisiana Coastal areas, most storms will develop near the higher terrain of the Rio Grande River late this afternoon and evening.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather

 

Forecast and Severe Outlook: Saturday, April 30th

Additional severe weather is Forecast after several days of Tornado Watches and multiple tornadoes across multiple states.   Yesterday featured one Tornado that came pretty close to Matt in Norman Oklahoma but fortunately all is well and he continues on with school to get ready to come back to us in a couple of weeks after finals.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

A strong storm over the Central Plains and Middle Mississippi Valley will slowly move eastward to the Ohio Valley by Sunday evening. Showers and thunderstorms will develop along and ahead of the associated front from parts of the Lower and Middle Mississippi Valley and the Western Gulf Coast. This convection will move to the Great Lakes and Ohio Valley and Central and Southern Appalachians while extending southwestward to the Lower Mississippi Valley by Sunday morning.  The showers and thunderstorms will expand into parts of the Southern Mid-Atlantic and Southeast by Sunday evening.

Rain and higher elevation snow will develop over parts of the Central Rockies and Central High Plains through Sunday morning.

Rain will develop over parts of the Central High Plains eastward to parts of the Western Ohio Valley on Saturday morning that will expand into parts of the Upper Great Lakes and parts of the Northeast and Northern Mid-Atlantic by Sunday morning. Rain will continue over parts of the Central High Plains and Central Plains through Sunday afternoon.

Current Model Analysis

6 hour model

On Saturday, strong to severe thunderstorms are forecast to move through Coastal Texas up into Arkansas. The cold front causing this convection will slowly slide east during the day.  This system is also bringing rain back across Kansas and Nebraska with heavy snow falling in Colorado, Southeastern Wyoming and portions of Western Nebraska.

Over the remainder of the Rockies and the Pacific coastline, showers and snow showers abound as a weak low pressure system makes it south towards Arizona.

Another weak low moves away from the East Coast and could bring some rain showers to the Mid-Atlantic states and Southern New England.

18 hour model

Saturday afternoon, the cold front will move quickly east and shift the axis of severe weather away from the Southern Plains and into the Ohio and Mississippi River Valleys. Heavy rains should be expected in Southern South Dakota and Nebraska.  Snow will continue into the afternoon over the Rockies of Colorado, Wyoming and Nebraska.

A low over Arizona will begin to bring rain to Southern Nevada and Northern and Central Arizona as shower activity dies out during the afternoon over the remainder of the Pacific Coast.

The Northeast looks dry after the rain moves out this morning.

36 hour model

By early Sunday, Rain will be making its way through the Great Lakes and Mid-Atlantic states on its way to the Northeast. Heavy rain should fall in the Appalachians and help dent the drought in the region.  Further west, Mountain snows will continue as weak low pressure systems continue to pivot through the Rockies.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

No Critical Fire Weather areas

Severe Weather Analysis

Summary

Strong to Severe thunderstorms are forecast today into this evening. Storms will develop across the Lower Mississippi Valley, the Tennessee Valley, the Ozarks, and the Ohio Valley.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 291,734 28,685,188 Houston, TX…Memphis, TN…Nashville, TN…New Orleans, LA…St. Louis, MO…
MARGINAL 214,264 32,249,913 Indianapolis, IN…Charlotte, NC…Atlanta, GA…Cincinnati, OH…Montgomery, AL…

Analysis

A closed upper level low is forecast to move slowly over the Central Plains and Middle to Lower Missouri Valley today. The cold front associated with this system moved east southeast across the Ozarks and ArkLaTex regions to the Upper Texas Coastal Plain bringing severe weather to the area.  We expect extensive early day convection along and ahead of this front near Coastal Texas this morning.

A relatively strong belt of deep layer southwesterly winds is forecast to overspread the area from the Ozarks to the Central Appalachians. The warm sector ahead of the cold front is seeing Dewpoints rise behind the warm front to the north.  Modest destabilization is expected due to day time heating even with the cloud cover from earlier convection.  Expect strong to severe thunderstorms to develop across Missouri and into Northeast Arkansas up into the Ohio Valley.  These storms will be in an area of strong veering wind profiles that could support supercell development.  These supercells would likely have severe hail and wind and possible develop a couple of tornadoes.

Further south, Severe Thunderstorm Watches were in effect overnight from Monroe Louisiana and near McAlester Oklahoma down to the Texas and Mexico border near Del Rio. Multiple squall lines moved through the area and continue on at this hour.  While activity is expected to weaken mid-morning, cold pool and outflow boundary focused reintensification is forecast, especially in the moist and unstable warm sector over parts of Louisiana Mississippi, Alabama and Tennessee.  A few tornadoes may be possible as these storms progress to the east through strong low level winds in the Lower Mississippi and Tennessee River Valleys.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather

 

Forecast and Severe Outlook: Wednesday April 27th

Severe Thunderstorm Watches from last night are now ending as thunderstorms have left damage from hail and wind in their wakes.  A few tornadoes spawned across the area from Texas up through Indiana but conditions were not a bad as they could have been with the severity of those storms.  Now for a look at today’s forecast.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

A strong storm over the Central Plains will move eastward to the Eastern Ohio Valley by Thursday evening. The system will produce showers and thunderstorms along and ahead of the associated boundary from parts of the Central and Southern Plains and the Middle and Lower Mississippi Valley that will move eastward to the Mid-Atlantic and Eastern Ohio Valley to the Southeast and parts of the Central Gulf Coast by Thursday.  Rain will also develop over parts of the Northern and Central Plains and the Northern High Plains through Thursday afternoon.  Rain will move into parts of the Upper Mississippi Valley into parts of the Upper Great Lakes overnight Wednesday and move into parts of the Great Lakes and Western Ohio Valley by Thursday evening.  Similarly, highest elevation snow and lower elevation rain will develop over parts of the Northern High Plains and Central Rockies through Thursday morning.

A second storm will move onshore over the West Coast and move southeastward to the Southern Rockies by Thursday evening. Rain will develop over the Pacific Northwest and Northern California Coast on Wednesday morning that will expand inland to parts of the Northern and Central Rockies by Wednesday evening with snow at some of the highest elevations.  The rain will settle over parts of Southern California and the Great Basin and the Central Rockies and Southwest by Thursday morning.  By Thursday evening rain will expand into parts of the Northern Intermountain Region to parts of the Northern High Plains and into parts of Southern California as well as parts of the Southern Rockies and Southern High Plains.  The rain and highest elevation snow will continue over the Great Basin and Southwest to the Central and Northern Rockies through  Thursday evening, too.

Current Model Analysis

6 hour model

On early Wednesday, a strengthening low pressure over the Central Plains will continue to bring heavy rains and severe weather to the region. Rain should be falling from South Central Texas straight up to North Dakota with snow falling in the mountains from Colorado to Montana as two weak low pressure systems help create additional instability over the Rockies.

In the Pacific Northwest, rain should be falling just off the coastline and showers should be expected to move on shore from time to time. This area of rain won’t hold together well and should mostly dissipate during the day.

In the eastern half of the US, rain is forecast to fall from St. Louis east along a frontal boundary straight to the coast of the DelMarVa. Showers and thunderstorms should be expected in Florida during the day and the snow that fell in Northern portions of New England should have moved well into Canada with only a few snow showers remaining in Northern Maine.

18 hour model

Wednesday afternoon, the cold front will move quickly east and shift the axis of severe weather away from the Southern Plains and into the Ohio and Mississippi River Valleys. Heavy rains should be expected in South Dakota and Northern Nebraska.

Snow and shower activity will be more focused over the Pacific Northwest and the Rockies but will diminish in overall coverage.

In the east, the heavier rains in the morning will begin to let up along the DelMarVa but will still continue out in Southern Illiniois and Western Kentucky.

36 hour model

By early Thursday, the next low pressure system should be making its way out of the Rockies by bringing heavy snow into Wyoming and Utah with rain on the Plains from Wyoming east into South Dakota and Nebraska.

For the Northeast and Great Lakes, the system that brought Severe Weather to the Plains on Tuesday will bring rain and snow. Many of the same areas that received snow on Tuesday will see it again on Thursday while areas that received rain will receive another good soaking rain.

 

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

No Critical Fire Weather areas are forecast

Severe Weather Analysis

Summary

 

Strong to Severe Thunderstorms are forecast for the Middle and Lower Mississippi Valley, Western Tennessee Valley and Southeast Texas.

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 279,117 24,136,894 Houston, TX…Memphis, TN…St. Louis, MO…Baton Rouge, LA…Shreveport, LA…
MARGINAL 278,557 35,670,593 Indianapolis, IN…Nashville, TN…Kansas City, MO…New Orleans, LA…Virginia Beach, VA…

Analysis

An upper level low is drifting slowly eastward across the Central Plains. An elongated Mesoscale Convective System, spanning from the Kansas Missouri Border to the Edwards Plateau in Texas, is moving southeastward ahead of this system.  This MCS will slowly die out and the remnants will be over the Louisiana and Texas coastline by lunch time Wednesday.  Locally strong winds and hail are the primary threats with the MCS.

In the wake of this MCS, daytime heating will contribute to upward development and intensification over the Lower Mississippi Valley near the boundary layer. These storms should move Northeast and large scale forcing over the Mid-Mississippi Valley will help them grow.  As the warm front lifts north into Illinois, the earlier activity associated with Tuesday’s severe weather will help to keep the instability low.  While some hail and strong winds are possible, this severe risk remains low.

 

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, April 25th

While the forecast for today brings a wide mix of news, the real weather stories remain the flooding in Texas and the Tuesday Severe Weather Threat.  For Texas, The Cypress Creek and Colorado River have dropped below flood stage but the majority of rivers in the area remain at or above the minimum flood stage, with the San Bernard River still in Major Flood stage.  These conditions are forecast to crest in the last of these areas over the next 2 days before diminishing completely.

For Tuesday, there remains a Significant risk of Severe Weather with the Storm Prediction Center adding a region of Moderate risk to the map.  There is a good chance that an area of High Risk will be added by tomorrow.   For a quick outline and maps of the event, please read down and see our Severe Weather Section, additional information will be posted Monday afternoon.

The current Surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

A developing upper-level low over the Great Basin will move eastward to the Central Rockies by Tuesday evening as weakening low pressure over Upper Midwest and it’s associated front will merge with the storm coming out of the Great Basin by Tuesday morning. The system will produce showers and thunderstorms over parts of the Great Lakes and Upper Mississippi Valley into parts of the Middle Mississippi Valley.  This system will expand into parts of the Lower Great Lakes and Ohio Valley by Monday evening.  Rain will also develop over parts of the Northern High Plains and Northern Plains on Monday morning continuing through Monday night.  Showers and thunderstorms will also develop over parts of the Western Gulf Coast/Lower Mississippi Valley and parts of the Eastern Gulf Coast into the Southern Appalachians on Monday afternoon into evening.

Additionally, the showers and thunderstorms that will move into parts of the Northern Mid-Atlantic by Tuesday morning will extend from the Mid-Atlantic westward to the Western Ohio Valley and Middle Mississippi Valley by Tuesday evening. Rain will also develop over parts of the Upper Great Lakes into New England overnight Monday ending over the Upper Great Lakes by Tuesday afternoon.

Current Model Analysis

6 hour model

On early Monday, A strong but weakening low pressure system will bring rain from the Great Lakes over through North Dakota with rain and snow in Montana, as well as rain along the accompanying cold front from Minnesota down into Kansas and Oklahoma. Thunderstorms have been present with the front overnight Sunday and the risk of severe weather will continue moving east with the front as it heads toward Chicago.

Another low pressure system over Southern Nevada will create an area of instability over the Rockies which will lead to valley rains and mountain snows. Several inches of snow can be expected in the higher elevations, especially over Northern California and Nevada.

In the Eastern portion of the Country, high pressure dominates for a generally warm and clear day with some air mass showers and thunderstorms possible across the Southeast and later in the day in the Northeast as the aforementioned storm moves east over the Lakes.

18 hour model

By Monday afternoon, low pressure slides east over Minnesota and begins bringing rain to Western New York along the warm front. Rain will continue through the Great Lakes region back through North Dakota and Montana with some areas of snow changing to rain during the day.

The low pressure over the Rockies intensifys some and will bring a larger area of snow to the Mountains in Nevada.

The high pressure over the Atlantic will slide South off the Carolinas helping with daytime heating and airmass showers and thunderstorms over Florida and Georgia.

36 hour model

By early Tuesday, the forecast calls for low pressure from the Lakes will shift east to New England as cold air slides south.  This could bring moderate snow to areas north of a line from Watertown New York to Portsmouth New Hampshire.  This line will fluctuate along elevations and will shift as the system moves east.

The low over the Rockies begins to eject out into the Plains over Colorado and the snow will shift east with it over Wyoming and portions of Colorado. Rain will fall down elevation on the Plains from Wyoming through South Dakota and Nebraska.

Current Severe Weather Outlook

Critical Fire Weather Update

Fire Weather

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
Critical 94,520 5,231,602 Phoenix, AZ…Albuquerque, NM…Mesa, AZ…Glendale, AZ…Chandler, AZ…

A strong mid-level disturbance will amplify over the Intermountain West today, and is forecast to spread strong mid-level flow into the Four Corners region. The Dryline will mark the dividing line between warm and windy conditions and the moistening air to the East.

Surface winds will strengthen area wide beginning late this morning with gusts as high as 60 MPH expected. 2 Critical areas have been delineated on the map in this outlook.  These are the regions that high winds will combine with the lowest Relative Humidity values under 15% over dry fuel beds.

Today’s Severe Weather Outlook

Severe Outlook

Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 29,335 13,108,281 Chicago, IL…Milwaukee, WI…Madison, WI…Aurora, IL…Rockford, IL…
MARGINAL 123,442 12,941,350 Detroit, MI…Grand Rapids, MI…Warren, MI…Sterling Heights, MI…Topeka, KS…

Severe Weather Analysis

SUMMARY

A few strong to severe storms are expected from a portion of the Upper Midwest into the Great Lakes area with a threat for large hail and damaging winds this afternoon and evening. Other strong storms are expected across a portion of the Central High Plains this evening and Northeastern Kansas tonight

 

Analysis

A weakening shortwave trough currently over the Central and Northern Plains is forecast to shift into the Great Lakes. A stalled cold front will extend from Wisconsin southward to Kansas and will impact the warm sector where daytime heating will warm the boundary layer this afternoon.  Storms are expected to redevelop this afternoon from Southern Wisconsin to Northern Illinois.  Wind shear will be sufficient for a few supercells with large hail and damaging winds as the primary threats before activity weakens after sunset.

West of there, as the warm front develops along with the low that is moving out of the Rockies, moist flow will return to the Central Plains. This moisture will allow a few storms to initiate in the upslope flow along the Rockies.  High based supercells capable of downburst winds and large hail are likely across Western Nebraska continuing into the night.  Eastern portions on Nebraska and Kansas will be impacted by the same set up and high based thunderstorms with hail are possible.

Looking forward to Tuesday, as predicted here, a moderate risk for severe weather has been added. Significant severe weather is expected over the Plains.  Any and all preparations you need to make should be completed by tonight.

Tuesday Severe Weather Outlook

day 2 severe

Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 175,496 17,072,997 San Antonio, TX…Dallas, TX…Austin, TX…Fort Worth, TX…Oklahoma City, OK…
MODERATE 55,875 3,058,241 Oklahoma City, OK…Wichita, KS…Norman, OK…Edmond, OK…Midwest City, OK…
ENHANCED 79,794 9,650,655 Dallas, TX…Fort Worth, TX…Tulsa, OK…Arlington, TX…Plano, TX…
SLIGHT 136,890 11,357,501 San Antonio, TX…Austin, TX…Kansas City, MO…Omaha, NE…Overland Park, KS…
MARGINAL 211,757 32,736,160 Philadelphia, PA…Baltimore, MD…Washington, DC…Cincinnati, OH…Lexington-Fayette, KY…
Significant Severe Thunderstorms are forecast across parts of the Southern and Central Plains Tuesday afternoon into Tuesday night. Strong, long lived Tornadoes are possible in addition to very large, and potentially giant, hail and strong damaging straight line winds.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

storm reports 2

Robert Millette

Staff Meteorologist

Firsthand Weather