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