Forecast and Severe Outlook for Tuesday, April 12th

 

Despite hundreds of severe weather reports, early indications are that the last 2 days have not had a confirmed tornado.  That trend looks to continue today as a cold front brings rain to the East Coast and the severe weather risk across South Texas presents low risk for Tornadic activity.

The current Surface Analysis

Today’s National Forecast

After a brief warm-up on Monday for much of the eastern U.S., a cold front is forecast to reach the coast by Tuesday evening and bring a return to slightly cooler conditions for the middle of the week. The cool-down behind this boundary will not be as significant as the last cold front that brought the widespread sub-freezing temperatures for overnight lows.  Showers and a few thunderstorms are possible ahead of the front on Tuesday.

Numerous showers and thunderstorms are expected along and ahead of the southern portion of the cold front near the Gulf Coast, especially on Tuesday. Conditions will be favorable for heavy rainfall along with scattered thunderstorms through Tuesday evening, with the best concentration over southern Texas to the Florida panhandle.  A few inches of rainfall is possible for some areas, and flooding remains a localized concern.  However, less in the way of severe thunderstorm coverage is expected compared to Monday.

Scattered showers and a few thunderstorms are likely from the Pacific Northwest to the central Rockies for the middle of the week, with the greatest rainfall totals expected near the Oregon and Washington coasts as a Pacific storm system makes its way onshore, with snow likely at the highest elevations.

Current Model Analysis

High pressure has moved off the East coast and been replaced by a cold front that will bring rain into the coastal plain during the day on Tuesday. This cold front will also be the impetus behind the slight risk of severe weather across Mississippi and Alabama early this morning.

For the Northern and Central Plains, a cold high pressure system continues to move south form Canada bringing dry but cold weather while the instability that has created spot showers and snow showers across the Rockies out to the West Coast remains in place and the showers are again expected early in the day.

By Tuesday afternoon, the cold front is moving east with severe threat finally diminishing with only a slight risk in portion of Texas.  Some snow may fall in the high elevations and extreme northenrn regions on New England as the cold high pushes into the Great Lakes region.  Low pressure moving down into Eastern Montana from Canada will continue to generate instability out west leading to additional showers in the area while day time heating driven showers and thunderstorms will occur across New Mexico and Western and Central Texas.

By early Wednesday, The cold front has moved off the coast and taken the precipitation with it ,leaving only cold air in its wake for the Northeast. The cold high will move rapidly back up into Canada and be well north of Toronto by Wednesday morning.  An area of rain and thunderstorms over Eastern Texas and Louisiana will occur as an overnight convective complex shifts east.

Current Severe Weather Outlook

Fire Weather Update

Day 1 Risk

Area (sq. mi.)

Area Pop.

Some Larger Population Centers in Risk Area

SLIGHT

12,266

218,750

Laredo, TX…Del Rio, TX…Uvalde, TX…Hondo, TX…

MARGINAL

39,482

6,594,661

Houston, TX…San Antonio, TX…Pasadena, TX…Sugar Land, TX…Missouri City, TX…

***Severe Weather Analysis***

…SUMMARY…

Severe Thunderstorms are likely across portions of Southeast Oklahoma and East Texas into parts of Arkansas, Louisiana, and Western Mississippi today and tonight. Large hail, damaging winds and a few tornadoes are all possible.

***Analysis***

Isolated showers and thunderstorms should occur by early afternoon due to the moistening upslope return frlow in the vicinity of Big Bend Area in Texas. Stronger forcing will overspread the region from the west, isolated severe thunderstorms are expected to develop over the higher terrain in Mexico and shift eastward across the Rio Grande during the evening.  Additional severe storms may occur in the area near the remnant of the cold front that continues to pull east near the Atlantic coast.

This activity should collectively shift eastward across the Edwards Plateau through the night. Conditions will intitially allow for supercells capable of producing large hail and damaging winds within the strongest cells.

This Week’s Flood Risk

Yesterday’s Storm Reports

Robert Millette

Staff Meteorologist

Firsthand Weather