Severe Thunderstorms in Texas; Critical Fire Weather in the Southwest

A slow moving, blocked upper level pattern to support late season snows Basin. An Elevated to Critical Fire Weather threat expected across the Southwest Tuesday and Wednesday. Additional Heavy rains possible along the Central Gulf Coast and Lower Mississippi Valley.

Forecast for Monday, April 12, 2021

across portions of the Northern Plains, Central Rockies and northern Great Basin...

...An Elevated to Critical Fire Weather threat expected across the Southwest Tuesday and Wednesday...

...Additional Heavy rains possible along the Central Gulf Coast and Lower Mississippi Valley...

The mid to upper level flow pattern across much of North America will continue to exhibit a high degree of blocking, resulting in very slow moving systems affecting large portions of the nation. The lead slow moving upper low over the Northern Plains/Upper Mississippi Valley region will continue to support late season accumulating snows across northern to eastern North Dakota into northwestern Minnesota Monday night night into Tuesday. The snow threat from this system will decrease significantly late Tuesday into Wednesday with only light snow possible from the Northern Plains into the Upper Great Lakes.

While the lead mid to upper level system meanders over the Northern Plains/Upper Mississippi Valley region, a second slow moving system will develop over the Pacific Northwest on Tuesday and sink only slowly southward into the northern Great Basin by Wednesday. This system will not have a lot of associated precipitation initially, but should expand its precipitation effects from Tuesday night into Wednesday across the northern Great Basin and into the Central Rockies. Late season heavy snows are possible across the Rockies of Colorado and Wyoming and across the Wasatch and Unitas of Utah.

Additional heavy rains are on tap late Tuesday into Wednesday across the Lower Mississippi Valley and Central Gulf coastal regions. These areas have been wet over the past week with rain totals 200-300% of average. This has resulted in high stream flow values and saturated soils. The additional heavy rainfall threat will also lead to an increasing threat of flooding across portions of the Lower Mississippi Valley and Central Gulf coast late Tuesday into Wednesday.

In contrast to the wet conditions along the Central Gulf Coast into the Lower Mississippi Valley, dry conditions, low relative humidities and gusty winds will support an Elevated to Critical Fire Weather Threat over the Southwest Tuesday and Wednesday. With the large scale pattern not expected to change much over the western U.S., with the above mentioned slow moving mid to upper level system, there will likely continue to be a fire weather threat over the Southwest into the end of this week.

Oravec