10:45 AM | ***A wild week of weather across the nation...severe weather outbreak to include tornadoes...significant snowfall in the Rockies...tropical activity***

There is an enhanced risk of severe weather later today and tonight from northeast Texas to central Missouri and this will include the threat of tornadoes from Texas to Missouri. Map courtesy NOAA/SPC

Overview

The calendar has flipped to November and the first full week of the new month will feature some wild weather across the nation. First, a severe weather outbreak is likely later today into late tonight across the nation’s mid-section and this includes the threat of tornadoes from Texas to Missouri. Second, accumulating snow is likely across the Rocky Mountain States, and it can be significant during the latter part of the week across Colorado and New Mexico. Finally, a surge of tropical activity has begun in parts of the Atlantic Basin and a tropical system now intensifying over the Caribbean Sea is likely to become a hurricane by later in the week as it heads towards the Gulf of Mexico.

Severe weather later today and tonight will be supported by a strong vorticity center at 500 mb that will lead to enhanced upward motion and instability in the (circled) region from northeast Texas to central Missouri. Map courtesy NOAA, tropicaltidbits.com

Severe weather outbreak to include the threat of tornadoes

While the peak of the tornado season in the US is during the March/April/May time period when about 70% of the annual total takes place, there is often a secondary surge during the fall months of October/November. In both of these active time periods, the overall atmospheric pattern is much the same in that cold, Canadian air heads towards the middle of the nation from the north and west and, at the same time, warm and humid air flows northward out of the Gulf of Mexico towards the central states. It just so happens that in the spring season there is an increasing frequency for the northward intrusion of the warm, humid air masses and a decreasing influx of cold air masses from Canada while, during the fall peak season, the opposite holds true.

Cold air pushing eastward across the Rockies today will clash with warm, humid air flowing northward from the Gulf of Mexico (in boxed region) and help to contribute to a severe weather from later today into late tonight across the nation’s mid-section. Map courtesy NOAA, tropicaltidbits.com

This kind of clash of air masses is taking place later today across the nation’s mid-section and there is plenty of support aloft for a significant severe weather outbreak. Not only is a cold air mass charging east across the Rocky Mountain States today with warm, humid air surging northward from the Gulf of Mexico, but a strong upper-level trough is edging eastward into this “battle zone” region and it will enhance upward motion significantly likely leading to a widespread severe weather outbreak. Today’s severe weather and tornado threat will be focused in the region from northeast Texas-to-central Missouri and can include portions of Oklahoma and Arkansas. The severe weather threat should persist into the late night hours across the mid-Mississippi Valley…gradually winding down as the atmosphere becomes less unstable.

Snow is falling today across portions of the Rocky Mountain States with some accumulations, but an even greater risk of snow accumulation will take place later in the week across Colorado and New Mexico. Map courtesy NOAA, tropicaltidbits.com

Significant snowfall in the Rockies

The new work week begins with snow falling across the Denver metro region and there have been some minor accumulations; however, the snow will wind down by the latter part of the morning. Temperatures are currently in the middle 30’s in this metro region and it stays chilly during the next couple of days and then a strong cold front should barrel through the region early on Wednesday. This next intrusion of cold air during the mid-week can set things up for significant snowfall in the Wednesday-to-Saturday time period with multiple low-pressure systems likely to have an impact. The details still have to be ironed out, but strong support for accumulating snow will exist in the upper atmosphere as yet another deep trough will push into the southwestern states. The best chance for significant snowfall later this week will likely take place in the region from Colorado to New Mexico, but even the northern Rocky Mountain States can see some accumulating snow in those higher elevation locations.

Tropical wave #18 (circled) is likely to become a named tropical storm (“Rafael”) by mid-week and it could intensify into a hurricane over the Gulf of Mexico later in the week. Map courtesy NOAA/NHC

Tropics coming to life

A tropical disturbance that propagates on a regular basis across the global tropics and tracked by the Madden-Julian Oscillation (MJ) index has now moved to a position over the Atlantic Basin and this re-positioning is leading to an overall increase in upward motion across the Caribbean Sea and Gulf of Mexico. As such, a tropical wave has just formed over the Caribbean Sea and - given favorable environmental factors of low wind shear, high moisture, and warm water temperatures - this wave is likely to strengthen into a named tropical storm (would be Rafael) as it closes in on western Cuba later in the week and perhaps to hurricane status. After that, the system should head towards the central Gulf of Mexico and it might have to fight an increase in southwesterly vertical wind shear and some drier air later in the weekend...likely limiting its overall potential as a hurricane as it approaches the northern Gulf coast. All residents from Florida’s Panhandle to Louisiana should monitor this system during the next few days as it could end up near the northern Gulf coast by later this weekend.

Looking ahead, the moisture from this tropical system may push northeastward into the Southeast US and there is even a chance it can go as far north and east as the Mid-Atlantic region/Northeast US. This possibility exists because of another incoming upper-level trough that’ll move to the middle of the nation by the weekend and the tropical moisture can be “picked up” and pushed northeastward on the front side of this next trough. Finally, this latest tropical system that is likely to become named “Rafael” may not be the last of the 2024 Atlantic Basin season. There are signs that yet another system could end up in the same Caribbean Sea/Gulf of Mexico region in a week or so.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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