Wintry Relapse Brewing – Major Tornado Outbreak Sunday?
Alerts Broadcaster Briefing: issued Friday by Media Logic meteorologist Andy Mair.
– We are preparing for a multi-day severe weather threat starting tomorrow through next Tuesday. Sunday is looking to be the worst day of the bunch with a day 3 moderate risk already issued. Hail will be the main threat tomorrow, but Sunday will pose a threat for large damaging, long track tornadoes.
THE RIGHT MIX OF INGREDIENTS
– Much like baking a cake, the perfect set of ingredients will come together this weekend allowing several days of severe weather to kick off. A low pressure system will form over the Rocky Mountains tomorrow afternoon and begin moving to the east stirring up severe weather. This will give the wind speeds and direction needed for severe supercell development. As you can see below, the low pressure will be pulling up warm moist air from the Gulf of Mexico while at the same time be driving the dryline east. This will create an explosive environment the next few days.
– A dryline will form just the east of the Rockies and will create the needed forcing for severe storms. Drylines are best known for their ability to generate discrete supercells that can create violent tornadoes.
– The Storm Prediction Center has issued a slight risk for Saturday from south central Texas up into southwest Minnesota. This will be the start of our multiday severe weather threat.
– Above is our in house TPI forecast model. You can see the bright pinks where the greatest tornado threat exists tomorrow. Storms are expected to begin firing in the early evening in western Oklahoma and move to the east through the risk area and die in Missouri overnight. Main threat will be hail, but we cannot rule out the chance for some tornadoes.
SUNDAY (POTENTIAL OUTBREAK DAY)
– Sunday is shaping up to be the most dangerous day during this severe weekend. It is believed by much of the meteorological community that what a weather system has done the previous days will tell you what can be expected about the current risk. So pay attention to what happens tomorrow and it may be a key as to what can be expected Sunday.
– Here is the current risk from the SPC. You can see a moderate risk already exists for much of Arkansas and a slight risk is in place from Iowa down through Texas. Many large metropolitan cities are at risk Sunday including Dallas, St. Louis and Kansas City. Little Rock is currently in the most danger being located in the moderate risk.
– A common tool used for forecasting severe weather is EHI (Energy Helicity Index). The brighter colors on the map indicate areas where the best cross over between instability and wind shear. This is the kind of environment supercells need to create long lived damaging tornadoes. You can see the bulls eye right over the current day 3 moderate risk.
– Our TPI forecast on Sunday is off the charts maxing out at 5. As it stands right now, this day may be an outbreak event. Large hail, damaging winds and long track tornadoes are all possible.
Is A Powerful El Nino Brewing In The Pacific Ocean? Odds statistically favor an El Nino warming phase of ENSO by the latter half of 2014; the question now is how strong will it be. Here’s an excerpt from a post at Skeptical Science:
- The current large build-up and eastward movement of heat in the equatorial subsurface ocean strongly hints at a powerful El Niño developing this year.
- A powerful El Niño is by no means guaranteed, but should one develop mid-2014 to mid-2015 would likely be the hottest 12 months ever recorded. Unfortunately widespread weather-related chaos and mass coral bleaching is almost certain to follow.
* image above courtesy of NOAA CPC.
NOAA CPC: Cool Bias For May. Here is the latest 30 day outlook for May, and an extended outlook into the summer months, showing a warm bias for much of the west, south and eastern USA, with a lingering cool/wet bias from the northern Rockies and Midwest into the Great Lakes. One big factor that’s flavoring this prediction: El Nino, which is forecast to strengthen into the summer months. Credit: NOAA.
Do April Showers Bring May Flowers? Temperature may be more of a signal for the flowers in your yard than rainfall, it turns out. Here’s an excerpt of a very interesting article with new research finds at FiveThirtyEight: “…Rain, in general, has an effect on timing and abundance of flowering, said David W. Inouye, a biology professor at the University of Maryland, College Park. Inouye, who has studied bloom times in the Rocky Mountains, noted that some plants flower at the start of a rainy season and that some species might flower a second time in late summer, following a good soaking. But for most species, first flowering is more closely tied to temperature than to rain...”
April Soaking Upper Midwest. NOAA’s NAM model prints out some 1-2″ rainfall amounts over the next 84 hours from the Dakotas to Minnesota, Wisconsin and northern Illinois.
It’s Spring – In Theory. The latest NAM snowfall accumulation shows potentially plowable amounts of snow for the central and northern Rockies, maybe a couple inches of slush from the western Dakotas into the Red River Valley of Minnesota early next week.