Wednesday, April 10, 2013

April 11th Severe Weather Event

I expect a severe weather event to unfold tomorrow, April 11th.

Short range model guidance suggests the cold front currently working its way east across the nation will fire off another day's worth of severe weather. Highest risk appears to be placed across Alabama and Georgia in the area of the highest instability. Overall instability is moderate at best, with highest values in the aforementioned areas. Helicity in the atmosphere will be decently high across all areas, but the lack of high instability makes for a rather low-moderate tornado risk. I can see a situation in which weak tornadoes evolve from this set-up, but I do not expect several big tornadoes across the Medium Risk area. High Wind index looks to be high for this event, as the typical cold front merging of severe thunderstorms occurs to form a squall line. New model forecasts indicate instability will be higher than previously thought, and that storm cells may be stronger than previously thought. I'm going to stay with my current thinking on the graphic above; I feel that the graphic best interprets my thinking right now.

Main concern for any tornadoes rests in the areas you see above with isolated storm cells. This image is valid for 8 PM Central Time, 9 PM Eastern Time on April 11th. Any tornadic activity is most likely to originate from isolated thunderstorms popping in Georgia, the Carolinas and Tennessee. These isolated storms would feed off of the instability and decent helicity to possibly provide a base for tornadic activity. The extent of this potential tornado activity is to be determined, and that determination should be made tomorrow morning.


Massive Snowstorm Headed for Minnesota

A recent forecast image from the American GFS model shows portions of Wisconsin, South Dakota and Minnesota receiving snow totals above 2 feet in some spots, with Minnesota possibly getting in on 30 inches of pure snow!

Bear in mind this forecast is unlikely to verify exactly, as it is very rare to see extreme snow totals like this at any time in the year, much less in mid-spring. A more recent forecast has the same states getting anywhere from 10-16 inches of snow, and this range still seems pretty high. While it does seem pretty high, it technically is realistic- it isn't spring without a major storm system bringing a big winter storm and big severe weather event. While the most recent forecast shows only 10-16 inches, previous forecasts today have shown amounts still flirting with 2 feet of solid snow in many places.


Very Wet Week Ahead

A very wet 10 days is ahead for the eastern half of the nation.

Multiple model forecasts from multiple forecast systems are projecting the next 10 days to be full of water for the eastern half of the nation. Shown above is the predicted total rainfall from the European model system. Past forecasts have been even wetter than this, but the latest forecast predicts many states east of the Plains receiving over 3 inches of rain. If you're looking for a mind-blowing statistic, look no further: in this forecast, each state on this map (excluding New Mexico and Arizona) is projected to receive over an inch of rain in the next 10 days. That may not seem like a lot, but when you remember that this forecast image accounts for all but a few states in the US Mainland, you get the idea of how big this wet trend is. A few smaller states in the Mid-Atlantic may be added to that exclusion list, as they are just so small it really is hit-or-miss as far as if they will get in on that 1 inch mark. The highest totals print out in Arkansas, Louisiana and Mississippi, where a whopping 5 inches of rain could hit multiple, small-scale areas in those states. Indiana and Michigan could also get in on those high totals. The top of the image indicates the highest total on this graphic is 6.6 inches, which appears to be forecasted to hit northern Arkansas. Get the rowboats out!


Tornado Warning - Tornado on the Ground - North of Clinton, AR

Tornado is ON THE GROUND north of Clinton, Arkansas. Life and property is threatened as this storm moves northeast.


Fifty-Six: 5:20 PM CT
Calico Rock, Pineville: 5:30 PM CT

Take shelter now. Please share to get the word out about this very dangerous situation.