UPDATE…10:30 P.M. EST…FEB 19, 2014
Based on analysis of forecast Severe Weather parameters tonight…the following map revision indicates where the most likely location for severe weather will occur (circled in blue), with the greatest probability of embedded isolated tornadoes (circled in red). I’ll have a complete synopsis in the morning.
Good afternoon everyone!
ALL GRAPHICS ARE LINKED
A little more active on the weather front this week. A developing surface low will begin to take shape out in the Central Plains by early Thursday morning, based on analysis of the current run of the GFS and NAM models. This low is forecast to progress quickly toward the NNE, and be over the Great Lakes region by late Thursday evening. Right now, based on parameters this far in advance, it appears the Great Lakes region will be in for some Lake Effects snow, and possibly freezing rain as the system advances. Blizzard conditions could be possible, again, based on the current information. This is likely to change somewhat over the next few runs, however I will be monitoring the situation.
However, along with this, we will have to deal with a trof and cold front, which is likely to bring about some severe weather for the Ohio, Tennessee, and Mississippi Valley regions on Thursday…shifting into the SE and Mid Atlantic regions on Friday.
The Storm Prediction Center (SPC) in Norman, OK. has issued a 4 – 8 day Severe Weather Outlook for days 4 – 5 in the forecast period
This office will address each threat separately, and will have a full synopsis of each, as they become the Day 1 Outlook. For all intents and purposes, we will address the DAY 4 threat today. Based on analysis of upper air maps, forecast sounding parameters from my F5 DATA Severe Weather software, and information contained in this morning’s outlook, I agree at the moment with the SPC forecast of mainly LINEAR, or QLCS (Quasi Linear Convective System) development associated with this front. There are some severe weather parameters forecast to be in place (i.e. Lifted Indices of -4 to -6 in areas, decent Theta-E (surface), SRH nearing or surpassing 450) to mention a few. However, what is lacking at the moment are any substantial CAPE values, which are at the moment, in the forecast parameters, to only be around 500 j/kg in some areas. As per the SPC outlook, there could be isolated tornadoes that could pop up out of the line. This would mainly be attributed at the moment to forecast speed shear, as the current forecast setup indicates a strong upper level jet, with a fairly strong jetstreak on the order of 100 – 120 knots approaching the areas mentioned. In addition, a 50 – 65 knot LLJ (Low Level Jet) is forecast to be in place as well.
Based on my analysis of CURRENT forecast parameters, the most probable area at the moment at greatest risk for Severe Thunderstorm Activity and Isolated Tornadoes, is in the area I have outlined within the DAY 4 Probability area.
I will have another look at model output, and forecast severe weather parameters on Wednesday, and will post any changes.
Have a blessed day!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)