WKU Meteorology

tornado warning northwest warren untill 4:15, rotation with storm heading into southern warren as well. seek shelter now.

scattered supercells are forming and a PDS tornado watch is in effect till 9pm.

Can this set-up be compared to some legendary textbook outbreaks?

My answer is no but close. The warm sector in the April 1974 case was more pronounced with warm and moist air being a month later. However in terms of severe events this should be the top event of the year and perhaps of the past few years.

Why is that?  ( Model images are invalid for this post after 00z Saturday Mar 3rd.)

1. Powerful jet at the 250 mb pressure level. 110-130 KT with our region in the favored exit region ( ahead of the jet streak-strongest winds at the 250 mb level)

Decent 500 mb shortwave and vort max to our northwest.

our region is just southwest of the triple point (warm front, cold front low pressure center meeting spot) in the prime heating hours of the day.

A key indicator for me in terms of a tornado threat is the risk for updrafts into storms known as helicity.

Values around 150-250 m/s^2 are favorable for a tornado threat. In this case the entire is that then some. Wednesday values were from 400-600 m/s^2 but that was with less instability.

twister data is the source. I’ll double check to see if the site is added in the links section.

instability, a good measure of that is CAPE. Values from 1000-2000 J/KG indicate moderate instability sufficient for severe weather.

Another indicator is the lapse rate temp difference with height. In the case of tomorrow it will steep increasing the instability and promoting the large hail chance.

In terms of chasing there will be a lot of interest in the region but keep in mind storm motions will be very fast and these storms will be dangerous as well. Please do any chasing very safely.

I’m not going to discuss the Monday morning snow again till Sunday, severe weather is of most concern, please refer to last update. Forecast details in last post as well.

This has the looks of a major severe weather event in the region for Friday afternoon and evening. A strong surge of moisture and instability will once again move northward through the region Friday afternoon with dewpoints over 60*F and Convective alivable potential energy (CAPE) values from 1000-1500 J/KG by late afternoon. A warm front will push through in the morning with the LLJ interacting with the warm front will produce some showers and storms in the morning from north to south with clearing by midday.  Similar to the last event shear parameters will be more than sufficient for a severe threat.

Our region has the best chance in the warm sector to reach the higher CAPE values of around 1500 J/KG. The higher CAPE values coupled with steeping lapse rates will promote an enviroment capable of having storms producing large hail.

Storm motions will be very quick as well coupled with a strong upper level jet moving through damaging winds will be a widespread threat.

By early afternoon scattered supercells will develop over Western Kentucky and move toward us around mid-afternoon. These scattered supercells will have hail cores and hook echos as well more than likely. Tornadoes may be found in the hook echos.  These supercells will organize into a linear fashion by evening with the overall main threat evolving into damaging winds. Like with the squall line on Wednesday any storm along it may develop rotation with little notice though the strongest tornadoes should be with any supercells.

highlights

– scattered supercells for mid-afternoon/early evening

– line of storms in the evening

– upgrade to high risk by SPC possible.

My main concern is from the late afternoon supercells. However the squall line will have widespread severe weather.  The best chance of having a bust with this event is from morning showers and storms limiting instability. I don’t think that will be to much of a limiting factor. I will comment with rapid fire posts similar to Wednesday.

As we head into next week it won’t feel like spirng break. The day 7 NWS forecast for Monday may bust by 15*F. As a clipper moves through with a mix of rain and snow showers. Temps should stay just above freezing for accums. Highs will only be in the 40’s with a raw nw flow. Quite  a turnaround. As usual with a clippers a snow swath of 1-2 inches will track to our north across the bluegrass and eastern KY.

We have another threat Friday for severe weather I’ll update on this later today.

the severe weather is clearing out. However the heavy rain from today has led to a chance for some flooding this afternoon.

This storm is heading toward the city of Bowling Green and a tornado warning remains in effect.

This one inclues the city of BG. untill 12:15

Some week rotation is present on doppler radar northeast of BG seek shelter now!

A thunderstorm will track over Warren county with winds up to 60 mph, small hail and heavy rain. a flood advisory is also in effect.