Update 1 – Latest on Storms Saturday 2/18 and Sunday 2/19

Update #1 – 4:00 PM EST 2/18/2012

Quick Update to show the latest graphics from the Storm Prediction Center this afternoon. The changes are subtle but do impact the local area and much of the southeast. For previous graphics see ‘original post’ below.

The primary hazards from the severe thunderstorms will be isolated tornadoes, damaging winds, hail and lightning.

Slight Risk : Now includes Most of West Central Georgia over towards Macon in Central Georgia and South Towards Albany.

Tornado Probability : The local area including Columbus GA. and Phenix City Al is at a 2% risk of seeing a Tornado with the 5% area now encroaching on the southern counties in the local area.

Wind Probability : The local area including Columbus GA. and Phenix City Al. south towards Albany is now well within a 15% risk of Damaging Winds with a 5% Risk covering much of Georgia back into Alabama. The 30% risk area has shifted slightly northeast.

Hail Probability : The local area including Columbus GA., much of Central GA towards Macon and Phenix City Al. and much of central Alabama is at a 5% risk of seeing large hail.

Per the SPC concerning this update:

ANOTHER CHANGE TO THE OUTLOOK IS TO EXTEND THE SLIGHT RISK AREA ENEWD ACROSS CNTRL GA WHERE THE GFS MOVES A CLUSTER OF STRONG CONVECTION AFTER MIDNIGHT. DUE TO THE VERY STRONG VERTICAL SHEAR…A TORNADO AND WIND DAMAGE THREAT COULD EXIST LATE IN THE PERIOD ACROSS CNTRL GA.

**********

Original Post at 9:38 AM EST 2/18/2012

The primary hazards from the severe thunderstorms will be isolated tornadoes, damaging winds, hail and lightning.

I will add, looking at models today, it seems the threat for really severe storms has diminished somewhat. This does not mean that one or more will not occur so don’t let your guard down.

Looking at soundings from the RUC this morning for 6 AM Saturday through 12 AM Sunday morning [ 18 hrs sounding ], looks like any stronger storms will hold off until this evening around 4 PM EST. This particular model is indicating at this time stronger storms late this evening. One such storm is possible around 10 PM EST. The Hodograph for this particular storm is showing Zero CAPE, Helicity 782 and Shear 59 m/s. As mentioned yesterday, this system is a low CAPE, moderate to high Shear event and this sounding shows that well.

The NAM sounding shows stronger storms holding off until around 6 PM EST, building through the evening where around 10 PM EST one of the possible stronger storms will push through, having Zero CAPE, Helicity 799 and Shear 52 m/s.

The GFS3 sounding shows stronger storms holding off until around 6 PM EST as well, then building through the evening where around 12 AM EST Sunday Morning one of the possible stronger storms will push through, having Zero CAPE, Helicity 775 and Shear 50 m/s.

All in all possible stronger storms should arrive in the area this evening around 5 PM EST. Continuing through the evening with stronger storms around 11 PM EST Saturday night continuing through the overnight into early morning hours of Sunday. Accompanying these thunderstorms will be lots of rain with the GFS showing storm totals of over 3 inches.

Here are the latest graphics from the Storm Prediction Center this morning….

Slight Risk : Extends north into the southern local area, including Columbus.

Tornado Probability : The Southern local area including Columbus is at a 2% risk of a Tornado.

Wind Probability : The local area including Columbus south is at a 15% risk of Damaging Winds with a 5% Risk covering the rest of the local area.

Hail Probability : The local area including Columbus, south and west of the city is at a 5% risk.

Here is this mornings outlook from the NWS Peachtree City, GA

Day One…Today and Tonight… Isolated severe thunderstorms are possible late tonight across parts of central Georgia. Synopsis… A strong storm system will move out of Texas and into the southeast United States through tonight. Primary Hazards… The primary hazards from the severe thunderstorms will be isolated tornadoes…damaging winds…large hail and lightning. The area of concern is along and south of a line from Columbus to Macon to Louisville and between midnight tonight and 7 am Sunday morning. Discussion… A ridge of high pressure will strengthen over north and central Georgia today as rain spreads across the state today. The strength of the ridge will depend on how far north a warm front will move into central Georgia tonight. At this time the warm front is expected to reach a Columbus to Macon to Louisville line late tonight. Areas south of the warm front will destabilize with capes reaching 600. Significant shear coupled with the relatively high capes and dewpoints in the lower 60s will be sufficient for isolated severe thunderstorms to develop after midnight tonight.

And the excessive rainfall outlook from the Hydrometeorological Prediction Center

As is the case when severe weather threatens the area, I will be posting updates on Facebook and Twitter as much as I can and to the best of my ability.

My MAIN accounts: On Twitter @CataulaGaWX where I post relevant information as storms approach the area, and Facebook Cataula Ga Weather where I try and do the same.

Also of interest is my other Twitter and Facebook accounts where All warnings for the local area are posted automatically as they are issued. Facebook Page:Cataula GA Weather Alerts And Twitter Stream @CataulaGaALERTS.

Previous posts :

Thursday, February 16, 2012 – Severe Weather Threat Saturday / Sunday – Georgia / Alabama 2/18-2/19/2012

Severe Weather Threat still on track Saturday / Sunday for Georgia / Alabama 2/18-2/19/2012

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