Update on another potential severe weather system on Friday

After a day like today, with a borderline moderate risk setup and Tornado Watch that ends up busting pretty bad, it would be understandable to head into the next event with a little skepticism.  However, this is what meteorologists do - mess one up, then get back up and charge full-steam into the next! So here we go!

Since most of our efforts the past few days have been concentrated on today's events, we haven't talked too much about Friday. That would be the weatherman's version of the old sports cliche about "overlooking the next opponent." With today behind us now, it's time to look ahead. Despite talking publicly mostly about today, we have also kept a close eye on Friday and models are in pretty decent agreement with the latter portion of the event - the cold frontal passage and the weather associated with it.  What they absolutely do NOT agree on is the early morning hours and we'll start there.

In the wake of today's cold front, humidity has plummeted as Gulf moisture was shoved south. However, this will be short-lived as a warm front ahead of Friday's system surges back north Thursday night, bringing that warm moist air back to the Mid-South. A couple of normally reliable models (GFS, ECMWF) indicate that rain and thunderstorms will break out in the pre-dawn hours Friday morning around this warm front, with some possibly containing hail and a threat of strong wind. The other model we use a great deal (NAM) is the one that performed the best leading up to today's system and it says "no dice" on Friday morning.  The Storm Prediction Center and NWS-Memphis go with the former theory and we'll try it  again as well! SPC places the metro in a Slight Risk for large hail and strong wind with some storms early Friday.

We'll then see a break in the precip in the wake of the retreating warm front and prior to the arrival of the cold front, which should move into the metro in the early evening hours. The break will be a chance for the atmosphere to A) energize on abundant Gulf moisture flowing north on gusty wind and B) likely destabilize with some sunshine and temps warming into the mid to upper 70s. All models indicate widespread convection firing ahead of the cold front late Friday afternoon into Friday night.  The big question is - like today - does this happen to our west (putting us in line for severe storms) or to our east (missing the metro entirely)?  It'll be close.  For now, we plan for the worst and hope for the best. A Slight Risk is also in place for Friday afternoon and evening with the primary threat being damaging wind and isolated tornadoes. I would say the highest risk is east of the metro, particularly NE MS, north AL, and middle TN ,where the tornado threat may be a little higher as well.  The MWN Storm Center has maps showing the details. The good news is that once this system moves through Friday night, we'll be left with DRY conditions (and mild) for several days, including a nice looking weekend!

Expect an update again tomorrow. The full MWN Forecast can be found here.

----
For weather information for Memphis and the Mid-South, where and when you need it, visit MemphisWeather.net on the web, m.memphisweather.net on your mobile phone, download our iPhone or Android apps, or visit us on Facebook or Twitter.

Severe weather threat for Wednesday becoming better defined

Looking over the morning computer model data, there appears to be a dual-threat for strong storms in the next 24 hours.  While neither is particularly impressive, I feel the more likely threat of strong to severe storms comes with the second.  While models still have some significant discrepancies, that is why you have MWN!

The first window of opportunity is somewhat of a broad brush and covers the early morning hours Wednesday, or roughly from 2-8am. The main threats during this time frame will be hail and possibly some high wind gusts in the strongest storms. We expect the strongest storms, and better chance of severe weather, to be to the north and west of the metro, or over northern AR and northwest TN.

Slight Risk (yellow) area for tonight, as defined by SPC

The second chance for severe weather is ahead of and along the actual cold front, which now appears to move through the metro around mid-afternoon.  Thus, we'll put this "window" at 11am-4pm.  *IF* the morning convection can lull for a few hours (or longer) before the front approaches, I actually feel like the chance of damaging wind or hail could be a little higher with a squall line during the afternoon hours.  SPC indicates that we are just west of a 30% risk area tomorrow (see below), meaning the chance of severe weather within 25 miles is nearing 30%. Contributing to the higher risk is the timing - during peak daytime heating when temps should be in the mid 70s with a few dry hours leading up to the front. If rain continues throughout the morning, it may be a bit more difficult to get severe weather in the afternoon.

Probability of severe weather on Wednesday, as defined by SPC. Red is 30%. Yellow/red areas also in Slight Risk.

Once this threat has moved out, we'll focus more on Friday's weather event, but suffice it to say, the setup on Friday is definitely more favorable for severe weather and will bear watching closely.

As you prepare for the possibility of severe weather in the upcoming 4 days or so, be sure to put MWN's StormWatch+ service in your "severe weather toolkit." Not only does it push severe weather alerts for your specific location to your smartphone, but it will wake you up at night if a watch or warning is issued! Just place it on your nightstand or dresser and leave the ringer on. An audio tone (that I have been told DOES wake you up!) will sound when an alert is issued.  Remember: sirens are NOT designed to wake you at night, unless you live right under one. A personalized weather alert service is your best defense. Learn more about StormWatch+ and download it at StormWatchPlus.com.

----
For weather information for Memphis and the Mid-South, where and when you need it, visit MemphisWeather.net on the web, m.memphisweather.net on your mobile phone, download our iPhone or Android apps, or visit us on Facebook or Twitter.