2:15PM 1/9/2020 – RZW Exec

THURSDAY AFTERNOON UPDATE: FORECAST ON TRACK… RZW Exec partners, good Thursday afternoon! No real changes to pass along from our previous RZW Exec update yesterday. The good news is our forecast and messaging is on track. The bad news is the forecast still supports a significant potential for tornadoes, damaging winds, and a lower (albeit still notable) risk of flash flooding and large hail on Saturday. The one change to pass along today is that the Storm Prediction Center has introduced a rare Level 4 (out of 5) risk zone for parts of Louisiana, southern Arkansas, and eastern Texas valid for tomorrow (Friday). Our area in Alabama and northwest Florida remains involved in the Level 3 risk, which is still quite significant, valid for Saturday.

The graphic below is the latest idea in terms of the timing of when severe weather will start across our area on Saturday. This will likely be a daytime event for most locales.

Below is the forecast discussion from this morning that debuted publicly at 7AM. This has been lightly edited to account for the addition of the higher Level 4 risk across northern Louisiana. Other than that, the forecast remains on track. Please let me know if you have any specific decision support needs or questions.

SHOWERS LIKELY LOCALLY ON FRIDAY; P.M. THUNDERSTORMS POSSIBLE… Rain chances will rise throughout the day on Friday. Rain will start over west Alabama and progressively spread across the area from west to east. High temperatures on Friday will be in the low-70s and temperatures won’t be moving that much at all because of all the cloud cover. There could be a few thunderstorms between 3PM and 8PM Friday, but I am not expecting severe storms in this timeframe. Depending on the specific setup, there could be a few strong to marginally severe storms Friday night into Saturday morning AHEAD of our greater severe weather risk on Saturday during the daytime hours. See more about this in the “1st round” paragraph, below.

SIGNIFICANT SEVERE WEATHER RISK UP TO OUR WEST ON FRIDAY… SPC continues to outlook much of east Texas, Louisiana, and southern Arkansas in their Level 3 (out of 5) enhanced risk zone valid for FRIDAY, with a smaller area of higher Level 4 risk for areas near Shreveport in northern Louisiana. This includes a chance of significant severe weather, including strong tornadoes, across parts of east Texas and Louisiana. Please be aware of this heightened risk of severe storms if you’re traveling to these areas. This includes places like Shreveport (LA), Alexandria (LA), Lufkin (TX), and Houston (TX).

1ST ROUND: SMALL RISK OF SEVERE STORMS LATE FRIDAY INTO EARLY SATURDAY… After 8PM on Friday evening, we will need to start closely monitoring radar trends as there will be a conditional risk of strong to severe thunderstorms across parts of coastal Alabama and northwest Florida. I use the word “conditional” because there remains a high chance “severe weather ingredients” won’t come together this early. Atmospheric instability will be increasing to the point where we will have some thunder and lightning involved in the stronger storms Friday night. Some of this instability may be able to combine with the increasing low-level jet winds and produce a tornado or two. This “1st round” part of the severe weather risk locally will run from 8PM Friday to 6AM on Saturday. Once we get to 6 o’clock Saturday morning, that is when our severe weather risk will really start to ramp up. Details below in the “2nd round” paragraph.

2ND ROUND: SIGNIFICANT RISK OF SEVERE STORMS SATURDAY – TIMING… 6AM to 6PM Saturday is the 12 hour window in which severe weather seems most likely to happen. The core window for severe weather will happen across Alabama and northwest Florida between 10AM and 5PM. Confidence is now much higher in this timeframe now that we are within 48 hours of this severe weather potential. There may be further timing refinements needed over the next day or so. Please check back for the latest on severe weather timing both tonight and on Friday.

SATURDAY SEVERE WEATHER OVERVIEW – WHAT TO EXPECT… We start Saturday morning at 6AM looking to our west at what probably will be a severe squall line of thunderstorms. There is some question as to whether we’ll have supercell/discrete storms out ahead of the main line of storms this early in the morning, but that IS a possibility. A Tornado Watch will probably first be posted for our area in the 4AM to 9AM timeframe. IF discrete storms start firing up or moving into our area from Mississippi, that will probably happen in the early morning (6AM to 9AM timeframe). Tornadoes, damaging wind gusts, flash flooding, and large hail will all be concerns on Saturday. Let’s discuss each hazard in detail, below.

LEVEL 3 RISK AREA ON SATURDAY… Much of Alabama, northwest Florida, Mississippi, and the northeast corner of Louisiana near New Orleans is involved in the Level 3 (out of 5) enhanced severe weather risk zone. ALL of south Alabama and northwest Florida is involved in this enhanced risk area. Here are a few of the locales involved in the Level 3 risk area. Note that even if your specific town isn’t included in this list, if you see surrounding towns or cities involved, you’re still included in the risk zone. Level 3 risk as of Wednesday night: Mobile, Pensacola, Birmingham, Montgomery, Andalusia, Opp, Florala, Georgiana, Greenville, McKenzie, Hayneville, Camden, Brewton, Atmore, Poarch, Huxford, Flomaton, Evergreen, Repton, Castleberry, Monroeville, Beatrice, Uriah, Thomasville, Grove Hill, Jackson, Coffeeville, Silas, Butler, Pennington, Livingston, McIntosh, Leroy, Citronelle, Bay Minette, Mount Vernon, Saraland, Satsuma, Prichard, Theodore, Bayou La Batre, Fort Morgan, Dauphin Island, Gulf Shores, Orange Beach, Perdido Key, Foley, Fairhope, Daphne, Spanish Fort, Loxley, Stockton, Century, Bratt, Walnut Hill, Molino, Gulf Breeze, Warrington, Milton, Pace, Berrydale, Jay, Navarre, Crestview, Destin, Baker, Fort Walton Beach, Tuscaloosa, Marion, Selma, and Demopolis.

TORNADO RISK ACROSS THE AREA; HIGHEST TORNADO RISK INLAND… Let me be clear in that ALL of our local area in south Alabama and northwest Florida has at least some tornado risk on Saturday. As of Thursday morning, it appears the greater tornado risk will happen across inland areas of south Alabama in Washington, Clarke, Monroe, Choctaw, Marengo, Wilcox, and Butler counties and areas farther to the north in west-central Alabama. These are the areas where the greatest amounts of helicity, instability, and wind will come together to create the greatest tornado risk.

DAMAGING WIND GUSTS POSSIBLE ACROSS THE AREA… There will be substantial amounts of wind in the atmosphere capable of producing severe storms across our area on Saturday. I would not be surprised if we had many reports of trees being blown down because of straight-line wind with this event. It should be reiterated that if your area goes under a Severe Thunderstorm Warning, this will be one of those events where we need to treat it like a Tornado Warning. The severe thunderstorm warnings mean business this time. Wind gusts of 70 mph may be possible when the squall line moves through midday on Saturday.

FLASH FLOODING RISK… If storms train over the same areas for multiple hours (this is a small possibility, especially if discrete storms happen out ahead of the main line of storms), the overall flash flooding risk will be elevated. If this happens, it is most likely to occur across parts of Mobile, Washington, Clarke, Monroe, and Choctaw counties in west Alabama. Most spots across our region will pick up 1 to 3 inches of rain in total because of this event.

LARGE HAIL RISK… The risk of large hail is conditional on IF discrete, supercell thunderstorms can form out ahead of the main line of storms. Hail probably won’t be much of an issue for most locales, although we will need to maintain at least some risk of large hail due to the potential for discrete, isolated storms.

SEVERE WEATHER RISK COMES TO AN END BY SATURDAY EVENING… All of the severe weather issues will end no later than 5PM on Saturday as cooler, more stable air moves into our region from the west. Drier conditions are expected late Saturday night into early Sunday before more showers become possible Sunday.

UNSETTLED WEEK AHEAD… More showers and thunderstorms will be possible from late Sunday into Monday, Tuesday, and Wednesday of the upcoming week with temperatures remaining in the 60s and 70s. There have been some indications of a low-end severe weather risk Monday into Tuesday of next week, although it is too early to know for sure whether severe storms will be an issue in that timeframe. We’ll keep you posted. Let’s get through Saturday first.

APP ALERTS… Many consistent updates will be posted over the next few days in the RedZone Weather app. redzoneweather.com/app is the link for the free download. Be sure to visit the Alerts tab (bottom right corner) and tap the large, yellow “Alert Settings” button to customize the alerts you’d like to receive from me. Everyone should toggle ON Medium-Level Alerts. If you like a lot of info, be sure to toggle ON Low-Level Alerts.

Testing 123

Leave a Reply