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Good morning!

A nice sunrise here at the house this morning! The skies will be giving way to clouds and eventually rain as the day goes on. What you see here is not the severe, that will be late this afternoon and evening.

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North Georgia is looking pretty good in terms of severe weather today. The tornado chances from the metro area northward are only about 2% or less.

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   Day 1 Severe Weather Outlook   
   NWS Storm Prediction Center Norman OK
   0110 AM CDT Sun Apr 19 2020

   Valid 191200Z - 201200Z

  •    ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM PARTS OF FAR EAST TEXAS EASTWARD ACROSS THE SOUTHEAST TO SOUTH-CENTRAL GEORGIA...

   CORRECTED FOR REGIONAL DESCRIPTORS

   ...SUMMARY...
   An outbreak of tornadoes and severe thunderstorms is expected today from parts of the lower Mississippi Valley across much of the the Southeast. In addition to tornadoes, many of the storms will have very large hail and wind damage. The severe threat will be greatest from north-central Louisiana eastward to southern and central Mississippi, southern and central Alabama into south-central Georgia. Additional severe storms with a threat for tornadoes, wind damage and hail will be possible in parts of east Texas this morning and in the Carolinas tonight.

   ...Regional Outbreak of Tornadoes and Damaging Winds Expected Across Parts of the Lower Mississippi Valley and Southeast Today...

   ...Lower Mississippi Valley/Southeast...
   A potent upper-level trough will move quickly eastward across the southern Plains today as a 60 to 75 kt mid-level jet moves eastward across the Southeast. Ahead of the system, a corridor of moderate to strong instability is forecast to develop from parts of the lower Mississippi Valley eastward across much of the Southeast. This combined with steep mid-level lapse rates and strong low-level shear will be very favorable for severe storms. As the mid-level jet moves eastward into the Southeast, a regional outbreak of severe weather including tornadoes appears likely from parts of the lower Mississippi Valley eastward across parts of Mississippi, Alabama and Georgia. The greatest threat for tornadoes is expected to last from late morning through the afternoon and evening into the overnight period.

   At the start of the period, a moist and unstable warm sector will be in place from southeast Texas eastward across much of the Gulf Coast. The northern edge of the moist sector will gradually move northward as moisture advection occurs. A severe convective cluster appears likely to be ongoing this morning from east Texas into the Arklatex where large hail and wind damage will be possible. As surface temperatures warm this morning, a threat for hailstones greater than 2 inches in diameter will be possible. If some of the storms become surface-based, a tornado threat could also develop. Eastward from this complex, an undisturbed moist sector will exist from south-central Louisiana eastward across the southern half of Mississippi, the southern half of Alabama into southern Georgia. RAP forecast soundings by early to mid afternoon along this corridor have MLCAPE of 2000 to 3000 J/kg with 0-6 km shear in the 50 to 60 kt range. This environment will likely be very favorable for supercells and tornadoes. 0-3 storm-relative helicities are forecast to be favorable being maintained in the 300 to 400 m2/s2 range in the late afternoon as a low-level jet becomes focused ahead of the approaching system. 

   The first round of severe storms is expected to move eastward out of east Texas into western Louisiana late this morning. Large hail and wind damage should be the main threat initially. But as the storms mature, tornadoes will be possible along the southern edge of the complex with supercells that become surface-based. This convective complex is expected to move eastward along a warm front across central Mississippi into west-central Alabama during the mid to late afternoon. The stronger and more dominant supercells that interact with the warm front may produce tornadoes, some potentially strong, along with wind damage and large hail. 

    In addition to the tornado threat, large hail and wind damage will be likely across a large part of the Southeast this afternoon and evening. The wind-damage threat is expected to increase as an MCS moves eastward across southeastern Alabama and into south-central Georgia by early this evening. Squall-line development will be possible ahead of the cold front tonight from central Georgia into the Carolinas, where a wind damage, large hail and a tornado threat will be possible.

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NWS Atlanta has more Georgia specific details.

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Would definitely classify the current state as the calm before the storm across the area as high pressure remains in control over the Carolinas with influence over the local area resulting in a continued dry northerly flow. Dewpoints hardly of the severe variety thus far with upper 30s and lower 40s the rule. All this points to a scenario in which area will be on the edge of surging moisture and  energy but also means demarcation of these 2 zones later today will be an area primed for severe storms including tornadoes and damaging winds.

Initially, it will be just an isentropic lift scenario with S to SW flow of 50 kts at 5k ft stream over the relatively cold dome mentioned above. All CAPE will be of the elevated variety but still sufficient for some thunder for Central portions. Things will change very quickly however through the early afternoon hours with a very sharp gradient of energy developing. Although surface based CAPE will remain near zero all the way down to the southern metro, we will see values in excess of 2000 J/KG approaching our far SW zones. The STP will be increasing to around 5 during this time as well allowing for a start to the tornado threat as well as damaging winds.

Further north of this, up to I-20, the pure dynamics of this system may be enough to overcome the relative lack of instability. Shear may prove to be too high the further north you go as updrafts will simply not be able to support. However, damaging winds will remain a likely component for the Atlanta metro and other areas along the I-20 corridor.

Main event looks to be along the front later in the evening for Central GA as instability and corresponding STP surges northward briefly. Although overall geographic footprint of this system may be smaller than last system, this one is not to be taken lightly by any means as tornadoes look likely along and south of a Columbus to Macon line. In addition, a few strong and long track tornadoes will be possible given sigtor ramping up during this timeframe and updraft helicities represented by most of the hi res guidance. Rapidly improving conditions for late Sunday night into Monday although winds will be gusty in cooler NW flow.

 

Rainfall amounts through 2 PM Monday. The heavier amounts are further south with the severe potential.
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I'll have updates all day long and I guess into the night as well. These systems need to start coming through a little earlier in the day, they are messing with my beauty sleep. 🙂 

Morristown didn't have any data today, so I only have Atlanta and Birmingham. I know that makes you sad. 🤪

Have a great day and check back for updates!

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*** ALERT ***
Spotter activation is requested for this afternoon and tonight across central and portions of north Georgia, along and south of I-20. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines.

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Looks like we get the rain and the action this time.  I will be a lot more alert than I was last Sunday. Rain amounts shifted more my way but we are back to needing it. Although Charleston NWS has forgotten about us again as usual.  We are slated to receive 5 inches of rain in 24 hours, yet they don't think we need a watch of any kind like all the counties west of us clear to Louisiana ..

 

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It sure doesn't feel stormy here in western Lumpkin county, but it does feel rainy. Temps are in the 40's and overcast.

I know, that's not very scientific. But I remember the hot, overcast stillness on the morning of the Palm Sunday outbreak of '94 and tend to use that as a reference.

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17 minutes ago, RickyD said:

Looks like we get the rain and the action this time.  I will be a lot more alert than I was last Sunday. Rain amounts shifted more my way but we are back to needing it. Although Charleston NWS has forgotten about us again as usual.  We are slated to receive 5 inches of rain in 24 hours, yet they don't think we need a watch of any kind like all the counties west of us clear to Louisiana ..

 

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Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
424 AM EDT Sun Apr 19 2020
 
Day 1
Valid 12Z Sun Apr 19 2020 - 12Z Mon Apr 20 2020 

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE SOUTHEAST...

Ingredients are in place for excessive rainfall today across 
portions of the Southeast. Flash flooding is expected to become 
numerous in coverage this afternoon through the evening hours, 
with significant, and potentially life threatening, flash flooding 
possible. The event features strong synoptic forcing, with a well 
defined mid level shortwave and dual left exit, right entrance, 
upper jet dynamics resulting in strongly divergent flow aloft. In 
the lower levels we will have impressive moisture transport and a 
west to east oriented convergence axis. Should have plenty of 
instability along/south of the convergence axis to support intense 
convective activity. PWs and IVT are both forecast above the 
climatological 99th percentile as well. 

Deep layer mean winds are quite fast off to the east northeast. 
However the direction and magnitude of the low level inflow is 
such that cell propagation (as shown by Corfidi vectors) should be 
more off to the east or even east southeast. This indicates that 
we will likely have some backbuilding of cells increasing the 
training potential. On top of that, the aforementioned moisture 
convergence axis will be quite broad and oriented west to 
east...which also supports west to east training of cells this 
afternoon and evening. 

Some model spread is noted with the latitude of the training 
convective axis. WPC favored the more southern solution depicted 
by some of the CAMs. Given the degree of upstream instability and 
the strength of the low level inflow...would expect convection to 
propagate east or east southeastward with time today (as mentioned 
above)...which supports the further south QPF solutions. We 
weighted the forecast heavily towards the 00z HREF, HRRR, HRRRv4, 
GEM regional...all of which had a similar axis of heaviest rain 
stretching from central MS, into central and southern AL/GA, and 
far southern SC. We are expecting 3 to 5 inches of rain along this 
corridor...with localized 5-7" amounts a possibility across AL/GA.

Overall we are expecting this event to materialize as a solid to 
high end Moderate risk over portions of central AL into central 
GA...with flash flooding numerous in nature, some of which could 
be locally significant and life threatening. Will need to monitor 
for the potential of a High risk upgrade at some point today.
If 
the elevated convection that develops in the 12z-18z time frame 
this morning ends up more concentrated over central AL/GA, then 
that could prime soil conditions for the afternoon/evening 
activity. If this occurs, that could push the event into the 
widespread severe flash flooding category...warranting a High risk 
upgrade. Unfortunately confidence is somewhat low on how the 
activity evolves this morning (actually higher confidence in 
convective evolution this afternoon/evening) and thus think 
keeping the risk at Moderate is the best option for now.

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SPC Day 1 Update

Quote

  Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0300 PM CDT Sun Apr 19 2020

   Valid 192000Z - 201200Z

  •    ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF LA INTO SOUTHERN/CENTRAL S/AL/GA...

   ...SUMMARY...
   A severe-weather outbreak is expected across much of the Deep South
   through tonight, with the greatest threat from east Texas and the
   Delta region eastward across parts of Mississippi, Alabama, and
   Georgia.  Multiple episodes of thunderstorms will likely result in
   several tornadoes (some strong), widespread damaging winds, and
   large hail.

   ...20Z Update...
   Primary change with this update was to make adjustments to the
   western edge of higher severe probabilities across parts of east TX
   into LA based on ongoing storms. The most favored corridor for all
   severe hazards through this afternoon will remain along/south of a
   convectively reinforced warm front extending from east TX into
   central LA/MS and parts of southern/central AL
. 18Z soundings from
   LCH and LIX show strong low-level flow, but a weakness in the
   mid-levels roughly in the 750-600 mb layer. This weakness is
   forecast to diminish this afternoon as the shortwave trough over the
   southern Plains continues to shift eastward towards the lower MS
   Valley this evening. A favorable corridor for strong tornadoes is
   still apparent along/south of the warm front across parts of central
   LA into southern/central MS/AL/GA. Both strong instability and shear
   will be present across these areas from this afternoon through the
   overnight hours as a southwesterly low-level jet and corresponding
   low-level shear both strengthen
. An outflow boundary from earlier
   storms draped across parts of southern MS/AL may also be a focus for
   greater tornado potential given locally backed low-level flow.

 

If you watched the video, you saw the warm air to the south, luckily for us, it's not in our area.

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43 minutes ago, audpogue said:

I really hope (unlike last Sunday) that I can just throw in my earplugs, don my sleep mask, snuggle with the dog, and sleep in my own bed.

Everything seems ok-ish for Barrow overnight?

I think so. We will have some heavy rain and even some thunder, but I think the severe will be well south of us.

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