Alert archive / Georgia / Mesoscale Discussions in 2020

Mesoscale Discussion 2

January 3, 202021 counties in Alabama; 5 counties in Florida; 32 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Jan 3, 2020, 4:40 AM CST for 21 counties in Alabama; 5 counties in Florida; 32 counties in Georgia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jan 3, 2020, 4:40 AM CST (10:40 UTC)
Expired
Jan 3, 2020, 7:15 AM CST
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 58 counties

Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Chambers County, AL, Cleburne County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Lee County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Tallapoosa County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Carroll County, GA, Chattahoochee County, GA, Clay County, GA, Clayton County, GA, Coweta County, GA, Crawford County, GA, Douglas County, GA, Fayette County, GA, Fulton County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Lamar County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Muscogee County, GA, Paulding County, GA, Pike County, GA, Polk County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Spalding County, GA, Stewart County, GA, Talbot County, GA, Taylor County, GA, Troup County, GA, Upson County, GA, Webster County, GA

The radar

The Ft Rucker radar (KEOX), 83 km from the middle of the area, began a volume at 10:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 10.7 hours before the alert went out and 170 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2020-01-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2020-01-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 694 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
429 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
694 m²/s²
0-3 km storm-relative helicity
722 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

277 
ACUS11 KWNS 031041
SWOMCD
SPC MCD 031040 
GAZ000-ALZ000-FLZ000-MSZ000-031315-

Mesoscale Discussion 0002
NWS Storm Prediction Center Norman OK
0440 AM CST Fri Jan 03 2020

Areas affected...southern Alabama...southwest Georgia...Florida
Panhandle

Concerning...Severe potential...Watch unlikely 

Valid 031040Z - 031315Z

Probability of Watch Issuance...20 percent

SUMMARY...Storms may continue to increase through the morning hours,
with isolated severe wind gusts the most probable threat from
southern Alabama into central Georgia. While a watch is unlikely in
the short-term, trends are being monitored for any increase in
intensity later this morning.

DISCUSSION...Surface analysis shows a cold front progressing east
from far southeast LA to the MS coast and into south-central AL.
Meanwhile, a tight temperature gradient exists near a warm front
from western into central GA.

Ahead of the cold front, relatively warm temperatures in the lower
70s F exist, along with dewpoints around 70 F especially from
southern AL to the Gulf Coast. GPS water vapor measurements over the
past several hours show a substantial increase in overall PWAT, with
maximum values approaching 1.70 inches. 

Showers have deepened over southern AL recently as the more robust
moisture interacts with the front. Already, small line segments have
developed, as deep-layer shear vectors are parallel to the front. 

Lapse rates aloft per forecast soundings earlier indicated a
subsidence inversion, which was hampering storm growth. However, the
moist boundary layer continues to deepen, allowing for deeper
convection (with increasing lightning trends). A general
strengthening is possible with some of these storms this morning, 
more so if pockets of heating can develop later this morning ahead
of this activity.

A few severe wind gusts are possible, especially with any
semi-organized small-scale bows. Some of these elements may
strengthen as they interact with the warm front over GA where lift
and low-level SRH will be maximized. A brief tornado is possible,
although gusty winds are most likely.

..Jewell/Grams.. 01/03/2020

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FFC...TAE...BMX...MOB...LIX...

LAT...LON   30298850 30858762 31448701 32008651 32728599 33598559
            34028533 34098502 33708427 33038385 32318397 31658468
            31128542 30588611 30318681 30188757 30108820 30168846
            30298850

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 3, 1:02 PM CSTMesoscale DiscussionSPCBaker, Baldwin, Ben Hill, Bibb, Bleckley, Burke and 46 more118 min

Nearby

Mesoscale Discussions in Georgia, 2020Mesoscale Discussions in Alabama, 2020Mesoscale Discussions in Florida, 2020Every mesoscale discussion in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.