Archive for June 3rd, 2012
Discussion from SPC
A band of storms is sagging ever so slowly into North Alabama late tonight.
Several severe thunderstorm and flash flood warnings are in effect for the Tennessee Valley.
Training will occur in some areas. This happens when storms repeatedly move along the same track, as is going to be the case along a west-northwest to east-southeast axis from western Tennessee across northern Mississippi and into North Alabama. Rainfall amounts will average 1 to 2 inches with some 3 to 4 inch amounts likely. Much of the Tennessee valley has recently gone to abnormally dry recently, so the rain will be beneficial if it doesn’t cause flooding.
Storms along the southwestern flank of the complex of storms still have the potential to be severe overnight with the main threats being hail and damaging winds. This potential should run down through Franklin, Lawrence, Cullman, Blount into Etowah and Calhoun Counties.
The tornado threat is decreasing though, which is good news.
here is the text of the discussion:
000
ACUS11 KWNS 040413
SWOMCD
SPC MCD 040413
GAZ000-ALZ000-TNZ000-MSZ000-040515-
MESOSCALE DISCUSSION 1044
NWS STORM PREDICTION CENTER NORMAN OK
1113 PM CDT SUN JUN 03 2012
AREAS AFFECTED…NERN MS…NRN AL…FAR SRN TN…NWRN GA
CONCERNING…TORNADO WATCH 348…
VALID 040413Z – 040515Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 348 CONTINUES.
SUMMARY…ALTHOUGH THE THREAT FOR TORNADOES APPEARS TO HAVE
DIMINISHED ALONG WITH OVERALL SEVERE POTENTIAL…ISOLATED DAMAGING
WINDS AND MARGINALLY SEVERE HAIL SHOULD PERSIST FOR THE NEXT FEW
HOURS WITH AN E/SEWD EVOLVING MCS ALONG THE TN/MS/AL BORDER AREA.
DISCUSSION…PRIMARY SEVERE RISK EXISTS ON SWRN FLANK OF MCS WHERE
ORIENTATION OF HIGHER REFLECTIVITY MORE NORMAL TO THE NEARLY
UNIDIRECTIONAL DEEP-LAYER WLYS WILL FAVOR A RISK FOR DAMAGING WINDS
AND MARGINALLY SEVERE HAIL. GIVEN THE COLD POOL CONFIGURATION…THIS
SHOULD YIELD A MORE SERN PROPAGATION WITH TIME AS THE FEED OF
STRONGER INSTABILITY OCCURS FROM W/SW IN MS. WITH ERN EXTENT…THE
PARALLELING ORIENTATION OF CONVECTION WITH THE DEEP-LAYER FLOW ALONG
WITH WEAKER INSTABILITY SHOULD PRECLUDE A SUBSTANTIAL SEVERE RISK
INTO NWRN GA BEYOND MARGINALLY SEVERE HAIL.
..GRAMS.. 06/04/2012
Things Finally Getting Going in North Alabama
The NWS Huntsville just issued a severe thunderstorm warning for the northern part of Limestone County.
There are severe storms entering Limestone County northwest of Athens. Those storms should stay north of Huntsville.
There are other storms around Huntsville, but they aren’t severe. Pea sized hail was reported in Huntsville a short time ago.
A tornado watch remains in effect for North Alabama in areas west of Huntsville.
The upper flow seems to have become more east southeast than the southeast that it was earlier. Keeping our fingers cross that this and the stabilized air from the earlier storms will prevent problems south of the Tennessee Valley overnight.
Still, keep those weather radios and apps and other warning systems on alert overnight.
Maybe Some Good News
Click image to enlarge
At least for Central Alabama…
The latest run of the RPM model is pretty believable. It is handling the current behavior of the storms over Tennessee and the weakening area of rain over Arkansas.
The model predicts that the storms over southern Tennessee will sag down into the Tennessee Valley of North Alabama overnight. The storms should gradually weaken, although there could be a few strong to severe ones over the northern tier of counties, and perhaps a couple of strong ones toward daybreak from Marshall County down to around Gadsden and Jacksonville in East Alabama.
The rainmass in Arkansas does not strengthen as it moves southeast. It in fact falls apart. (Not good news since we need the rain, but good news in that the threat of severe weather seems greatly diminished.
Still, we will need to keep a close eye on things through the night just in case something doesn’t play out this way.
I think that what is working in our favor is the fact that the earlier storms stabilized the atmosphere over northern Mississippi and northwestern Alabama. We will take it.
More storms will likely form during the day tomorrow to our northwest and come our way in the northwesterly flow aloft. There probably will be more severe weather tomorrow.
Rethinking the Tornado Threat
The tornado watches to our north and northwest have given everyone a little bit of a pause tonight. It’s June. We’re not supposed to have tornadoes in Alabama in June. But as we always say, when it comes to severe weather, expect the unexpected.
The NWS Birmingham is adding a low end tornado threat to their hazardous weather outlook for the overnight hours. There is just enough spin in the lower levels of the atmosphere ahead of the storms coming out of Arkansas and Tennessee.
So, we will be monitoring for a tornado threat overnight. The good news is that the airmass over Northwest Alabama down through the Birmingham area was worked over by the earlier severe weather. There is some CAPE across Northwest Alabama, but it should continue to diminish.
Keep your Weatheradios and apps on alert all night and we will have the latest throughout the night.
The NWS Memphis has several tornado warnings out right night, including one for a tornado that is about to cross the Mississippi River out of extreme Southeast Missouri into Tennessee, grazing extreme northeastern Arkansas.
The storm is near Holland. It will pass near Cooter, MO. This is north of Blytheville AR. The storm will pass near or just south of Dyersburg TN before 9 p.m. Spotters indicated that there was a tornado at 8:08 p.m. near West Hermondale. Three inch hail is indicated with this storm.
Another possible tornado was reported near Egypt AR at 8:01.
North Alabama Tornado Watch
Western Tennessee, northern Mississippi and extreme Northwest Alabama will all be going under a tornado watch in a few minutes.
It will last until 3 a.m.
Alabama Counties include: Colbert, Franklin, Lauderdale, Lawrence, Limestone, Morgan [AL] till Jun 04, 3:00 AM CDT.
Thunderstorms are breaking out over western Tennessee at this hour, and severe thunderstorm warnings are in effect.
A large complex of storms is over northern Arkansas as well, and addiitonal warnings are in effect there. There is also a tornado watch for Arkansas as well as parts of southern Missouri.
We don’t expect the storms to present a big tornado threat for North Alabama, but because it is a big watch, North Alabama got “lumped into” the tornado watch.
