Follow us on

Listen live to Atlanta's breaking news, severe weather, & traffic online

recent on-air advertisers

Now Playing

News/Talk WSB
Listen live to ...

Kirk Mellish's Weather Commentary

Posted: 4:43 p.m. Friday, March 27, 2009

Severe weather probable but not certain, devil in the details 

By Kirk Mellish

Last minute timing issues and mesoscale details remain in question for tomorrow's chance of severe weather, fingers crossed we get missed by the worst, as could happen, not much more clear about tomorrow, depends on timing of front and upper energy, and mesoscale features not resolvable this early, general risk is there, but delineating highest threat area or time is not possible now, chance it is worst West, South and North of us, breaks over us, then gets worse again East, North and South of us but not a safe bet or forecast, could also be afternoon into evening, not just mid-day, so could have one round early in the day then a second bigger round late day. Also with soggy soils and drought weakened trees may not take much wind for tree/power issues. A few of the usual creeks and streams are having minor flooding this afternoon. Here are the latest thoughts from the severe weather experts at the old SELS group at NOAA (Severe Local Storms), here is their discussion:

...EAST OF MISSISSIPPI VALLEY...
GIVEN THE INITIAL CLOSE PROXIMITY OF THE DEVELOPING CYCLONE TO A
MOIST...POTENTIALLY UNSTABLE AIR MASS OVER MUCH OF THE GULF OF
MEXICO/GULF COAST REGION...A RAPID RETURN FLOW AND SUBSEQUENT
DESTABILIZATION APPEARS PROBABLE THROUGH ALL BUT PARTS OF THE
NORTHEAST SATURDAY. THIS WILL CONTRIBUTE TO THE POTENTIAL FOR THE
CONTINUATION OF A SIGNIFICANT SEVERE WEATHER OUTBREAK THAT COULD
BECOME INCREASINGLY WIDESPREAD...BETWEEN THE MISSISSIPPI RIVER AND
THE APPALACHIANS...AND ACROSS THE EASTERN GULF/SOUTH ATLANTIC COAST
STATES. A BROAD BELT OF 50-70 KT SOUTHWESTERLY 500 MB FLOW IS
EXPECTED TO OVERSPREAD THIS REGION...WITH STRONGER CORES NOSING
NORTHEASTWARD THROUGH THE OHIO/TENNESSEE VALLEYS AND TO THE LEE OF
THE SOUTHERN APPALACHIANS. THIS WILL OCCUR COINCIDENT WITH A BROAD
SWATH OF 30-50+ KT SOUTHERLY 850 MB FLOW TO THE EAST/SOUTH OF THE
CYCLONE. THE STRONGEST LOW-LEVEL JET CORE...PERHAPS 50-70 KT...IS
GENERALLY PROGGED TO DEVELOP EAST OF THE SOUTHERN APPALACHIANS
SATURDAY EVENING/NIGHT. DEEP LAYER SHEAR WILL BE STRONG AND
SUPPORTIVE OF SUPERCELLS AND ORGANIZED SEVERE STORM CLUSTERS...WITH
LARGE CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS FAVORABLE FOR TORNADOES
AND DAMAGING CONVECTIVE WIND GUSTS.

THE POSSIBILITY OF SUBSTANTIAL EARLY PERIOD CONVECTIVE DEVELOPMENT
...AND WIDESPREAD CLOUD COVER/RAIN ASSOCIATED WITH IT...STILL POSES
SOME FORECAST UNCERTAINTY. IN PARTICULAR...IT IS POSSIBLE THAT A
LINGERING WEAKENING CONVECTIVE CLUSTER...OR A SIGNIFICANT REMNANT
CONVECTIVE OUTFLOW...COULD EXTEND ACROSS PARTS OF SOUTHEAST
ALABAMA/SOUTHERN GEORGIA/NORTHERN FLORIDA AT 12Z SATURDAY. IF THIS
BECOMES THE CASE...HIGHEST SEVERE PROBABILITIES MAY EXIST ALONG THE
RETREATING OUTFLOW...AND AHEAD OF AN EASTWARD ADVANCING COLD
FRONT...IN CLOSER PROXIMITY TO EASTERN GULF/SOUTH ATLANTIC COASTAL
AREAS. OTHERWISE...SEVERE POTENTIAL MAY BE CONSIDERABLY GREATER
FARTHER NORTH THAN CURRENTLY INDICATED IN THE CATEGORICAL
OUTLOOK...PARTICULARLY ACROSS EASTERN ALABAMA AND GEORGIA DURING THE
DAY...PERHAPS EAST NORTHEASTWARD ACROSS THE CAROLINAS DURING THE
EVENING/OVERNIGHT HOURS.