SEVERE WEATHER DISCUSSION: SATURDAY, 2/15/25

Awesome news for Saturday. Thibodaux is having a huge event downtown Saturday. The king cake festival

Saturday night's trough will actually be digging with the trough base swinging right overtop South Louisiana. Compared to yesterday which had rising mid level heights/anticyclonic curvature/poor lapse rates (highlighted in more details in yesterday's thread), this Saturday has more positives for severe wx going for it than yesterday, but still doesn't appear to have any sort of extreme parameters...shear vector is oriented more parallel to the boundary vs perpendicular so that tells me more of a QLCS with maybe an isolated storm or two ahead of the line.

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1250 AM CST FRI FEB 14 2025

VALID 151200Z - 161200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EXTREME
EAST TEXAS...NORTHERN LOUISIANA...SOUTHEAST ARKANSAS...SOUTHWEST
TENNESSEE...MUCH OF MISSISSIPPI...AND WEST-CENTRAL ALABAMA...

..SUMMARY

SEVERE WEATHER IS EXPECTED FROM EAST TEXAS INTO MUCH OF THE
SOUTHEAST AND PARTS OF THE MID-SOUTH ON SATURDAY. SCATTERED TO
NUMEROUS DAMAGING WIND GUSTS AND A FEW TORNADOES ARE THE PRIMARY
THREATS. STORMS ARE EXPECTED FROM LATE AFTERNOON THROUGH THE
OVERNIGHT HOURS.

..MID-SOUTH AND SOUTHEAST

AN UPPER TROUGH WILL MIGRATE EAST ACROSS THE PLAINS TO THE MS VALLEY
ON SATURDAY. STRONG SOUTHWESTERLY DEEP-LAYER FLOW, CHARACTERIZED BY
A 500 MB JET STREAK AROUND 80-100 KT, WILL OVERSPREAD THE REGION,
MAINLY NEAR/AFTER 00Z. AS STRONGER HEIGHT FALLS APPROACH THE
ARKLATEX AND MS VALLEY, A LOW-LEVEL JET GREATER THAN 50 KT WILL
DEVELOP FROM LA INTO TN/KY. MEANWHILE AT THE SURFACE, SOUTHERLY
LOW-LEVEL FLOW WILL ALLOW 60S F DEWPOINTS TO MARCH NORTHWARD,
REACHING AS FAR NORTH AS WESTERN TN. BOUNDARY-LAYER MOISTURE INTO
THE MID-60S F IS EXPECTED TO REMAIN SOUTH OF THE MS/TN BORDER.

A SURFACE LOW IS EXPECTED TO DEEPEN DURING THE AFTERNOON INTO THE
NIGHTTIME HOURS AS IT TRACKS FROM AR TO OH. A COLD FRONT ATTENDANT
TO THE LOW WILL SWEEP EAST/SOUTHEAST FROM LATE AFTERNOON INTO EARLY
SUNDAY. WARM ADVECTION ACROSS THIS BOUNDARY WILL RESULT IN
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS FROM EAST TX INTO THE
LOWER OH VALLEY FOR MUCH OF THE DAY. THIS WILL LIMIT THE NORTHWARD
EXTENT OF THE ADVANCING WARM SECTOR, WITH A WARM FRONT EXPECTED TO
STALL ACROSS TN INTO NORTHERN GA. LARGE-SCALE ASCENT IS NOT EXPECTED
TO OVERSPREAD THE REGION UNTIL EVENING, SO OPEN WARM SECTOR
CONVECTION LIKELY WILL REMAIN LIMITED DIURNALLY.

BY LATE AFTERNOON, MORE ROBUST CONVECTION IS EXPECTED TO DEVELOP
ALONG THE SHARPENING COLD FRONT FROM EASTERN AR INTO EAST TX/WESTERN
LA WITHIN A PLUME OF 1000-1500 J/KG MLCAPE AND STRONG VERTICAL
SHEAR. A QLCS PRODUCING A SWATH OF DAMAGING GUSTS IS LIKELY TO MOVE
ACROSS THE REGION THROUGH THE OVERNIGHT HOURS. FAVORABLE LOW-LEVEL
SHEAR, CHARACTERIZED BY ENLARGED, LOOPING HODOGRAPHS SUGGESTS
TORNADOES ALSO WILL BE POSSIBLE WITH MESOVORTEX FORMATION ALONG THE
LINE, IN ADDITION TO ANY LINE-EMBEDDED SUPERCELLS. A MORE
CONDITIONAL THREAT EXISTS WITH ANY SUPERCELLS THAT CAN DEVELOP AHEAD
OF THE LINE IN THE OPEN WARM SECTOR, SOMETHING THAT REMAINS
UNCERTAIN AT THIS TIME. ANY CELLS THAT DO DEVELOP AHEAD OF THE LINE
WILL POSE A RISK FOR TORNADOES AND DAMAGING GUSTS, AND COULD ALSO
POSE A RISK FOR INCREASING TORNADO POTENTIAL AS THEY INTERACT WITH
THE QLCS.

THE NORTH AND EAST EXTENT OF THE SEVERE RISK AREAS REMAINS A BIT
UNCERTAIN, IN PART DUE TO COLD AIR DAMMING INTO THE SOUTHERN
APPALACHIANS AND HOW MUCH THIS IS ABLE TO ERODE. A GENERAL DECREASE
IN BOUNDARY-LAYER MOISTURE AND INSTABILITY IS EXPECTED WITH
NORTHEAST EXTENT DURING THE OVERNIGHT HOURS. HOWEVER, THE EXPECTED
INTENSE DEEP-LAYER WIND FIELD WILL LIKELY MAINTAIN SOME DAMAGING
WIND AND TORNADO RISK INTO AL AND PERHAPS PARTS OF WESTERN GA.

..LEITMAN.. 02/14/2025

This is a widespread damaging wind event signal especially to our north but it extends into SELA.

Big change in the first day 1 outlook. Enhanced risk with a 10% tornado hatched area now just to the north of the I-10 and 12 corridors

After Wednesday’s dud everyone is ignoring tonight.

That may not be wise. It wouldn’t shock me if we have a fairly large event by our standards.

HRRR showing discrete supercells forming just west of us tonight. These would have the risk for tornadoes and then as they mesh into a line, widespread wind damage.