Enhanced Risk of Severe Storms Tue:

The Storm Prediction Center has issued an “Enhanced Risk” of severe storms tomorrow across a large swath of Mississippi, Alabama, Tennessee, and Kentucky. The dominant storm mode will likely be a squall line, but a few isolated tornadoes directly ahead of, and within the line are possible. Several reports of damaging winds are likely.

SPC Enhanced Risk
SPC Enhanced Risk

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1143 AM CST MON FEB 01 2016

VALID 021200Z – 031200Z

…THERE IS AN ENH RISK OF SVR TSTMS FROM CENTRAL AND NORTHERN
MS…AND NORTHWEST/NORTHERN AL TO WESTERN AND CENTRAL KY…AND
EXTREME SOUTHERN IN…

…THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ENH RISK FROM
THE LOWER MS VALLEY TO THE LOWER OH VALLEY…

…THERE IS A MRGL RISK OF SVR TSTMS IMMEDIATELY SURROUNDING THE
SLGT RISK AREA…

…SUMMARY…
SCATTERED SEVERE STORMS CAPABLE OF PRODUCING DAMAGING WINDS AND A
FEW TORNADOES ARE EXPECTED FROM THE LOWER MISSISSIPPI VALLEY TO THE
LOWER OHIO VALLEY TUESDAY AFTERNOON. THESE STORMS AND A CONTINUED
SEVERE WEATHER THREAT WILL SPREAD EAST…REACHING PARTS OF SOUTHWEST
OHIO TO ALABAMA TUESDAY EVENING.

…SYNOPSIS…
MODEL GUIDANCE REMAINS CONSISTENT SHOWING AN INITIAL CLOSED
LOW/SHORTWAVE TROUGH AND ATTENDANT STRONGER FORCING FOR ASCENT
TRACKING FROM THE SOUTHERN/CENTRAL GREAT PLAINS INTO THE UPPER MS
VALLEY AND UPPER GREAT LAKES REGION DURING DAY 2. 12-HR 500-MB
HEIGHT FALLS ACROSS THE WARM SECTOR ARE EXPECTED TO BE WEAK THROUGH
TUESDAY AFTERNOON…WITH 30-60-METER HEIGHT FALLS ACROSS THE
CATEGORICAL RISK AREAS TUESDAY EVENING/NIGHT. IN THE LOW LEVELS…A
SURFACE LOW WILL FOLLOW A SIMILAR TRACK OF THE PARENT UPPER TROUGH
FROM KS TO THE UPPER GREAT LAKES. A TRAILING WIND SHIFT/PACIFIC
FRONT WILL ADVANCE TO THE EAST AND SHOULD EXTEND FROM THE IL/IND
BORDER SOUTHWARD IN VICINITY OF THE MS RIVER FROM SOUTHEAST MO/KY
BORDER INTO SOUTHERN LA BY 03/00Z. THIS FRONT WILL MOVE EAST
TUESDAY NIGHT THROUGH THE OH/TN VALLEYS AND INTO THE CENTRAL GULF
COAST STATES. MEANWHILE…A WARM FRONT WILL SHIFT POLEWARD FROM THE
TN VALLEY INTO THE OH VALLEY.

…LOWER MS VALLEY/CENTRAL GULF COAST STATES TO OH VALLEY…
AN INCREASE IN SOUTHERLY LOW-LEVEL FLOW ACROSS THE WARM SECTOR AHEAD
OF THE PACIFIC FRONT WILL ALLOW FOR POLEWARD MOISTURE RETURN DURING
DAY 2 WITH MID-60S SURFACE DEW POINTS BEING GENERALLY FROM MS/AL AND
SOUTHWARD. SURFACE DEW POINT NEAR 60 F COULD REACH THE LOWER OH
RIVER VALLEY /INTO FAR SOUTHERN INDIANA/. DESPITE THE MOISTURE
RETURN…WEAK LAPSE RATES ARE EXPECTED TO TEMPER INSTABILITY ACROSS
MUCH OF THE WARM SECTOR. GREATEST MUCAPE AROUND 1000 J/KG MAY BE
CONFINED TO THE GULF COAST.

GIVEN STRONGER FORCING FOR ASCENT IS EXPECTED TO REMAIN NORTH OF
MUCH OF THE CATEGORICAL SEVERE RISK AREAS THROUGH TUESDAY
AFTERNOON…CAPPING ISSUES REMAIN A LIMITING FACTOR WITH
THUNDERSTORM DEVELOPMENT MORE LIKELY TO OCCUR BETWEEN 18-21Z.
DEEP-LAYER WIND FIELDS ARE EXPECTED TO INCREASE THROUGH THE DAY 2
PERIOD WITH STRENGTHENING EFFECTIVE BULK SHEAR SUPPORTING ORGANIZED
STORMS.

STORMS THAT CAN DEVELOP FROM THE MID-SOUTH /EASTERN AR…NORTHERN
MS…AND WESTERN TN/ NORTHWARD WILL LIKELY BE LINEAR /POTENTIAL
QLCS/ AS THESE AREAS WILL BE CLOSER TO STRONGER FORCING FOR
ASCENT…DESPITE HAVING WEAKER INSTABILITY. MEANWHILE…STORM
DEVELOPMENT SOUTHWARD TUESDAY AFTERNOON SHOULD TEND TO BE MORE
DISCRETE MODE…GIVEN WEAKER FORCING ALOFT. STRONG LOW-LEVEL
HODOGRAPH CURVATURE ACROSS THE WARM SECTOR WOULD FAVOR A TORNADO
THREAT…WHILE WEAK INSTABILITY POLEWARD SHOULD TEND TO LIMIT THE
COVERAGE OF THIS THREAT AWAY FROM THE GULF COAST STATES.

AS GREATER HEIGHT FALLS SPREAD ACROSS THE CATEGORICAL SEVERE RISK
AREAS TUESDAY NIGHT…POTENTIAL EXISTS FOR A LINE OF STORMS TO
DEVELOP AND ADVANCE EAST REACHING SOUTHWEST OH TO AL WITH A THREAT
FOR DAMAGING WINDS AND AN ISOLATED TORNADO AS DEEP-LAYER WINDS
STRENGTHEN.

..PETERS.. 02/01/2016

Storm Prediction Center Outlooks