Today’s Severe Weather to Set Up South & East of I-44 in Oklahoma Today


Today, the severe weather could get going along or near the I-44 corridor. With the cold front/dryline intersection near the Oklahoma City metro area later tonight, storms will fire up very rapidly. Here is where the Storm Prediction Center is saying about this. Do expect this to change by midday.

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0753 AM CDT FRI APR 22 2011

VALID 221300Z – 231200Z

…THERE IS A SLGT RISK OF SVR TSTMS MAINLY THIS AFTERNOON INTO
TONIGHT FROM THE SRN PLAINS TO THE OH VALLEY…

…SYNOPSIS…
A WELL-DEFINED MIDLEVEL SHORTWAVE TROUGH EMERGING OVER WRN NEB/SD
THIS MORNING WILL MOVE EWD/ENEWD TOWARD MI AND STRENGTHEN THROUGH
TONIGHT…WHILE A REMNANT LEE CYCLONE IN CENTRAL KS DEVELOPS NEWD IN
ADVANCE OF THE MIDLEVEL TROUGH. THE SURFACE WARM SECTOR AND ITS MID
60S BOUNDARY LAYER DEWPOINTS WILL SURGE NEWD TODAY FROM OK/AR TO
MO/IL TODAY IN CONJUNCTION WITH THE SURFACE LOW.

…MO/IL/INDIANA THROUGH TONIGHT…
AN ONGOING MCS JUST N OF THE WARM FRONT IN NE KS/NW MO IS EXPECTED
TO PERSIST INTO THE DAY WHILE PROGRESSING EWD OVER NRN MO INTO
CENTRAL IL. THIS CONVECTION WILL BE MAINTAINED BY WAA ON THE NOSE
OF A SWLY LLJ…AND A FEED OF STEEP MIDLEVEL LAPSE RATES FROM THE
WSW. ISOLATED LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH
THIS CONVECTION.

IN THE WAKE OF THE MORNING WAA STORMS…THE BOUNDARY LAYER WILL
WARM/MOISTEN NEWD FROM OK/AR INTO MO/IL…WHILE MIDLEVEL LAPSE RATES
REMAIN STEEP. THE STEEP LAPSE RATES WILL INITIALLY PROVIDE A
CAP…BUT SURFACE HEATING/MIXING AND LOW-LEVEL ASCENT ALONG A SW-NE
ORIENTED COLD FRONT /TRAILING THE SURFACE LOW/ SHOULD RESULT IN
SURFACE-BASED THUNDERSTORM DEVELOPMENT BY LATE AFTERNOON FROM
CENTRAL MO INTO ERN AND SRN OK. STRONG INSTABILITY IS EXPECTED IN
ADVANCE OF THE COLD FRONT…WITH AFTERNOON MLCAPE RANGING FROM
2500-3500 J/KG IN SRN/ERN OK TO ROUGHLY 2000 J/KG IN PROXIMITY TO
THE SURFACE LOW AND WARM FRONT IN MO/IL. THIS
INSTABILITY…COMBINED WITH 0-6 KM BULK SHEAR IN EXCESS OF 50
KT…WILL SUPPORT A THREAT FOR ORGANIZED SEVERE STORMS…INCLUDING
SUPERCELLS.

CONVECTIVE MODE ALONG THE COLD FRONT IS OF SOME CONCERN…GIVEN
DEEP-LAYER FLOW/SHEAR VECTORS SOMEWHAT PARALLEL TO THE BOUNDARY.
THE MOST PROBABLE SCENARIO APPEARS TO BE FOR SEMI-DISCRETE
SUPERCELLS IN THE FIRST FEW HOURS AFTER INITIATION…WITH THE
POTENTIAL TO PRODUCE VERY LARGE HAIL AND A FEW TORNADOES. LOW-LEVEL
SHEAR WILL BE MORE FAVORABLE FOR TORNADOES NEAR THE WARM FRONT INTO
IL/INDIANA BY LATE AFTERNOON/EVENING…THOUGH SUFFICIENT LOW-LEVEL
SHEAR /0-1 KM SRH OF 150-200 M2 PER S2/ IS STILL EXPECTED AHEAD OF
THE COLD FRONT IN THE ZONE OF STRONGEST INSTABILITY INTO ERN OK.
LATER INTO THE EVENING…CONVECTION SHOULD TEND TO GROW UPSCALE INTO
LINE SEGMENTS WITH AN ACCOMPANYING RISK FOR DAMAGING WINDS AS THE
SYNOPTIC SYSTEM PROGRESSES EWD. FARTHER W…CONVECTION COULD
PERSIST WELL INTO THE OVERNIGHT HOURS ACROSS ERN OK AS THE SURFACE
FRONT STALLS AND A LOW-LEVEL WAA REGIME DEVELOPS ALONG/N OF THE
BOUNDARY.

…N CENTRAL AND CENTRAL TX LATE THIS AFTERNOON/EVENING…
THE MORE WIDESPREAD CONVECTION IS EXPECTED TO REMAIN NE OF THE
DRYLINE/COLD FRONT INTERSECTION ACROSS S CENTRAL OK.
HOWEVER…STRONG SURFACE HEATING ALONG THE DRYLINE COULD RESULT IN
SUFFICIENT WEAKENING OF THE CAP TO ALLOW ISOLATED THUNDERSTORM
DEVELOPMENT LATE THIS AFTERNOON/EVENING ACROSS CENTRAL/N CENTRAL TX.
MLCAPE AOA 2000 J/KG AND 0-6 KM BULK SHEAR AOA 30 KT WILL BE AT
LEAST MARGINALLY FAVORABLE FOR SUPERCELLS. ISOLATED LARGE HAIL
AND/OR DAMAGING GUSTS SHOULD BE THE PRIMARY SEVERE STORM THREATS
GIVEN RELATIVELY WEAK LOW-LEVEL SHEAR AND A DEEP MIXED BOUNDARY
LAYER.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s