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Significant Severe Weather Episode Possible for Tomorrow… #ARwx #MSwx #LAwx #TNwx

The Storm Prediction Center in Norman, Oklahoma has highlighted an area in the mid-South tomorrow for risk of tornadoes and damaging winds. Let’s get into the details…

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There is the moderate risk area indicated in Arkansas, Louisiana, Mississippi, and Tennessee for tomorrow. This is from the updated Day Two outlook today for tomorrow.

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The hatched area you see there in the moderate risk area is indicating the chance for explosive thunderstorm development for tomorrow.

Here is the text from the Storm Prediction Center on the current Day Two Outlook…

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST MON JAN 28 2013

VALID 291200Z – 301200Z

…THERE IS A MDT RISK OF SVR TSTMS FROM NRN LA…CNTRL AND ERN
AR…EXTREME SWRN TN AND NWRN TO WCNTRL MS…

…THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE SRN
PLAINS…LOWER THROUGH MID MS VALLEY INTO WRN PARTS OF THE TN AND OH
VALLEYS…

…SYNOPSIS…

THE HIGH AMPLITUDE UPPER TROUGH NOW OVER THE WRN U.S. WILL ADVANCE
EWD…WITH MODEL CONSENSUS INDICATING THAT THE TROUGH AXIS WILL BE
LOCATED FROM MN THROUGH CNTRL/ERN TX BY THE END OF THIS PERIOD. MID
LEVEL JET AND ATTENDANT VORT MAX LOCATED WITHIN BASE OF THE TROUGH
SHOULD EJECT FROM THE SRN PLAINS THROUGH THE LOWER-MID MS VALLEY
TUESDAY NIGHT. AS THIS OCCURS A CYCLONE WILL DEEPEN AND LIFT NEWD
THROUGH THE MID MS VALLEY REGION. A POLAR FRONT WILL EXTEND FROM THE
SFC LOW OVER IA SWWD INTO CNTRL/SRN HIGH PLAINS EARLY TUESDAY…WITH
A PACIFIC FRONT/DRYLINE EXTENDING SWD THROUGH WRN TX. POLAR FRONT
WILL ADVANCE SEWD DURING THE DAY…WHILE THE PACIFIC FRONT SURGES
EWD AND MERGES WITH DRYLINE…CONTINUING THROUGH THE LOWER MS VALLEY
OVERNIGHT.

…SRN PLAINS THROUGH LOWER MS VALLEY REGION…

POTENTIAL EXISTS FOR A SIGNIFICANT SEVERE WEATHER EVENT TUESDAY WITH
DAMAGING WIND AND TORNADOES THE PRIMARY THREATS…ESPECIALLY DURING
THE EVENING AND OVERNIGHT IN MODERATE RISK AREA. OBSERVATIONS SHOW A
RESERVOIR OF MIDDLE TO UPPER 60S DEWPOINTS FROM CNTRL INTO SRN TX.
SLY BOUNDARY LAYER FLOW ALREADY EXISTS FROM THE SRN PLAINS INTO THE
LOWER MS VALLEY AND WILL STRENGTHEN TUESDAY IN ASSOCIATION WITH AN
INTENSIFYING LLJ. WIDESPREAD MULTI-LAYER CLOUDS WILL LIMIT BOUNDARY
LAYER WARMING DURING THE DAY. HOWEVER…MID 60S DEWPOINTS SHOULD
ADVECT AS FAR NORTH AS SERN OK INTO CNTRL AR AND NRN MS BENEATH A
PLUME OF 6.5 C/KM MID LEVEL LAPSE RATES RESULTING IN AT LEAST
500-1000 J/KG MLCAPE.

STORMS ARE EXPECTED TO DEVELOP WITHIN PRE-FRONTAL CONFLUENCE BAND
ACROSS CNTRL/ERN OK INTO NCNTRL/NERN TX EARLY TUESDAY AND SHIFT EWD
AND NEWD DURING THE DAY. OTHER STORMS MAY DEVELOP FARTHER SOUTH
THROUGH ERN TX DURING THE AFTERNOON ALONG MERGING PACIFIC FRONT AND
SHIFT EWD THROUGH THE LOWER MS VALLEY. THE BOUNDARY LAYER WILL
MOISTEN SUFFICIENTLY FOR THIS ACTIVITY TO BECOME SFC BASED. STORMS
WILL BE EMBEDDED WITHIN STRONG DEEP LAYER FLOW WITH A 50+ KT SLY LLJ
AND MID LEVEL WINDS INCREASING TO 80 KT. STORMS ARE EXPECTED TO
EVOLVE INTO A PREDOMINANT QLCS WITH EMBEDDED SUPERCELL AND BOWING
SEGMENTS POSING A RISK FOR DAMAGING WIND AND TORNADOES. TORNADO
THREAT MAY INCREASE OVERNIGHT…ESPECIALLY IN MODERATE RISK AREA
WHERE LLJ INTENSIFYING TO IN EXCESS OF 70 KT WILL BE COLLOCATED WITH
NRN EDGE OF MID 60S DEWPOINTS.

…UPPER MS VALLEY THROUGH TN VALLEY REGION…

OTHER STORMS WILL EXPAND NEWD THROUGH THE MID MS VALLEY AND SWRN
PARTS OF OH VALLEY WHERE INSTABILITY WILL BE MORE LIMITED…BUT
SUFFICIENT FOR A THREAT FOR DAMAGING WIND WITH PRIMARY MODE BEING
LINES AND BOWING SEGMENTS WITH MESO VORTICES. A FEW EMBEDDED
SUPERCELLS WILL ALSO BE POSSIBLE GIVEN SIZE OF HODOGRAPHS AND
STRENGTH OF DEEP LAYER FLOW/SHEAR SUGGESTING A FEW TORNADOES CANNOT
BE RULED OUT.

..DIAL.. 01/28/2013

Stay with Weather or Knot for the latest on this potential for a significant severe weather problem.

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Upgrade to Moderate Risk…

MESOSCALE DISCUSSION 1960
NWS STORM PREDICTION CENTER NORMAN OK
1019 AM CDT TUE SEP 18 2012

AREAS AFFECTED…FAR NRN SC…CNTRL/ERN NC…CNTRL/ERN VA…DISTRICT
OF COLUMBIA…CNTRL/ERN MD…MUCH OF DE…ERN PA…WRN/NRN
NJ…PARTS OF ERN NY

CONCERNING…OUTLOOK UPGRADE

VALID 181519Z – 181645Z

SUMMARY…A CATEGORICAL UPGRADE TO MODERATE RISK IS PLANNED FOR THE
UPCOMING 1630 UTC DAY-1 CONVECTIVE OUTLOOK FROM PARTS OF THE
CAROLINAS NWD INTO PARTS OF ERN NY.

DISCUSSION…STRONG LOW-LEVEL AND DEEP SHEAR IN ASSOCIATION WITH A
CONUS-FULL-LATITUDE TROUGH WILL SUPPORT MULTIPLE QLCS SEGMENTS
ACROSS A BROAD WARM SECTOR OVER THE ERN CONUS. WIDESPREAD SVR WIND
GUSTS WILL BE THE MAIN CONCERN ACROSS THE UPCOMING MODERATE RISK
AREA…AND SVR WIND PROBABILITIES WILL BE INCREASED TO 45 PERCENT
ACROSS THIS REGION. HOWEVER…TORNADOES WILL ALSO BE
POSSIBLE…PARTICULARLY WITH EMBEDDED LEWP STRUCTURES…LINE
BREAKS…AND DISCRETE CONVECTION EVOLVING AHEAD AN APPROACHING
EXTENSIVE COLD FRONT. PLEASE SEE THE FORTHCOMING OUTLOOK FOR
ADDITIONAL METEOROLOGICAL INFORMATION.

..COHEN/CARBIN/MEAD.. 09/18/2012

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