cincywx
Member
no significant changes to d1. new disco is a great read, highlights the remaining uncertainties while noting the implications of the worst scenarios. emphasis mine.
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 AM CDT TUE APR 04 2023
VALID 041300Z - 051200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
EASTERN IOWA...NORTHWESTERN ILLINOIS...EXTREME SOUTHWESTERN
WISCONSIN...NORTHEASTERN AND SOUTHERN MISSOURI...ARKANSAS...AND
EXTREME EASTERN OKLAHOMA...
..SUMMARY
TORNADOES, SEVERE THUNDERSTORM GUSTS AND LARGE HAIL ARE POSSIBLE
TODAY AND TONIGHT FROM THE UPPER GREAT LAKES TO CENTRAL TEXAS.
POTENTIAL FOR UNUSUALLY STRONG TORNADOES IS FOCUSED TODAY OVER PARTS
OF THE MID/UPPER MISSISSIPPI VALLEY, AND TONIGHT OVER PARTS OF THE
OZARKS TO THE ARKLATEX REGION.
..SYNOPSIS
THE DOMINANT UPPER-TROPOSPHERIC FEATURE FOR THIS FORECAST WILL BE A
SYNOPTIC-SCALE TROUGH AND BROAD SWATH OF ASSOCIATED CYCLONIC FLOW
OVER THE WESTERN CONUS. MOISTURE-CHANNEL IMAGERY INDICATES THAT A
CYCLONE ALOFT IS FORMING ACROSS THE UINTA MOUNTAINS/FLAMING GORGE
REGION OF UT/WY, ALONG THE TROUGH EXTENDING SOUTHWESTWARD OVER THE
LOWER COLORADO RIVER VALLEY AND NORTHERN/CENTRAL BAJA. THE 500-MB
LOW SHOULD MIGRATE/REDEVELOP NORTHEASTWARD TO THE BLACK HILLS BY
00Z, WITH TROUGH ACROSS EASTERN CO, NORTHERN/WESTERN NM, AND
NORTHWESTERN MX. BY 12Z, THE LOW SHOULD REACH EASTERN ND, WITH
TROUGH ACROSS CENTRAL NE, WESTERN KS, AND CENTRAL/SOUTHWESTERN NM.
THE ASSOCIATED SURFACE LOW WAS ANALYZED AT 11Z BETWEEN SLN-GBD, WITH
ANOTHER LOW OVER SOUTHEASTERN CO, AND A QUASISTATIONARY FRONT
CONNECTING THEM. A WARM FRONT EXTENDED EASTWARD FROM THE KS LOW
OVER CENTRAL MO, SOUTHERN IL AND WEST-CENTRAL KY. A DRYLINE WAS
DRAWN FROM THE SAME LOW SOUTH-SOUTHWESTWARD OVER WESTERN OK,
NORTHWEST/WEST-CENTRAL TX, AND NORTHERN COAHUILA. THE KS LOW SHOULD
SHIFT NORTHEASTWARD TO WEST-CENTRAL IA BY 00Z, WITH COLD FRONT
ACROSS EXTREME SOUTHEASTERN NE TO CENTRAL KS. FROM THERE, TWO
BRANCHES OF THE COLD FRONT WILL BECOME APPARENT: AN ARCTIC BOUNDARY
ARCHING ACROSS WESTERN KS TO CENTRAL CO, AND A PACIFIC FRONT ACROSS
THE TX PANHANDLE TO FAR WEST TX.
THE DRYLINE SHOULD MIX EASTWARD DURING THE DAY AND REACH
NORTHWESTERN MO, EASTERN KS, EAST-CENTRAL OK, NORTH-CENTRAL TX, TO
THE RIO GRANDE VALLEY BETWEEN DRT-LRD. THE WARM FRONT SHOULD EXTEND
FROM THE LOW ACROSS EASTERN IA, NORTHERN PARTS OF IL/IN, AND
WESTERN/CENTRAL OH. OVERNIGHT, THE PACIFIC FRONT WILL OVERTAKE (BY
THEN) THE QUASISTATIONARY TO SLOWLY RETREATING DRYLINE FROM
NORTH-SOUTH, SUCH THAT BY 12Z, THE COMBINED BOUNDARY WILL EXTEND
FROM A LOW OVER NORTHWESTERN WI ACROSS EASTERN IA, SOUTHWESTERN MO,
NORTHWESTERN AR, AND ACROSS NORTHEAST THROUGH SOUTH-CENTRAL TX TO
NEAR LRD. THE WARM FRONT, AT THAT TIME, SHOULD EXTEND ACROSS
CENTRAL WI, SOUTHERN LOWER MI, AND NORTHERN OH.
A VAST AREA OF AT LEAST MARGINAL SEVERE POTENTIAL IS EVIDENT FROM
THE UPPER GREAT LAKES NORTH OF THE WARM FRONT -- WHERE HAIL FROM
ELEVATED THUNDERSTORMS WILL BE THE MAIN CONCERN -- TO PORTIONS OF
CENTRAL/EAST TX TONIGHT AS CONVECTION GROWS NEAR THE COLD FRONT AND
POSES MAINLY A WIND/HAIL THREAT. TWO RELATIVE CONCENTRATIONS OF
PARTICULARLY INTENSE AND DESTRUCTIVE TORNADO POTENTIAL ARE APPARENT,
BUT STILL WITH ENOUGH UNCERTAINTIES ATTACHED TO PRECLUDE
UNCONDITIONAL CATEGORICAL UPGRADE(S) AT THIS OUTLOOK CYCLE.
..MID/UPPER MISSISSIPPI VALLEY REGION, UPPER GREAT LAKES
MORNING CONVECTION NORTH OF THE WARM FRONT WILL ROOTED IN A
FAVORABLY UNSTABLE, ELEVATED INFLOW LAYER AMID FAVORABLE DEEP SHEAR,
AND WILL POSE AN ISOLATED LARGE-HAIL THREAT. EPISODES OF ADDITIONAL
THUNDERSTORMS (ALSO OFFERING SEVERE HAIL) ARE POSSIBLE THROUGH THIS
EVENING IN THIS REGIME.
THE MAIN CONCERN, HOWEVER, WILL BE THIS AFTERNOON INTO EVENING EAST
AND SOUTHEAST OF THE SURFACE LOW, FROM THE WARM FRONT SOUTHWARD
100-200 NM INTO THE WARM SECTOR, IN AND NEAR THE "MODERATE" AREA.
AT LEAST ISOLATED SUPERCELLS WILL BE POSSIBLE, WITH POTENTIAL FOR
STRONG TO VIOLENT TORNADOES, VERY LARGE HAIL, AND LOCALLY SEVERE
GUSTS. A "MIDDLE GROUND" OR CONSENSUS SCENARIO SUGGESTS THAT, ONCE
THICKER LOW-CLOUD COVER ERODES/ADVECTS PAST THE AREA THIS AFTERNOON,
A FEW SUPERCELLS FORM IN AND CROSS A WARM SECTOR CHARACTERIZED BY
LARGE HODOGRAPHS, STRONG DEEP SHEAR, AND CLIMATOLOGICALLY RARE
BUOYANCY, THEN CROSS A VERY FAVORABLE WARM-FRONTAL ZONE. MLCAPE OF
2500-3500 J/KG IS POSSIBLE BENEATH 7.5-8 DEG C/KM MIDLEVEL LAPSE
RATES AND SURFACE DEWPOINTS AT LEAST IN THE MID 60S F. ISALLOBARIC
FORCING AND RELATED BACKED FLOW IN THE WARM SECTOR, WITHIN A COUPLE
DEGREES OF THE LATITUDE OF THE LOW, SHOULD YIELD ENLARGED LOW-LEVEL
HODOGRAPHS, WITH EFFECTIVE SRH OF 300-500 J/KG, EXCEEDING 600 J/KG
ALONG THE WARM FRONT, AND 60-70 KT EFFECTIVE-SHEAR MAGNITUDES.
OPTIMAL VALUES OF BOTH CAPE AND SHEAR MAY BE SOMEWHAT HIGHER IF THE
MOST AGGRESSIVE PROGS VERIFY, AND SHOULD BE VERY STRONG ALONG THE
WARM FRONT.
THE MAIN UNCERTAINTY INVOLVES WARM-SECTOR STORM COVERAGE AND
MATURATION TIME BEFORE CROSSING TOO DEEP INTO THE WARM-FRONTAL ZONE
TO REMAIN SURFACE-BASED. A BIG INFLUENCE ON THIS POTENTIAL WILL BE
THE EXTENT AND MAGNITUDE OF MOISTURE DEFICIT RELATED TO VERTICAL
MIXING. MODELS ARE FOLLOWING THEIR USUAL BIASES IN THIS REGARD --
BUT TO SOMEWHAT OF AN EXTREME -- WITH (FOR EXAMPLE) WRF-BASED PROGS
LIKE THE NAM, SREF MEMBERS AND SOME HREF MEMBERS BEING MORE COOL AND
MOIST UNDER AN EML, BUT ULTIMATELY DEVELOPING GREATER DENSITY OF
STORMS FARTHER SOUTH (WITH MORE MATURATION ROOM) IN THE WARM SECTOR
AS HEATING ERODES MLCINH. MEANWHILE RAP-BASED PROGS (INCLUDING
HRRR) DEVELOP LESS ACTIVITY, WITH A DEEP, WELL-MIXED BOUNDARY LAYER
MORE SUITED TOWARD WIND POTENTIAL EVIDENT IN THEIR FORECAST
SOUNDINGS. IF THE EML REMAINS STRONG THROUGH THE AFTERNOON, THE
DEEP-MIXING SCENARIO IS LOW-PROBABILITY, BUT LIFT IN THE WARM SECTOR
ALSO MAY BE RESTRICTED. A CORRIDOR OF FRONTAL CONVECTION ALSO
SHOULD DEVELOP FROM LATE AFTERNOON INTO TONIGHT FROM CENTRAL IA TO
EASTERN KS, MOVING EASTWARD. THIS ACTIVITY MAY INCLUDE EARLY-STAGE
SUPERCELLS WITH ALL SEVERE HAZARDS POSSIBLE, BUT EVOLVING TO
WIND-DOMINANT QLCS MODE WITH A FEW TORNADOES ALSO POSSIBLE.
UPSTREAM RAOBS AT 00Z LAST NIGHT, AND 850-MB MOISTURE ANALYSIS,
REVEALED A CHANNEL OF DRY AIR AND SHALLOWNESS OF THE MOIST BOUNDARY
LAYER FROM THE TEXAS COAST NORTH-NORTHEASTWARD INTO MO -- UPSTREAM
FROM TODAY'S THREAT AREA. HOWEVER, THAT CHANNEL WAS NARROW, PERHAPS
SAMPLED BEST BY THE LCH RAOB AMONG THOSE AVAILABLE AT THIS WRITING
AT 12Z, AND MAY BE CONSTRICTED FURTHER AND SHUNTED EASTWARD ENOUGH
TO NOT BE A MAJOR IMPEDIMENT TO CONVECTION, AMID THE SYNOPTIC MASS
RESPONSE TO THE APPROACHING TROUGH. STILL, THIS UNCERTAINTY KEEPS
THE RANGE OF REASONABLE DEVELOPMENT SCENARIOS TOO LARGE TO DO MUCH
WITH THE OUTLOOK AS IT STANDS, GIVEN A VERY FAVORABLE OVERALL
MESO-ALPHA-SCALE SETUP AS DISCUSSED ABOVE.
..OZARKS TO ARKLATEX AND CENTRAL TX
ISOLATED WARM-SECTOR OR DRYLINE THUNDERSTORMS MAY DEVELOP BEFORE
DARK, WHICH COULD BECOME SUPERCELLS WITH ALL SEVERE HAZARDS POSSIBLE
IF THEY CAN BE SUSTAINED INTO AN INCREASINGLY MOIST BOUNDARY LAYER
WITH EASTWARD EXTENT. HOWEVER, THE GREATER SEVERE THREAT SHOULD
DEVELOP THIS EVENING INTO TONIGHT, AS DEEP-LAYER LIFT AND THE LLJ
EACH INCREASE, ALONG WITH HODOGRAPH SIZE AND LOW-LEVEL MOISTURE.
THE COMBINATION OF THOSE FACTORS WILL EXPAND THE CAPE/SHEAR
PARAMETER SPACE TO FAVOR LONG-LIVED SUPERCELLS WITH A THREAT FOR
SIGNIFICANT (EF2+ TORNADOES) AT NIGHT, ALONG WITH DAMAGING HAIL AND
ISOLATED SEVERE GUSTS. SURVIVING DIURNAL AND/OR MORE NEWLY
DEVELOPED EVENING CONVECTION COULD ENCOUNTER 2500-3500 J/KG MLCAPE,
LLJ-ENLARGED HODOGRAPHS WITH EFFECTIVE SRH 300-500 J/KG, AND 1/2-KM
SRH NEARLY THAT LARGE.
COVERAGE OF PREFRONTAL/PRE-DRYLINE CONVECTION ALSO IS UNCERTAIN OVER
THIS AREA BECAUSE OF THE STRONG EML SAMPLED UPSTREAM THIS MORNING BY
DRT AND FWD RAOBS. STILL, ASSOCIATED MLCINH SHOULD HOLD STEADY OR
PERHAPS EVEN DIMINISH FOR A FEW HOURS THIS EVENING AS BOUNDARY-LAYER
THETA-E INCREASES (WITH UPPER 60S F SURFACE DEWPOINTS LIKELY). AS
THE FRONT/DRYLINE COMBINATION IMPINGES ON THE REGION OVERNIGHT,
THUNDERSTORM COVERAGE SHOULD INCREASE ALONG THE ASSOCIATED CORRIDOR
OF MAXIMIZED LIFT, WITH ALL SEVERE HAZARDS POSSIBLE.
..EDWARDS/SMITH.. 04/04/2023
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 AM CDT TUE APR 04 2023
VALID 041300Z - 051200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
EASTERN IOWA...NORTHWESTERN ILLINOIS...EXTREME SOUTHWESTERN
WISCONSIN...NORTHEASTERN AND SOUTHERN MISSOURI...ARKANSAS...AND
EXTREME EASTERN OKLAHOMA...
..SUMMARY
TORNADOES, SEVERE THUNDERSTORM GUSTS AND LARGE HAIL ARE POSSIBLE
TODAY AND TONIGHT FROM THE UPPER GREAT LAKES TO CENTRAL TEXAS.
POTENTIAL FOR UNUSUALLY STRONG TORNADOES IS FOCUSED TODAY OVER PARTS
OF THE MID/UPPER MISSISSIPPI VALLEY, AND TONIGHT OVER PARTS OF THE
OZARKS TO THE ARKLATEX REGION.
..SYNOPSIS
THE DOMINANT UPPER-TROPOSPHERIC FEATURE FOR THIS FORECAST WILL BE A
SYNOPTIC-SCALE TROUGH AND BROAD SWATH OF ASSOCIATED CYCLONIC FLOW
OVER THE WESTERN CONUS. MOISTURE-CHANNEL IMAGERY INDICATES THAT A
CYCLONE ALOFT IS FORMING ACROSS THE UINTA MOUNTAINS/FLAMING GORGE
REGION OF UT/WY, ALONG THE TROUGH EXTENDING SOUTHWESTWARD OVER THE
LOWER COLORADO RIVER VALLEY AND NORTHERN/CENTRAL BAJA. THE 500-MB
LOW SHOULD MIGRATE/REDEVELOP NORTHEASTWARD TO THE BLACK HILLS BY
00Z, WITH TROUGH ACROSS EASTERN CO, NORTHERN/WESTERN NM, AND
NORTHWESTERN MX. BY 12Z, THE LOW SHOULD REACH EASTERN ND, WITH
TROUGH ACROSS CENTRAL NE, WESTERN KS, AND CENTRAL/SOUTHWESTERN NM.
THE ASSOCIATED SURFACE LOW WAS ANALYZED AT 11Z BETWEEN SLN-GBD, WITH
ANOTHER LOW OVER SOUTHEASTERN CO, AND A QUASISTATIONARY FRONT
CONNECTING THEM. A WARM FRONT EXTENDED EASTWARD FROM THE KS LOW
OVER CENTRAL MO, SOUTHERN IL AND WEST-CENTRAL KY. A DRYLINE WAS
DRAWN FROM THE SAME LOW SOUTH-SOUTHWESTWARD OVER WESTERN OK,
NORTHWEST/WEST-CENTRAL TX, AND NORTHERN COAHUILA. THE KS LOW SHOULD
SHIFT NORTHEASTWARD TO WEST-CENTRAL IA BY 00Z, WITH COLD FRONT
ACROSS EXTREME SOUTHEASTERN NE TO CENTRAL KS. FROM THERE, TWO
BRANCHES OF THE COLD FRONT WILL BECOME APPARENT: AN ARCTIC BOUNDARY
ARCHING ACROSS WESTERN KS TO CENTRAL CO, AND A PACIFIC FRONT ACROSS
THE TX PANHANDLE TO FAR WEST TX.
THE DRYLINE SHOULD MIX EASTWARD DURING THE DAY AND REACH
NORTHWESTERN MO, EASTERN KS, EAST-CENTRAL OK, NORTH-CENTRAL TX, TO
THE RIO GRANDE VALLEY BETWEEN DRT-LRD. THE WARM FRONT SHOULD EXTEND
FROM THE LOW ACROSS EASTERN IA, NORTHERN PARTS OF IL/IN, AND
WESTERN/CENTRAL OH. OVERNIGHT, THE PACIFIC FRONT WILL OVERTAKE (BY
THEN) THE QUASISTATIONARY TO SLOWLY RETREATING DRYLINE FROM
NORTH-SOUTH, SUCH THAT BY 12Z, THE COMBINED BOUNDARY WILL EXTEND
FROM A LOW OVER NORTHWESTERN WI ACROSS EASTERN IA, SOUTHWESTERN MO,
NORTHWESTERN AR, AND ACROSS NORTHEAST THROUGH SOUTH-CENTRAL TX TO
NEAR LRD. THE WARM FRONT, AT THAT TIME, SHOULD EXTEND ACROSS
CENTRAL WI, SOUTHERN LOWER MI, AND NORTHERN OH.
A VAST AREA OF AT LEAST MARGINAL SEVERE POTENTIAL IS EVIDENT FROM
THE UPPER GREAT LAKES NORTH OF THE WARM FRONT -- WHERE HAIL FROM
ELEVATED THUNDERSTORMS WILL BE THE MAIN CONCERN -- TO PORTIONS OF
CENTRAL/EAST TX TONIGHT AS CONVECTION GROWS NEAR THE COLD FRONT AND
POSES MAINLY A WIND/HAIL THREAT. TWO RELATIVE CONCENTRATIONS OF
PARTICULARLY INTENSE AND DESTRUCTIVE TORNADO POTENTIAL ARE APPARENT,
BUT STILL WITH ENOUGH UNCERTAINTIES ATTACHED TO PRECLUDE
UNCONDITIONAL CATEGORICAL UPGRADE(S) AT THIS OUTLOOK CYCLE.
..MID/UPPER MISSISSIPPI VALLEY REGION, UPPER GREAT LAKES
MORNING CONVECTION NORTH OF THE WARM FRONT WILL ROOTED IN A
FAVORABLY UNSTABLE, ELEVATED INFLOW LAYER AMID FAVORABLE DEEP SHEAR,
AND WILL POSE AN ISOLATED LARGE-HAIL THREAT. EPISODES OF ADDITIONAL
THUNDERSTORMS (ALSO OFFERING SEVERE HAIL) ARE POSSIBLE THROUGH THIS
EVENING IN THIS REGIME.
THE MAIN CONCERN, HOWEVER, WILL BE THIS AFTERNOON INTO EVENING EAST
AND SOUTHEAST OF THE SURFACE LOW, FROM THE WARM FRONT SOUTHWARD
100-200 NM INTO THE WARM SECTOR, IN AND NEAR THE "MODERATE" AREA.
AT LEAST ISOLATED SUPERCELLS WILL BE POSSIBLE, WITH POTENTIAL FOR
STRONG TO VIOLENT TORNADOES, VERY LARGE HAIL, AND LOCALLY SEVERE
GUSTS. A "MIDDLE GROUND" OR CONSENSUS SCENARIO SUGGESTS THAT, ONCE
THICKER LOW-CLOUD COVER ERODES/ADVECTS PAST THE AREA THIS AFTERNOON,
A FEW SUPERCELLS FORM IN AND CROSS A WARM SECTOR CHARACTERIZED BY
LARGE HODOGRAPHS, STRONG DEEP SHEAR, AND CLIMATOLOGICALLY RARE
BUOYANCY, THEN CROSS A VERY FAVORABLE WARM-FRONTAL ZONE. MLCAPE OF
2500-3500 J/KG IS POSSIBLE BENEATH 7.5-8 DEG C/KM MIDLEVEL LAPSE
RATES AND SURFACE DEWPOINTS AT LEAST IN THE MID 60S F. ISALLOBARIC
FORCING AND RELATED BACKED FLOW IN THE WARM SECTOR, WITHIN A COUPLE
DEGREES OF THE LATITUDE OF THE LOW, SHOULD YIELD ENLARGED LOW-LEVEL
HODOGRAPHS, WITH EFFECTIVE SRH OF 300-500 J/KG, EXCEEDING 600 J/KG
ALONG THE WARM FRONT, AND 60-70 KT EFFECTIVE-SHEAR MAGNITUDES.
OPTIMAL VALUES OF BOTH CAPE AND SHEAR MAY BE SOMEWHAT HIGHER IF THE
MOST AGGRESSIVE PROGS VERIFY, AND SHOULD BE VERY STRONG ALONG THE
WARM FRONT.
THE MAIN UNCERTAINTY INVOLVES WARM-SECTOR STORM COVERAGE AND
MATURATION TIME BEFORE CROSSING TOO DEEP INTO THE WARM-FRONTAL ZONE
TO REMAIN SURFACE-BASED. A BIG INFLUENCE ON THIS POTENTIAL WILL BE
THE EXTENT AND MAGNITUDE OF MOISTURE DEFICIT RELATED TO VERTICAL
MIXING. MODELS ARE FOLLOWING THEIR USUAL BIASES IN THIS REGARD --
BUT TO SOMEWHAT OF AN EXTREME -- WITH (FOR EXAMPLE) WRF-BASED PROGS
LIKE THE NAM, SREF MEMBERS AND SOME HREF MEMBERS BEING MORE COOL AND
MOIST UNDER AN EML, BUT ULTIMATELY DEVELOPING GREATER DENSITY OF
STORMS FARTHER SOUTH (WITH MORE MATURATION ROOM) IN THE WARM SECTOR
AS HEATING ERODES MLCINH. MEANWHILE RAP-BASED PROGS (INCLUDING
HRRR) DEVELOP LESS ACTIVITY, WITH A DEEP, WELL-MIXED BOUNDARY LAYER
MORE SUITED TOWARD WIND POTENTIAL EVIDENT IN THEIR FORECAST
SOUNDINGS. IF THE EML REMAINS STRONG THROUGH THE AFTERNOON, THE
DEEP-MIXING SCENARIO IS LOW-PROBABILITY, BUT LIFT IN THE WARM SECTOR
ALSO MAY BE RESTRICTED. A CORRIDOR OF FRONTAL CONVECTION ALSO
SHOULD DEVELOP FROM LATE AFTERNOON INTO TONIGHT FROM CENTRAL IA TO
EASTERN KS, MOVING EASTWARD. THIS ACTIVITY MAY INCLUDE EARLY-STAGE
SUPERCELLS WITH ALL SEVERE HAZARDS POSSIBLE, BUT EVOLVING TO
WIND-DOMINANT QLCS MODE WITH A FEW TORNADOES ALSO POSSIBLE.
UPSTREAM RAOBS AT 00Z LAST NIGHT, AND 850-MB MOISTURE ANALYSIS,
REVEALED A CHANNEL OF DRY AIR AND SHALLOWNESS OF THE MOIST BOUNDARY
LAYER FROM THE TEXAS COAST NORTH-NORTHEASTWARD INTO MO -- UPSTREAM
FROM TODAY'S THREAT AREA. HOWEVER, THAT CHANNEL WAS NARROW, PERHAPS
SAMPLED BEST BY THE LCH RAOB AMONG THOSE AVAILABLE AT THIS WRITING
AT 12Z, AND MAY BE CONSTRICTED FURTHER AND SHUNTED EASTWARD ENOUGH
TO NOT BE A MAJOR IMPEDIMENT TO CONVECTION, AMID THE SYNOPTIC MASS
RESPONSE TO THE APPROACHING TROUGH. STILL, THIS UNCERTAINTY KEEPS
THE RANGE OF REASONABLE DEVELOPMENT SCENARIOS TOO LARGE TO DO MUCH
WITH THE OUTLOOK AS IT STANDS, GIVEN A VERY FAVORABLE OVERALL
MESO-ALPHA-SCALE SETUP AS DISCUSSED ABOVE.
..OZARKS TO ARKLATEX AND CENTRAL TX
ISOLATED WARM-SECTOR OR DRYLINE THUNDERSTORMS MAY DEVELOP BEFORE
DARK, WHICH COULD BECOME SUPERCELLS WITH ALL SEVERE HAZARDS POSSIBLE
IF THEY CAN BE SUSTAINED INTO AN INCREASINGLY MOIST BOUNDARY LAYER
WITH EASTWARD EXTENT. HOWEVER, THE GREATER SEVERE THREAT SHOULD
DEVELOP THIS EVENING INTO TONIGHT, AS DEEP-LAYER LIFT AND THE LLJ
EACH INCREASE, ALONG WITH HODOGRAPH SIZE AND LOW-LEVEL MOISTURE.
THE COMBINATION OF THOSE FACTORS WILL EXPAND THE CAPE/SHEAR
PARAMETER SPACE TO FAVOR LONG-LIVED SUPERCELLS WITH A THREAT FOR
SIGNIFICANT (EF2+ TORNADOES) AT NIGHT, ALONG WITH DAMAGING HAIL AND
ISOLATED SEVERE GUSTS. SURVIVING DIURNAL AND/OR MORE NEWLY
DEVELOPED EVENING CONVECTION COULD ENCOUNTER 2500-3500 J/KG MLCAPE,
LLJ-ENLARGED HODOGRAPHS WITH EFFECTIVE SRH 300-500 J/KG, AND 1/2-KM
SRH NEARLY THAT LARGE.
COVERAGE OF PREFRONTAL/PRE-DRYLINE CONVECTION ALSO IS UNCERTAIN OVER
THIS AREA BECAUSE OF THE STRONG EML SAMPLED UPSTREAM THIS MORNING BY
DRT AND FWD RAOBS. STILL, ASSOCIATED MLCINH SHOULD HOLD STEADY OR
PERHAPS EVEN DIMINISH FOR A FEW HOURS THIS EVENING AS BOUNDARY-LAYER
THETA-E INCREASES (WITH UPPER 60S F SURFACE DEWPOINTS LIKELY). AS
THE FRONT/DRYLINE COMBINATION IMPINGES ON THE REGION OVERNIGHT,
THUNDERSTORM COVERAGE SHOULD INCREASE ALONG THE ASSOCIATED CORRIDOR
OF MAXIMIZED LIFT, WITH ALL SEVERE HAZARDS POSSIBLE.
..EDWARDS/SMITH.. 04/04/2023
