YUP LOOKS LIKE MORE AND MORE INSTABILITY SHIFTING EAST EACH RUN
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Severe Severe Weather Potential February 23rd
- Thread starter Darklordsuperstorm
- Start date
From James Spann
Sent from my Pixel 2 using Tapatalk
Sent from my Pixel 2 using Tapatalk
Snowflowxxl
Member
Crazy Dew Points for this time of year.
VERY CRAZY FOR THIS TIME OF YEAR AND IT MAY GET CRAZIER BE4 THIS GETS STARTED
Snowflowxxl
Member
HRRR hasn't really changed its tune all day, showing a big threat. Reed Timmer also posted on Instagram recently calling for a Outbreak from 2-11pm tomorrow.
YOU GOT HIS POST HANDY
Snowflowxxl
Member
IF TRENDS KEEP GOING LIKE THEY ARE I WOULD SUSPECT THE "PINK" AREA TO SHIFT FURTHER EAST
Nam 3km is very interesting, that’s for sure, has what looks like some Elevated mixed layer type action here, allowing lapses to be nearly dry adiabatic, 7.7 C ML lapse rate is pretty steep, You can see that CAP aswell, also those cloud bases are gonna be very low, thing about this event is that wind energy, it’s very strong 
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Snowflowxxl
Member
MODERATE RISK!
Big pause tho, that’s alot of early morning convection, typically with that CAPE is much less realized than thought in setups, if a moderate risk was to bust, it would be because of this 
Snowflowxxl
Member
I want to drive to Tupelo in the morning but I just don't know. Guess it will be a game time decision. Don't get too many opportunities like this on the weekend to chase.
This gives me chills, if you live in those areas with the moderate/enhanced/slight, please be careful out there and be weather aware, this gives me chills, just hope that early morning convection ruins instability
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTHERN MISSISSIPPI...SOUTHWEST TENNESSEE AND FAR NORTHWEST
ALABAMA...
...SUMMARY...
Scattered severe thunderstorms are expected to develop today from
the Arklatex region and lower to mid Mississippi Valley eastward
into the Tennessee and Ohio Valleys. Tornadoes, wind damage and
isolated large hail will be possible across much of the area.
...Significant tornado and wind damage event expected across parts
of the lower to mid Mississippi and Tennessee Valleys today...
...Arklatex/Lower to Mid Mississippi Valley/Tennessee and Ohio
Valleys...
A well organized negatively-tilted upper-level trough will move
across the southern Plains today as a 90 to 100 kt mid-level jet
moves through the base of the trough. At the surface, a low will
gradually deepen and move northeastward across the central Plains
into the lower Missouri Valley. A surface trough is forecast to
extend southward into the lower Mississippi Valley with a moist
airmass located across the region. Surface dewpoints in the upper
60s and lower 70s F will overspread northern Louisiana, southeast
Arkansas and most of Mississippi by midday. At the start of the
period, a cluster of thunderstorms should be ongoing from northern
Mississippi into western and middle Tennessee. The stronger storms
embedded in the cluster may have an isolated severe threat. This
activity is forecast to move northeastward away the moderate risk
area allowing for the moist sector to warm up late this morning. In
response, a corridor of moderate instability is expected to be in
place by midday from northeast Louisiana into far southeast Arkansas
and western Tennessee. As large-scale ascent increases ahead of the
southern Plains upper-level trough, thunderstorms are forecast to
develop during the morning along the surface trough in the Arklatex
with this convection moving northeastward into southeastern Arkansas
by midday. More isolated thunderstorms will be possible across the
moist sector from northern Louisiana into north-central Mississippi.
During the early to mid afternoon, convective coverage should
increase with scattered thunderstorms moving east-northeastward
across the Enhanced and Moderate Risk areas.
RAP forecast soundings across the Moderate Risk area from
north-central Mississippi into southwest Tennessee at 21Z show
moderate instability and impressive kinematic profiles. MLCAPE is
forecast to be from 1000 to 1200 J/kg with 0-6 km shear in the 50 to
55 kt range. This will support supercell formation with cells that
remain discrete. In addition, hodographs are long and looped with
0-3 km storm relative helicity values in the 350 to 450 m2/s2 range.
This low-level shear environment will be favorable for tornadoes. A
potential for long-track significant tornadoes will exist across the
Moderate Risk area from late this morning through much of the
afternoon. Wind damage and isolated large hail will also be possible
with supercells. A squall-line is also expected to develop and move
across the Enhanced and Moderate risk areas during the late
afternoon and early evening. Wind damage, isolated large hail and a
few tornadoes will also be possible with the stronger thunderstorms
embedded in the line. This squall-line with wind damage potential
should move across middle Tennessee and north-central Alabama during
the evening.
Further north across the Ohio Valley, scattered thunderstorms are
forecast to move northeastward into western Kentucky and southern
Indiana during the afternoon. Forecast soundings at 21Z for Paducah
show MLCAPE near 800 J/kg with 0-6 km shear of 65 kt. This combined
with strong low-level shear will be sufficient for severe storms
capable of producing tornadoes and wind damage. Most of the severe
convection should remain south of the Ohio River. Due to the weaker
instability in the Ohio Valley, severe coverage is expected to be
less.
Sorry if this is so long but just wanted to put this here
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTHERN MISSISSIPPI...SOUTHWEST TENNESSEE AND FAR NORTHWEST
ALABAMA...
...SUMMARY...
Scattered severe thunderstorms are expected to develop today from
the Arklatex region and lower to mid Mississippi Valley eastward
into the Tennessee and Ohio Valleys. Tornadoes, wind damage and
isolated large hail will be possible across much of the area.
...Significant tornado and wind damage event expected across parts
of the lower to mid Mississippi and Tennessee Valleys today...
...Arklatex/Lower to Mid Mississippi Valley/Tennessee and Ohio
Valleys...
A well organized negatively-tilted upper-level trough will move
across the southern Plains today as a 90 to 100 kt mid-level jet
moves through the base of the trough. At the surface, a low will
gradually deepen and move northeastward across the central Plains
into the lower Missouri Valley. A surface trough is forecast to
extend southward into the lower Mississippi Valley with a moist
airmass located across the region. Surface dewpoints in the upper
60s and lower 70s F will overspread northern Louisiana, southeast
Arkansas and most of Mississippi by midday. At the start of the
period, a cluster of thunderstorms should be ongoing from northern
Mississippi into western and middle Tennessee. The stronger storms
embedded in the cluster may have an isolated severe threat. This
activity is forecast to move northeastward away the moderate risk
area allowing for the moist sector to warm up late this morning. In
response, a corridor of moderate instability is expected to be in
place by midday from northeast Louisiana into far southeast Arkansas
and western Tennessee. As large-scale ascent increases ahead of the
southern Plains upper-level trough, thunderstorms are forecast to
develop during the morning along the surface trough in the Arklatex
with this convection moving northeastward into southeastern Arkansas
by midday. More isolated thunderstorms will be possible across the
moist sector from northern Louisiana into north-central Mississippi.
During the early to mid afternoon, convective coverage should
increase with scattered thunderstorms moving east-northeastward
across the Enhanced and Moderate Risk areas.
RAP forecast soundings across the Moderate Risk area from
north-central Mississippi into southwest Tennessee at 21Z show
moderate instability and impressive kinematic profiles. MLCAPE is
forecast to be from 1000 to 1200 J/kg with 0-6 km shear in the 50 to
55 kt range. This will support supercell formation with cells that
remain discrete. In addition, hodographs are long and looped with
0-3 km storm relative helicity values in the 350 to 450 m2/s2 range.
This low-level shear environment will be favorable for tornadoes. A
potential for long-track significant tornadoes will exist across the
Moderate Risk area from late this morning through much of the
afternoon. Wind damage and isolated large hail will also be possible
with supercells. A squall-line is also expected to develop and move
across the Enhanced and Moderate risk areas during the late
afternoon and early evening. Wind damage, isolated large hail and a
few tornadoes will also be possible with the stronger thunderstorms
embedded in the line. This squall-line with wind damage potential
should move across middle Tennessee and north-central Alabama during
the evening.
Further north across the Ohio Valley, scattered thunderstorms are
forecast to move northeastward into western Kentucky and southern
Indiana during the afternoon. Forecast soundings at 21Z for Paducah
show MLCAPE near 800 J/kg with 0-6 km shear of 65 kt. This combined
with strong low-level shear will be sufficient for severe storms
capable of producing tornadoes and wind damage. Most of the severe
convection should remain south of the Ohio River. Due to the weaker
instability in the Ohio Valley, severe coverage is expected to be
less.
Sorry if this is so long but just wanted to put this here
FROM JAX MS NWS CHATROOM AFD
TONIGHT THROUGH SATURDAY...
MORE THUNDERSTORMS HAVE DEVELOPED AND ARE MOVING UP OVER THE
SOUTHWESTERN PORTIONS OF THE AREA THIS AFTERNOON. WITH LAPSE RATES
OF AROUND 6.0 TO 6.5 C/KM AND DECENT SHEAR, SOME OF THESE STORMS
COULD BECOME STRONG TO SEVERE. A MARGINAL RISK IS IN EFFECT
GENERALLY ALONG AND WEST OF THE I-55 CORRIDOR. THESE STORMS WILL
CONTINUE TO MOVE NORTH INTO THE EVENING HOURS, AND MAY PRODUCE
MORE HEAVY RAINFALL FOR ALREADY SOAKED AREAS ALONG THE HIGHWAY 82
CORRIDOR. THESE STORMS MAY PRODUCE ANOTHER ONE TO THREE INCHES
BEFORE MOVING NORTH OF THE AREA OVERNIGHT. WE SHOULD GET A BREAK
FROM THE HEAVY RAINFALL DURING THE VERY EARLY MORNING HOURS
THROUGH LATE MORNING, BUT SHOWERS WILL CONTINUE TO BE POSSIBLE
THROUGH THIS PERIOD.
A STRONG DISTURBANCE ALOFT WILL APPROACH THE AREA FROM THE WEST
SATURDAY MORNING AND SWEEP ACROSS THE AREA THROUGH SATURDAY EVENING.
ANTICIPATE THUNDERSTORMS TO STRENGTHEN ALONG A PRE-FRONTAL TROUGH BY
LATE MORNING IN NORTHEAST LOUISIANA AND APPROACH THE MISSISSIPPI
RIVER AROUND LUNCHTIME. WITH STRONG SHEAR AND GOOD INSTABILITY,
TORNADOES SOME POSSIBLY STRONG WILL BE POSSIBLE ACROSS AREAS
GENERALLY NORTH OF THE I-20 CORRIDOR. AN ENHANCED RISK IS IN EFFECT
FOR THESE AREAS. FURTHER TO THE SOUTH IN THE SLIGHT RISK AREA, THE
FORCING WILL BE WEAKER, BUT TORNADOES WILL BE ALSO BE POSSIBLE. WITH
LAPSE RATES OF 7.0-7.5 C/KM, LARGE HAIL UP TO THE SIZE OF GOLF BALLS
WILL BE POSSIBLE ACROSS MUCH OF THE AREA. FURTHER TO THE SOUTH
ACROSS THE PINE BELT AREA, THE SEVERE POTENTIAL WILL BE LIMITED DUE
TO STRONG CAPPING. A STRONG STORM OR TWO CANNOT BE RULED OUT THOUGH.
ANOTHER ISSUE ON SATURDAY WILL BE STRONG WINDS, DUE TO A VERY TIGHT
SURFACE PRESSURE GRADIENT OUT AHEAD AND JUST BEHIND THE PRE-FRONTAL
TROUGH. GUSTS FROM 40-49 MPH ARE LIKELY FOR AREAS GENERALLY ALONG
AND NORTH OF THE NATCHES TRACE CORRIDOR. A WIND ADVISORY HAS BEEN
ISSUED FOR THESE AREAS. TEMPERATURES WILL BE VERY WARM SATURDAY WITH
HIGHS IN THE LOW 80S ACROSS MUCH OF THE AREA. /15/
TONIGHT THROUGH SATURDAY...
MORE THUNDERSTORMS HAVE DEVELOPED AND ARE MOVING UP OVER THE
SOUTHWESTERN PORTIONS OF THE AREA THIS AFTERNOON. WITH LAPSE RATES
OF AROUND 6.0 TO 6.5 C/KM AND DECENT SHEAR, SOME OF THESE STORMS
COULD BECOME STRONG TO SEVERE. A MARGINAL RISK IS IN EFFECT
GENERALLY ALONG AND WEST OF THE I-55 CORRIDOR. THESE STORMS WILL
CONTINUE TO MOVE NORTH INTO THE EVENING HOURS, AND MAY PRODUCE
MORE HEAVY RAINFALL FOR ALREADY SOAKED AREAS ALONG THE HIGHWAY 82
CORRIDOR. THESE STORMS MAY PRODUCE ANOTHER ONE TO THREE INCHES
BEFORE MOVING NORTH OF THE AREA OVERNIGHT. WE SHOULD GET A BREAK
FROM THE HEAVY RAINFALL DURING THE VERY EARLY MORNING HOURS
THROUGH LATE MORNING, BUT SHOWERS WILL CONTINUE TO BE POSSIBLE
THROUGH THIS PERIOD.
A STRONG DISTURBANCE ALOFT WILL APPROACH THE AREA FROM THE WEST
SATURDAY MORNING AND SWEEP ACROSS THE AREA THROUGH SATURDAY EVENING.
ANTICIPATE THUNDERSTORMS TO STRENGTHEN ALONG A PRE-FRONTAL TROUGH BY
LATE MORNING IN NORTHEAST LOUISIANA AND APPROACH THE MISSISSIPPI
RIVER AROUND LUNCHTIME. WITH STRONG SHEAR AND GOOD INSTABILITY,
TORNADOES SOME POSSIBLY STRONG WILL BE POSSIBLE ACROSS AREAS
GENERALLY NORTH OF THE I-20 CORRIDOR. AN ENHANCED RISK IS IN EFFECT
FOR THESE AREAS. FURTHER TO THE SOUTH IN THE SLIGHT RISK AREA, THE
FORCING WILL BE WEAKER, BUT TORNADOES WILL BE ALSO BE POSSIBLE. WITH
LAPSE RATES OF 7.0-7.5 C/KM, LARGE HAIL UP TO THE SIZE OF GOLF BALLS
WILL BE POSSIBLE ACROSS MUCH OF THE AREA. FURTHER TO THE SOUTH
ACROSS THE PINE BELT AREA, THE SEVERE POTENTIAL WILL BE LIMITED DUE
TO STRONG CAPPING. A STRONG STORM OR TWO CANNOT BE RULED OUT THOUGH.
ANOTHER ISSUE ON SATURDAY WILL BE STRONG WINDS, DUE TO A VERY TIGHT
SURFACE PRESSURE GRADIENT OUT AHEAD AND JUST BEHIND THE PRE-FRONTAL
TROUGH. GUSTS FROM 40-49 MPH ARE LIKELY FOR AREAS GENERALLY ALONG
AND NORTH OF THE NATCHES TRACE CORRIDOR. A WIND ADVISORY HAS BEEN
ISSUED FOR THESE AREAS. TEMPERATURES WILL BE VERY WARM SATURDAY WITH
HIGHS IN THE LOW 80S ACROSS MUCH OF THE AREA. /15/
AND MEMPHIS NWS
FOR TONIGHT AND TOMORROW...CLOSED UPPER LOW IN SOUTHERN ARIZONA IS
PROGGED BY THE MODELS TO TRACK EAST TO THE TEXAS PANHANDLE BY
TOMORROW MORNING BEFORE TURNING NORTHEAST TO WISCONSIN BY
TOMORROW NIGHT. ON THE SURFACE CYCLOGENESIS ON THE LEE OF THE
ROCKIES WILL INITIATE TONIGHT WITH A 995MB CENTRAL PRESSURE BY
23/12Z. THIS LOW WILL TRACK TOWARDS THE UPPER MIDWEST DURING THE
DAY SWINGING BOTH A WARM FRONT NORTH AND AND A COLD/OCCLUDED
FRONT EAST. THE SHIELD OF RAIN OCCURRING NOW ACROSS THE MIDSOUTH
WELL AHEAD OF THE WARM FRONT SEEN NEAR I-20 WILL GRADUALLY LIFT
NORTH TONIGHT...WITH THUNDER LIKELY AS THE LLJ INCREASES TO
45-50KTS. A FEW SURFACE-BASED STORMS MAY FORM AFTER MIDNIGHT AS
CAPE ALSO INCREASES. ONE OR TWO OF THESE STORMS COULD BRIEFLY
REACH SEVERE LIMITS WITH ROTATION AS WELL. THE WARM FRONT MAY NOT
REACH THE TN/KY BORDER UNTIL NEAR NOON TOMORROW. AT WHICH TIME A
PRE-FRONTAL TROUGH OUT AHEAD OF THE COLD FRONT SHOULD START
SPARKING OFF A BROKEN LINE OF STORMS FROM ROUGHLY LITTLE ROCK
SOUTH TO NORTHERN LOUISIANA. WITH FORECAST SOUNDINGS SHOWING NO
CIN AS FAR NORTH AS I-40 A FEW DISCRETE CELLS MAY ALSO FORM
FARTHER EAST IN THE WARM SECTOR...ESPECIALLY OVER NORTH
MISSISSIPPI WHERE PEEKS OF SUN MAY BE OBSERVED AND THE HIGHEST
SEVERE WEATHER INGREDIENTS WILL CONVERGE. HEIGHT FALLS OF 20-30DM
WILL OVERSPREAD THE MIDSOUTH DURING THE AFTERNOON'S ADVANCING
CONVECTIVE LINE. INTERESTING TO SEE THE NEAR 1500 J/KG CAPE OVER
NORTHEAST MISSISSIPPI OFF THE ECMWF. TYPICALLY THE EURO IS MORE
CONSERVATIVE. THOUGH STRAIGHT LINE WINDS ARE THE MAIN THREAT A
STRONG/SIGNIFICANT TORNADO IS NOW POSSIBLE...ESPECIALLY WITH ANY
DISCRETE CELL. CONVECTION WILL EXIT THE FAR SOUTHEAST COUNTIES
EARLY TOMORROW EVENING WITH GRADUAL CLEARING. NOW FOR THE
FLOODING/RAINFALL. UNFORTUNATELY AN ADDITIONAL 2-4 INCHES MAY FALL
TONIGHT NORTH OF A CLARKSDALE TO CORINTH MS LINE...WITH 1-2
INCHES OVER THE FAR SOUTH AND ACROSS THE FAR NORTH. ONGOING FLOOD
WARNINGS WILL LIKELY BE EXTENDED AND EXPANDED. ALREADY SEEING
LARGE TREES FALLING FROM THE GROUND SATURATION AND 15KTS OF
WIND...SO IT'S NOT TAKING MUCH. GUIDANCE SHOWS SOUTH WINDS
INCREASING TOMORROW TO 15-25MPH WITH HIGHER GUSTS...SO A WIND
ADVISORY FOR MOST OF THE REGION HAS BEEN ISSUED. WINDS WILL
CONTINUE BEHIND THE FRONT TOMORROW EVENING AS THEY VEER WESTERLY.
POWER OUTAGES ARE EXPECTED AND MAY BE PROLONGED.
FOR TONIGHT AND TOMORROW...CLOSED UPPER LOW IN SOUTHERN ARIZONA IS
PROGGED BY THE MODELS TO TRACK EAST TO THE TEXAS PANHANDLE BY
TOMORROW MORNING BEFORE TURNING NORTHEAST TO WISCONSIN BY
TOMORROW NIGHT. ON THE SURFACE CYCLOGENESIS ON THE LEE OF THE
ROCKIES WILL INITIATE TONIGHT WITH A 995MB CENTRAL PRESSURE BY
23/12Z. THIS LOW WILL TRACK TOWARDS THE UPPER MIDWEST DURING THE
DAY SWINGING BOTH A WARM FRONT NORTH AND AND A COLD/OCCLUDED
FRONT EAST. THE SHIELD OF RAIN OCCURRING NOW ACROSS THE MIDSOUTH
WELL AHEAD OF THE WARM FRONT SEEN NEAR I-20 WILL GRADUALLY LIFT
NORTH TONIGHT...WITH THUNDER LIKELY AS THE LLJ INCREASES TO
45-50KTS. A FEW SURFACE-BASED STORMS MAY FORM AFTER MIDNIGHT AS
CAPE ALSO INCREASES. ONE OR TWO OF THESE STORMS COULD BRIEFLY
REACH SEVERE LIMITS WITH ROTATION AS WELL. THE WARM FRONT MAY NOT
REACH THE TN/KY BORDER UNTIL NEAR NOON TOMORROW. AT WHICH TIME A
PRE-FRONTAL TROUGH OUT AHEAD OF THE COLD FRONT SHOULD START
SPARKING OFF A BROKEN LINE OF STORMS FROM ROUGHLY LITTLE ROCK
SOUTH TO NORTHERN LOUISIANA. WITH FORECAST SOUNDINGS SHOWING NO
CIN AS FAR NORTH AS I-40 A FEW DISCRETE CELLS MAY ALSO FORM
FARTHER EAST IN THE WARM SECTOR...ESPECIALLY OVER NORTH
MISSISSIPPI WHERE PEEKS OF SUN MAY BE OBSERVED AND THE HIGHEST
SEVERE WEATHER INGREDIENTS WILL CONVERGE. HEIGHT FALLS OF 20-30DM
WILL OVERSPREAD THE MIDSOUTH DURING THE AFTERNOON'S ADVANCING
CONVECTIVE LINE. INTERESTING TO SEE THE NEAR 1500 J/KG CAPE OVER
NORTHEAST MISSISSIPPI OFF THE ECMWF. TYPICALLY THE EURO IS MORE
CONSERVATIVE. THOUGH STRAIGHT LINE WINDS ARE THE MAIN THREAT A
STRONG/SIGNIFICANT TORNADO IS NOW POSSIBLE...ESPECIALLY WITH ANY
DISCRETE CELL. CONVECTION WILL EXIT THE FAR SOUTHEAST COUNTIES
EARLY TOMORROW EVENING WITH GRADUAL CLEARING. NOW FOR THE
FLOODING/RAINFALL. UNFORTUNATELY AN ADDITIONAL 2-4 INCHES MAY FALL
TONIGHT NORTH OF A CLARKSDALE TO CORINTH MS LINE...WITH 1-2
INCHES OVER THE FAR SOUTH AND ACROSS THE FAR NORTH. ONGOING FLOOD
WARNINGS WILL LIKELY BE EXTENDED AND EXPANDED. ALREADY SEEING
LARGE TREES FALLING FROM THE GROUND SATURATION AND 15KTS OF
WIND...SO IT'S NOT TAKING MUCH. GUIDANCE SHOWS SOUTH WINDS
INCREASING TOMORROW TO 15-25MPH WITH HIGHER GUSTS...SO A WIND
ADVISORY FOR MOST OF THE REGION HAS BEEN ISSUED. WINDS WILL
CONTINUE BEHIND THE FRONT TOMORROW EVENING AS THEY VEER WESTERLY.
POWER OUTAGES ARE EXPECTED AND MAY BE PROLONGED.
LATEST FROM NWS BMX
.SHORT TERM...
TODAY AND TONIGHT.
* A SIGNIFICANT THREAT FOR SEVERE WEATHER EXISTS FOR THE
NORTHWESTERN HALF OF CENTRAL ALABAMA THIS AFTERNOON & OVERNIGHT
PERIOD. THREATS INCLUDE STRONG TORNADOES, DAMAGING WIND GUSTS
UP TO 60 MPH, AND QUARTER-SIZE HAIL.
* GREATEST POTENTIAL FOR ALL MODES OF SEVERE WEATHER WILL PRIMARILY
RESIDE IN AREAS CURRENTLY OUTLINED BY THE ENHANCED RISK (3/5) &
MODERATE (4/5) RISK AREAS NORTHWEST OF INTERSTATE 59.
* A FLOOD WATCH REMAINS IN EFFECT FOR THE NORTHERN HALF OF CENTRAL
ALABAMA THROUGH 6 AM SUNDAY MORNING.
SYNOPSIS...
GOES-EAST WATER VAPOR IMAGERY & RAP MESOANALYSIS DEPICT A DYNAMIC &
STRENGTHENING MID/UPPER-LEVEL DISTURBANCE NEAR THE SOUTHERN ROCKIES.
THIS UPPER TROUGH IS EXHIBITING A NEUTRAL TILT WITH 500MB HEIGHTS
~544 DECAMETERS. RIDGING TO OUR SOUTHWEST HAS ESTABLISHED A BROAD
SWATH OF SOUTHWESTERLY 700-300MB FLOW WITH SOUTHEAST TO SOUTHERLY
SURFACE WINDS (DEPENDING ON LOCATION RELATIVE TO THE SURFACE FRONT).
SOUTH OF THE FRONT, SOUTHERLY SURFACE WINDS ALONG WITH A 30-40 KT
850MB LOW-LEVEL JET HAVE ADVECTED TROPICAL AIR OF CARIBBEAN ORIGINS
(PWS 1.5-1.6" PER 06Z VORTEXSE SOUNDINGS) INTO THE SOUTHERN GULF
COAST STATES. THE WARM FRONT IS NOW APPROACHING TUSCALOOSA
SOUTHEASTWARD TOWARDS EUFAULA AS OF 09Z. SURFACE DEWPOINTS SOUTH
OF THE FRONT HAVE GENERALLY RANGED IN THE MID TO UPPER 60S
OVERNIGHT, THOUGH OBSERVATION STATIONS ACROSS SOUTHERN MS &
SOUTHWESTERN AL HAVE SHOWN DEWPOINTS ~70-72 DEGREES (F) SUPPORTIVE
OF SBCAPE ALREADY UP TO ~1,500 J/KG. AREAS OF MODERATE TO HEAVY
RAINFALL WITH EMBEDDED THUNDERSTORMS HAVE LINGERED TO OUR
NORTHWEST OVERNIGHT ACROSS NORTHERN MS, NORTHERN AL, & SOUTHERN TN
WHERE A DANGEROUS FLOODING EVENT IS ONGOING.
DISCUSSION...
THE PRIMARY UPPER-LEVEL FEATURE TO OUR WEST IS PROGGED TO EJECT
NORTHEASTWARD INTO THE GREAT PLAINS TODAY & PHASE WITH THE SUB-
TROPICAL JET. A STRONG H5 JET STREAK WITH WINDS IN EXCESS OF 100 KTS
IS EXPECTED TO DEVELOP AT THE BASE OF THE TROUGH NORTH OF THE
ARKLATEX REGION. DESPITE NOT HAVING THE BEST JET STREAK ORIENTATION,
HEIGHT FALLS & DEEP-LAYER FORCING ALONG WITH AN EASTWARD MOVING
SURFACE FRONT/DRY LINE FEATURE WILL PROVIDE FOCUS FOR DOWNSTREAM
CONVECTIVE INITIATION ACROSS THE LOWER MISSISSIPPI RIVER VALLEY
(MRV). SEVERE CONVECTIVE WEATHER IS EXPECTED ACROSS THIS REGION UP
TO AN AREA GENERALLY WHERE THE WARM FRONT/TRIPLE POINT SETS UP NEAR
WESTERN KY/TN. AFTERNOON BOUNDARY LAYER DESTABILIZATION WITH SURFACE
DEWPOINTS IN THE UPPER 60S TO NEAR 70 IS EXPECTED TO INCREASE SBCAPE
VALUES TO ~750-1,500 J/KG, ESPECIALLY ACROSS THE WESTERN & SOUTHERN
PORTIONS OF OUR FORECAST AREA WHERE TEMPERATURES IN THE UPPER 70S &
LOWER 80S ARE POSSIBLE GIVEN SUFFICIENT INSOLATION & MIXING. WITH
DEEP-LAYER SHEAR VALUES (50-60 KTS 0-6KM BULK SHEAR, 400-500 0-3KM
SRH) & THEIR ORIENTATION TO THE FRONT/TROUGH, ANY STRONGER
STORMS/UPDRAFTS WILL LIKELY BECOME SUPERCELLULAR ACROSS MISSISSIPPI
& EVENTUALLY INTO OUR WESTERN & NORTHWESTERN COUNTIES IN THE LATE
AFTERNOON/EVENING. LOW LCL HEIGHTS (400-700 METERS) & LOW-LEVEL WIND
SHEAR (300-400 0-1KM SRH) W/ BROAD HODOGRAPH CURVATURE SUGGEST ANY
ORGANIZED THUNDERSTORMS/SUPERCELLS WILL CARRY A SIGNIFICANT TORNADO
THREAT WHETHER THEY REMAIN DISCRETE CELLS OR MANAGE TO CONGEAL INTO
A SQUALL LINE OR QLCS. FORECAST SOUNDINGS ALSO SUGGEST MORE ROBUST
CAPE IN THE HAIL GROWTH ZONE, SO STRONGER STORMS WILL ALSO CARRY AN
ISOLATED SEVERE HAIL THREAT.
CURRENTLY FORECAST TIMING PROGS THE THREAT FOR SEVERE WEATHER TO
ENTER THE NORTHWEST AROUND 5 PM AT WHICH TIME SEVERE PARAMETERS WILL
BE HIGH. TRENDS AFTER SUNSET POINT TO A GENERAL WEAKENING OF
INSTABILITY AS WE LOSE DIABATIC HEATING, THOUGH THE TROPICAL AIRMASS
WILL STILL SUPPORT STRONG UPDRAFTS WITH SUFFICIENT SBCAPE VALUES
~500-1,000 J/KG. AS THIS SYSTEM MOVES EASTWARD/SOUTHEASTWARD
TOWARDS THE I-59 CORRIDOR (TRANSITION TO SLIGHT RISK AREA) ITS
ORIENTATION WILL BECOME MORE PARALLEL TO SHEAR VECTORS. THIS
EVENTUALLY FAVORS A DIMINISHING TORNADO THREAT, THOUGH EXPECT A
TORNADO THREAT THROUGH MIDNIGHT & EARLY MORNING. DAMAGING WINDS WILL
ALSO CARRY A THREAT INTO THIS REGION IF ANY STRONGER DOWNDRAFTS CAN
TRANSPORT LLJ ENERGY TO THE SURFACE. LOSS OF DEEP-LAYER FORCING &
INSTABILITY SIGNAL MORE WEAKENING AS THE SYSTEM APPROACHES THE I-85
CORRIDOR ~3 AM SUNDAY WHERE A TRANSITION TO SUB-SEVERE CONDITIONS IS
EXPECTED. SCATTERED PRE-FRONTAL SHOWERS & THUNDERSTORMS ARE ALSO
EXPECTED THROUGHOUT THE MORNING & EARLY AFTERNOON, THOUGH LATEST
FORECAST SOUNDINGS SUGGEST AN ELEVATED MIXED LAYER & ASSOCIATED
INVERSION ALOFT WHICH WOULD HELP TO LIMIT THIS ACTIVITY.
HERE IS THE HWO FROM BMX
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.
.DAY ONE...THROUGH TONIGHT.
SEVERE THUNDERSTORMS ARE LIKELY TODAY. HAZARDOUS THREATS INCLUDE
STRONG TORNADOES, DAMAGING WINDS, AND HAIL. AT THIS TIME, THE THREAT
APPEARS TO BEGIN AROUND 5 PM IN THE WEST AND MAY CONTINUE THROUGH 3
AM IN THE EAST. THESE THREATS ARE GREATEST NEAR AND NORTH OF A LINE
FROM DEMOPOLIS TO CALERA TO CENTRE. OUTSIDE THESE AREAS, SOME
THUNDERSTORMS CAN BE EXPECTED BUT SHOULD BE WEAKER IN INTENSITY.
AREAS OF LOCALLY HEAVY RAINFALL WILL REMAIN POSSIBLE TODAY AND
TONIGHT. THEREFORE, THE FLOOD POTENTIAL REMAINS HIGH. ANY HEAVY RAIN
ON ALREADY SATURATED GROUNDS WILL ONLY ENHANCE THE FLOOD POTENTIAL.
THE MAIN FLOOD THREAT AREA WILL BE NEAR AND NORTH OF AN ALICEVILLE
TO CALERA TO WEDOWEE LINE. ELSEWHERE, MINOR FLOODING IS POSSIBLE IF
SHOWERS AND STORMS MOVE OVER THE SAME AREAS MORE THAN ONCE.
CENTRAL ALABAMA RIVERS WILL EXPERIENCE HEFTY RISES THE NEXT SEVERAL
DAYS. RIVER STAGES WILL REACH INTO THE MINOR AND MODERATE FLOOD
LEVELS. CHECK THE LATEST RIVER FLOOD PRODUCTS FOR SPECIFIC
INFORMATION.
.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.
CENTRAL ALABAMA RIVERS WILL CONTINUE TO EXPERIENCE HEFTY RISES THE
NEXT SEVERAL DAYS. RIVER STAGES WILL REACH INTO THE MINOR AND
MODERATE FLOOD LEVELS. CHECK THE LATEST RIVER FLOOD PRODUCTS FOR
SPECIFIC INFORMATION.
.SPOTTER INFORMATION STATEMENT...
ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE NEEDED
THROUGH SUNDAY.
.SHORT TERM...
TODAY AND TONIGHT.
* A SIGNIFICANT THREAT FOR SEVERE WEATHER EXISTS FOR THE
NORTHWESTERN HALF OF CENTRAL ALABAMA THIS AFTERNOON & OVERNIGHT
PERIOD. THREATS INCLUDE STRONG TORNADOES, DAMAGING WIND GUSTS
UP TO 60 MPH, AND QUARTER-SIZE HAIL.
* GREATEST POTENTIAL FOR ALL MODES OF SEVERE WEATHER WILL PRIMARILY
RESIDE IN AREAS CURRENTLY OUTLINED BY THE ENHANCED RISK (3/5) &
MODERATE (4/5) RISK AREAS NORTHWEST OF INTERSTATE 59.
* A FLOOD WATCH REMAINS IN EFFECT FOR THE NORTHERN HALF OF CENTRAL
ALABAMA THROUGH 6 AM SUNDAY MORNING.
SYNOPSIS...
GOES-EAST WATER VAPOR IMAGERY & RAP MESOANALYSIS DEPICT A DYNAMIC &
STRENGTHENING MID/UPPER-LEVEL DISTURBANCE NEAR THE SOUTHERN ROCKIES.
THIS UPPER TROUGH IS EXHIBITING A NEUTRAL TILT WITH 500MB HEIGHTS
~544 DECAMETERS. RIDGING TO OUR SOUTHWEST HAS ESTABLISHED A BROAD
SWATH OF SOUTHWESTERLY 700-300MB FLOW WITH SOUTHEAST TO SOUTHERLY
SURFACE WINDS (DEPENDING ON LOCATION RELATIVE TO THE SURFACE FRONT).
SOUTH OF THE FRONT, SOUTHERLY SURFACE WINDS ALONG WITH A 30-40 KT
850MB LOW-LEVEL JET HAVE ADVECTED TROPICAL AIR OF CARIBBEAN ORIGINS
(PWS 1.5-1.6" PER 06Z VORTEXSE SOUNDINGS) INTO THE SOUTHERN GULF
COAST STATES. THE WARM FRONT IS NOW APPROACHING TUSCALOOSA
SOUTHEASTWARD TOWARDS EUFAULA AS OF 09Z. SURFACE DEWPOINTS SOUTH
OF THE FRONT HAVE GENERALLY RANGED IN THE MID TO UPPER 60S
OVERNIGHT, THOUGH OBSERVATION STATIONS ACROSS SOUTHERN MS &
SOUTHWESTERN AL HAVE SHOWN DEWPOINTS ~70-72 DEGREES (F) SUPPORTIVE
OF SBCAPE ALREADY UP TO ~1,500 J/KG. AREAS OF MODERATE TO HEAVY
RAINFALL WITH EMBEDDED THUNDERSTORMS HAVE LINGERED TO OUR
NORTHWEST OVERNIGHT ACROSS NORTHERN MS, NORTHERN AL, & SOUTHERN TN
WHERE A DANGEROUS FLOODING EVENT IS ONGOING.
DISCUSSION...
THE PRIMARY UPPER-LEVEL FEATURE TO OUR WEST IS PROGGED TO EJECT
NORTHEASTWARD INTO THE GREAT PLAINS TODAY & PHASE WITH THE SUB-
TROPICAL JET. A STRONG H5 JET STREAK WITH WINDS IN EXCESS OF 100 KTS
IS EXPECTED TO DEVELOP AT THE BASE OF THE TROUGH NORTH OF THE
ARKLATEX REGION. DESPITE NOT HAVING THE BEST JET STREAK ORIENTATION,
HEIGHT FALLS & DEEP-LAYER FORCING ALONG WITH AN EASTWARD MOVING
SURFACE FRONT/DRY LINE FEATURE WILL PROVIDE FOCUS FOR DOWNSTREAM
CONVECTIVE INITIATION ACROSS THE LOWER MISSISSIPPI RIVER VALLEY
(MRV). SEVERE CONVECTIVE WEATHER IS EXPECTED ACROSS THIS REGION UP
TO AN AREA GENERALLY WHERE THE WARM FRONT/TRIPLE POINT SETS UP NEAR
WESTERN KY/TN. AFTERNOON BOUNDARY LAYER DESTABILIZATION WITH SURFACE
DEWPOINTS IN THE UPPER 60S TO NEAR 70 IS EXPECTED TO INCREASE SBCAPE
VALUES TO ~750-1,500 J/KG, ESPECIALLY ACROSS THE WESTERN & SOUTHERN
PORTIONS OF OUR FORECAST AREA WHERE TEMPERATURES IN THE UPPER 70S &
LOWER 80S ARE POSSIBLE GIVEN SUFFICIENT INSOLATION & MIXING. WITH
DEEP-LAYER SHEAR VALUES (50-60 KTS 0-6KM BULK SHEAR, 400-500 0-3KM
SRH) & THEIR ORIENTATION TO THE FRONT/TROUGH, ANY STRONGER
STORMS/UPDRAFTS WILL LIKELY BECOME SUPERCELLULAR ACROSS MISSISSIPPI
& EVENTUALLY INTO OUR WESTERN & NORTHWESTERN COUNTIES IN THE LATE
AFTERNOON/EVENING. LOW LCL HEIGHTS (400-700 METERS) & LOW-LEVEL WIND
SHEAR (300-400 0-1KM SRH) W/ BROAD HODOGRAPH CURVATURE SUGGEST ANY
ORGANIZED THUNDERSTORMS/SUPERCELLS WILL CARRY A SIGNIFICANT TORNADO
THREAT WHETHER THEY REMAIN DISCRETE CELLS OR MANAGE TO CONGEAL INTO
A SQUALL LINE OR QLCS. FORECAST SOUNDINGS ALSO SUGGEST MORE ROBUST
CAPE IN THE HAIL GROWTH ZONE, SO STRONGER STORMS WILL ALSO CARRY AN
ISOLATED SEVERE HAIL THREAT.
CURRENTLY FORECAST TIMING PROGS THE THREAT FOR SEVERE WEATHER TO
ENTER THE NORTHWEST AROUND 5 PM AT WHICH TIME SEVERE PARAMETERS WILL
BE HIGH. TRENDS AFTER SUNSET POINT TO A GENERAL WEAKENING OF
INSTABILITY AS WE LOSE DIABATIC HEATING, THOUGH THE TROPICAL AIRMASS
WILL STILL SUPPORT STRONG UPDRAFTS WITH SUFFICIENT SBCAPE VALUES
~500-1,000 J/KG. AS THIS SYSTEM MOVES EASTWARD/SOUTHEASTWARD
TOWARDS THE I-59 CORRIDOR (TRANSITION TO SLIGHT RISK AREA) ITS
ORIENTATION WILL BECOME MORE PARALLEL TO SHEAR VECTORS. THIS
EVENTUALLY FAVORS A DIMINISHING TORNADO THREAT, THOUGH EXPECT A
TORNADO THREAT THROUGH MIDNIGHT & EARLY MORNING. DAMAGING WINDS WILL
ALSO CARRY A THREAT INTO THIS REGION IF ANY STRONGER DOWNDRAFTS CAN
TRANSPORT LLJ ENERGY TO THE SURFACE. LOSS OF DEEP-LAYER FORCING &
INSTABILITY SIGNAL MORE WEAKENING AS THE SYSTEM APPROACHES THE I-85
CORRIDOR ~3 AM SUNDAY WHERE A TRANSITION TO SUB-SEVERE CONDITIONS IS
EXPECTED. SCATTERED PRE-FRONTAL SHOWERS & THUNDERSTORMS ARE ALSO
EXPECTED THROUGHOUT THE MORNING & EARLY AFTERNOON, THOUGH LATEST
FORECAST SOUNDINGS SUGGEST AN ELEVATED MIXED LAYER & ASSOCIATED
INVERSION ALOFT WHICH WOULD HELP TO LIMIT THIS ACTIVITY.
HERE IS THE HWO FROM BMX
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.
.DAY ONE...THROUGH TONIGHT.
SEVERE THUNDERSTORMS ARE LIKELY TODAY. HAZARDOUS THREATS INCLUDE
STRONG TORNADOES, DAMAGING WINDS, AND HAIL. AT THIS TIME, THE THREAT
APPEARS TO BEGIN AROUND 5 PM IN THE WEST AND MAY CONTINUE THROUGH 3
AM IN THE EAST. THESE THREATS ARE GREATEST NEAR AND NORTH OF A LINE
FROM DEMOPOLIS TO CALERA TO CENTRE. OUTSIDE THESE AREAS, SOME
THUNDERSTORMS CAN BE EXPECTED BUT SHOULD BE WEAKER IN INTENSITY.
AREAS OF LOCALLY HEAVY RAINFALL WILL REMAIN POSSIBLE TODAY AND
TONIGHT. THEREFORE, THE FLOOD POTENTIAL REMAINS HIGH. ANY HEAVY RAIN
ON ALREADY SATURATED GROUNDS WILL ONLY ENHANCE THE FLOOD POTENTIAL.
THE MAIN FLOOD THREAT AREA WILL BE NEAR AND NORTH OF AN ALICEVILLE
TO CALERA TO WEDOWEE LINE. ELSEWHERE, MINOR FLOODING IS POSSIBLE IF
SHOWERS AND STORMS MOVE OVER THE SAME AREAS MORE THAN ONCE.
CENTRAL ALABAMA RIVERS WILL EXPERIENCE HEFTY RISES THE NEXT SEVERAL
DAYS. RIVER STAGES WILL REACH INTO THE MINOR AND MODERATE FLOOD
LEVELS. CHECK THE LATEST RIVER FLOOD PRODUCTS FOR SPECIFIC
INFORMATION.
.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.
CENTRAL ALABAMA RIVERS WILL CONTINUE TO EXPERIENCE HEFTY RISES THE
NEXT SEVERAL DAYS. RIVER STAGES WILL REACH INTO THE MINOR AND
MODERATE FLOOD LEVELS. CHECK THE LATEST RIVER FLOOD PRODUCTS FOR
SPECIFIC INFORMATION.
.SPOTTER INFORMATION STATEMENT...
ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE NEEDED
THROUGH SUNDAY.
Last edited:
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
420 AM CST SAT FEB 23 2019
...FOCUS TRANSITIONING TO SEVERE WEATHER POTENTIAL LATER TODAY...
.DISCUSSION...
A SIGNIFICANT SEVERE WEATHER EPISODE IS EXPECTED TO UNFOLD ACROSS
THE REGION TODAY AS A STRONG STORM SYSTEM MOVES THROUGH. A POTENT
NEGATIVELY TILTED SHORTWAVE TROUGH AND ASSOCIATED JET ENERGY WILL
LIFT NORTHEAST FROM THE SOUTHERN PLAINS INTO THE MIDWEST TODAY INTO
TONIGHT. SURFACE CYCLOGENESIS IS UNDERWAY ACROSS THE TEXAS PANHANDLE
WITH A DEEPENING LOW PROGGED TO LIFT THROUGH KANSAS AND INTO NORTH
CENTRAL MISSOURI. A ROBUST WARM SECTOR CONTINUES TO SURGE NORTH THIS
MORNING WITH SURFACE BASED INSTABILITY AND UPPER 60S DEWPOINTS
ALREADY ENCROACHING ON THE HWY 82 CORRIDOR. WIDESPREAD ELEVATED
SHOWER AND THUNDERSTORM ACTIVITY HAS GRADUALLY SHIFTED NORTH DURING
THE EARLY MORNING HOURS AND IS NOW FOCUSED ACROSS FAR NORTHERN
MISSISSIPPI AND INTO TENNESSEE. SCATTERED WARM AIR ADVECTION SHOWERS
WERE ALSO NOTED WITHIN THE OPEN WARM SECTOR AND WILL CONTINUE
THROUGH THE MORNING INTO THE AFTERNOON.
THE MAIN FOCUS WILL QUICKLY SHIFT TO ORGANIZED AND SIGNIFICANT
SEVERE WEATHER FROM ROUGHLY NOON TO 8PM. LATEST SUITE OF HI-RES CAM
GUIDANCE IS IN FAIRLY GOOD AGREEMENT THAT UPSTREAM CONVECTION WILL
DEVELOP BY MID MORNING ACROSS CENTRAL LOUISIANA AND WILL PUSH
THROUGH THE CWA THROUGH THE DAY INTO THE EARLY EVENING HOURS. THIS
CONVECTION WILL RESIDE WITHIN A PREFRONTAL SURFACE TROUGH AHEAD OF A
PSEUDO DRYLINE AS THE ACTUAL COLD FRONT WILL LAG FURTHER NORTHWEST.
LOW-LEVEL MASS RESPONSE TO THE DEEPENING SURFACE CYCLONE WILL HELP
INCREASE LOW-LEVEL WIND FIELDS THAT WILL FOSTER ELONGATED
CYCLONICALLY CURVED HODOGRAPHS. 50-55KTS OF DEEP LAYER SHEAR
ORIENTED OFF THE INITIATING BOUNDARY WILL BE MORE THAN SUFFICIENT
FOR DISCRETE SUPERCELL DEVELOPMENT AS MID-LEVEL HEIGHT FALLS
OVERSPREAD THE AREA. UPPER 60S TO LOW 70S DEWPOINTS WILL SUPPORT
1000-1500 J/KG OF MLCAPE, WITH GREATER INSTABILITY POSSIBLE IF GAPS
IN CLOUD COVER CAN BE REALIZED. THE MOST FAVORABLE PARAMETER SPACE
WILL RESIDE ACROSS THE HWY 82 CORRIDOR WHERE A MODERATE RISK AREA
HAS BEEN INTRODUCED AFTER COLLABORATION WITH SPC AND NEIGHBORING
OFFICES. IT IS ACROSS THIS AREA WHERE TORNADOES, SOME OF WHICH COULD
BE STRONG AND LONG TRACK, WILL BE MOST LIKELY. THE ENHANCED RISK
AREA WAS ALSO EXPANDED SOUTH TO INCLUDE ALL OF THE I-20 CORRIDOR
WHERE DISCRETE SUPERCELLS WILL ALSO BE POSSIBLE. TORNADOES, A FEW OF
WHICH COULD BE STRONG, WILL ALSO BE POSSIBLE ACROSS THIS AREA.
FURTHER SOUTH, TORNADOES WILL ALSO BE POSSIBLE, HOWEVER CONFIDENCE
IN BOTH COVERAGE AND SEVERITY OF STORMS BEGINS TO DECREASE FURTHER
SOUTH OF THE BETTER PARAMETER SPACE AND HEIGHT FALLS. THE LOWEST
CONFIDENCE REMAINS ACROSS THE FAR SOUTHEASTERN PORTION OF THE CWA
WHERE GUIDANCE HAS BEEN LESS IMPRESSIVE WITH CONVECTIVE POTENTIAL.
WILL CONTINUE TO ADVERTISE THIS LOWER THREAT WITH A MARGINAL RISK.
STEEP MID-LEVEL LAPSE RATES OF 7-7.5 C/KM WILL SUPPORT LARGE HAIL UP
TO GOLF BALL SIZE, ESPECIALLY WITH ANY DISCRETE SUPERCELLS THAT ARE
ABLE TO MAINTAIN INTENSE UPDRAFTS. THERE ARE INDICATIONS THAT A
BROKEN QLCS COULD DEVELOP BEHIND THE INITIAL DISCRETE SUPERCELLS. IF
THIS SCENARIO PANS OUT DAMAGING WINDS OF 60-70MPH WILL ALSO BE
POSSIBLE.
NATIONAL WEATHER SERVICE JACKSON MS
420 AM CST SAT FEB 23 2019
...FOCUS TRANSITIONING TO SEVERE WEATHER POTENTIAL LATER TODAY...
.DISCUSSION...
A SIGNIFICANT SEVERE WEATHER EPISODE IS EXPECTED TO UNFOLD ACROSS
THE REGION TODAY AS A STRONG STORM SYSTEM MOVES THROUGH. A POTENT
NEGATIVELY TILTED SHORTWAVE TROUGH AND ASSOCIATED JET ENERGY WILL
LIFT NORTHEAST FROM THE SOUTHERN PLAINS INTO THE MIDWEST TODAY INTO
TONIGHT. SURFACE CYCLOGENESIS IS UNDERWAY ACROSS THE TEXAS PANHANDLE
WITH A DEEPENING LOW PROGGED TO LIFT THROUGH KANSAS AND INTO NORTH
CENTRAL MISSOURI. A ROBUST WARM SECTOR CONTINUES TO SURGE NORTH THIS
MORNING WITH SURFACE BASED INSTABILITY AND UPPER 60S DEWPOINTS
ALREADY ENCROACHING ON THE HWY 82 CORRIDOR. WIDESPREAD ELEVATED
SHOWER AND THUNDERSTORM ACTIVITY HAS GRADUALLY SHIFTED NORTH DURING
THE EARLY MORNING HOURS AND IS NOW FOCUSED ACROSS FAR NORTHERN
MISSISSIPPI AND INTO TENNESSEE. SCATTERED WARM AIR ADVECTION SHOWERS
WERE ALSO NOTED WITHIN THE OPEN WARM SECTOR AND WILL CONTINUE
THROUGH THE MORNING INTO THE AFTERNOON.
THE MAIN FOCUS WILL QUICKLY SHIFT TO ORGANIZED AND SIGNIFICANT
SEVERE WEATHER FROM ROUGHLY NOON TO 8PM. LATEST SUITE OF HI-RES CAM
GUIDANCE IS IN FAIRLY GOOD AGREEMENT THAT UPSTREAM CONVECTION WILL
DEVELOP BY MID MORNING ACROSS CENTRAL LOUISIANA AND WILL PUSH
THROUGH THE CWA THROUGH THE DAY INTO THE EARLY EVENING HOURS. THIS
CONVECTION WILL RESIDE WITHIN A PREFRONTAL SURFACE TROUGH AHEAD OF A
PSEUDO DRYLINE AS THE ACTUAL COLD FRONT WILL LAG FURTHER NORTHWEST.
LOW-LEVEL MASS RESPONSE TO THE DEEPENING SURFACE CYCLONE WILL HELP
INCREASE LOW-LEVEL WIND FIELDS THAT WILL FOSTER ELONGATED
CYCLONICALLY CURVED HODOGRAPHS. 50-55KTS OF DEEP LAYER SHEAR
ORIENTED OFF THE INITIATING BOUNDARY WILL BE MORE THAN SUFFICIENT
FOR DISCRETE SUPERCELL DEVELOPMENT AS MID-LEVEL HEIGHT FALLS
OVERSPREAD THE AREA. UPPER 60S TO LOW 70S DEWPOINTS WILL SUPPORT
1000-1500 J/KG OF MLCAPE, WITH GREATER INSTABILITY POSSIBLE IF GAPS
IN CLOUD COVER CAN BE REALIZED. THE MOST FAVORABLE PARAMETER SPACE
WILL RESIDE ACROSS THE HWY 82 CORRIDOR WHERE A MODERATE RISK AREA
HAS BEEN INTRODUCED AFTER COLLABORATION WITH SPC AND NEIGHBORING
OFFICES. IT IS ACROSS THIS AREA WHERE TORNADOES, SOME OF WHICH COULD
BE STRONG AND LONG TRACK, WILL BE MOST LIKELY. THE ENHANCED RISK
AREA WAS ALSO EXPANDED SOUTH TO INCLUDE ALL OF THE I-20 CORRIDOR
WHERE DISCRETE SUPERCELLS WILL ALSO BE POSSIBLE. TORNADOES, A FEW OF
WHICH COULD BE STRONG, WILL ALSO BE POSSIBLE ACROSS THIS AREA.
FURTHER SOUTH, TORNADOES WILL ALSO BE POSSIBLE, HOWEVER CONFIDENCE
IN BOTH COVERAGE AND SEVERITY OF STORMS BEGINS TO DECREASE FURTHER
SOUTH OF THE BETTER PARAMETER SPACE AND HEIGHT FALLS. THE LOWEST
CONFIDENCE REMAINS ACROSS THE FAR SOUTHEASTERN PORTION OF THE CWA
WHERE GUIDANCE HAS BEEN LESS IMPRESSIVE WITH CONVECTIVE POTENTIAL.
WILL CONTINUE TO ADVERTISE THIS LOWER THREAT WITH A MARGINAL RISK.
STEEP MID-LEVEL LAPSE RATES OF 7-7.5 C/KM WILL SUPPORT LARGE HAIL UP
TO GOLF BALL SIZE, ESPECIALLY WITH ANY DISCRETE SUPERCELLS THAT ARE
ABLE TO MAINTAIN INTENSE UPDRAFTS. THERE ARE INDICATIONS THAT A
BROKEN QLCS COULD DEVELOP BEHIND THE INITIAL DISCRETE SUPERCELLS. IF
THIS SCENARIO PANS OUT DAMAGING WINDS OF 60-70MPH WILL ALSO BE
POSSIBLE.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
441 AM CST SAT FEB 23 2019
.DISCUSSION...
ACTIVE WEATHER DAY FOR THE MIDSOUTH, BEGINNING WITH ONGOING RIVER
AND LOWLAND FLOODING FROM PERSISTENT MODERATE TO HEAVY RAINS. AS
OF 3 AM CST TODAY, SEVEN DAY RAINFALL TOTALS RANGED FROM 6 TO 12
INCHES OVER NORTH MISSISSIPPI. ANY ADDITIONAL RAINFALL TODAY WILL
EXACERBATE OR AT LEAST EXTEND ONGOING FLOODING.
4 AM CST/10Z SURFACE MAP SHOWED A TWO WARM FRONTS. THE NORTHERNMOST
FRONT EXTENDED FROM THE NORTHWEST TIP OF TN DOWN TO THE SOUTH OF
JONESBORO AND NEWPORT, AR. A SECOND, MORE CONSEQUENTIAL MARINE
WARM FRONT EXTENDED EAST-WEST ACROSS CENTRAL MS, WITH DEWPOINTS
SOUTH OF THE FRONT AROUND 70F.
THE MARINE WARM FRONT WILL LIFT INTO THE MIDSOUTH LATER THIS
MORNING. NAM BUFR SOUNDINGS DEPICT LITTLE TO NO INHIBITION TO
SURFACE-BASED CONVECTION DURING THE THE LATE MORNING. THE 06Z 3KM
NAM-NEST MODEL DEPICTS DEVELOPING SURFACE-BASED STORMS ALONG THE
MARINE WARM FRONT, AIDED BY RAPIDLY INCREASING DIFFLUENCE ALOFT
AHEAD OF AN APPROACHING MIDLEVEL DRY SLOT. ALTHOUGH THE
(OCCLUDED) SYNOPTIC SURFACE LOW WILL REMAIN WELL-REMOVED OVER
KS/OK, A WEAKER SECONDARY SURFACE WAVE MAY FORM NEAR THE TRIPLE
POINT WHERE THE MARINE WARM FRONT INTERSECTS A PRE-FRONTAL
PRESSURE TROF. THE IMPLICATIONS OF SUCH A FRONTAL WAVE WOULD BE
INCREASED DIRECTIONAL SHEAR FROM BACKING WINDS OVER NORTH MS BY
LATE MORNING, AND PERHAPS INCREASED TORNADO POTENTIAL.
THE BIGGEST UNCERTAINTY WITH RESPECT TO TORNADO POTENTIAL WILL BE
THE AMOUNT OF RAINFALL NEAR THE NORTHWARD-ADVANCING MARINE WARM
FRONT AND THE EFFECT OF DILUTING BOUNDARIES. MODEL SOUNDINGS SHOW
SURFACE-BASED CONVECTION UNCAPPED FROM THE START, POINTING TOWARD
A GRADUAL INCREASE IN THUNDERSTORM COVERAGE, RATHER THAN A QUIET
PERIOD FOLLOWED BY EXPLOSIVE DEVELOPMENT ALONG WELL-DEFINED
FRONTAL BOUNDARIES. IN ANY CASE, SUFFICIENT CAPE WILL BE IN PLACE
FROM KINEMATIC PROCESSES (INSTABILITY BROUGHT INTO THE AREA),
ALONG WITH ADEQUATE LOW LEVEL HELICITY FOR INCREASED TORNADO
CONCERN BY LATE MORNING, PARTICULARLY SOUTH OF I-40. THE MARINE
WARM FRONT WILL LIFT INTO WEST TN BY EARLY AFTERNOON, ABOUT THE
TIME STORMS INCREASE OVER EAST AR, EVENTUALLY FORMING A SQUALL
LINE. MAIN THREAT WITH THE SQUALL LINE WILL BE DAMAGING WINDS,
BUT A FEW BRIEF TORNADOES WILL ALSO BE POSSIBLE, EMBEDDED IN THE
SQUALL LINE.
THE POTENTIAL DANGER FROM STRAIGHT-LINE THUNDERSTORM WINDS WILL
BE OF PARTICULAR CONCERN TODAY. DUE TO SATURATED SOILS, EVEN SUB-
SEVERE WINDS MAY TOPPLE LARGE TREES, PUTTING NEARBY STRUCTURES
AND VEHICLES AT RISK.
FOLLOWING THE EARLY TO MIDEVENING EXIT OF THE SQUALL LINE, DRY AND
SEASONAL WEATHER WILL PREVAIL ACROSS THE MIDSOUTH THROUGH AT
LEAST TUESDAY OF NEXT WEEK. MEDIUM RANGE MODELS CONTINUE TO SHOW
VARYING RAIN CHANCES DURING THE MID TO LATE WEEK PERIODS UNDER
MAINLY ZONAL FLOW.
NATIONAL WEATHER SERVICE MEMPHIS TN
441 AM CST SAT FEB 23 2019
.DISCUSSION...
ACTIVE WEATHER DAY FOR THE MIDSOUTH, BEGINNING WITH ONGOING RIVER
AND LOWLAND FLOODING FROM PERSISTENT MODERATE TO HEAVY RAINS. AS
OF 3 AM CST TODAY, SEVEN DAY RAINFALL TOTALS RANGED FROM 6 TO 12
INCHES OVER NORTH MISSISSIPPI. ANY ADDITIONAL RAINFALL TODAY WILL
EXACERBATE OR AT LEAST EXTEND ONGOING FLOODING.
4 AM CST/10Z SURFACE MAP SHOWED A TWO WARM FRONTS. THE NORTHERNMOST
FRONT EXTENDED FROM THE NORTHWEST TIP OF TN DOWN TO THE SOUTH OF
JONESBORO AND NEWPORT, AR. A SECOND, MORE CONSEQUENTIAL MARINE
WARM FRONT EXTENDED EAST-WEST ACROSS CENTRAL MS, WITH DEWPOINTS
SOUTH OF THE FRONT AROUND 70F.
THE MARINE WARM FRONT WILL LIFT INTO THE MIDSOUTH LATER THIS
MORNING. NAM BUFR SOUNDINGS DEPICT LITTLE TO NO INHIBITION TO
SURFACE-BASED CONVECTION DURING THE THE LATE MORNING. THE 06Z 3KM
NAM-NEST MODEL DEPICTS DEVELOPING SURFACE-BASED STORMS ALONG THE
MARINE WARM FRONT, AIDED BY RAPIDLY INCREASING DIFFLUENCE ALOFT
AHEAD OF AN APPROACHING MIDLEVEL DRY SLOT. ALTHOUGH THE
(OCCLUDED) SYNOPTIC SURFACE LOW WILL REMAIN WELL-REMOVED OVER
KS/OK, A WEAKER SECONDARY SURFACE WAVE MAY FORM NEAR THE TRIPLE
POINT WHERE THE MARINE WARM FRONT INTERSECTS A PRE-FRONTAL
PRESSURE TROF. THE IMPLICATIONS OF SUCH A FRONTAL WAVE WOULD BE
INCREASED DIRECTIONAL SHEAR FROM BACKING WINDS OVER NORTH MS BY
LATE MORNING, AND PERHAPS INCREASED TORNADO POTENTIAL.
THE BIGGEST UNCERTAINTY WITH RESPECT TO TORNADO POTENTIAL WILL BE
THE AMOUNT OF RAINFALL NEAR THE NORTHWARD-ADVANCING MARINE WARM
FRONT AND THE EFFECT OF DILUTING BOUNDARIES. MODEL SOUNDINGS SHOW
SURFACE-BASED CONVECTION UNCAPPED FROM THE START, POINTING TOWARD
A GRADUAL INCREASE IN THUNDERSTORM COVERAGE, RATHER THAN A QUIET
PERIOD FOLLOWED BY EXPLOSIVE DEVELOPMENT ALONG WELL-DEFINED
FRONTAL BOUNDARIES. IN ANY CASE, SUFFICIENT CAPE WILL BE IN PLACE
FROM KINEMATIC PROCESSES (INSTABILITY BROUGHT INTO THE AREA),
ALONG WITH ADEQUATE LOW LEVEL HELICITY FOR INCREASED TORNADO
CONCERN BY LATE MORNING, PARTICULARLY SOUTH OF I-40. THE MARINE
WARM FRONT WILL LIFT INTO WEST TN BY EARLY AFTERNOON, ABOUT THE
TIME STORMS INCREASE OVER EAST AR, EVENTUALLY FORMING A SQUALL
LINE. MAIN THREAT WITH THE SQUALL LINE WILL BE DAMAGING WINDS,
BUT A FEW BRIEF TORNADOES WILL ALSO BE POSSIBLE, EMBEDDED IN THE
SQUALL LINE.
THE POTENTIAL DANGER FROM STRAIGHT-LINE THUNDERSTORM WINDS WILL
BE OF PARTICULAR CONCERN TODAY. DUE TO SATURATED SOILS, EVEN SUB-
SEVERE WINDS MAY TOPPLE LARGE TREES, PUTTING NEARBY STRUCTURES
AND VEHICLES AT RISK.
FOLLOWING THE EARLY TO MIDEVENING EXIT OF THE SQUALL LINE, DRY AND
SEASONAL WEATHER WILL PREVAIL ACROSS THE MIDSOUTH THROUGH AT
LEAST TUESDAY OF NEXT WEEK. MEDIUM RANGE MODELS CONTINUE TO SHOW
VARYING RAIN CHANCES DURING THE MID TO LATE WEEK PERIODS UNDER
MAINLY ZONAL FLOW.
HSVweather
Member
Latest day 1 just issued with little change
https://www.spc.noaa.gov/products/outlook/day1otlk.html
Also, new meso issued with a watch possible in Louisiana and Arkansas https://www.spc.noaa.gov/products/md/md0123.html
https://www.spc.noaa.gov/products/outlook/day1otlk.html
Also, new meso issued with a watch possible in Louisiana and Arkansas https://www.spc.noaa.gov/products/md/md0123.html