SEVERE WEATHER THREAT 9/12/09- 9/13/09 [Archive]

View Full Version : SEVERE WEATHER THREAT 9/12/09- 9/13/09

ROLLTIDE

09-10-2009, 10:39 AM

Could it be the return of Severe weather ?

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0254 AM CDT THU SEP 10 2009

VALID 121200Z - 131200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

MODEL CONSENSUS IS THAT UPPER LOW THAT WILL CLOSE OFF OVER THE NRN
PLAINS FRIDAY WILL DRIFT WWD BENEATH UPPER RIDGE INTO WY SATURDAY.
FRONTAL BOUNDARY WILL REMAIN STALLED FROM THE UPPER MS VALLEY SWWD
THROUGH THE CNTRL PLAINS...AND UPPER LOW WILL REMAIN NORTH AND WEST
OF MOIST WARM SECTOR. WEAK UPPER WAVES WILL MOVE EWD ACROSS TX INTO
THE LOWER MS VALLEY REGION.

...LOWER MS VALLEY REGION...

DEEP MOIST PROFILES AND A WEAK SLOW MOVING UPPER TROUGH WILL PROMOTE
AREAS OF SCATTERED THUNDERSTORMS ACROSS THE SRN PLAINS AND LOWER MS
VALLEY. OPERATIONAL NAM DEEPENS A SURFACE LOW OVER THE NWRN
GULF...DEVELOPING A 50KT LOW LEVEL JET EAST OF THE CENTER AND MOVES
IT ONTO THE LA COAST DURING THE DAY. NAM FORECAST SOUNDINGS SHOW
LARGE HODOGRAPHS ACROSS LA AND MS IN ASSOCIATION WITH THIS
FEATURE...AND IF THE SOLUTION WERE TO VERIFY...A THREAT WOULD EXIST
FOR ISOLATED TORNADOES. OVER DEEPENING OF THE LOW APPEARS LARGELY
RELATED TO CONVECTIVE FEEDBACK WHICH REDUCES CONFIDENCE IN THIS
SOLUTION. GIVEN THE MOIST ENVIRONMENT...PRESENCE OF LOW LATITUDE
UPPER WAVES AND LIKELIHOOD OF CONVECTION OVER THE NWRN GULF...IT IS
PLAUSIBLE THAT A LOW MAY DEVELOP IN THIS AREA. HOWEVER...UNCERTAINTY
REGARDING STRENGTH AND EVOLUTION OF THE LOW WARRANTS ONLY 5% SEVERE
PROBABILITIES AT THIS TIME.

..DIAL.. 09/10/2009

CLICK TO GET WUUS03 PTSDY3 (http://www.spc.noaa.gov/products/outlook/archive/2009/KWNSPTSDY3_200909100730.txt) PRODUCT
</pre>

nightrider

09-10-2009, 11:22 AM

Could it be the return of Severe weather ?

I hope so!

ROLLTIDE

09-10-2009, 12:51 PM

ROLLTIDE

09-11-2009, 03:54 AM

Day 2 outlook

MIDDLE GULF COAST REGION...
CONDITIONAL POTENTIAL EXISTS FOR SUPERCELLS IN FRONTAL ZONE...MAINLY
VERY NEAR IMMEDIATE COAST BETWEEN SERN LA AND CENTRAL FL PANHANDLE.
VERTICAL JUXTAPOSITION OF BACKED LOW LEVEL FLOW INVOF FRONTAL ZONE
AND 30-35 KT ESELY LLJ JUST OFF SFC WILL RESULT IN ENLARGED LOW
LEVEL HODOGRAPHS. MARITIME/TROPICAL AIR MASS ALONG AND S OF FRONT
WILL BE CHARACTERIZED BY VERY RICH LOW LEVEL MOISTURE...WITH SFC DEW
POINTS LOW-MID 70S F AND FCST SOUNDINGS SUGGESTING PW COMMONLY ABOVE
2 INCHES...WITH MINIMAL MLCINH ALONG AND S OF FRONT. SFC-BASED
EFFECTIVE PARCELS MAY EXTEND N OF FRONT AND INLAND....BUT HOW FAR IS
UNCERTAIN ATTM. MESOSCALE PERTURBATIONS IN FRONTAL POSITION AND
LOW-LEVEL KINEMATIC GEOMETRY MAY FOCUS POTENTIAL FOR TSTMS FORMING
OVER GULF TO INTERACT WITH FRONTAL ZONE AND ROTATE...ESPECIALLY IF
CELLS ARE RELATIVELY DISCRETE. GIVEN WEAK LAPSE RATES AND LACK OF
APPARENT FACTORS TO YIELD APPRECIABLE HAIL/DOWNBURST/DAMAGING WIND
THREATS...SVR MODE SHOULD BE ESSENTIALLY TORNADO OR NOTHING. IF
VERY SAME SCENARIO WERE PRESENT FOR DAY-1...MRGL/2-PERCENT TORNADO
PROBABILITY WOULD BE ASSIGNED...HOWEVER UNCONDITIONAL SVR
PROBABILITIES APPEAR LESS THAN 5 PERCENT ATTM.
</pre>

ROLLTIDE

09-11-2009, 03:55 AM

Day 3

MIDDLE GULF COAST STATES...
REGIME DESCRIBED IN DAY-2 OUTLOOK IS EXPECTED TO WEAKEN SOMEWHAT
ABOVE SFC...WITH PRIMARY LLJ REDEVELOPING ACROSS AR AND ARKLATEX
REGION CLOSER TO DEEP-LAYER LOW...AND MORE REMOVED FROM
MARITIME/TROPICAL AIR MASS. NARROW CORRIDOR OF FAVORABLY BACKED
BOUNDARY LAYER FLOW WILL PERSIST ALONG AND JUST N OF SFC
FRONT...HOWEVER WINDS FROM AROUND 2 KM AGL THROUGH MIDLEVELS ARE
PROGGED TO BE RELATIVELY WEAK...MAKING ANY SUPERCELL POTENTIAL TOO
CONDITIONAL..BRIEF AND LOCALIZED TO WARRANT AOA 5-PERCENT GRID
PROBABILITIES ATTM.
</pre>

nightrider

09-11-2009, 08:04 AM

weather.gov
National Weather Service

Watches, Warnings & Advisories
Local weather forecast by "City, St" or zip code
One product issued by NWS for: 4 Miles W Chataignier LA
--------------------------------------------------------------------------------

Hazardous Weather Outlook
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
540 AM CDT FRI SEP 11 2009

GMZ430-432-435-450-452-455-470-472-475-LAZ027>033-041>045-051>055-
TXZ180>182-201-215-216-121045-
SABINE LAKE-CALCASIEU LAKE-VERMILION BAY-
COASTAL WATERS FROM CAMERON, LA TO HIGH ISLAND, TX OUT 20 NM-
COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON, LA OUT 20 NM-
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY,
LA OUT 20 NM-
WATERS FROM CAMERON, LA TO HIGH ISLAND, TX EXTENDING FROM 20 NM
TO 60 NM-
WATERS FROM INTRACOASTAL CITY, LA TO CAMERON, LA EXTENDING FROM
20 NM TO 60 NM-
WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA
EXTENDING FROM 20 NM TO 60 NM-VERNON-RAPIDES-AVOYELLES-BEAUREGARD-
ALLEN-EVANGELINE-ST. LANDRY-CALCASIEU-JEFFERSON DAVIS-ACADIA-
LAFAYETTE-UPPER ST. MARTIN-CAMERON-VERMILION-IBERIA-ST. MARY-
LOWER ST. MARTIN-TYLER-JASPER-NEWTON-HARDIN-JEFFERSON-ORANGE-
540 AM CDT FRI SEP 11 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE NORTHWEST
GULF OF MEXICO...CENTRAL LOUISIANA...SOUTH CENTRAL LOUISIANA...
SOUTHWEST LOUISIANA...WEST CENTRAL LOUISIANA AND SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

WIND SHEAR PROFILES WILL BECOME MARGINALLY FAVORABLE
FOR AN ISOLATED TORNADO OR TWO LATER TODAY AND TONIGHT...MAINLY
ALONG AND SOUTH OF INTERSTATE 10. .

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

ISOLATED RAINFALL TOTALS UP TO 6 INCHES POSSIBLE FROM SATURDAY
INTO SUNDAY. IN ADDITION...WIND SHEAR PROFILES WILL BE MARGINALLY
FAVORABLE FOR AN ISOLATED TORNADO OR TWO FROM SATURDAY INTO EARLY SUNDAY

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE TODAY AND TOMORROW.

ROLLTIDE

09-11-2009, 03:58 PM

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
346 PM CDT FRI SEP 11 2009

THE NATIONAL WEATHER SERVICE IN CORPUS CHRISTI HAS ISSUED A

* TORNADO WARNING FOR...
CENTRAL JIM WELLS COUNTY IN SOUTH TEXAS...
NORTHWESTERN KLEBERG COUNTY IN SOUTH TEXAS...
SOUTHWESTERN NUECES COUNTY IN SOUTH TEXAS...

* UNTIL 430 PM CDT

* AT 345 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 7 MILES
SOUTHEAST OF BEN BOLT...OR 10 MILES NORTHWEST OF KINGSVILLE...
MOVING EAST AT 5 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
KINGSVILLE NAVAL AIR STATION...DRISCOLL AND BISHOP

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

ROLLTIDE

09-12-2009, 04:28 AM

SPC

SERN TX INTO THE CENTRAL GULF COAST STATES/LOWER MS VALLEY...
RELATIVELY WIDESPREAD/PERSISTENT CONVECTION IS FORECAST ACROSS THE
CENTRAL GULF COAST REGION THIS PERIOD...AS THE LARGE UPPER LOW
DRIFTS SLOWLY NNEWD ACROSS THE S CENTRAL CONUS. WITH THIS LIKELY TO
LIMIT DESTABILIZATION ACROSS THE GULF COAST REGION...WIDESPREAD 500
J/KG MIXED-LAYER CAPE WILL BE POSSIBLE WITHIN THE WARM SECTOR --
AIDED BY A VERY MOIST BOUNDARY LAYER.

ATTM...MODELS SUGGEST THAT 25 TO 35 KT MID-LEVEL SWLYS WILL RESIDE
ACROSS THIS REGION...ON THE SERN PERIPHERY OF THE LOW. THIS SHOULD
RESULT IN FAVORABLE SHEAR FOR ORGANIZED/ROTATING STORMS --
PARTICULARLY NEAR AND N OF THE ROUGHLY W-E WARM FRONT...WHERE
LOW-LEVEL FLOW WILL REMAIN MORE BACKED/ESELY. WHILE LIMITED BY THE
OVERALL LACK OF INSTABILITY...SOME SEVERE POTENTIAL APPEARS EVIDENT
GIVEN THE FAVORABLY MOIST/SHEARED ENVIRONMENT. THUS...WILL
INTRODUCE 5% SEVERE PROBABILITY ACROSS THIS REGION...WHERE LOCALLY
GUSTY WINDS OR EVEN AN ISOLATED TORNADO WILL BE POSSIBLE WITH A
COUPLE OF THE LONGER-LIVED STORMS.

http://www.spc.noaa.gov/products/outlook/day2probotlk_0600_any.gif

ROLLTIDE

09-13-2009, 03:33 AM

Day 1

http://www.spc.noaa.gov/products/outlook/day1probotlk_1200_torn.gif

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1243 AM CDT SUN SEP 13 2009

VALID 131200Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT
OVER ERN MT...

...SYNOPSIS...

UPPER LOW CURRENTLY RETROGRADING NWWD INTO THE NRN HIGH PLAINS WILL
BEGIN TO LIFT MORE RAPIDLY NWD TODAY /THROUGH MT/ IN RESPONSE TO
APPROACH OF PROGRESSIVE...UPSTREAM SYSTEM MOVING ONTO THE PACIFIC
COAST. IN CONTRAST...A MORE STAGNANT AIRFLOW PATTERN WILL EXIST
OVER THE SRN STATES...PUNCTUATED BY UPPER LOW OVER TX/OK. A PV
ANOMALY IS FORECAST TO ROTATE AROUND THIS FEATURE FROM THE TX COAST
INTO THE LOWER MS VALLEY...LIKELY FOCUSING A LARGE AREA OF TSTMS
OVER THE CNTRL GULF STATES.

...NRN HIGH PLAINS...

13/00Z REGIONAL OBSERVED SOUNDINGS SHOW THAT LOW-LEVEL MOISTURE
REMAINS SOMEWHAT LIMITED WITH DEWPOINTS IN THE 40S TO LOWER 50S AND
LOWEST 100 MB MEAN MIXING RATIOS OF 6-8 G/KG. HOWEVER...STEEP
MIDLEVEL LAPSE RATES ASSOCIATED WITH COLD POOL /AROUND -16 C AT 500
MB/ OF UPPER SYSTEM WILL CONTRIBUTE TO POCKETS OF MODERATE
INSTABILITY BY AFTERNOON WITH MLCAPE OF AROUND 1000 J/KG.

PRIMARY FOCUS FOR STORM INITIATION APPEARS TO BE A WEAK SURFACE LOW
AND ATTENDANT FRONTAL BOUNDARY DEVELOPING FROM WY NWD INTO MT.
FORECAST SOUNDINGS SUGGEST THAT CAPPING ASSOCIATED WITH EML MAY
DELAY TSTM DEVELOPMENT UNTIL LATE AFTERNOON OR EARLY EVENING.
HOWEVER...WHEN STORMS DEVELOP...THE PRESENCE OF THE STEEP LAPSE
RATES...VEERING WINDS WITH HEIGHT AND 40-45 KT OF DEEP-LAYER SHEAR
SUGGEST THE POTENTIAL FOR ORGANIZED STORMS INCLUDING SUPERCELLS WITH
THE PRIMARY SEVERE THREAT BEING HAIL.

...WRN/CNTRL GULF COAST...

SYNOPTIC PATTERN WILL REMAIN QUITE SIMILAR TO THAT OF SATURDAY...
FEATURING AN IMPULSE ROTATING AROUND PRIMARY UPPER LOW WHICH WILL
SUPPORT WEAK CYCLOGENESIS OVER THE LOWER SABINE VALLEY. ATTENDANT
WARM FRONT MAY MOVE FURTHER INLAND /COMPARED TO SAT/...ALLOWING A
QUITE MOIST /DEWPOINTS IN THE LOWER TO MID 70S/ AIR MASS TO DEVELOP
NWD THROUGH THE I-10 CORRIDOR. LAPSE RATES WILL REMAIN AOB MOIST
ADIABATIC...THOUGH THE RICH BOUNDARY LAYER MOISTURE AND SOME HEATING
WILL CONTRIBUTE TO MLCAPE OF 1000-1500 J/KG.

MID AND HIGH-LEVEL FLOW WILL STRENGTHEN THROUGH THE DAY...HOWEVER
LOW-LEVEL WIND FIELDS AND RESULTANT NEAR-GROUND SHEAR WILL REMAIN
COMPARABLY WEAKER. AS SUCH...SETUP WILL FAVOR THE DEVELOPMENT OF
STRONG STORM CLUSTERS WHICH MAY EXHIBIT EPISODIC UPDRAFT ROTATION.
WHILE A BRIEF TORNADO AND/OR STRONG WIND GUST IS POSSIBLE...THIS
THREAT APPEARS TOO MARGINAL TO WARRANT A CATEGORICAL SLIGHT RISK.

..MEAD/JEWELL.. 09/13/2009

CLICK TO GET WUUS01 PTSDY1 PRODUCT

ROLLTIDE

09-13-2009, 08:41 AM

SLIGHT RISK

RN/CNTRL GULF CST...
SETUP OVER THE WRN/CNTRL GULF CST REGION WILL REMAIN SIMILAR TO THAT
ON SAT. CONTINUED NE MOTION OF AFOREMENTIONED UPR IMPULSE
SHOULD...HOWEVER...FAVOR A MORE DECIDED NWD ADVANCE OF W/E WARM
FRONT NOW OVER THE NRN GULF RELATIVE TO SAT. BY LATE THIS AFTN THE
BOUNDARY SHOULD EXTEND FROM NEAR LFK EWD THROUGH CNTRL LA INTO S
CNTRL MS. ADVANCE OF THE FRONT WILL ALLOW VERY RICH MOISTURE /SFC
DEWPOINTS IN THE MID 70S F AND PW AOA 2.00 INCHES/ TO OVERSPREAD
AREAS ALONG AND N OF THE I-10 CORRIDOR.

MID LVL SSWLY WINDS WILL STRENGTHEN THROUGH THE DAY...WITH 700-500
MB FLOW EXPECTED TO REACH 25-30 KTS. LOW-LVL WINDS...HOWEVER...
SHOULD REMAIN FAIRLY WEAK AS ANY DEEPENING OF SFC LOW NOW OVER SE TX
IS EXPECTED TO BE MINIMAL. NEVERTHELESS...COMBINATION OF SUSTAINED
WAA WITH RICH MOISTURE AND LOW-LVL VEERING WIND PROFILES WILL FAVOR
THE DEVELOPMENT OF NUMEROUS STORM CLUSTERS NEAR WARM FRONT. THESE
MAY EXHIBIT PERIODIC LOW LVL ROTATION...AND COULD POSE A THREAT FOR
A FEW TORNADOES AND/OR STG WIND GUSTS.

</pre>

wxchaser420

09-13-2009, 10:57 AM

http://www.spc.noaa.gov/products/outlook/day1probotlk_1300_torn.gif

SPC upgraded to %5, thats a very intense low swirling around in TX.

http://w1.spc.woc.noaa.gov/exper/mesoanalysis/s3/activity_loop.gif

From NWS Jackson.

.TODAY AND TONIGHT...WIDESPREAD SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP AND MOVE NORTHWARD OVER MUCH OF THE FORECAST
AREA TODAY AND TONIGHT. THE HEAVIEST CONCENTRATION OF SHOWERS AND
THUNDERSTORMS WILL BE NEAR AND ALONG A WEAK WARM FRONT WHICH IS
FORECASTED TO MOVE ONSHORE AND ACROSS THE FORECAST AREA LATER THIS
AFTERNOON AND TONIGHT. DUE TO THE DEEP LAYERED MOISTURE IN THE LOWER
AND UPPER LEVELS OF THE ATMOSPHERE SOME LOCALIZED FLOODING WILL
STILL BE POSSIBLE THROUGH TONIGHT. THE GREATEST RAINFALL TOTALS WILL
BE WEST AND NORTH OF MOBILE ALABAMA WHICH INCLUDES MOST INLAND AREAS
OF SOUTHEAST MISSISSIPPI...STRETCHING EASTWARD INTO INLAND AREAS OF
SOUTHWEST ALABAMA MOSTLY WEST OF THE I-65 CORRIDOR.

BY LATER TONIGHT...AS LOW PRESSURE OVER SOUTHEAST TEXAS EASES
SLIGHTLY EAST...THE COMBINATION OF A SUSTAINED ENVIRONMENT RICH IN
DEEP LAYER MOISTURE AND INDICATIONS OF VEERING WIND PROFILES IN THE
LOWER LEVELS OF THE ATMOSPHERE FAVORS THE DEVELOPMENT OF NUMEROUS
STORM CLUSTERS NEAR WARM FRONT. THE STORM PREDICTION CENTER IN
NORMAN OKLAHOMA SUGGESTS THAT THESE MAY EXHIBIT PERIODIC LOW LEVEL
ROTATION AND COULD POSE A THREAT FOR A FEW TORNADOES AND OR STRONG
WIND GUSTS. LATEST GUIDANCE INDICATES THAT THIS POTENTIAL LOOKS TO
EXIST MAINLY OVER SOUTHERN MISSISSIPPI...EXTREME SOUTHWEST ALABAMA
AND THE ADJACENT COASTAL WATERS MAINLY AFTER MIDNIGHT THROUGH
DAYBREAK MONDAY.

ROLLTIDE

09-13-2009, 11:29 AM

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1124 AM CDT SUN SEP 13 2009

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* TORNADO WARNING FOR...
NORTHWESTERN TANGIPAHOA PARISH IN SOUTHEAST LOUISIANA...
SOUTHWESTERN PIKE COUNTY IN SOUTHERN MISSISSIPPI...

* UNTIL 1145 AM CDT

* AT 1124 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR KENTWOOD...
OR 10 MILES NORTHEAST OF GREENSBURG...MOVING NORTHEAST AT 10 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OSYKA

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS UNDER A WORKBENCH OR OTHER
PIECE OF STURDY FURNITURE. SEEK SHELTER ON THE LOWEST FLOOR OF THE
BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE
BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY AWAY FROM
WINDOWS.

ROLLTIDE

09-13-2009, 11:42 AM

KMOB update

AREA FORECAST DISCUSSION...MESOSCALE UPDATE
NATIONAL WEATHER SERVICE MOBILE AL
1135 AM CDT SUN SEP 13 2009

.MESOSCALE UPDATE...WEATHER MAPS THIS MORNING ALONG WITH WATER VAPOR
IMAGERY/ANIMATIONS SHOW LOW PRESSURE SYSTEM OVER EASTERN TEXAS. WITH
HEIGHT...A WESTWARD TILT TO THE LOWER PRESSURES WAS OBSERVED WITH
BROAD SURFACE LOW ANALYZED JUST OFF THE CENTRAL AND UPPER TEXAS
COAST...WHILE THE H850-H30 LOW PRESSURE REFLECTION WAS POSITIONED
NEAR WACO TEXAS. A POSITIVE TILT TO THE PRESSURE TROF ALOFT WAS
PROVIDING FOR A WELL DEFINED DIFFLUENT FLOW AT HIGH LEVELS OVER THE
NORTHWEST/CENTRAL GULF STATES. BENEATH THIS FLOW...RESIDES A WEST TO
EAST SURFACE WARM FRONTAL BOUNDARY THAT EXTENDS ACROSS SOUTHERN
LOUISIANA TO OFF THE CENTRAL GULF COAST...WHICH WILL PROVIDE FOR THE
SURFACE FOCUS. MID/UPPER LEVEL IMPULSES ARE FORECAST TO EJECT
NORTHEAST OUT OF THE BASE OF THE EAST TEXAS UPPER LEVEL STORM SYSTEM
AS TO ENHANCE DEEP LAYER LIFT ATOP THE SURFACE BOUNDARY. WITHIN THIS
AREA OF LIFT...FORECASTERS ARE SEEING AN INCREASE IN COLDER CLOUD
TOPS/CONVECTION UPSTREAM FROM CENTRAL LOUISIANA...SOUTHWARD INTO THE
GULF. THIS CONVECTION SHOULD CONTINUE EASTWARD TODAY AND AM
ANTICIPATING THE RADAR SCOPE TO BECOME MORE ACTIVE AS HIGH LEVEL
ENERGY APPROACHES FROM THE SOUTHWEST AND ENVIRONMENT BECOMES MORE
UNSTABLE. DEEP LAYER ENVIRONMENTAL MOISTURE REMAINS HIGH WITH 13.12
COASTAL SOUNDINGS SHOWING PWAT'S AT 2-2.25". THE POTENTIAL OF HEAVY
RAIN DOES EXIST AND WILL REMAIN IN THE GRIDDED FORECASTS IN THE NEAR
TERM. COULD BE SOME LOCALIZED FLOODING PROBLEMS WHEN STORMS GET
GOING.

THE RISK OF SEVERE WEATHER THOUGH IS MORE COMPLICATED. LAPSE RATES
ARE NOT OVERLY IMPRESSIVE WITH MODIFIED SOUNDINGS BLO 7C/KM. VISIBLE
SATELLITE IMAGERY THOUGH IS SHOWING BREAKS IN THE OVERCAST AND THIS WILL
ALLOW ENOUGH INSOLATION AS TO THE CAUSE THE LOCAL ENVIRONMENT TO
DESTABILIZE BEFORE CLOUDINESS ADVECTS IN FROM THE WEST. RUC MODIFIED
SOUNDINGS SHOWS MLCAPES TO ~2200 J/KG THIS AFTN OVER THE SOUTHWEST ZONES
WHICH IS PRIMING THE LOCAL ENVIRONMENT FOR CONVECTIVE INITIATION.
JUST TO OUR WEST...RADAR TRENDS ARE SHOWING TSTMS DEVELOPING AND
THESE WILL BE MOVING EASTWARD WITH NEW DEVELOPMENT ALSO OCCURRING
THROUGH THE AFTERNOON. LATEST MESOSCALE ANALYSIS OF SHEAR IS SHOWING
0-1KM HELICITIES ~150 M2/S2 JUST TO OUR WEST AND THIS IS BORDERLINE
FOR SUPPORTING A FEW ROTATING LOW TOP SUPERCELLS/TORNADOES. WILL BE
MONITORING SOUTHEAST MISSISSIPPI AND SOUTHWEST ALABAMA THROUGH THE
AFTERNOON. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ISSUED BY
THE STORM PREDICTION CENTER IN NORMAN OKLAHOMA IN THE NEAR TERM
COVERING THESE AREAS.

THE LATEST WET MICROBURST RISK ASSESSMENT FOR THE POTENTIAL OF
STRONG CONVECTIVE DOWNBURST WINDS IS MODERATE. /10

</pre>

ROLLTIDE

09-13-2009, 01:14 PM

LIX: New Orleans [Orleans Co, LA] emergency mngr reports FLASH FLOOD at 12:30 PM CDT -- a couple of vehicles stranded in flooded underpass at downman road and haynes blvd. some street flooding near lakefront airport

ROLLTIDE

09-13-2009, 01:45 PM

LIX: 4 Sw Waveland [Han**** Co, MS] law enforcement reports WATER SPOUT at 01:42 PM CDT -- waterspout sighted from beach blvd near silver slipper casino. klix wsr-88d radar shows rotating cell approx 2 miles ssw of bayou clear...moving ene. reported by han**** 911.

ROLLTIDE

09-14-2009, 06:22 AM

http://www.srh.noaa.gov/images/fxc/lix/graphicast/image1.gif

ROLLTIDE

09-14-2009, 06:30 AM

SPC

...CNTRL GULF STATES...

SYNOPTIC PATTERN SIMILAR TO THAT OF THIS PAST WEEKEND WILL PERSIST
THROUGH THE PERIOD...FEATURING THE SLOW EWD MOVEMENT OF A SURFACE
LOW FROM E TX INTO LA. ASSOCIATED WARM FRONT WILL CONCURRENTLY
PIVOT NWWD THROUGH NRN PARTS OF MS/AL AND WRN TN TO VICINITY OF THE
MS RIVER. WARM SECTOR AIR MASS WILL CONTINUE TO BE CHARACTERIZED BY
BOUNDARY LAYER DEWPOINTS IN THE LOW/MID 70S AND PW VALUES AOA 2
INCHES. MIDLEVEL LAPSE RATES WILL REMAIN WEAK...BUT POCKETS OF
STRONGER HEATING COUPLED WITH THE ABUNDANT MOISTURE WILL CONTRIBUTE
TO MODERATE AFTERNOON INSTABILITY WITH MLCAPE OF 1000-2000 J/KG.

VORTICITY MAXIMA ROTATING AROUND PARENT UPPER LOW WILL LIKELY FOSTER
NUMEROUS DIURNAL TSTMS WITHIN SYSTEM WARM SECTOR...SOME OF WHICH MAY
BRIEFLY APPROACH SEVERE LEVELS. VERTICAL SHEAR /BOTH IN THE LOW
LEVELS AND THROUGH A DEEP LAYER/ WILL REMAIN SOMEWHAT MARGINAL FOR
STORM ORGANIZATION/ROTATION. NONETHELESS...A LOW PROBABILITY THREAT
FOR A BRIEF TORNADO AND/OR STRONG WIND GUSTS WILL EXIST WITH ANY
LONGER-LIVED STORMS.

</pre>

ROLLTIDE

09-14-2009, 06:18 PM

MOB: Non-NWS Report -- from SpotterNetwork (unverified) @ 06:12 PM CDT -- (S) FFlood -- -- Spotter is 0 miles N of Wheelerville, AL (Mobile county) [30.693/-88.193] -- At the intersection of University blvd and old shell road the water was 6+ inch(flowing over the curb which I know is six inches). The storm drains lining University Blvd were over flowing into the street. Water moving swiftly. At least one accident on University Blvd. Injuries is Unknown. The university of south alabama also has some storm drain overflow, some parking lots flooded. (SN#4340)

ROLLTIDE

09-15-2009, 11:29 AM

MESOSCALE DISCUSSION 2017
NWS STORM PREDICTION CENTER NORMAN OK
1114 AM CDT TUE SEP 15 2009

AREAS AFFECTED...CENTRAL/SOUTHERN MS AND SOUTHERN AL/WESTERN FL
PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 151614Z - 151815Z

POTENTIAL FOR ISOLATED WIND DAMAGE AND PERHAPS A BRIEF TORNADO MAY
GRADUALLY INCREASE THROUGH EARLY AFTERNOON ACROSS CENTRAL/SOUTHERN
MS AND SOUTHERN AL/ADJACENT FL PANHANDLE. LIMITED/MARGINAL NATURE OF
THE RISK IS CURRENTLY EXPECTED TO PRECLUDE A WATCH ISSUANCE.

AS A VERTICALLY STACKED LOW CONTINUES TO REMAIN QUASI-STATIONARY
ACROSS THE ARKLATEX VICINITY...SHOWERS/TSTMS HAVE INCREASED OVER THE
PAST FEW HOURS IN THE WARM/VERY MOIST AND WEAKLY CAPPED WARM SECTOR
ACROSS SOUTHEAST LA AND THE SOUTHERN PORTIONS OF MS/AL. 12Z OBSERVED
RAOBS AND MORE CONTEMPORARY WSR-88D DERIVED WINDS ONLY REFLECT
MODEST LOW LEVEL SRH /UP TO 100 MS PER S2/ WITH RESPECT TO UPDRAFT
ROTATION. NONETHELESS...WITHIN A VERY MOIST AIRMASS...THIS COULD BE
SUFFICIENT FOR A BRIEF TORNADO OR WIND DAMAGE...PERHAPS FAVORED
ALONG A NW-SE AXIS COINCIDENT WITH A SUBTLE WARM/DIFFERENTIAL
HEATING FRONT ACROSS SOUTHERN MS/AL...WHERE LOW LEVEL FLOW IS
MODESTLY BACKED. WHILE WEAK LAPSE RATES ALOFT AND WEAK DEEP LAYER
TROPOSPHERIC FLOW WILL BE LIMITING FACTORS...A FEW SEVERE STORMS
CAPABLE OF WIND DAMAGE/PERHAPS A BRIEF TORNADO WILL BE POSSIBLE
THROUGH THE AFTERNOON INTO EARLY EVENING.

..GUYER.. 09/15/2009
</pre>

http://www.spc.noaa.gov/products/md/mcd2017.gif

nightrider

09-16-2009, 12:26 PM

http://www.spc.noaa.gov/products/md/mcd2021.gif

MESOSCALE DISCUSSION 2021
NWS STORM PREDICTION CENTER NORMAN OK
1213 PM CDT WED SEP 16 2009

AREAS AFFECTED...CENTRAL/SOUTHERN AL AND FL PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 161713Z - 161915Z

POTENTIAL FOR A BRIEF/ISOLATED TORNADO OR TWO...AND WIND
DAMAGE...MAY MODESTLY INCREASE THROUGH THE AFTERNOON MAINLY ACROSS
PORTIONS OF CENTRAL/SOUTHERN AL. ISOLATED/MARGINAL NATURE OF THE
RISK SHOULD PRECLUDE A WATCH ISSUANCE...BUT DEVELOPMENTAL TRENDS
WILL CONTINUE TO BE MONITORED.

AS THE PARENT CYCLONE REMAINS OVER THE ARKLATEX VICINITY...AN
INCREASE IN SHOWERS/TSTMS APPEARS TO BE TIED TO A SUBTROPICAL/MID
LEVEL DISTURBANCE CROSSING THE CENTRAL GULF AND ADJACENT GULF COAST
STATES...ALONG WITH A VERY MOIST/WEAKLY CAPPED BOUNDARY LAYER. AS
HAS BEEN THE CASE FOR THE PAST FEW DAYS...WEAK DEEP LAYER FLOW/POOR
MID LEVEL LAPSE RATES WILL REMAIN LIMITING FACTORS FOR A MORE
APPRECIABLE SEVERE RISK. NONETHELESS...THE COMBINATION OF AMPLE
SURFACE HEATING /LOWER 80S F/ AND LOWER TO MIDDLE 70S F
DEWPOINTS...ALONG WITH MODESTLY BACKED /SOUTHEASTERLY/ LOW LEVEL
FLOW ESPECIALLY ACROSS CENTRAL/SOUTHERN AL WITH 0-1 KM SRH TO AROUND
100 MS/S2...MAY BE SUFFICIENT FOR ISOLATED/BRIEF TORNADOES AND/OR
WIND DAMAGE.

nightrider

09-16-2009, 02:10 PM

weather.gov
National Weather Service

Watches, Warnings & Advisories
Local weather forecast by "City, St" or zip code
2 products issued by NWS for: 4 Miles SSE Jones AL
--------------------------------------------------------------------------------

Tornado Warning
TORNADO WARNING
ALC001-161930-
/O.NEW.KBMX.TO.W.0143.090916T1857Z-090916T1930Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
157 PM CDT WED SEP 16 2009

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* TORNADO WARNING FOR...
WEST CENTRAL AUTAUGA COUNTY IN CENTRAL ALABAMA...

* UNTIL 230 PM CDT

* AT 156 PM CDT...THE NATIONAL WEATHER SERVICE DETECTED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 11 MILES SOUTHWEST OF
VIDA JUNCTION...MOVING NORTHEAST AT 15 MPH.

* THE TORNADO WILL BE NEAR...
VIDA JUNCTION BY 230 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

&&

TO REPORT SEVERE WEATHER...
CALL 1-800-856-0758.

nightrider

09-16-2009, 09:25 PM