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Severe Weather Outbreak May 10th - 11th To Many States To Name! A Large Portion of the U.S. Rate Topic: -----

#101 User is offline   Jebman Icon

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Weather Observations
24.0 F (-4.4 C)

Wind is
Calm
Humidity:
84%
Pressure:
1021.4mb
Visibility:
7.00 mile(s)
Conditions:
Overcast
Location:
LWX
Updated:
Feb 9 2010, 6:54 am EST

Data Source: NWS

Post icon  Posted 10 May 2008 - 01:22 AM

View PostIndianaWeatherOnline, on May 10 2008, 12:28 AM, said:

Here ya go Jebman ;)


Thank you IndianaWeatherOnline and ALhurricane!!!

Have an excellent evening!!
Have an even BETTER day tomorrow!!! :) :) :)

#102 User is offline   IndianaWeatherOnline Icon

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Weather Observations
22.0 F (-5.6 C)

Wind is
East at 13.8 MPH (12 KT)
Humidity:
89%
Pressure:
1013.2mb
Visibility:
0.75 mile(s)
Conditions:
Light Snow Blowing Snow Fog/Mist
Location:
KDAY
Updated:
Feb 9 2010, 6:56 am EST

Data Source: NWS

Posted 10 May 2008 - 01:24 AM

View PostJebman, on May 10 2008, 02:22 AM, said:

Thank you IndianaWeatherOnline and ALhurricane!!!

Have an excellent evening!!
Have an even BETTER day tomorrow!!! :) :) :)


Haha you too Jebman, anything for ya bro ;)

#103 User is offline   smokeater342 Icon

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Weather Observations
41.0 F (5.0 C)

Wind is
Calm
Humidity:
79%
Pressure:
1016.0mb
Visibility:
10.00 mile(s)
Conditions:
Overcast
Location:
KNJHAMMO1
Updated:
Feb 9 2010, 6:53 am EST

Data Source: NWS

Posted 10 May 2008 - 01:32 AM

All i know is...everybody in the affected areas this weekend...stay safe.....is this ever gonna be a long weekend.....

#104 User is offline   Calderon Icon

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Weather Observations
50.0 F (10.0 C)

Wind is
Southeast at 5.8 MPH (5 KT)
Humidity:
96%
Pressure:
1013.7mb
Visibility:
8.00 mile(s)
Conditions:
Mostly Cloudy
Location:
KNIP
Updated:
Feb 9 2010, 5:53 am EST

Data Source: NWS

Posted 10 May 2008 - 01:33 AM

View Posttornadotony, on May 10 2008, 02:21 AM, said:

That is setting up for a High Risk.


Definetly agreed. They are probably just waiting to see more model runs for 12Z and how the morning shapes up before making a call. Its a close as I've ever seen a HIGH risk being called without it actually being HIGH.

#105 User is offline   wxmann_91 Icon

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Posted 10 May 2008 - 01:35 AM

View PostFred Gossage, on May 9 2008, 04:24 PM, said:

No offense intended, and I don't think he will take the following as such.... he knows me and how I express myself rather well by now, but Jim's cold frontal concerns aren't really with true merit until no earlier than mid-evening either... in my opinion at least..... Thunderstorms should be able to initiate by mid-afternoon along and near the warm front. There's not a thermonuclear cap in place. The temperatures tomorrow would have to stay in the low to mid 70s for the cap to not break until the cold front comes in.... and there are no real sources for widespread clouds and precip tomorrow morning to help that be the case. I will agree that once the cold front starts coming into the area of concern, we will likely transition toward more of an MCS situation with less of a high-end type tornado threat, but by then, we will have probably had no less than 3 or 4 hours of discrete supercells taking advantage of the incredible environment in place. And as far as moisture depth..... rich boundary layer moisture (very low dewpoint depressions) is shown on forecast soundings to extend clear up to the 750-700mb range.... I don't think that's going to be much of an issue either.

None taken. And yes, the cold front concerns are starting from the mid evening and moving on from that (basically after around, as I said in my post, 02Z)... any supercells in the afternoon don't have to worry about that. I am thinking more along the lines of I-40 now rather than further north, forgot about the fact that models overdo warm front progression. I am somewhat worried about the cap, but only south of the LA/AR border latitude should that be a factor. And I agree, morning convection looks to be no problem with this setup.

SPC's current MDT looks good, I think.

#106 User is offline   Calderon Icon

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Weather Observations
50.0 F (10.0 C)

Wind is
Southeast at 5.8 MPH (5 KT)
Humidity:
96%
Pressure:
1013.7mb
Visibility:
8.00 mile(s)
Conditions:
Mostly Cloudy
Location:
KNIP
Updated:
Feb 9 2010, 5:53 am EST

Data Source: NWS

Posted 10 May 2008 - 02:52 AM

Just got off the phone with NWS JAX on a conference call with us, Mayport and the Coast Guard at Cecil Field. They do expect a very powerful line of storms here Sunday evening or early that night. They also expect widespread wind damage, and don't rule out winds up to 90mph! I don't know where they got that, but those would be the highest gusts since May 27, 1997 when here at NAS JAX, they recorded the JAX CWA record of 106mph.

#107 User is offline   Calderon Icon

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Weather Observations
50.0 F (10.0 C)

Wind is
Southeast at 5.8 MPH (5 KT)
Humidity:
96%
Pressure:
1013.7mb
Visibility:
8.00 mile(s)
Conditions:
Mostly Cloudy
Location:
KNIP
Updated:
Feb 9 2010, 5:53 am EST

Data Source: NWS

Post icon  Posted 10 May 2008 - 04:14 AM

Attached File  mcd0853.gif (22.06K)
Number of downloads: 0
MESOSCALE DISCUSSION 0853
NWS STORM PREDICTION CENTER NORMAN OK
0405 AM CDT SAT MAY 10 2008

AREAS AFFECTED...FAR EASTERN OK/SOUTHERN MO/MUCH OF AR/SOUTHERN
IL/WESTERN KY/WESTERN AND MIDDLE TN/NORTHERN AL/MUCH OF GA

CONCERNING...OUTLOOK UPGRADE

VALID 100905Z - 101100Z

A VERY ACTIVE SEVERE WEATHER DAY IS EXPECTED THIS AFTERNOON AND
TONIGHT. AN INITIAL /06Z/ MODERATE RISK EXISTS ACROSS MUCH OF THE
ARKLATEX/MID SOUTH REGION AND CENTRAL GULF COAST STATES. THIS
MODERATE RISK WILL BE EXPANDED NORTH/EASTWARD WITH THE UPCOMING 13Z
DAY 1 CONVECTIVE OUTLOOK.

ESPECIALLY REGARDING THE NORTH EXTENT...PRIMARY CONCERN IS THE
POTENTIAL INTENSIFICATION OF THE MID LEVEL TROUGH LATE TODAY...WITH
RAPID DEEPENING OF THE SURFACE LOW FROM EASTERN KS INTO THE MIDDLE
MISSISSIPPI VALLEY TONIGHT. EXPECTED EXPANSION OF THE 13Z MODERATE
RISK WOULD NOW INCLUDE FAR EASTERN OK/NORTHERN AR/SOUTHERN
MO/SOUTHERN IL/WESTERN KY/WESTERN AND MIDDLE TN INTO NORTHERN
AL/MUCH OF GA. A PUBLIC SEVERE WEATHER OUTLOOK /PWO/ WILL BE ISSUED
SHORTLY.

..GUYER.. 05/10/2008


ATTN...WFO...MRX...FFC...TAE...LMK...OHX...BMX...HUN...PAH...MEG...LSX...LZK...SGF...SHV...TSA...

Why in the hell do they not just throw a HIGH into the mix already. Thats the biggest MOD area I've seen since 2007!

#108 User is offline   Calderon Icon

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Weather Observations
50.0 F (10.0 C)

Wind is
Southeast at 5.8 MPH (5 KT)
Humidity:
96%
Pressure:
1013.7mb
Visibility:
8.00 mile(s)
Conditions:
Mostly Cloudy
Location:
KNIP
Updated:
Feb 9 2010, 5:53 am EST

Data Source: NWS

Posted 10 May 2008 - 05:15 AM

Nice PWO just thrown out there!

PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0506 AM CDT SAT MAY 10 2008

...SEVERE THUNDERSTORMS ARE EXPECTED FROM THE ARKLATEX AND MID SOUTH
REGION EASTWARD ACROSS THE GULF COAST STATES TODAY AND TONIGHT...

THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF A FEW STRONG TORNADOES...WIDESPREAD DAMAGING WIND AND
VERY LARGE HAIL FROM THE ARKLATEX AND MID SOUTH REGION EASTWARD
ACROSS THE GULF COAST STATES TODAY AND TONIGHT.

THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE

CENTRAL AND NORTHERN ALABAMA
MUCH OF ARKANSAS
MUCH OF GEORGIA
FAR SOUTHERN ILLINOIS
FAR WESTERN KENTUCKY
NORTHERN LOUISIANA
CENTRAL AND NORTHERN MISSISSIPPI
FAR EASTERN OKLAHOMA
WESTERN AND MIDDLE TENNESSEE
FAR EASTERN TEXAS

A STRONG UPPER LEVEL TROUGH WILL MOVE EASTWARD ACROSS THE PLAINS
STATES THIS AFTERNOON...EMERGING INTO THE LOWER MISSISSIPPI VALLEY
BY LATE TODAY AND CONTINUING ACROSS THE TENNESSEE VALLEY REGION AND
GULF COAST STATES OVERNIGHT INTO SUNDAY MORNING. A VERY MOIST AND
UNSTABLE AIR MASS IS ALREADY IN PLACE FROM TEXAS EASTWARD ALONG THE
GULF COAST...AND THIS UNSTABLE AIR WILL EXPAND NORTHWARD WITH TIME
AS LOW PRESSURE DEEPENS ACROSS THE MID MISSISSIPPI VALLEY. WHILE
TORNADOES...DAMAGING WIND AND VERY LARGE HAIL WILL BE POSSIBLE
ANYWHERE WITHIN THE MODERATE RISK AREA...THE GREATEST THREAT FOR
STRONG TORNADOES WILL OCCUR THIS AFTERNOON AND EVENING OVER CENTRAL
AND EASTERN ARKANSAS...NORTHERN MISSISSIPPI AND WESTERN TENNESSEE.
IN ADDITION TO THE THREAT OF A FEW TORNADOES...WIDESPREAD DAMAGING
WINDS WILL BE POSSIBLE DURING THE EVENING AND OVERNIGHT HOURS ACROSS
MISSISSIPPI...ALABAMA...AND GEORGIA.

THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE WEATHER
SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA WEATHER
RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.

#109 User is offline   snowflake22 Icon

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Weather Observations
F ( C)

Wind is
Calm
Humidity:
%
Pressure:
mb
Visibility:
mile(s)
Conditions:
N/A
Location:
WU-KFLPOMPA5
Updated:
,

Posted 10 May 2008 - 06:23 AM

I honestly believe we are very close to the cusp of a High Risk today, as strongly evidenced by the expansion of the MDT region. The current setup speaks for itself, with a broad region of +50 kt 850-300 mb mean westerly shear and a very expansive area of +60 Tds and high CAPE values along the Gulf Coast and inland. The deeper low solution will likely verify correctly, which will produce more backed winds along the Mississippi Valley and Arklatex regions. This will sharply increase inland SBCAPE values and allow the more northerly warm front position depicted by the models (which is usually indicative of a well known bias) to potentially verify in this situation. Any return flow will be unlimited, with widespread sufficient low level moisture in place. A backed LLJ will very likely be present at the time of the best juxtaposition between the thermodynamics and kinematics around initiation time. Strong/violent tornado potential will be very high along the warm front and immediate regions to the south.

I'm actually very worried for some of the same areas that were impacted by Super Tuesday.

#110 User is offline   tornadotony Icon

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Weather Observations
23.0 F (-5.0 C)

Wind is
East at 4.6 MPH (4 KT)
Humidity:
86%
Pressure:
1021.3mb
Visibility:
1.00 mile(s)
Conditions:
Light Snow
Location:
KIGQ
Updated:
Feb 9 2010, 4:47 am CST

Data Source: NWS

Posted 10 May 2008 - 06:32 AM

View Postsnowflake22, on May 10 2008, 06:23 AM, said:

I honestly believe we are very close to the cusp of a High Risk today, as strongly evidenced by the expansion of the MDT region. The current setup speaks for itself, with a broad region of +50 kt 850-300 mb mean westerly shear and a very expansive area of +60 Tds and high CAPE values along the Gulf Coast and inland. The deeper low solution will likely verify correctly, which will produce more backed winds along the Mississippi Valley and Arklatex regions. This will sharply increase inland SBCAPE values and allow the more northerly warm front position depicted by the models (which is usually indicative of a well known bias) to potentially verify in this situation. Any return flow will be unlimited, with widespread sufficient low level moisture in place. Strong/violent tornado potential will be very high along the warm front and immediate regions to the south.

Yeah they've got another hour until the outlook comes out. I would not at all be surprised to see pink on it, specifically for MEG's CWA, "the 'greatest threat' area." The main reason that the SPC sent out an MD for the MDT expansion is because it includes, per the graphic, some areas that currently have See Text probabilities.

#111 User is offline   snowflake22 Icon

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Weather Observations
F ( C)

Wind is
Calm
Humidity:
%
Pressure:
mb
Visibility:
mile(s)
Conditions:
N/A
Location:
WU-KFLPOMPA5
Updated:
,

Posted 10 May 2008 - 06:45 AM

I expect several MEG-Paducah-Arklatex stations to begin coverage very shortly, as it will become the day's top event. Kevin (JKTinMemphis) will have a busy day at the office...

I could be the only one, but I'm slightly disturbed about the lack of leading coverage on several stations, including WREG in Memphis, Tennessee.

http://www.wreg.com/

I just feel like this deserves more public attention, in my view.

#112 User is offline   snowflake22 Icon

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Weather Observations
F ( C)

Wind is
Calm
Humidity:
%
Pressure:
mb
Visibility:
mile(s)
Conditions:
N/A
Location:
WU-KFLPOMPA5
Updated:
,

Posted 10 May 2008 - 07:28 AM

SPC AC 101210

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0710 AM CDT SAT MAY 10 2008

VALID 101300Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ARKLATEX AND MID SOUTH
REGION EASTWARD ACROSS THE GULF COAST STATES TODAY AND TONIGHT...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
THE SRN PLAINS EWD TO THE ATLANTIC COAST AND NWD TO LOWER OH
VALLEY...

....WIDESPREAD SEVERE THUNDERSTORMS INCLUDING TORNADOES EXPECTED
FROM THE LOWER MS VALLEY EWD ACROSS GULF STATES AND WRN TN VALLEY...


A COMPLEX AND POTENTIALLY DANGEROUS SEVERE WEATHER SITUATION WILL
DEVELOP TODAY AS A VIGOROUS UPPER SYSTEM FROM THE ROCKIES AND
POWERFUL LATE SPRING UPPER JET LEAD TO A RAPIDLY DEEPENING LOW
PRESSURE SYSTEM CENTRAL U.S BEGINNING THIS AFTERNOON.

MOIST AND POTENTIALLY VERY UNSTABLE AIRMASS IS IN PLACE FROM ERN TX
ACROSS GULF STATES TO THE S OF STALLED FRONTAL ZONE FROM NRN GA TO
SRN AR.

PRECEEDING THE ROCKIES UPPER TROUGH A MID LEVEL WIND MAX WILL
QUICKLY CROSS THE SRN PLAINS AND ENHANCE BOTH LIFT AND SHEAR FOR
SEVERE THUNDERSTORM DEVELOPMENT BY EARLY AFTERNOON VICINITY WRN
PORTION OF STALLED FRONTAL ZONE. WITH AN ELEVATED MIXED LAYER IN
PLACE ACROSS THE WARM SECTOR AND STRONG HEATING...MLCAPES WILL
RAPIDLY CLIMB TO ABOVE 2500 J/KG. BY MID AFTERNOON MUCH OF THE WARM
SECTOR S OF FRONT WILL BE RIPE FOR THUNDERSTORM DEVELOPMENT.
SUPERCELLS INCLUDING BOTH TORNADOES AND LARGE HAIL WILL BE MOST
LIKELY AHEAD OF THE WIND MAX VICINITY FRONTAL ZONE SRN AR. 60-70KT
OF DEEP LAYER SHEAR COUPLED WITH THE INSTABILITY WILL CREATE
CONDITIONS FAVORABLE FOR LONG LIVED SUPERCELLS INCLUDING THREAT OF
STRONG TORNADOES. ORGANIZED STORMS/SUPERCELLS WILL MOVE RAPIDLY EWD
UNDER THE STRONG JET MAX ACROSS MS/AL TO GA TONIGHT. THIS COMPLEX
COULD EVOLVE INTO A DERECHO TYPE SYSTEM WITH AN ENHANCED WIND DAMAGE
POTENTIAL. ADDITIONAL SEVERE STORMS ARE LIKELY IN ADVANCE OF THE
MORE ORGANIZED THREAT ACROSS THE INTERIOR GULF STATES THIS AFTERNOON
GIVEN THE AVAILABLE SHEAR/INSTABILITY IN PLACE.

AS THE SURFACE LOW BEGINS THE DEEPENING PROCESS OVER ERN KS THIS
AFTERNOON...LOW LEVEL MOISTURE WILL RAPIDLY SPREAD NEWD ACROSS LOWER
MO INTO LOWER OH VALLEYS. SEVERE THUNDERSTORMS WILL INITIALLY
DEVELOP AHEAD OF THE SURFACE LOW AND ALONG THE COLD FRONT EXPENDING
SWD INTO ERN OK/NRN TX. VERY IMPRESSIVE DEEPENING OF THE SURFACE
AND UPPER LOW FORECASTED TONIGHT EXPECTED TO LEAD TO AT LEAST A
FORCED SQUALL LINE OF DAMAGING WINDS AND EMBEDDED SUPERCELLS THAT
WILL TRACK ACROSS THE LOWER MO VALLEY INTO MID MS VALLEY OVERNIGHT.

THE TORNADO POTENTIAL THIS AREA WILL BE DEPENDENT ON AMOUNT OF
DESTABILIZATION THAT CAN OCCUR AND HOW FAR N. GFS IS INDICATING
THERE WILL BE SUFFICIENT INSTABILITY FOR BOTH VERY DAMAGING WINDS
AND TORNADIC SUPERCELLS AS THE SQUALL LINE MOVES RAPIDLY EWD DRIVEN
BY THE 100KT 500MB WIND MAX ROTATING AROUND THE DEEPENING LOW ACROSS
NRN MO. HAVE SHIFTED BOTH THE MDT/SLGT RISK AREAS SIGNIFICANTLY NWD
TO ACCOUNT FOR THE EXPECTED GREATER INSTABILITY.

ALONG WITH THE TORNADO POTENTIAL...SIGNIFICANT WIND DAMAGE WILL
ACCOMPANY THE SQUALL LINE POSSIBLY AS FAR E AS LOWER OH AND WRN TN
VALLEYS LATER TONIGHT.

GIVEN THE COMPLEXITY/INTENSITY OF THE DEVELOPING STORM SYSTEM AND
AVAILABILITY OF UNSTABLE GULF AIR...THE NEXT 24-48 HOURS EXPECTED TO
SEE A LARGE AREA AFFECTED BY SEVERE THUNDERSTORMS INCLUDING THE
POTENTIAL FOR STRONG TORNADOES AND PARTICULARLY DAMAGING WINDS.

..HALES/JEWELL.. 05/10/2008

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
CURRENT UTC TIME: 1228Z (8:28AM), RELOAD THIS PAGE TO UPDATE THE TIME

Attached File  MDTRiskMay10081.gif (17.17K)
Number of downloads: 0

That is a massive MDT Risk for today. Wow... I'm simply a little surprised that the MEG area didn't receive a High Risk. Regardless, I completely agree with the CPC's wording and thoughts for today.

#113 User is offline   smokeater342 Icon

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Weather Observations
41.0 F (5.0 C)

Wind is
Calm
Humidity:
79%
Pressure:
1016.0mb
Visibility:
10.00 mile(s)
Conditions:
Overcast
Location:
KNJHAMMO1
Updated:
Feb 9 2010, 6:53 am EST

Data Source: NWS

Posted 10 May 2008 - 07:34 AM

I think thats just about the biggest 15% risk area i've ever seen....

#114 User is online   Solak Icon

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Weather Observations
34.0 F (1.0 C)

Wind is
Calm
Humidity:
100%
Pressure:
1017.8mb
Visibility:
10.00 mile(s)
Conditions:
Fair
Location:
KJNX
Updated:
Feb 9 2010, 5:56 am EST

Data Source: NWS

Posted 10 May 2008 - 07:47 AM

Posted Image

MESOSCALE DISCUSSION 0855
NWS STORM PREDICTION CENTER NORMAN OK
0736 AM CDT SAT MAY 10 2008

AREAS AFFECTED...CENTRAL/EASTERN OK AND SOUTHEAST KS INTO SOUTHWEST
MO AND WESTERN AR

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 101236Z - 101500Z

RISK FOR LARGE HAIL /AND PERHAPS EVEN DAMAGING WINDS/ APPEARS LIKELY
TO STEADILY INCREASE THROUGH THE MID/LATE MORNING HOURS ACROSS
CENTRAL/EASTERN OK INTO ADJACENT PORTIONS OF EASTERN KS/WESTERN AR
AND SOUTHWEST MO. A WATCH APPEARS LIKELY LATER THIS MORNING.

LARGE SCALE HEIGHT FALLS ARE GRADUALLY OCCURRING AHEAD OF A MID
LEVEL TROUGH CROSSING THE CENTRAL/SOUTHERN ROCKIES...WITH
CONSIDERABLE MID LEVEL MOISTENING/CLOUD TOP COOLING OCCURRING EARLY
THIS MORNING PER SATELLITE IMAGERY. MORNING SOUNDINGS AND REGIONAL
PROFILERS/WSR-88D DERIVED WINDS ARE SAMPLING A 40+ KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET ACROSS TX/OK INTO KS. AS LOW TO
MID LEVEL ISENTROPIC ASCENT/ELEVATED MOISTURE TRANSPORT CONTINUES TO
MARKEDLY INCREASE AHEAD OF THE UPPER TROUGH...STORMS APPEAR LIKELY
TO EXPAND IN COVERAGE/INTENSITY THROUGH 15Z-18Z ACROSS
CENTRAL/EASTERN OK INTO ADJACENT PORTIONS OF KS/MO/AR.

MORNING OBSERVED SOUNDINGS SAMPLE A POTENTIALLY VERY UNSTABLE
AIRMASS ACROSS TX/OK EARLY THIS MORNING. VERY STEEP /8.0-8.5 C PER
KM/ MID LEVEL LAPSE RATES WERE SAMPLED BY THE 12Z NORMAN RAOB...WITH
3500 J/KG MUCAPE ATOP A CONSIDERABLY MOISTENED 850 MB LAYER...WITH
THE IMPLICATION THAT ELEVATED CONVECTIVE INITIATION IS LIKELY IN THE
NEXT FEW HOURS. THE 12Z RAOB FROM DALLAS-FORT WORTH EXHIBITED
SIMILAR POTENTIAL INSTABILITY OF 3700 J/KG MUCAPE...ALTHOUGH A STOUT
CAP WAS OBSERVED AT 850 MB.

WITH STRONG DEEP LAYER SHEAR /45-55 KT/ AND QUICKLY
INCREASING/NORTH-SPREADING INSTABILITY ABOVE THE SURFACE...MID LEVEL
ROTATION WILL LIKELY BE ATTAINED RATHER QUICKLY AFTER STORM
INITIATION. THUS...ELEVATED SUPERCELLS WITH LARGE HAIL ARE LIKELY AS
THE MORNING WEARS ON. HOWEVER...EVEN WITH A RELATIVELY STABLE
BOUNDARY LAYER THIS MORNING...A DAMAGING WIND THREAT CANNOT BE RULED
OUT /ESPECIALLY LATER THIS MORNING/ GIVEN THE LAPSE RATES AND DEGREE
OF DRY AIR INITIALLY IN THE MID LEVELS.

..GUYER.. 05/10/2008

#115 User is offline   snowflake22 Icon

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Weather Observations
F ( C)

Wind is
Calm
Humidity:
%
Pressure:
mb
Visibility:
mile(s)
Conditions:
N/A
Location:
WU-KFLPOMPA5
Updated:
,

Posted 10 May 2008 - 07:57 AM

Unlike the previous events, I doubt the isolated "hailer" activity over Oklahoma (mentioned above) will affect the rest of the event. I think the cap will only enhance the environment for tornadic supercells later today. Firstly, we are observing a stronger low-level/mid-level (850 mb) cap over the eastern Plains when compared to previous recent events that did not feature large numbers of tornadoes. Therefore, these storms will likely not overspread the warm sector before weakening or dissipating. We will simply not see as significant disruption of the low level moisture and instability, unlike previous events. The capping will also allow discrete supercellular generation from the AR/OK border eastward as the best kinematics enter the region in conjunction with VERY high MUCAPE and SBCAPE values, in addition to low level moisture that is NOT excessively tapped or "exhausted". Shear values (as mentioned by the SPC and others) at the 850-300 mb level will continue to remain very high and increase as the LLJ remains backed over Arkansas. In other words, everything will likely "match up" because of the later timing. In addition to discrete tornadic supercells along the Arkansas and Oklahoma border, I also expect initiation further east along the Mississippi Valley; both expected initiation locations are well ahead of the cold front. The Mississippi Valley strong/violent tornado threat is also highlighted by the SPC.

I think everything is favoring a significant event. It would be certainly interesting to hear Fred's thoughts...

#116 User is offline   snowflake22 Icon

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Weather Observations
F ( C)

Wind is
Calm
Humidity:
%
Pressure:
mb
Visibility:
mile(s)
Conditions:
N/A
Location:
WU-KFLPOMPA5
Updated:
,

Posted 10 May 2008 - 09:51 AM

MESOSCALE DISCUSSION 0856
NWS STORM PREDICTION CENTER NORMAN OK
0940 AM CDT SAT MAY 10 2008

AREAS AFFECTED...PARTS OF SRN AR INTO NRN LA...MS

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 101440Z - 101545Z

A WW MAY BE NEEDED SHORTLY. IT APPEARS THAT THE RISK FOR TORNADOES
COULD INCREASE BY EARLY AFTERNOON...IN ADDITION TO AN INCREASING
RISK FOR LARGE HAIL.

THUNDERSTORMS CONTINUE TO SLOWLY INTENSIFY WITHIN LOWER/MID
TROPOSPHERIC WARM ADVECTION REGIME ACROSS WESTERN/SOUTHERN ARKANSAS.
THIS FORCING APPEARS TO BE OCCURRING JUST AHEAD OF A SUBTROPICAL
IMPULSE ALREADY PROGRESSING INTO THE SOUTHERN PLAINS...IN ADVANCE OF
MORE PROMINENT INTENSIFYING POLAR IMPULSE DIGGING ACROSS THE CENTRAL
ROCKIES. AND...THIS WILL CONTINUE TO SPREAD EASTWARD TOWARD THE
TENNESSEE VALLEY LATE THIS MORNING INTO THE AFTERNOON HOURS.

WHILE LARGE HAIL MAY BE THE PRIMARY SEVERE THREAT...AT LEAST
INITIALLY...WITH ACTIVITY DEVELOPING ABOVE A RELATIVELY COOL/STABLE
BOUNDARY LAYER...THERE IS CONCERN THAT THE BOUNDARY LAYER MAY BEGIN
A RAPID DESTABILIZATION AS A SURFACE WARM FRONT REDEVELOPS NORTHWARD
THROUGH THE OZARK PLATEAU. BOUNDARY CURRENTLY EXTENDS NEAR THE
LOUISIANA/ARKANSAS BORDER...AND A VEERING OF SURFACE WINDS FROM
EASTERLY TO SOUTHERLY BY EARLY AFTERNOON WILL ALLOW UPPER 60S TO
AROUND 70F SURFACE DEW POINTS TO OVERSPREAD REGION.

MIXED BOUNDARY LAYER CAPE INCREASING IN EXCESS OF 2000 J/KG...
COUPLED WITH INCREASING LOW-LEVEL SHEAR AS SOUTHERLY 850 MB FLOW
STRENGTHENS TO 30+ KT...MAY SUPPORT AN INCREASING RISK FOR TORNADOES
WITH SUPERCELLS IN THE PRESENCE OF STRONG DEEP LAYER SHEAR.

..KERR.. 05/10/2008


ATTN...WFO...MEG...JAN...LZK...SHV...

33779436 35149394 35739212 34979040 34438915 33298905
32339012 32549331

Attached File  SBCAPEARMay10081.gif (38.89K)
Number of downloads: 0

+1,000 SBCAPE is rapidly advancing northward. Violent supercell initiation in Arkansas should begin very shortly over the next few hours...

#117 User is offline   ScottL Icon

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Posted 10 May 2008 - 10:06 AM

Cells starting to fire near Fort Smith. One has a just picked up a hail icon per GR2AE. Lightning has also increased with these cells in the last 5-10 minutes.

#118 User is offline   janetjanet998 Icon

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Posted 10 May 2008 - 10:09 AM

This is going to be huge folks

#119 User is offline   Pilot_Guy Icon

  • Texas Storm Chasers
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Weather Observations
29.0 F (-1.7 C)

Wind is
Northwest at 17.3 MPH (15 KT)
Humidity:
72%
Pressure:
1022.5mb
Visibility:
10.00 mile(s)
Conditions:
Fair
Location:
KRBD
Updated:
Feb 9 2010, 4:53 am CST

Data Source: NWS

Posted 10 May 2008 - 10:11 AM

Tornado Watch #292 just issued

Also, As I am a newbie to the severe weather area, I was wondering, Were there storms suppose to form this early, and if not, what will this do to later convection? I know that this will leave outflow boundries, which will help later, but what about the cloudcover?

#120 User is offline   psualum95 Icon

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Weather Observations
41.0 F (5.0 C)

Wind is
Calm
Humidity:
79%
Pressure:
1016.0mb
Visibility:
10.00 mile(s)
Conditions:
Overcast
Location:
kflorlan1
Updated:
Feb 9 2010, 6:53 am EST

Data Source: NWS

Posted 10 May 2008 - 10:18 AM

Posted Image

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 292
NWS STORM PREDICTION CENTER NORMAN OK
1010 AM CDT SAT MAY 10 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTHERN ARKANSAS
NORTHERN LOUISIANA
WEST-CENTRAL MISSISSIPPI

EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 1010 AM UNTIL
400 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTH NORTHWEST OF
TEXARKANA ARKANSAS TO 25 MILES NORTH NORTHEAST OF JACKSON
MISSISSIPPI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

DISCUSSION...WELL-DEFINED WARM FRONT CURRENTLY ALONG LA/AR BORDER
EAST TO CNTRL MS WILL CONTINUE TO LIFT NWD ACROSS WATCH AREA INTO
THE AFTERNOON AS INCREASING LARGE SCALE ASCENT SPREADS EAST WITH
STRONG UPPER WAVE. INCREASINGLY MOIST/UNSTABLE AIR MASS WILL FUEL
TSTM DEVELOPMENT WITH SURFACE-BASED SUPERCELLS MOST LIKELY
DEVELOPING ACROSS THE AREA LATER THIS AFTERNOON. SHEAR PROFILES IN
THE WARM SECTOR...AND ESPECIALLY NEAR THE WARM FRONT...ARE FORECAST
TO BE QUITE SUPPORTIVE OF LOW LEVEL STORM ROTATION/MESOCYCLONES WITH
EFFECTIVE SRH VALUES IN SOME AREAS FORECAST TO EXCEED 200 M2/S2.
THUS...A FEW TORNADIC SUPERCELLS APPEAR POSSIBLE WITH ADDITIONAL
THREATS OF LARGE HAIL AND DAMAGING OUTFLOW WINDS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 27030.


...CARBIN

TORNADO WATCH PROBABILITIES FOR WT 0292
NWS STORM PREDICTION CENTER NORMAN OK
1014 AM CDT SAT MAY 10 2008

WT 0292
PROBABILITY TABLE:
PROB OF 2 OR MORE TORNADOES : 40%
PROB OF 1 OR MORE STRONG /F2-F5/ TORNADOES : 30%
PROB OF 10 OR MORE SEVERE WIND EVENTS : 30%
PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS : 20%
PROB OF 10 OR MORE SEVERE HAIL EVENTS : 40%
PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES : 30%
PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS : 70%

&&
ATTRIBUTE TABLE:
MAX HAIL /INCHES/ : 2.0
MAX WIND GUSTS SURFACE /KNOTS/ : 60
MAX TOPS /X 100 FEET/ : 450
MEAN STORM MOTION VECTOR /DEGREES AND KNOTS/ : 27030
PARTICULARLY DANGEROUS SITUATION : NO

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