April '10 Weather Discussion

[venture]

Welcome to April...well almost.

Starting this up to handle discussion on potential severe weather that will be possible going into April.

April 2nd
First real severe weather threat of the year, but timing may be slightly off for this. Temps will be starting off in the low to mid 60s across the state with gusty SSE winds over most of the area. Moisture will increase throughout the early part of the day with dewpoints into the low 60s up through most of Central OK. System currently appears to kick through OK during the early afternoon right now. Instabilities won't have a long time to get all that high, but ahead of the front/dryline there will be a moderately unstable atmosphere. There will be some veering to the wind, but shear won't be all that strong - at least as currently forecast. The system will move quickly to the east dropping temps into the low 50s by early evening. Rainfall wise, some areas could see more than an inch of precip - so we'll have to watch that.

April 3rd
Potential we might see some wrap around activity. Atmosphere will be somewhat unstable but moisture will be low, temps won't be very warm, and precip should be restricted to Northern OK.

April 5th
Better shot at severe weather this day, as it appears. Atmosphere is projected to be moderately to very unstable. Main risk area appears to be the Central and Eastern thirds of the state. Western OK appears to be missing this one. Temps will range from upper 60s north, to mid 70s south. Just along and east of I-35, dewpoints are forecast to get into the mid 60s. Surface winds don't appear to be all that strong this day and the other lower levels of wind don't look all that impressive. Activity appears to be isolated to scattered, but the instability will be there for a severe weather day.

April 7th - AM
Early morning event here, which seems a bit odd for this early in the season. Rainfall amounts are projected to be light, but instability looks very high again. I'm not really buying this, but here we'll go. This will be occurring early in the morning on the 7th and will impact mostly Central and Eastern OK. Temps should be in the mid to upper 60s at the time with dewpoints well into the 60s.

April 9th into 10th
Maybe something here, but doesn't look like enough to mention in detail just yet.

Welcome to Spring.

[Thunder]

Venture, the correct term is....

"Welcome to wall-to-wall coverage."

[venture]

Update withe 00Z GFS run tonight.

April 2nd
Continues to evolve into a severe weather day. GFS has slowed the system down considerably since my last update. Dryline will approach I-35 around early-mid evening between 7 and 9 pm. Dewpoints ahead of this will be in the low 60s. Air temps will be in the mid to upper 60s, some 70s behind the dryline (drier air warming faster). Winds appear to be SSE 15-25 mph for the day. Wind profiler does show some minor shifts in wind direction with height, but mostly will be out of the south. Instability estimates right now has CAPE between 1000 to 2000 j/kg ahead of the dryline and Lifted Index values right around -5. This depicts a moderately unstable to atmosphere to play with. Greatest risk for severe weather will probably be just to the west of I-35.

OKC Specific Forecast Sounding
Since sounding images tend to vanish quick, I'll type the values out.
PW: 1.16 (pretty wet sounding), RH 70.3%, MAXT 75°F, L57: 6.5 (unstable), LCL 948 mb, LI -2.9 (marginally unstable), TT 52 (isolated servere storms), KI 32 (moderate chance of storms), SW 316 (severe storms possible), EI -1.2 (isolated severe storms), CAPE 703 (unstable), CAP 0.5 (fairly weak), Storm Motion from 225° (SW) at 35 kts, HEL 141 (borderline for supercell structures), SHR 0 (weak shear), SRDS 93 (strong), EHI 0.6, BRN 8.5 (strongly sheared environment).

Lawton Specifics
PW 1.09 (wet), RH 73%, MAXT: 75, L57: 6.3 (conditional unstable), LCL 912 mb, LI -4.2 (moderate instability), SI -2 (marginal instability), TT: 54 (widely scattered severe storms), KI: 37 (moderate chance for storms), SW: 310 (severe storms possible), EI: -1.6 (isolated severe storms), CAPE: 1062 (moderate instability), CAP 1.6 (moderate cap), Storm Motion is from 232° (SW) at 29 kts, HEL 63 (weak), SHR 0 (weak), SRDS 31 (some shear), EHI 0.6 weak, BRN 13.5 (environment may be too sheared for conditions).

So overall...I would say a slight risk of severe storms is a given, with the greatest risk being hail and wind. Storms should form into a squall line as they march east and weaken.

April 3rd
Chance of rain in the state, especially Western Half. Some areas of the state won't get out of the 40s.

April 6th
Putting this in there because the ingredients will be there for severe weather, but looks like a very strong cap also in place. If storms are able to develop or the CAP doesn't actually happen (which I wouldn't be shocked this early in the season), this could be a day to watch. I won't go into too much of a discussion on this as we get closer.

KOKC Sounding
PW: 0.85 (moist, but some what dry), RH 30.5 (very low), MAXT: 89°F, L57: 7.5 (conditional unstable), LCL 887mb (pretty high up), LI -3.8 (moderate instability), SI -0.5 (marginal instability), TT 50 (convection likely), KI 18 (small potential for convection/storms), SW: 366 (severe storms possible), EI: -1.8 (isolated severe storms), CAPE 1182 (moderate instability), CAP 5.1 (monster cap), Storm Motion from 257 ° (WSW) at 30 kts, HEL 453 (tornadic development possible) SHR +0 (yawn), SRDS 88 (moderate shear), EHI 3.1 (moderate tornado strength - EF1 to EF3), BRN 8.9 (environment severely oversheared)

So basically what all that means. Some ingredients are there for tornadic storms, but there are a lot of other factors that will rip storms apart before they can even think of starting. Marginal day at best if anything can even develop.

April 10th-12th
Looks like potential for isolated to scattered storms through this period. On the 10th - Temps in the upper 60s central and east, near 80 west. Dewpoints in the 60s Central and east. CAPE around 1000-1500 j/kg with LI values around -5. Should be some decent directional shear, so will put this at a day to watch as we get closer. 11th storms will get going out west (note a strong event possible into KS/MO/NE). Temps near 70 with dews in the 60s. CAPE values generally around 1000 j/kg and LI's around -4 to -5. Decent direction sheer this day as well. Looks like storms get cranking mostly in the overnight period going into the 12th and we could see some very heavy rain from them at this time.

We'll see what happens. Severe weather is a pain to get more than a day out, so this is all a very rough guess. You can also tell how erratic long term models are seeing as days I mentioned a few days ago aren't even mentioned this time.

[Thunder]

You do realize that I am not happy with you, right? I have to work on that day! I was suppose to be off, but they scheduled me. So, no chasing for me. >_<

[SkyWestOKC]

2nd looks great, I don't have to work! Too bad I have the darned 0430 shift the following morning, might cut into "operations".

[venture]

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0212 AM CDT TUE MAR 30 2010

VALID 011200Z - 021200Z

...SYNOPSIS...
PATTERN SHIFT UNDERWAY ATTM...TOWARD ERN RIDGING AND WRN
TROUGHING...WILL INCLUDE STG SHORTWAVE TROUGH MOVING ASHORE CA COAST
DAY-2...THEN EWD ACROSS 4-CORNERS STATES THIS PERIOD. BY
2/12Z...STG CONSENSUS OF OPERATIONAL MODELS AND SREF GUIDANCE
INDICATES TROUGH WILL EXTEND FROM WY SSWWD ACROSS WRN NM THEN SWD
OVER ADJACENT PORTIONS NWRN MEX. EMBEDDED 500 MB VORTICITY MAX OVER
WRN NM MAY BE ACCOMPANIED BY CLOSED CIRCULATION. BY THAT TIME...STG
MID-UPPER LEVEL SPEED MAX WILL EXTEND OVER CA...SONORA...ERN
NM...AND WRN KS. MEANWHILE...WEAK UPPER LOW SHOULD FORM OVER SERN
GULF AND DRIFT GENERALLY NWD LATE IN PERIOD...AS HEIGHTS BEGIN
FALLING OVER WRN GULF IN ADVANCE OF MIDLATITUDE SHORTWAVE TROUGH.

COMBINED LEE-SIDE/FRONTAL-WAVE SFC CYCLONE DESCRIBED IN DAY-2
OUTLOOK IS FCST TO REDEVELOP WWD ACROSS PORTIONS NWRN KS/ERN CO
EARLY IN PERIOD...THEN MOVE EWD ACROSS CENTRAL HIGH PLAINS ALONG
WITH FRONTAL ZONE. SOME DISCREPANCIES STILL ARE EVIDENT IN PROGS OF
LOW-LEVEL MASS-FIELD RESPONSE TO APCHG UPPER PERTURBATION...BUT GEN
CONSENSUS APPEARS REASONABLE DEPICTING FRONTAL ZONE FROM SRN MN TO
NWRN KS/NERN CO/SWRN NEB AREA BY 2/00Z...THEN SWWD ACROSS NRN
PORTIONS TX PANHANDLE AND SERN NM. BY 2/12Z...FRONT MAY EXTEND FROM
WEAK WAVE CYCLONE OVER PORTIONS WI/NM SWWD ACROSS ERN
NEB...CENTRAL/SWRN KS...AND PERMIAN BASIN/LOWER PECOS REGION OF W
TX. DRYLINE SHOULD BECOME BETTER-DEFINED WITH TIME FROM FRONTAL
INTERSECTION OVER SWRN NEB OR NWRN KS...SWD ACROSS NWRN OK/ERN TX
PANHANDLE AREA AND W-CENTRAL TX...TO RIO GRANDE VALLEY BETWEEN DRT
AND BIG BEND. FRONT WILL OVERTAKE DRYLINE FROM N-S ACROSS KS...OK
AND PARTS OF W TX OVERNIGHT.

...CENTRAL/SRN PLAINS...
BROAD/STG WAA REGIME IN LOW LEVELS WILL BE UNDERWAY BY START OF
PERIOD ACROSS CENTRAL/SRN PLAINS S OF THAT FRONTAL ZONE...WITH SLOW
RETURN OF PROGRESSIVELY MORE WELL-MODIFIED AIR MASS FROM GULF.
THREE DAYS OF AIR MASS MODIFICATION OVER GULF SHOULD BE SUFFICIENT
TO YIELD SFC DEW POINTS COMMONLY 50S WITH POCKETS OF LOW 60S F BY
2/00Z...IN CORRIDOR FROM W-CENTRAL TX NNEWD ACROSS CENTRAL KS TO
IA...AHEAD OF FRONT/DRYLINE. SREF CONSENSUS INDICATES THIS...THOUGH
WITH CONSIDERABLE SPREAD FROM MEAN WHEN ASSESSING INDIVIDUAL MODEL
SETS WITHIN ENSEMBLE.

STG SFC HEATING WITHIN WRN EDGE OF MOIST SECTOR MAY CONTRIBUTE TO
DEVELOPMENT OF NARROW CORRIDOR OF MLCAPE NEAR 1000 J/KG JUST AHEAD
OF FRONT AND DRYLINE FROM MID-AFTERNOON INTO EARLY
EVENING...MAINTAINED SOMEWHAT NOCTURNALLY BY BOUNDARY LAYER MOIST
ADVECTION. MEANWHILE...DEEP-LAYER VERTICAL SHEAR WILL INCREASE
ACROSS MUCH OF CENTRAL/SRN PLAINS AS TROUGH APCHS.

PRIMARY LIMITING FACTOR FOR CONVECTIVE INITIATION ALONG
FRONT/DRYLINE...BOTH DURING DAYLIGHT HOURS AND FOR MUCH OF
EVENING/OVERNIGHT...WILL BE PRESENCE OF VERY STG CAPPING BENEATH
STOUT/ANTECEDENT ELEVATED MIXED LAYER AIR. CAP STRENGTH ON MODIFIED
FCST SOUNDINGS SUGGEST POTENTIAL FOR SVR WILL BE MUCH TOO
CONDITIONAL FOR ALMOST ALL OF DAY-3 TO FCST CATEGORICAL SVR RISK
ATTM. HOWEVER...AS STRENGTHENING FRONTAL ZONE IMPINGES UPON
INCREASING MOISTURE...MIDLEVEL FLOW BECOMES MORE MERIDIONAL...AND
WINDS BACK WITH HEIGHT IN 600-800MB LAYER...LINE OF TSTMS MAY
DEVELOP NEAR END OF PERIOD. ANY CONVECTION FORMING IN THIS REGIME
WOULD POSE SVR RISK...BUT INITIATION BEFORE 2/12Z APPEARS TOO
UNCERTAIN TO ASSIGN MORE THAN 5% UNCONDITIONAL PROBABILITIES ATTM.

..EDWARDS.. 03/30/2010



DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0354 AM CDT TUE MAR 30 2010

VALID 021200Z - 071200Z

...DISCUSSION...
STG WRN TROUGHING IS EXPECTED FROM WY-NM TO NWRN MEX BY START OF
DAY-4/2ND-3RD...WITH CONSENSUS AMONG BOTH ENSEMBLE AND OPERATIONAL
MODELS THAT THIS FEATURE WILL TURN NEWD LATE DAY-4 AND INTO
DAY-5/3RD-4TH...REACHING VICINITY LS BY END OF DAY-5. SFC CYCLONE
LIKEWISE SHOULD EJECT NEWD FROM SRN PLAINS TO UPPER MS VALLEY...AS
COLD FRONT SWEEPS EWD/SEWD OVER MID-UPPER MS VALLEY AND SRN PLAINS.
UKMET APPEARS TO BE LESS-RELIABLE FAST OUTLIER COMPARED TO
ECMWF/SPECTRAL AND MOST MREF MEMBERS. FRONT SHOULD WEAKEN ACROSS S
TX DAYS 5-6/3RD-5TH AS UPPER SUPPORT WILL BE WELL-REMOVED.

GREATEST SVR POTENTIAL APPEARS TO BE DAY-4 INVOF FRONT...BEGINNING
EARLY IN PERIOD OVER WRN PORTIONS SRN PLAINS...WHEN GEOMETRY OF MASS
FIELDS...MAX AVAILABILITY OF MOISTURE TO THIS SYSTEM...AND PROBABLE
ALIGNMENT OF FRONT SUGGEST LIKELIHOOD OF DOMINANT LINEAR
ORGANIZATION. DEEP-LAYER SHEAR CERTAINLY COULD BE SUFFICIENT TO
SUPPORT SUPERCELLS ESPECIALLY NEAR SRN PORTION OF CONVECTIVE ZONE
OVER TX...WHERE CAPPING WILL BE STRONGER DUE TO ANTECEDENT ELEVATED
MIXED LAYER. ACTUAL CORRIDOR OF POTENTIAL SVR THREAT IS LONGER THAN
30% AREA HERE...WHICH INSTEAD REPRESENTS BEST ESTIMATE OF
JUXTAPOSITION OF MOVING FRONTAL ZONE...RICHEST RETURNING MOISTURE
AND STG DEEP-LAYER SHEAR.

..EDWARDS.. 03/30/2010

[Thunder]

Venture, rather than posting what the NWS had posted, tell us these things in your own words. It is more interesting to read thru it that way.

[venture]

Venture, rather than posting what the NWS had posted, tell us these things in your own words. It is more interesting to read thru it that way.

Yeah I'm going to tonight. I just like a day or two to go by between my discussions so models can chew through whatever they need to.

[Thunder]

No no no. We'd like to see how things can change from a meteorologist's perspective. Give us a breakdown of what you see currently that will happen, then the next change, you give us further update.

[venture]

Ran out of time this morning. Will get to my own discussion in a few hours.



DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1247 AM CDT WED MAR 31 2010

VALID 011200Z - 021200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
MID-UPPER HEIGHTS CONTINUE TO FALL OVER WRN CONUS AND RISE OVER MOST
OF ERN STATES...AS MID-UPPER CYCLONE MOVES OFFSHORE MID-ATLANTIC/SRN
NEW ENGLAND REGION...AND SERIES OF SHORTWAVE TROUGHS AFFECT W COAST
STATES. MOST IMPORTANT OF THESE PERTURBATIONS WILL BE SHORTWAVE
TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY INVOF 41N138W. AS
THIS FEATURE MOVES TOWARD MEAN TROUGH...IT WILL AMPLIFY
CONSIDERABLY. THIS TROUGH THEN SHOULD TURN EWD AND MOVE FROM
POSITION OVER SRN CA AND NRN BAJA AROUND 1/12Z TO NM AND INTERIOR
NWRN MEX BY 2/12Z...AS PART OF REGIME OF HIGH-AMPLITUDE TROUGHING
EXTENDING NNEWD ACROSS DAKOTAS. AHEAD OF THAT...AND DURING LATTER
HALF OF PERIOD...120-140 KT/SSWLY 250 MB SPEED MAX WILL TRANSLATE
EWD ACROSS NRN/CENTRAL PLAINS AND CENTRAL/SRN HIGH PLAINS.

VIGOROUS LEE-SIDE TROUGHING AND FRONTOGENESIS IN LOW-LEVELS SHOULD
RESULT IN 1/12Z SFC CYCLONE OVER NWRN CO WITH QUASISTATIONARY
FRONTAL ZONE CURVING EWD/NEWD OVER NEB TO SRN MN. BY 2/00Z...LOW
SHOULD RESIDE OVER CENTRAL/SWRN NEB AT INFLECTION POINT IN FRONTAL
ZONE. FRONT SHOULD EXTEND SSWWD ACROSS WRN TX PANHANDLE AND SERN
NM...MOVING SLOWLY EWD OVERNIGHT ACROSS WRN KS...AND INTO WRN OK AND
NW TX. DRYLINE WILL BECOME BETTER-DEFINED WITH TIME FROM
W-CENTRAL/SWRN KS SWWD ACROSS W-CENTRAL/SW TX...AS BROAD SWATH OF
PARTIALLY MODIFIED RETURN-FLOW AIR ADVECTS MOISTURE POLEWARD THROUGH
WARM SECTOR.

...CENTRAL/SRN PLAINS...
SFC ANALYSIS SHOWS SUFFICIENT MARINE MODIFICATION HAS OCCURRED TO
YIELD BROAD FIELD OF 60-64 F SFC DEW POINTS OVER ROUGHLY SWRN 1/3 OF
GULF...WITH 50S F ASHORE ENTIRE TX COASTAL PLAIN. MODIFIED 31/00Z
RAOBS AROUND GULF INDICATE MARINE BOUNDARY LAYER IS RELATIVELY
SHALLOW AND MAY BE EASILY MIXED WHERE STG DIABATIC HEATING DOES TAKE
PLACE...AT LEAST TO EXTENT THAT STG CAPPING WILL PERMIT. MIXING AND
RELATED BOUNDARY LAYER DESTABILIZATION COULD BE RESTRICTED DIURNALLY
DUE TO LOW CLOUDS COVERING MUCH OF MOIST SECTOR...ALTHOUGH NARROW
CORRIDOR AHEAD OF FRONT/DRYLINE SHOULD CLEAR LONG ENOUGH FOR AT
LEAST A FEW HOURS OF STG HEATING. EXPECT PLUME OF LOW-50S TO
LOW-60S F SFC DEW POINTS BY 2/00Z FROM N-CENTRAL/NW TX TO N-CENTRAL
KS.

SEVERAL DAYS OF PRIOR SWLY FLOW ALOFT WILL HAVE YIELDED STOUT
ELEVATED MIXED-LAYER AIR MASS CHARACTERIZED BY STEEP MIDLEVEL LAPSE
RATES...BUT ALSO STG CAPPING OF BOUNDARY LAYER BENEATH. THIS SHOULD
PRECLUDE AFTERNOON TSTMS OVER MOST OF OUTLOOK AREA...ALTHOUGH
DEEP-LAYER SHEAR PROFILES WILL SUPPORT CONDITIONAL SVR POTENTIAL
WITH ANY TSTM THAT CAN DEVELOP. IF AN ISOLATED DIURNAL TSTM CAN
FORM...PRIND PROBABILITY WOULD BE RELATIVELY MAXIMIZED BY LATE
AFTERNOON OVER N-CENTRAL OR W-CENTRAL KS -- NEAR COLD FRONT/DRYLINE
INTERSECTION AND IN RELATIVE PROXIMITY TO RELATIVE LOW-LEVEL
CONVERGENCE MAX REPRESENTED BY SFC CYCLONE. THREAT IS TOO
CONDITIONAL/ISOLATED FOR CATEGORICAL OUTLOOK ATTM.

MAIN CONVECTIVE POTENTIAL..AND CONDITIONAL SVR THREAT...WILL BE NEAR
END OF PERIOD IN CORRIDOR FROM N-CENTRAL KS TO WRN OK AND NW AND
W-CENTRAL TX. AS TIME PROGRESSES AFTER 2/06Z...PROBABILITY WILL
INCREASE FOR LINE OF TSTMS TO DEVELOP ALONG KS/OK SEGMENT OF COLD
FRONT SSWWD TOWARD AND PERHAPS ALONG DRYLINE. QUESTION ATTM IS NOT
SO MUCH WHETHER THIS WILL OCCUR...BUT INSTEAD...TO WHAT EXTENT
BEFORE VERSUS AFTER 2/12Z. TIMING WILL DEPEND ON MESOSCALE FACTORS
SUCH AS STRENGTH OF FRONTOGENETIC FORCING AND CONVECTIVE-SCALE
LIFT...IN ENVIRONMENT WHERE FLOW BACKING WITH HEIGHT IN 800-600 MB
LAYER INDICATES LIKELIHOOD THAT LINEAR MODE WOULD BECOME DOMINANT
FAIRLY QUICKLY AFTER INITIATION. SOME SUBSET OF THIS CORRIDOR MAY
BE UPGRADED CATEGORICALLY IF CONFIDENCE INCREASES IN A FEW HOURS OF
ORGANIZED CONVECTION BEFORE 12Z...GIVEN STRENGTH OF DEEP-LAYER WIND
FIELDS.

..EDWARDS.. 03/31/2010



DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0229 AM CDT WED MAR 31 2010

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN PLAINS TO ARKLATEX
REGION AND AR...

...SYNOPSIS...
BY 2/12Z...SERIES OF MID-UPPER LEVEL SHORTWAVE TROUGHS -- NOW
CONTRIBUTING TO HEIGHT FALLS OVER MUCH OF WRN CONUS -- WILL LEAD TO
HIGH-AMPLITUDE TROUGH FROM DAKOTAS SSWWD ACROSS CENTRAL HIGH
PLAINS...SRN NM AND INTERIOR NWRN MEX. ANCHORING/SRN SHORTWAVE
TROUGH SHOULD MOVE EWD TO W TX BY 3/00Z...THEN PIVOT GRADUALLY ENEWD
ACROSS CENTRAL/NRN TX AND PERHAPS ARKLATEX REGION BY END OF PERIOD.
MINOR TIMING DIFFERENCES REMAIN IN MOST SHORT-RANGE PROGS...AND
UNLIKE OPERATIONAL SPECTRAL/WRF...SOME SREF MEMBERS INDICATE CLOSED
500 MB LOW BY MIDDLE OF PERIOD OVER W TX. DESPITE THESE MESOSCALE
DIFFERENCES...GENERAL TREND IS FOR MORE PROGRESSIVE AND STRONGER
HEIGHT FALLS AT LOWER LATITUDES THAN PROGS HAVE INDICATED BEFORE.

AT SFC...COLD FRONT SHOULD EXTEND FROM MN LOW SSWWD ACROSS WRN OK
AND E-CENTRAL TX EARLY IN PERIOD...MOVING EWD AND SEWD TO NEAR WRN
WI...NWRN MO...SRN OK AND SW TX BY 3/00Z...WITH DRYLINE INTERSECTING
FRONT OVER SRN OK OR N-CENTRAL TX. BY 3/12Z...FRONT SHOULD
ACCELERATE TO LM...ERN AR AND SWRN LA/SE TX AREA AS MID-UPPER TROUGH
APCHS.

...SRN PLAINS TO ARKLATEX REGION AND AR...
WHILE NOT OPTIMAL FOR THIS TIME OF YEAR...MOISTURE RETURN BY DAY-3
SHOULD BE SUFFICIENT TO SUPPORT DEVELOPMENT OF LINE OF STG-SVR TSTMS
LATE DAY-2 INTO EARLY DAY-3 PERIOD ALONG COLD FRONT...AS THAT
BOUNDARY IMPINGES UPON MOIST SECTOR. EXPECT UPPER 50S TO MID 60S F
DEW POINTS IN PRE-STORM/PRE-FRONTAL AIR MASS ACROSS CENTRAL TX INTO
OK AND SERN KS...VERTICAL SHEAR STRENGTHENING WITH TIME EARLY IN
PERIOD AS UPPER TROUGH AND PRECEDING...NEARLY MERIDIONAL UPPER JET
MAX APCH.

ADDITIONAL DEVELOPMENT OF TSTMS...WITH DAMAGING WIND...LARGE HAIL
AND TORNADOES ALL POSSIBLE...COULD DEVELOP FARTHER S ACROSS PORTIONS
CENTRAL/NRN TX AND SRN OK DURING DAY AS COMBINATION OF LOW-LEVEL
THETAE ADVECTION AND AREAS OF DIABATIC HEATING ASSIST WITH AIR MASS
RECOVERY BEHIND MORNING ACTIVITY. SPATIAL AND TEMPORAL EXTENT OF
SUCH DESTABILIZATION IS UNCERTAIN...OTHERWISE THIS COULD BE
SIGNIFICANT SVR EVENT GIVEN STRENGTH OF DEEP-LAYER WIND FIELDS.
ANTECEDENT LOW CLOUDS MAY RENDER ONLY NARROW CORRIDOR OF STG SFC
HEATING AHEAD OF FRONT AND DRYLINE DURING AFTERNOON. VERTICAL SHEAR
WILL BE STG ENOUGH TO SUPPORT TORNADO POTENTIAL...WHICH WILL DEPEND
LARGELY ON FACTORS SUCH AS PREDOMINANCE OF DISCRETE OR SEMI-DISCRETE
STORM MODES THAT ARE TOO SMALL IN SCALE TO FCST THIS FAR IN ADVANCE.

CONVECTION SHOULD PERSIST INTO EVENING AND OVERNIGHT HOURS OVER
PORTIONS E TX...ERN OK...NWRN LA AND AR...GRADUALLY OUTRUNNING
FAVORABLE DESTABILIZATION FOR SFC-BASED EFFECTIVE INFLOW PARCELS.
SVR PROBABILITIES THEREFORE ARE SLOPED GENTLY DOWNWARD WITH EWD
EXTENT OVER OUTLOOK AREA.

..EDWARDS.. 03/31/2010

[Thunder]

... ... ... ... ... Venture?

[venture]

Sorry haven't had time to do my own discussion.



DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1125 AM CDT THU APR 01 2010

VALID 011630Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR NWRN TX...WRN AND NRN
OK...AND SRN KS...

...SYNOPSIS...
DEEP LAYER OF MID-UPPER LEVEL SWLY FLOW AHEAD OF GREAT BASIN TROUGH
WILL MAINTAIN STRONG EML AIRMASS DURING THE DAY ABOVE A SHALLOW
LAYER OF MODEST BOUNDARY LAYER MOISTURE ADVECTING NWD ACROSS THE
SRN/CENTRAL PLAINS. AS THE WRN CONUS TROUGH BEGINS APPROACHING THE
CENTRAL/SRN ROCKIES...HEIGHT FALLS WILL INCREASE ACROSS THE
PLAINS...AIDING IN STRENGTHENING LOW LEVEL SLY FLOW FROM TX NWD INTO
THE UPPER MS VALLEY REGION...AS WELL AS DEEPENING SURFACE LOW
PRESSURE OVER THE CENTRAL HIGH PLAINS. STATIONARY FRONT POSITIONED
AHEAD OF THE LOW AT 13Z IS FORECAST TO RETREAT NWD AS A WARM FRONT
INTO THE UPPER MS VALLEY REGION...WHILE TRAILING DRYLINE INTO THE
SRN PLAINS BEGINS TO SHARPEN AS WELL MIXED BOUNDARY LAYER AIRMASS
SWEEPS EWD OFF THE HIGH PLAINS INTO DOWNSTREAM MID-UPPER 50S
DEWPOINTS. THUNDERSTORMS ARE FORECAST TO FORM OVERNIGHT ALONG AND N
OF THE WARM FRONT WITHIN INCREASING LOW LEVEL WAA REGIME...WHILE AN
EPISODE OF LATE PERIOD STRONG/SVR STORMS IS EXPECTED ALONG THE
DRYLINE AS STRONG FORCING FOR ASCENT WITH THE UPPER TROUGH EMERGES
OVER THE GREAT PLAINS.

...TX/OK/KS OVERNIGHT/EARLY FRIDAY...
MORNING UPPER AIR ANALYSIS AND 12Z RAOBS ACROSS THE GREAT PLAINS
INDICATE A STRONG EML CAPPING INVERSION PRESENT ABOVE MARGINAL
BOUNDARY LAYER MOISTURE /MEAN MIXING RATIO AOB 9-10 G PER KG...PWAT
VALUES AOB 0.60 IN/. THOUGH AN ISOLATED THUNDERSTORM EMANATING OFF
OF THE WARM/WELL MIXED BOUNDARY LAYER W OF THE DRYLINE CAN NOT BE
COMPLETELY RULED OUT DURING THE LATE AFTERNOON/EARLY EVENING...MODEL
GUIDANCE INDICATES THAT THE HIGHEST PROBABILITY FOR STORM INITIATION
WILL OCCUR DURING THE OVERNIGHT HOURS /GENERALLY AFTER 06Z/. SURFACE
PRESSURE FALLS BEHIND THE DRYLINE OVER THE CENTRAL HIGH PLAINS ARE
FORECAST TO DRAW UPPER 50S/LOW 60S DEWPOINTS NWWD INTO WRN
OK/PORTIONS OF SRN KS THROUGH THE AFTERNOON AND EVENING.
HOWEVER...THIS MOIST LAYER IS EXPECTED TO BE CAPPED BY OVERLAYING
EML DURING THE DAY. AS THE NIGHT PROGRESSES...STEEP MID LEVEL LAPSE
RATES /NEAR 8 C PER KM IN THE 700-500 MB LAYER/ AND INCREASING LOW
LEVEL MOISTURE WILL CONTRIBUTE TOWARD THE DEVELOPMENT OF AN AXIS OF
MUCAPE VALUES AROUND 1000-1500 J/KG IMMEDIATELY AHEAD OF THE
DRYLINE.

MODEL GUIDANCE INDICATES THE CAP WILL BEGIN TO WEAKEN SUBSTANTIALLY
TOWARD 06Z AS LARGE SCALE ASCENT OVERSPREADS TX/OK/KS WITH THE
APPROACHING UPPER TROUGH OVER THE CENTRAL/SRN ROCKIES...WITH
THUNDERSTORMS DEVELOPING ALONG THE DRYLINE AS THIS TAKES PLACE. THE
STEEP LAPSE RATE ENVIRONMENT/MODERATE CAPE ENVIRONMENT COMBINED WITH
EFFECTIVE BULK SHEAR VALUES AROUND 50-65 KT WILL FAVOR ORGANIZED
THUNDERSTORM DEVELOPMENT INCLUDING SUPERCELLS...POSING A THREAT OF
LARGE HAIL. GIVEN THE DEGREE OF FORCING FOR ASCENT ALONG THE DRYLINE
AS WELL AS INCREASINGLY MERIDIONAL DEEP LAYER FLOW/SHEAR ALONG THE
BOUNDARY...STORMS MAY GROW UPSCALE INTO A LINE AS THEY MOVE EWD
TOWARD S-CENTRAL KS/CENTRAL OK...LEADING TO A RISK OF ISOLATED
DAMAGING WIND GUSTS. IN ADDITION...FORECAST SOUNDINGS INDICATE THAT
MOISTENING NOCTURNAL BOUNDARY LAYER AND DECREASING CIN MAY FAVOR
NEAR SURFACE BASED THUNDERSTORM DEVELOPMENT...AND WITH EFFECTIVE SRH
VALUES NEAR 300 M2 S-2...A NON ZERO TORNADO THREAT WILL EXIST.

[venture]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1220 PM CDT THU APR 01 2010

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO VALLEY REGION
SWD INTO E TX AND EWD INTO THE OZARKS/ARKLATEX AREAS...

...SYNOPSIS...
HIGHLY-AMPLIFIED FLOW PATTERN IS FORECAST TO PERSIST ALOFT THIS
PERIOD...ESPECIALLY OVER THE ERN 2/3 OF THE U.S. AS A TROUGH
EJECTING INTO THE CENTRAL PLAINS IMPINGES ON A STEADFAST RIDGE OVER
THE EAST. MEANWHILE...A SECOND TROUGH IS PROGGED TO MOVE ONSHORE
OVER THE PAC NW THROUGH THE FIRST HALF OF THE PERIOD...BUT THEN
WEAKEN OVERNIGHT AS IT SHIFTS INLAND.

AT THE SURFACE...LOW PRESSURE IS FORECAST TO MOVE SLOWLY ENEWD
ACROSS MN AND VICINITY...WHILE A TRAILING N-S COLD FRONT SHIFTS
ACROSS THE PLAINS STATES THROUGH THE DAY AND INTO THE MS VALLEY
REGION LATE IN THE PERIOD.

...MID MO VALLEY SWD INTO ERN TX AND EWD TO THE OZARKS/ARKLATEX...
THUNDERSTORMS -- AND AT LEAST SOME HAIL/WIND THREAT -- SHOULD BE
ONGOING AT THE START OF THE PERIOD...MAINLY FROM CENTRAL KS SWD INTO
WRN PORTIONS OF N TX ALONG/AHEAD OF THE ADVANCING COLD FRONT. VERY
MODEST INSTABILITY EARLY IN THE DAY SHOULD INCREASE A BIT INTO THE
AFTERNOON AHEAD OF THE ONGOING CONVECTION...AS A NARROW PLUME OF
LOW-LEVEL MOIST ADVECTION CONTINUES AHEAD OF THE FRONT.
HOWEVER...THE SLOW INCREASE IN BOUNDARY-LAYER MOISTENING WILL BE AT
LEAST SOMEWHAT OFFSET BY WHAT SHOULD BE FAIRLY EXPANSIVE PRE-FRONTAL
CLOUDINESS -- SUFFICIENT TO RETARD DAYTIME HEATING TO SOME DEGREE.
NONETHELESS...EXPECT CONVECTION TO EXPAND NNEWD ALONG THE FRONT
TOWARD/ACROSS THE MID MO VALLEY REGION...AND ALSO SWD INTO E CENTRAL
TX -- THOUGH INCREASING CAPPING WITH SWD EXTENT ACROSS TX SHOULD ACT
AS A HINDRANCE TO SWD DEVELOPMENT DESPITE SOMEWHAT MORE FAVORABLE
THERMODYNAMIC EVOLUTION.

WHILE LARGELY MERIDIONAL...DEEP-LAYER WIND FIELD WILL BE QUITE
STRONG...SUPPORTIVE OF ORGANIZED/ROTATING STORMS. MEAN WIND ROUGHLY
PARALLEL TO THE FRONT SUGGESTS A PRIMARILY LINEAR STORM MODE --
POSSIBLY WITH A FEW EMBEDDED ROTATING STORMS/COMMA HEADS. DAMAGING
WINDS SHOULD BE THE MOST SIGNIFICANT SEVERE POTENTIAL...THOUGH
MARGINALLY-SEVERE HAIL MAY BE THE MORE WIDESPREAD SEVERE WEATHER
OCCURRENCE. AN ISOLATED TORNADO OR TWO ALSO CANNOT BE RULED OUT --
WITH THE GREATEST POTENTIAL APPARENT ACROSS E TX WHERE GREATER
LOW-LEVEL MOISTURE AND THUS INSTABILITY ALONG WITH SOMEWHAT LESS
MERIDIONAL FLOW FIELD IS EXPECTED.

THE LINE OF CONVECTION SHOULD CONTINUE EWD OVERNIGHT...WEAKENING
SIGNIFICANTLY AFTER SUNSET ACROSS NRN PORTIONS OF THE RISK
AREA...BUT REMAINING MORE ORGANIZED/POTENTIALLY SEVERE INTO THE
OVERNIGHT HOURS FARTHER S AS STORMS MOVE ACROSS THE OZARKS/ARKLATEX
REGION THROUGH THE END OF THE PERIOD.

[venture]

DAY 1 CONVECTIVE OUTLOOK AMEND 1
NWS STORM PREDICTION CENTER NORMAN OK
0937 PM CDT THU APR 01 2010

VALID 020100Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF
CENTRAL/SOUTHERN PLAINS...

AMENDED SLIGHT RISK FOR KS/NEB

EXPANDED SLIGHT RISK ACROSS KS AND INTO SOUTHERN NEB COINCIDENT WITH
ISSUANCE OF SEVERE TSTM WATCH 41.

...CNTRL/SRN PLAINS...

00Z SOUNDINGS ACROSS THE SRN/CNTRL PLAINS EXHIBIT SUBSTANTIAL
INHIBITION...UPWARDS OF 600 J/KG AT OUN...ABOVE MARGINALLY MOIST
BOUNDARY LAYER. THERMAL PROFILES WILL...HOWEVER...ADJUST LATE
TONIGHT AS SHORTWAVE TROUGH APPROACHES RESULTING IN MORE THAN
ADEQUATE MODIFICATION FOR THUNDERSTORM DEVELOPMENT. LATEST THINKING
IS DEEP CONVECTION MAY ACTUALLY INITIATE ACROSS PARTS OF NWRN TX
BEFORE ACTIVITY SPREADS/DEVELOPS NEWD INTO CNTRL OK/SRN KS ALONG
I-35 CORRIDOR BY SUNRISE. OVERALL...EARLIER THOUGHTS REGARDING
SEVERE POTENTIAL CONTINUES AS SIGNIFICANT LARGE SCALE ASCENT SHOULD
OVERSPREAD SLOWLY MOISTENING BOUNDARY LAYER ACROSS TX/OK/KS.
GREATEST SEVERE THREAT SHOULD BE LARGE HAIL AND GUSTY WINDS.



URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 41
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT THU APR 1 2010

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

MUCH OF CENTRAL KANSAS
PARTS OF SOUTH CENTRAL NEBRASKA
PARTS OF NORTHWEST OKLAHOMA
PARTS OF EASTERN TEXAS PANHANDLE

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 925 PM
UNTIL 400 AM CDT.

WIDELY SCATTERED DAMAGING WINDS
ISOLATED WIND GUSTS TO 70 MPH POSSIBLE
SCATTERED LARGE HAIL TO 2.0 INCHES IN DIAMETER
ISOLATED TORNADOES

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 5 MILES NORTH
NORTHWEST OF GRAND ISLAND NEBRASKA TO 55 MILES SOUTH OF GAGE
OKLAHOMA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...AS THE STRONG COLD FRONT HAS INTERSECTED THE DRY
LINE...THUNDERSTORMS ARE RAPIDLY DEVELOPING. WITH A VERY STRONG
UPPER TROUGH AND ASSOCIATED WIND FIELD MOVING EWD INTO HIGH
PLAINS...THE MARGINAL MOISTURE/INSTABILITY EXPECTED TO BE SUFFICIENT
FOR A FEW THUNDERSTORMS TO BECOME SEVERE. PRIMARY THREAT WILL BE
LARGE HAIL AND LOCALLY DAMAGING WINDS. GIVEN THE STRENGTH OF THE
SYSTEM THERE IS THE POSSIBILITY OF A FEW ROTATING STORMS ENHANCING
THE SEVERE THREAT PRIOR BECOMING A MORE LINEAR MODE OVERNIGHT AS THE
STORMS MOVE EWD.

[venture]

MESOSCALE DISCUSSION 0233
NWS STORM PREDICTION CENTER NORMAN OK
1150 PM CDT THU APR 01 2010

AREAS AFFECTED...SOUTH CENTRAL NEB/CENTRAL KS TO WESTERN/CENTRAL OK
AND WESTERN NORTH TX

CONCERNING...SEVERE THUNDERSTORM WATCH 41...

VALID 020450Z - 020615Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 41
CONTINUES.

SEVERE TSTM WATCH 41 CONTINUES UNTIL 09Z...WITH A CONTINUED RISK FOR
SEVERE HAIL/DAMAGING WINDS.

MODESTLY BROKEN/NNE-SSW ORIENTED QUASI-LINEAR CONVECTIVE LINE
CONTINUES TO STEADILY PROGRESS EASTWARD ACROSS FAR SOUTH CENTRAL
NEB/CENTRAL KS/NORTHWEST OK EARLY IN THE OVERNIGHT. ADDITIONAL
DEVELOPMENT HAS RECENTLY BEEN NOTED NEAR/SOUTH OF I-40 IN WESTERN
OK...AND THIS MAY ULTIMATELY WARRANT A SOUTHWARD EXPANSION OF SEVERE
TSTM WATCH 41...WITH THE POSSIBILITY OF SOUTHWARD DEVELOPMENT
PERHAPS INTO THE WESTERN PART OF NORTH TX OVER THE NEXT SEVERAL
HOURS.

THE SEVERE EPISODE MAY HAVE ALREADY PEAKED ACROSS MUCH OF CENTRAL
KS/SOUTH CENTRAL NEB GIVEN A DOMINATE LINEAR CONVECTIVE MODE AND A
MODEST/NARROW WARM SECTOR AHEAD OF THE QLCS. NONETHELESS...MAINLY
MARGINAL HAIL/GUSTY WINDS WILL REMAIN POSSIBLE. FARTHER SOUTH...THE
SEVERE THREAT MAY INCREASE TO A DEGREE OVER THE NEXT SEVERAL HOURS
ACROSS WESTERN INTO CENTRAL OK...AS WELL AS ADJACENT PORTIONS OF
NORTH TX. SOME SUPERCELL STRUCTURES CAPABLE OF HAIL MAY BE THE
PRIMARY RISK INITIALLY...BUT NEAR-SEVERE WINDS/PERHAPS EVEN A
TORNADO CANNOT BE RULED OUT WITH MODAL EVOLUTIONS LATER
TONIGHT...ESPECIALLY WHERE SURFACE DEWPOINTS REACH AROUND 60F OR
ABOVE /BASED ON ADJUSTED MODEL SOUNDINGS/.

[venture]

Some storm development continuing in Dewey County as well was Hardeman Co, TX just across the Red River. We'll see if anything happens with these areas. Area ahead of the front and dryline remain unstable for cap is settling in pretty good now.

[venture]

MESOSCALE DISCUSSION 0234
NWS STORM PREDICTION CENTER NORMAN OK
0348 AM CDT FRI APR 02 2010

AREAS AFFECTED...NW TX...SW OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 020848Z - 021015Z

AN ISOLATED LARGE HAIL THREAT WILL BE POSSIBLE OVER THE NEXT FEW
HOURS ACROSS NW TX AND MAY ALSO DEVELOP ACROSS SW OK. THE THREAT IS
EXPECTED TO REMAIN TOO MARGINAL TO WARRANT WW ISSUANCE.

A LINE OF THUNDERSTORMS IS ONGOING IN NW TX ALONG A COLD FRONT WITH
OBJECTIVE ANALYSIS SHOWING A SMALL AREA OF MODERATE INSTABILITY
LOCATED ABOUT 60 STATUTE MILES TO THE EAST OF THE CONVECTION. AS THE
STORMS MOVE GRADUALLY EWD INTO INCREASING INSTABILITY AND LOW-LEVEL
MOISTURE...SOME INTENSIFICATION MAY OCCUR. DEVELOPMENT WILL ALSO BE
POSSIBLE NWD INTO SW OK. FORECAST SOUNDINGS ACROSS NW TX EARLY THIS
MORNING SUGGEST MID-LEVEL LAPSE RATES ARE STEEP WHICH ALONG WITH
ABOUT 60 KT OF DEEP LAYER SHEAR SHOULD SUPPORT AN ISOLATED LARGE
HAIL THREAT. IN ADDITION...LOW-LEVEL FLOW IS INCREASING ACROSS
WCNTRL TX DUE TO A 40 TO 50 KT LOW-LEVEL JET LOCATED IN THE TX HILL
COUNTRY. THIS MAY HELP INCREASE CONVECTIVE COVERAGE BUT THE STORMS
SHOULD REMAIN ELEVATED LIMITING THE THREAT FOR DAMAGING WIND GUSTS.

..BROYLES.. 04/02/2010

[venture]

MESOSCALE DISCUSSION 0235
NWS STORM PREDICTION CENTER NORMAN OK
0612 AM CDT FRI APR 02 2010

AREAS AFFECTED...CNTRL AND SRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 021112Z - 021215Z

AN ISOLATED LARGE HAIL THREAT WILL LIKELY CONTINUE FOR A FEW MORE
HOURS ACROSS CNTRL OK. A WIND DAMAGE THREAT MAY DEVELOP AS STORMS
ORGANIZE THIS MORNING. A WW MAY BE NECESSARY ACROSS THE REGION OVER
THE NEXT HALF HOUR.

A LINE OF THUNDERSTORMS IS CURRENTLY ONGOING ALONG A COLD FRONT ON
THE WRN EDGE OF MOIST AXIS WHERE SFC DEWPOINTS HAVE INCREASED INTO
THE LOWER 60S F ACROSS CNTRL OK. THIS LINE IS GRADUALLY INTENSIFYING
DUE TO INCREASING LARGE-SCALE ASCENT DUE TO AN APPROACHING
UPPER-LEVEL TROUGH TO THE WEST. OBJECTIVE ANALYSIS SHOWS A 80 TO 95
KT MID-LEVEL JET OVER THE ERN TX PANHANDLE. THE ERN EDGE OF THE JET
IS MOVING INTO CNTRL OK WHICH HAS INCREASED DEEP LAYER SHEAR INTO
THE 60 TO 70 KT RANGE. THIS COMBINED WITH STEEP MID-LEVEL LAPSE
RATES SHOULD BE FAVORABLE FOR SUPERCELLS AND ISOLATED LARGE HAIL. AS
THE STORMS MOVE INTO THE MOIST AXIS AND STRONGER LOW-LEVEL FLOW...AN
ISOLATED WIND DAMAGE THREAT MAY DEVELOP ESPECIALLY IF A BOWING LINE
SEGMENT CAN ORGANIZE.

..BROYLES.. 04/02/2010

[venture]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
615 AM CDT FRI APR 2 2010

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
EXTREME SOUTHEASTERN CANADIAN COUNTY IN CENTRAL OKLAHOMA...
CLEVELAND COUNTY IN CENTRAL OKLAHOMA...
GRADY COUNTY IN CENTRAL OKLAHOMA...
WESTERN MCCLAIN COUNTY IN CENTRAL OKLAHOMA...

* UNTIL 700 AM CDT

* AT 615 AM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM 5 MILES SOUTHWEST OF ALEX...MOVING NORTHEAST AT 65
MPH.

HAZARDS IN THE WARNING INCLUDE...
HAIL UP TO THE SIZE OF HALF DOLLARS...
WIND GUSTS TO 70 MPH...

* LOCATIONS IN THE WARNING INCLUDE AGAWAM...ALEX...AMBER...
BLANCHARD...BRADLEY...BRIDGE CREEK...CHICKASHA...COLE...CRINER...
DIBBLE...GOLDSBY...LAKE THUNDERBIRD...LEXINGTON...MIDDLEBERG...
MOORE...NEWCASTLE...NINNEKAH...NOBLE...NORMAN...PU RCELL...
SLAUGHTERVILLE...SOUTHERN OKLAHOMA CITY...STANLEY DRAPER LAKE...
STELLA...TABLER...TUTTLE AND WASHINGTON.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 92 AND 120.

THIS INCLUDES INTERSTATE 44 BETWEEN MILE MARKERS 74 AND 113.

[venture]

Severe thunderstorm watch outline update for ws 42
nws storm prediction center norman ok
620 am cdt fri apr 2 2010

severe thunderstorm watch 42 is in effect until 1000 am cdt
for the following locations

okc005-013-019-027-029-037-049-051-063-067-069-081-083-085-087-
091-095-099-107-109-111-117-119-121-123-125-133-137-021500-
/o.new.kwns.sv.a.0042.100402t1120z-100402t1500z/

ok
. Oklahoma counties included are

atoka bryan carter
cleveland coal creek
garvin grady hughes
jefferson johnston lincoln
logan love marshall
mcclain mcintosh murray
okfuskee oklahoma okmulgee
pawnee payne pittsburg
pontotoc pottawatomie seminole
stephens
$$



URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 42
NWS STORM PREDICTION CENTER NORMAN OK
620 AM CDT FRI APR 2 2010

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

PARTS OF CENTRAL AND EASTERN OKLAHOMA

EFFECTIVE THIS FRIDAY MORNING FROM 620 AM UNTIL 1000 AM CDT.

WIDELY SCATTERED DAMAGING WINDS
ISOLATED WIND GUSTS TO 70 MPH POSSIBLE
WIDELY SCATTERED LARGE HAIL TO 1.5 INCHES IN DIAMETER
ISOLATED TORNADOES

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES EAST
NORTHEAST OF CHANDLER OKLAHOMA TO 30 MILES SOUTH SOUTHWEST OF
ARDMORE OKLAHOMA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...RAPIDLY MOVING STORMS ROOTED JUST ABOVE THE SURFACE
WILL LIKELY CONTINUE FOR A FEW HOURS ACROSS CENTRAL OK...IN ADVANCE
OF A REMNANT DRYLINE/COLD FRONT. GIVEN THE HIGH MOMENTUM FLOW JUST
OFF THE GROUND AND AT LEAST WEAK SURFACE-BASED INSTABILITY...THERE
WILL BE A THREAT FOR DAMAGING WINDS WITH THE STRONGER EMBEDDED
BOWING SEGMENTS. ALSO...STEEP MID LEVEL LAPSE RATES WILL SUPPORT
THE THREAT FOR LARGE HAIL WITH THE MORE INTENSE UPDRAFTS.

[sacolton]

Nothing but sunshine this weekend and next week. Woo hoo!

[Thunder]

So.... I hear we had a small tornado that NWS and the stations didn't catch, eh?

Specifically near NW 10th and MacArthur Blvd.

[venture]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT SUN APR 04 2010

VALID 041200Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MO/MIDDLE MS
RIVER VALLEYS....

...NORTHERN/WESTERN OK TO NORTHWEST TX LATE THIS AFTERNOON/EARLY
EVENING...
AMPLE HEATING/MODEST CONVERGENCE IN VICINITY OF SOUTHWARD SAGGING
FRONT AND/OR DRYLINE COULD SUPPORT ISOLATED STRONG/SEVERE TSTMS LATE
THIS AFTERNOON/EARLY EVENING ACROSS PORTIONS OF NORTHERN/WESTERN OK
AND PERHAPS NORTHWEST TX. SCENARIO IS RATHER CONDITIONAL GIVEN
LIMITED SUPPORT ON THE LARGE SCALE AND MODEST NEAR-SURFACE
CONVERGENCE...BUT AN INCREASINGLY MOIST BOUNDARY LAYER BENEATH
MODERATELY STRONG WSW FLOW ALOFT COULD SUPPORT A SUPERCELL OR TWO
WITH HAIL POSSIBLE.




DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CDT SUN APR 04 2010

VALID 051200Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID-UPR MS
VLY/CORN BELT...

...CNTRL/SRN HIGH PLAINS...
SUBTLE LARGE-SCALE HEIGHT FALLS WILL BEGIN TO EDGE ONTO THE HIGH
PLAINS MONDAY AFTN/EVE AND THE DRYLINE CIRCULATION WILL LIKELY
DEEPEN AMIDST STRONG BOUNDARY LAYER HEATING FROM NWRN TX INTO CNTRL
KS. THIS MAY WEAKEN CINH SUFFICIENTLY TO SUPPORT AN ISOLD TSTM OR
TWO...MOST LIKELY IN NWRN OK OR SWRN KS WHERE MLCAPE WILL LIKELY
EXCEED 2000 J/KG. DEEP LAYER SHEAR OF 50 KTS AND STEEP LAPSE RATES
WILL FAVOR SUPERCELLS WITH PRIMARILY LARGE HAIL. STRONG EML IN
PLACE WILL LIMIT NUMBER OF STORMS WITH ACTIVITY PROBABLY ONLY
SURVIVING A FEW HOURS BEFORE WEAKENING OVER SCNTRL KS/NCNTRL-WRN OK.

[venture]

Quick update...

Front is continuing to move through NW Oklahoma. Initial develop is trying to start now in Dewey County near Putnam. This is in an area of some rising cumulus and will need to be watched. It is in an area of decent instability and moisture, but there is a very strong cap today. We'll see if it can do anything.

[venture]

716PM - Developing is now continuing along the Dryline in far western OK and the front just up the line a bit. Initial cell has weakened but a strong one is going up just behind it along the boundary. Another cell has developed in Roger Mills County.

Strongest cell is between Seiling and Canton in NE Dewey County.

725PM Update: NE Dewey County cell is increasing in intensity rapidly. Same for cell in NE Roger Mills County.