May '10 Weather Discussion

[jstanthrnme]

venture, I got a couple of questions for you that I've been wondering all afternoon.

1. What is a good estimate on the number of storm chasers / spotters that were spread across the state today?

2. Why is it that tornadoes and hook echos form on the south side of a storm? Is it the coriolis effect?

[Thunder]

I think that is where the inflow enter the storm from the south/southwest.

David, I got a question for you. Can a storm's outflow become another storm's inflow?

[Peach fuzz]

When I went to clinton during that storm I counted 26 different states from ME and MA to CA and WA... prolly around 2-300 storm vehicles... that was a crazy day, we had clear skies but looking east it was gnarly

[Bunty]

I don't think the storm chasers got too crazy in or near Stillwater as this video with a brief shot of highway 51 suggests. The tornado shown, about 5 mi. west of Stillwater, was possibly at the time tearing up a mobile home near Range Rd. and McElroy, fortunately, not occupied at the time. Interesting how a strong gust of wind accompanies the touchdown of the tornado.

[venture]

Slight Risk today...cleaned up the outlook to focus mainly on our setup.



DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0744 AM CDT MON MAY 24 2010

VALID 241300Z - 251200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF WESTERN
NEBRASKA....MUCH OF SOUTH DAKOTA...AND PARTS OF NORTH DAKOTA...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
FROM ND AND MN SWD TO WEST TX...

...A SIGNIFICANT SEVERE WEATHER EPISODE APPEARS INCREASINGLY LIKELY
ACROSS PARTS OF THE CENTRAL AND NORTHERN GREAT PLAINS TODAY...

...THUNDERSTORMS DEVELOPING ACROSS THESE AREAS THIS AFTERNOON WILL
HAVE STRONG POTENTIAL TO PRODUCE TORNADOES...LARGE/DAMAGING
HAIL...AND DESTRUCTIVE WINDS...

...SYNOPSIS...
MORNING WATER VAPOR SATELLITE IMAGERY SHOWS A POTENT SHORT WAVE
TROUGH OVER THE FOUR CORNERS AREA PIVOTING THROUGH THE BASE OF A
LARGER SCALE TROUGH SYSTEM THAT HAS DOMINATED THE WRN STATES FOR
SEVERAL DAYS. MODEL GUIDANCE IS VERY CONSISTENT WITH THE TRACK AND
EVOLUTION OF THIS DISTURBANCE...TAKING THE SHORT WAVE AND ASSOCIATED
75-80KT MID LEVEL JET STREAK RAPIDLY NEWD TO THE NEB PANHANDLE AREA
BY 00Z THIS EVENING...AND THEN CLOSING OFF A 500MB LOW OVER NERN MT
BY TUESDAY MORNING. INTENSE FORCING FOR UPWARD VERTICAL MOTION WILL
OVERSPREAD THE CNTRL AND NRN HIGH PLAINS FROM LATE MORNING THROUGH
THIS EVENING AS THE UPPER TROUGH TAKES ON A PRONOUNCED NEGATIVE TILT
AND DRIVES SIGNIFICANT SURFACE CYCLOGENESIS.

RESULTING SURFACE LOW WILL DEEPEN RAPIDLY WHILE TRACKING ALMOST DUE
NORTH FROM NERN CO TO WRN ND THROUGH THIS EVENING. WARM
FRONT...CURRENTLY SITUATED FROM NEB PNHDL TO ERN SD TO CNTRL
MN...WILL RETREAT QUICKLY NWD ACROSS THE REST OF SD AND INTO ND BY
EVENING. TRAILING DRY LINE WILL MAKE SOME PROGRESS EAST FROM ERN
CO/NM THIS MORNING...INTO KS AND NEB THROUGH THE AFTERNOON...AND
THEN PERHAPS SURGING EWD ACROSS NEB AND NRN KS LATER TODAY AS THE
LOW INTENSIFIES TO THE NORTH.

FARTHER SOUTH...DRY LINE ADVANCE WILL LIKELY BE SLOWER DUE TO LARGE
MERIDIONAL COMPONENT TO THE DEEP-LAYER FLOW.

ELSEWHERE...A BLOCKING ANTICYCLONE WILL TAKE FORM FROM THE GREAT
LAKES TO NEW ENGLAND. SOUTH OF THE CLOSED ANTICYCLONE AT 500MB...A
WEAK SHORT WAVE TROUGH TRACKING SOUTH ACROSS THE CAROLINAS WILL
BECOME ABSORBED BY LARGER DEEP-LAYER CYCLONIC CIRCULATION DRIFTING
SHOREWARD FROM THE ATLANTIC.


...SRN PLAINS...
STORM DEVELOPMENT FROM OK/TX PNHDLS SWD TO THE RIO GRANDE MAY BE
MORE SCATTERED THAN FARTHER NORTH. HOWEVER...IT APPEARS THAT FORCING
FOR ASCENT ACCOMPANYING THE SHORT WAVE TROUGH WILL AT LEAST BRUSH
SOME OF THIS AREA AND...IN COMBINATION WITH DEEP MIXING ON THE DRY
LINE...A FEW TO SEVERAL ROBUST THUNDERSTORMS SHOULD ERUPT THROUGH
THE AFTERNOON. SUPERCELL HAIL/WIND AND TORNADO POTENTIAL WILL EXIST
WITH STORMS PRIMARILY ACROSS THE PNHDLS AND ADJACENT PARTS OF TX/OK.
FARTHER SOUTH...GENERALLY WEAKER FLOW SUGGESTS MORE ORGANIZED
MULTICELL STORMS WITH HAIL AND ISOLATED DAMAGING WIND GUSTS.

[venture]

Day 1 convective outlook
nws storm prediction center norman ok
0754 am cdt tue may 25 2010

valid 251300z - 261200z

...there is a slgt risk of svr tstms over northern maine...

...there is a slgt risk of svr tstms from lake superior south across
the upper ms valley and southwestward to southeast co and the
southern high plains...

...synopsis...
A complex upper air flow regime exists across the lower 48 this
morning as an intense occluded cyclone tracks north from the nrn
plains to the canadian prairie provinces...and an expansive
anticyclone covers the great lakes and northeast. South of the upper
high...a large upper low with a number of embedded smaller-scale
vortices was drifting wwd toward the southeast u.s.
Coast. To the north...a short wave trough and associated decaying
mcs were cresting the ridge axis in eastern canada.

Despite the highly amplified pattern...mid level winds are aob 40kt
over much of the conus. The exceptions being a 80kt sly jet streak
on the ern flank of the occluded cyclone over the nrn plains...and a
belt of modest 40-50kt flow within the base of the larger scale
trough across the west.

At the surface...an ill-defined synoptic frontal zone associated
with the occluded low was fragmented by numerous convective outflows
from mn/ia to ks. A number of other convective outflow boundaries
exist south of the front...over ok and tx. Abundant boundary layer
moisture remains in place along the decaying frontal zone...and
amidst the various outflows and weakening convective systems in ok
and tx.

...upper ms valley...
As the occluded low lifts into canada and influence of the
anticyclone to the east diminishes...this area may undergo weak
height falls. Given the proximity of residual frontal zone and
outflow boundaries...coupled with potential for strong
destabilization and weak convective inhibition...expect
thunderstorms to increase. Given generally weak flow aloft...bulk
shear will not be particularly supportive of sustained or
well-organized updrafts. However...magnitude of instability and
focusing potential of the front and other boundaries suggests that
multicell activity will increase along with an increasing chance for
some hail and locally damaging wind gusts.

...srn plains to sern co...
There is a large amount of uncertainty about convective development
and mode across this area today. Most guidance has not done well
depicting the currently decaying and poorly organized mcs over
ks/ok. Outflow and debris cloudiness from this convection will
likely play a role in new storm development in a very unstable but
generally weakly sheared flow regime.

Some synoptic scale support for more widespread development may
occur across the high plains later this afternoon when a subtle
short wave trough...evident on water vapor imagery across four
corners area attm...moves newd. Lift with this feature...coupled
with mixing along the dry line near the nm/tx border should be
adequate for thunderstorm development these areas and east across
west tx and north into parts of ks/co. Additional storm development
appears possible as air mass recovers/destabilizes invof residual
front in ks. Pockets of stronger effective shear will marginally
support supercell storms with large hail and wind and perhaps a
tornado or two. Most of this activity will tend to die off several
hours after sunset.

Moist post-frontal upslope flow and aforementioned weak short wave
may be sufficient for high plains storms to form within weak to
modest instability across sern co. Shear in these areas will be a
bit more favorable for storm rotation with some hail/wind and
perhaps a tornado or two.

[venture]

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0232 AM CDT FRI MAY 28 2010

VALID 301200Z - 311200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE SRN AND
CNTRL PLAINS...

...SYNOPSIS...

SHORTWAVE TROUGH WILL EJECT NEWD THROUGH THE UPPER MS VALLEY INTO
SRN ONTARIO SUNDAY AFTERNOON AND EVENING. COLD FRONT WILL MOVE EWD
THROUGH THE UPPER MS VALLEY AND UPPER GREAT LAKES WITH TRAILING
PORTIONS CONTINUING SWD THROUGH KS INTO ERN NM WHERE IT WILL LIKELY
STALL. CUTOFF UPPER LOW WILL PERSIST OVER THE SERN STATES.

...ERN NM...TX PANHANDLE...NWRN OK AND KS...

DIABATIC WARMING OF THE MOIST BOUNDARY LAYER AND MODERATELY STEEP
LAPSE RATES WILL RESULT IN MODERATE INSTABILITY IN VICINITY OF THE
FRONT SUNDAY. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP WITHIN THE
FRONTAL ZONE ACROSS KS DURING THE AFTERNOON AS WELL AS WITHIN THE
MODEST POST FRONTAL UPSLOPE REGIME OVER ERN NM. STRONGER FLOW
ASSOCIATED WITH THE UPPER TROUGH OVER THE NRN PLAINS AND UPPER MS
VALLEY WILL REMAIN POST FRONTAL WITH GENERALLY 20-30 KT MID-UPPER
FLOW NEAR THE FRONT. HOWEVER...ELY TO NELY LOW LEVEL WINDS NORTH OF
THIS BOUNDARY WILL CONTRIBUTE TO 35 KT 0-6 KM SHEAR. MULTICELLS ARE
EXPECTED TO BE THE DOMINANT MODE...BUT SOME STORMS COULD DEVELOP
SUPERCELL CHARACTERISTICS. STORMS MAY CONTINUE INTO THE OVERNIGHT
SUPPORTED BY ISENTROPIC LIFT ABOVE THE BOUNDARY. ISOLATED LARGE HAIL
AND DOWNBURST WINDS WILL BE THE MAIN THREATS THROUGH ABOUT MID
EVENING.

[urbanity]

Opinion | OKG Scene.com

[venture]

If you wish to discuss issues with media reporting of facts on stories, this isn't the thread to do it. Yes the weather was a contributor to those reports, but you are wanting to address something completely different by posting an Opinion article on the accuracy of news reporting. Please keep this thread for general weather or forecast questions only as your link is centered around something that has no place here.

[venture]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 AM CDT SAT MAY 29 2010

VALID 301200Z - 311200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

WRN U.S. UPPER TROUGH WILL LIFT NEWD INTO THE NRN PLAINS/UPPER MS
VALLEY SUNDAY RESULTING IN DE-AMPLIFICATION OF UPPER RIDGE. A JET
STREAK IS FORECAST TO EJECT NEWD FROM BASE OF THE TROUGH INTO MN AND
SRN ONTARIO SUNDAY AFTERNOON AND EVENING. COLD FRONT WILL CONTINUE
EWD THROUGH THE UPPER MS VALLEY AND GREAT LAKES. THE TRAILING
PORTIONS OF THIS BOUNDARY WILL MOVE SWD THROUGH KS INTO ERN NM WHERE
IT WILL LIKELY STALL. CUTOFF UPPER LOW WILL PERSIST OVER THE SERN
STATES.

...ERN NM...TX PANHANDLE...NWRN OK AND KS...

DEWPOINTS FROM 60-65F WILL REMAIN IN PRE-FRONTAL WARM SECTOR FROM KS
SWD INTO OK WITH MORE LIMITED MOISTURE FARTHER WEST ACROSS THE HIGH
PLAINS OF TX AND NM. DIABATIC WARMING OF THE MOIST BOUNDARY LAYER
AND 7-7.5 C/KM 700-500 MB LAPSE RATES WILL RESULT IN 2000 J/KG
MLCAPE FROM SRN KS INTO OK WITH CAPE VALUES GENERALLY AOB 1000 J/KG
OVER THE HIGH PLAINS. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP IN
FRONTAL ZONE FROM THE SRN TX PANHANDLE INTO WRN OK AND SRN KS AND
WITHIN THE MODEST POST FRONTAL UPSLOPE REGIME OVER ERN NM. STRONGER
FLOW ALOFT ATTENDING NRN PLAINS TROUGH WILL REMAIN POST FRONTAL WITH
GENERALLY 15-25 KT 500 MB FLOW AND 25-35 KT 0-6 KM SHEAR NEAR THE
FRONT SUPPORTIVE OF MULTICELLS. STORMS MAY CONTINUE INTO THE
OVERNIGHT SUPPORTED BY ISENTROPIC LIFT ABOVE THE BOUNDARY. ISOLATED
HAIL AND DOWNBURST WINDS WILL BE POSSIBLE WITH THE STRONGER STORMS.
HOWEVER...OVERALL SEVERE THREAT DOES NOT APPEAR PARTICULARLY
ROBUST...AND CONFIDENCE IS NOT HIGH THAT COVERAGE OF SEVERE EVENTS
WILL BE SUFFICIENT TO WARRANT MORE THAN 5% SEVERE PROBABILITIES AT
THIS TIME.

[Bunty]

Severe thunderstorm watch now in effect for north central and some of central Oklahoma until midnight: