Severe Weather Outlook - Mon 7/13 through Mon 7/20

[USG '60]

A can in my back yard (near 23rd and May) had nearly 2 inches in it this morning. It was dry and empty yesterday.

[westsidesooner]

Amazing that USG got 2" while just 4 miles away it just sprinkled.

Here are a couple of pics I got as the storm passed just north and east of Wiley Post. I found it strange that planes would still be taking off and landing with so much strong wind in the area. In some of them (pics 9 on) you can see the dust cloud under the "lowering" and the sunlit hail core just behind it. As always they are best viewed by clicking the full screen option on the upper right.

2009-07-17 | Slideshow

[venture]

Something like this?



I can remember seeing it once on a hail storm in SE Oklahoma back on March 30, 2006. Not as defined as this pic though.

[westsidesooner]

Similar....there was more seperation between the top of the cumulonimbus and the lenticular cloud though. Ive only seen them in the mountains before yesterday. I'm kicking myself for not having my camera ready, it was really beautiful. Some storm spotter I am huh.....lol

[venture]

This is one that I could find from the date I mentioned - sounds closer to what you are describing.

[westsidesooner]

Thats more like what I saw..is it caused by an unusally strong updraft? just goes to show why you should always have your camera ready.

[Bunty]

The encounter of the updraft with a cooler than normal layer of air has a lot to do with it as well.

[venture]

Severe weather statement
national weather service norman ok
800 pm cdt sat jul 18 2009

okc083-190145-
/o.con.koun.sv.w.0561.000000t0000z-090719t0145z/
logan ok-
800 pm cdt sat jul 18 2009

...a severe thunderstorm warning remains in effect until 845 pm cdt
for southeastern logan county...

At 801 pm cdt...national weather service doppler radar detected a
severe thunderstorm 5 miles north of guthrie...moving south at 25
mph.

Hazards in the warning include...
Hail up to the size of ping pong balls...
Wind gusts to 60 mph...

* locations in the warning include guthrie...meridian and seward.

[venture]

Bulletin - immediate broadcast requested
severe thunderstorm warning
national weather service norman ok
826 pm cdt sat jul 18 2009

the national weather service in norman has issued a

* severe thunderstorm warning for...
Southern logan county in central oklahoma...
Eastern oklahoma county in central oklahoma...

* until 930 pm cdt

* at 826 pm cdt...national weather service doppler radar indicated a
severe thunderstorm 10 miles north of edmond...moving south at 25
mph.

Hazards in the warning include...
Hail up to the size of golf balls...
Wind gusts to 60 mph...

* locations in the warning include arcadia...choctaw...del city...
Eastern oklahoma city...edmond...forest park...jones...lake
aluma...midwest city...newalla...nicoma park...spencer...tinker air
force base and valley brook.

[venture]

Large hail core moving in Edmond.

[venture]

Hail core is now east of Bryant along I-35 and 15th and then back to the NNW to Coltrane and Covell.

There is also an area of strong winds in central Edmond, up to around 50 mph right now it looks like.

[Karried]

yep, it's here. Lightening strikes, thunder and dark, dark clouds!

[venture]

New hail core developing further south and west of the previous core. This is from Memorial and Bryant to the SSE at Main/Britton and Sooner.

[Thunder]

I was at work and stopped to take some pictures. This is the leading edge of the storms. The lines is beautiful.







I took these with my cell phone at 8:30.

[venture]

Very nice.

Warning has been allowed to expire. Also on a side note, working on testing a new chat room over on AC WX... BlaB Lite 4

I'll mainly just be in there during severe weather, so the next time we get any...i'll be sure to be in there.

[Thunder]

Well, it sure did not last long.

Venture, can you explain what make a storm go up so quickly then die the same way?

[venture]

Weak disturbance moved through this evening that helped give some help with lift. But typically you are looking at daytime heating helping things out - since things die pretty quick after sunset when it is the main catalyst.

OUN had this in their discussion tonight:

.UPDATE...A LONE SUPERCELL OCCURRED THIS EVENING IN A REGION OF
SLIGHTLY ENHANCED LOW LEVEL MOISTURE...AND AHEAD OF A PRONOUNCED
MID LEVEL TROUGH PER SATELLITE AND PROFILER DATA. FOR THE REST OF
THE NIGHT...THE 00Z NAM PRODUCES LITTLE PRECIPITATION...BUT THERE
ARE SOME REASONS TO KEEP LOW POPS IN TWO AREAS. THE MODEL DOES
PRODUCE LIFT AND NEAR SATURATION ALONG TWO DISTINCT MAXIMA IN 700
MB TEMPERATURE GRADIENT...ONE EAST OF OKLAHOMA CITY...AND THE
OTHER ALONG THE MAIN FRONTAL ZONE OVER SOUTHWEST OKLAHOMA AND
WESTERN NORTH TEXAS. ALTHOUGH LOW LEVELS REMAIN STABLE...WITH
LIGHT WINDS AND LITTLE FOCUS FOR LIFT...THE PRESENCE OF MODERATE
TO STEEP LAPSE RATES AND A SEASONABLY STRONG UPPER LEVEL
JET...HAVE SWAYED US TO MAINTAIN LOW POPS THROUGH THE NIGHT.

[venture]

Day 2 Outlook for Monday indicating that there may be a setup for a derecho event in KS and OK tomorrow afternoon/evening/night.

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1227 PM CDT SUN JUL 19 2009

VALID 201200Z - 211200Z

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

...SYNOPSIS...
AREA OF LOW PRESSURE ALOFT WILL REMAIN OVER THE OH VALLEY...AS LARGE
AND PERSISTENT UPPER RIDGE REMAINS IN THE WEST. A COLD UPPER
LOW/TROUGH WILL MOVE ESEWD ACROSS SOUTH CENTRAL CANADA...WITH THE
SRN PORTION OF THE TROUGH DIGGING INTO THE NRN/CENTRAL PLAINS. AHEAD
OF THIS SYSTEM...A COLD FRONT WILL MOVE SEWD AND LIKELY EXTEND FROM
FAR ERN ND SWWD INTO ERN CO BY LATE MONDAY AFTERNOON.

...CENTRAL/SRN PLAINS...
ELEVATED THUNDERSTORMS MAY BE ONGOING DURING THE MORNING FROM WRN OK
NWD INTO CENTRAL NEB WITHIN ZONE OF 850-700 MB WARM ADVECTION. STEEP
LAPSE RATES AND EFFECTIVE SHEAR AT 40-45 KT MAY SUPPORT AN ISOLATED
SEVERE HAIL THREAT WITH THESE STORMS AS THEY SHIFT SEWD.

DURING THE AFTERNOON...A BAND OF 30-35 KT NWLY WINDS ALOFT WILL
OVERSPREAD THE CENTRAL PLAINS. PREVIOUS AND CURRENT MODELS HAVE BEEN
CONSISTENT IN A SHORTWAVE TROUGH MOVING SEWD OUT OF THE CANADIAN
TROUGH AND INTO THE CENTRAL PLAINS. THIS MORNINGS NAM/GFS PLACE THIS
IMPULSE OVER NWRN KS AT 21/00Z. ASSOCIATED LARGE SCALE LIFT AND
STRONG HEATING OF MOIST BOUNDARY LAYER SHOULD BE FAVORABLE FOR
NUMEROUS SURFACE BASED STORMS TO DEVELOP... ESPECIALLY FROM SWRN NEB
SWD INTO THE TX PANHANDLE. MODERATE TO STRONG INSTABILITY AND
STRENGTHENING WINDS ALOFT WILL BE SUPPORTIVE OF SUPERCELLS WITH THE
INITIAL STORMS. DESPITE STRONGLY VEERING WIND PROFILES...WEAK WINDS
AT 700 MB INDICATE THE GREATER THREAT WITH INITIAL STORMS WILL BE
VERY LARGE HAIL.

HOWEVER...THE WEAK WINDS AT 700 MB...WITH INCREASING NWLY WINDS
ALOFT...WILL BE FAVORABLE FOR THE STRONG STORM OUTFLOWS TO MERGE AND
CONSOLIDATE INTO ONE OR MORE LINEAR MCS/S WITH COLD POOLS.
COMBINATION OF FORECAST INSTABILITY AXIS EXTENDING FROM WRN KS SEWD
INTO THE WRN OK AND STRENGTHENING SLY LOW LEVEL JET SUGGEST THE
MCS/S WILL MOVE MORE SWD THAN EWD. CORFIDI PARAMETERS ALSO INDICATE
FORWARD PROPAGATING SPEED WILL BE NEAR 40 KTS. THIS SPEED COMBINED
WITH MODERATE INSTABILITY/STRENGTHENING WINDS ALOFT AND ASSOCIATED
COLD POOL INDICATE A WIDESPREAD DAMAGING WIND EVENT IS POSSIBLE. FOR
THIS REASON...HIGHER PROBABILITIES FOR SEVERE ARE INCLUDED ON THIS
OUTLOOK...AND IF IT BECOMES CLEAR THAT SUCH AN EVENT IS LIKELY
...PORTIONS OF THE AREA MAY BE UPGRADED TO A MODERATE RISK ON THE
DAY 1 OUTLOOK.

[westsidesooner]

Tomorrow night is looking interesting. I wonder if the orange shade is where they expect the mcs to traverse?

NWS Quote:

TAKING A LOOK OUT TOWARD MONDAY NIGHT...THE NEXT WELL DEFINED
UPPER TROUGH WILL APPROACH...ACCOMPANIED BY A SURFACE TRIPLE POINT
OVER SOUTHWEST KANSAS. ALL THE PARAMETERS...INCLUDING NORTHWEST
FLOW OVER A QUASISTATIONARY BOUNDARY...WOULD APPEAR TO BE IN PLACE
FOR A SIGNIFICANT OUTBREAK OF SEVERE STORMS. WE HAVE SEEN A
TENDENCY FOR THIS PATTERN TO PRODUCE PARTICULARLY DAMAGING WINDS
AND SOME LARGE HAIL THE PAST SEVERAL DAYS...

&

[Karried]

Do we get tornados this time of year?

[Luke]

Tornadoes have occurred in every month of the year in the US.

Sorry.

[Thunder]

Do we get tornados this time of year?

Altho it is very, very low probability at this time of the year for the state, specifically the metro area, it is still not out of the question. A tornado or two can still spawn.

Remember that time Venture did not have such prediction and one dropped near his house. These things have a mind of their own and do as they please.

[venture]

Probably of MCS/Derecho activity is a bit in doubt tonight, we'll see how things develop through the day.

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0101 AM CDT MON JUL 20 2009

VALID 201200Z - 211200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE PLAINS...

...PLAINS...
ISOLATED TO SCATTERED/LINGERING ELEVATED TSTMS WILL BE ONGOING
ACROSS THE NORTHERN TO SOUTH-CENTRAL PLAINS AT DAYBREAK THIS
MORNING. WHILE THIS ACTIVITY COULD POSE AN ISOLATED SEVERE HAIL
THREAT EARLY TODAY AS STORMS SHIFT SOUTHEASTWARD OVER THE REGION...A
MORE APPRECIABLE SEVERE RISK WILL LIKELY UNFOLD LATER THIS
AFTERNOON/EVENING.

AS A POTENT UPPER TROUGH SHIFTS EASTWARD OVER THE CENTRAL CANADIAN
PROVINCES...PERTURBED/STRENGTHENING MID-HIGH LEVEL NORTHWESTERLY
FLOW WILL DEVELOP SOUTHEASTWARD ESPECIALLY OVER THE NORTHERN/CENTRAL
PLAINS TODAY. PRIMARY IMPETUS FOR APPRECIABLE SEVERE DEVELOPMENT
LATER TODAY MAY BE TIED TO A SHORTWAVE TROUGH/SPEED MAXIMA CROSSING
THE NORTHERN INTERMOUNTAIN REGION EARLY THIS MORNING...AS IT DIGS
SOUTHEASTWARD OVER THE NORTH-CENTRAL HIGH PLAINS THIS AFTERNOON.
REGARDLESS...IT SEEMS PROBABLE THAT TSTMS WILL DEVELOP/INCREASE
THROUGH THE AFTERNOON ACROSS THE NORTH-CENTRAL PLAINS...WITH THE
STRONGEST SURFACE BASED DEVELOPMENT LIKELY INITIALLY ALONG THE
SURFACE COLD FRONT/POTENTIAL PREFRONTAL TROUGH ACROSS NEB AND
ADJACENT SOUTHERN/EASTERN SD...AND PERHAPS NORTHERN KS. OTHER STORMS
SHOULD ALSO DEVELOP ACROSS THE FRONT RANGE OF EASTERN WY/NORTHEAST
CO AMIDST A DEVELOPING POST-FRONTAL UPSLOPE REGIME.

STRONG VEERING THROUGH THE LOW TO MID TROPOSPHERE AND MODERATELY
STRONG MID-HIGH LEVEL NORTHWESTERLY FLOW WILL SUPPORT AN INITIAL
SUPERCELLULAR MODE...WITH LARGE HAIL AS THE PRIMARY RISK. WITH
TIME...STORMS SHOULD CONSOLIDATE AND SPREAD SOUTHEASTWARD THROUGH
THE EVENING. WITH AN INCREASING/STRENGTHENING SOUTHERLY LOW LEVEL
JET ACROSS THE SOUTH-CENTRAL PLAINS TONIGHT...CONGEALING
STORMS/INCREASING COLD POOLS WILL LIKELY FOSTER THE DEVELOPMENT OF
ONE OR MORE FORWARD PROPAGATING SEVERE MCS/S WITH AN ENHANCED
DAMAGING WIND THREAT.

INITIALLY MODEST BOUNDARY LAYER MOISTURE ACROSS THE BULK OF THE
CENTRAL/SOUTHERN PLAINS...AND UNCERTAINTY REGARDING THE STRENGTH OF
NORTHWESTERLY MID LEVEL FLOW/TIMING OF CONVECTIVELY ENHANCED
PERTURBATIONS...PRECLUDES A CATEGORICAL MODERATE RISK AT THIS TIME.

[venture]

Do we get tornados this time of year?

They can always happen if things come together. The threat today though is for a widespread wide damage...which can sometimes be worse than a tornado, but at least you know where it is going for the most part.

[venture]

Some model disagreement on how to handle today. Majority of models predict storms will form up in KS/NE and slide SE through Eastern OK today. However, a couple models - that I tend to favor - develop a complex and drop it through the western half of the state (one of those even still develops the eastern complex).

Day 1 Outlook update is pretty brief...

...PLAINS STATES...
MORNING WATER VAPOR LOOPS SHOW SEVERAL SUBTLE SHORTWAVE TROUGHS
ROTATING AROUND PERIPHERY OF UPPER RIDGE CENTERED OVER THE SOUTHWEST
STATES. THESE TROUGHS WILL MOVE INTO THE CENTRAL PLAINS THIS
AFTERNOON AND HELP TO FOCUS THUNDERSTORM DEVELOPMENT. SEVERAL
CLUSTERS OF STORMS ARE ONGOING THIS MORNING FROM THE NEB INTO
TX...IN BROAD REGION OF LOW LEVEL WARM ADVECTION AND LIFT. A FEW OF
THESE STORMS MAY CONTINUE TO POSE A RISK OF HAIL THROUGH THE MORNING
HOURS...BUT AN OVERALL WEAKENING TREND TO THESE STORMS IS EXPECTED
BY EARLY AFTERNOON. LATER TODAY...THUNDERSTORMS ARE EXPECTED TO
INTENSIFY ALONG A COLD FRONT SURGING INTO NEB. THIS ACTIVITY WILL
LIKELY BE SUPERCELLS WITH A RISK OF VERY LARGE HAIL AND DAMAGING
WINDS. STORMS SHOULD BECOME MORE NUMEROUS THROUGH THE EVENING AND
EVENTUALLY ORGANIZE INTO ONE OR MORE MCSS THAT WILL TRACK
SOUTHEASTWARD ACROSS PARTS OF KS/OK AND WESTERN MO.