General Weather Discussion - March 2015

[venture]

[bchris02]

Do you think OKC will see any significant rain out of this? At this point a torrential downpour is needed to refill lakes and streams.

[Anonymous.]

Really depends on where storms fire and how matured they are when they hit OKC. But yes, severe storms is how many Oklahoma lakes and ponds fill up.

[venture]

One storm finally starting to pull up a bit in SE OK, northeast of McAlester.

[SomeGuy]

I didn't catch KFOR but David Payne is being very level headed about tomorrow, I figured they'd take the opportunity to hype the thing up.

Mike Morgan was definitely hyping the heck out of the storm saying that there will be large hail,, damaging winds and multiple tornadoes up to E F2. Mike Morgan needs to relax a bit sometimes imo.

[venture]

Couple of SVR warnings out in SE OK, so today is the new record for latest severe warning for the state.

[Anonymous.]

I am starting to grow a little more concerned with the trend of delayed cold front tomorrow evening. Earlier runs showed the front blasting through and basically cutting any surface action the cells have early on.

Could get some pretty big HP supercells on the dryline that shove east, also training could occur along storm's outflow boundaries somewhere from WC OK to C OK depending how far back the storms fire. Like V mentioned, if wind shear profiles were more favorable, the setup would be ripe for larger tornados. Could have some flash flooding where cells train.

Right now I wouldn't rule out early spin ups, especially if dryline cells can stay discrete and not muddy each other up. Also this will increase hail sizes.

[venture]

Interesting shift in the outlook tonight.

Enhanced Risk now from Lawton to Pauls Valley north to the entire Metro area and then north of I-40 to the east and due north to the KS border. Slight risk for the rest of the area in Southern Oklahoma.

Highest tornado risk at 5% over NE OK, 2% tornado area over the Metro.

Hail risk area at 30% for the ENH RISK area. Sig Hail / Hatched area from the Metro back tot he Northeast.





DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1244 AM CDT WED MAR 25 2015

VALID 251200Z - 261200Z

...THERE IS AN ENH RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
ACROSS PARTS OF NORTH CENTRAL AND NORTHEAST OKLAHOMA...ADJACENT
SOUTHEAST KANSAS...SOUTHWEST MISSOURI AND NORTHWEST ARKANSAS...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ENH
RISK...ACROSS PARTS OF THE SOUTH CENTRAL PLAINS INTO THE OZARK
PLATEAU...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
CENTRAL AND SOUTHERN PLAINS EAST NORTHEASTWARD INTO PARTS OF THE
LOWER OHIO VALLEY...

...SUMMARY...
SEVERE THUNDERSTORMS...MAINLY CAPABLE OF PRODUCING LARGE HAIL AND
LOCALLY DAMAGING WIND GUSTS...ARE EXPECTED ACROSS PARTS OF THE SOUTH
CENTRAL PLAINS INTO THE OZARK PLATEAU LATE THIS AFTERNOON AND
EVENING.

...SYNOPSIS...
SIGNIFICANT AMPLIFICATION IS ONGOING WITHIN A BRANCH OF MID-LATITUDE
WESTERLIES ACROSS THE EASTERN PACIFIC INTO WESTERN NORTH AMERICA.
AS LARGE-SCALE MID/UPPER RIDGING CONTINUES TO BUILD NEAR THE PACIFIC
COAST DURING THIS PERIOD...MODELS INDICATE THAT LARGE-SCALE
TROUGHING WILL BEGIN TO EVOLVE DOWNSTREAM...EAST OF THE
ROCKIES...THROUGH THE VICINITY OF THE APPALACHIANS.

WITHIN THIS LATTER REGIME...ONE NOTABLE SHORT WAVE IMPULSE IS
FORECAST TO PIVOT RAPIDLY NORTHEASTWARD...FROM THE OHIO VALLEY
THROUGH THE ST. LAWRENCE VALLEY BY LATE TONIGHT. AN ASSOCIATED
SURFACE LOW MAY CONSOLIDATE WITH ANOTHER LOW OVER THE GREAT LAKES
REGION...BEFORE CONTINUING INTO QUEBEC LATE IN THE PERIOD...WITH A
TRAILING COLD FRONT ADVANCING SOUTHEASTWARD ACROSS THE CENTRAL
UNITED STATES.

INITIALLY STALLED OVER PARTS OF THE LOWER OHIO VALLEY/OZARK PLATEAU
AND CENTRAL PLAINS...MODELS SUGGEST THAT THE SOUTHWESTERN FLANK OF
THIS FRONT WILL BEGIN A MORE RAPID SOUTHWARD SURGE...IN RESPONSE TO
ANOTHER SIGNIFICANT SHORT WAVE IMPULSE DIGGING SOUTHEAST OF THE
CENTRAL ROCKIES THROUGH MUCH OF THE SOUTH CENTRAL PLAINS BY 12Z
THURSDAY. THIS MAY BE ACCOMPANIED BY WIDESPREAD CONVECTIVE
DEVELOPMENT...AND THE RISK FOR SEVERE STORMS.

...SOUTH CENTRAL PLAINS/OZARK PLATEAU INTO LOWER OHIO VALLEY...
SOME BOUNDARY LAYER MOISTENING CONTINUES ALONG AND SOUTH OF THE
FRONT...BUT A SUBSTANTIVE RETURN FLOW OF MOISTURE OFF THE GULF OF
MEXICO STILL APPEARS UNLIKELY DURING THIS PERIOD. MODEL SURFACE DEW
POINT FORECASTS FOR THIS AFTERNOON MAY STILL BE AT LEAST A BIT TOO
HIGH. HOWEVER...NORTHEASTWARD ADVECTION OF WARM ELEVATED MIXED
LAYER AIR IS EXPECTED TO AGAIN CONTRIBUTE TO VERY STEEP MID-LEVEL
LAPSE RATES BY THIS AFTERNOON. THIS PROBABLY WILL SUPPORT SIZABLE
CAPE /PERHAPS AT OR ABOVE 2000 J PER KG/ WITHIN AT LEAST A NARROW
CORRIDOR ALONG THE FRONTAL ZONE. IN THE PRESENCE OF STRONG SHEAR
BENEATH 40-50 KT WESTERLY 500 MB FLOW...CONDITIONS SHOULD BECOME
CONDUCIVE TO THE DEVELOPMENT OF SEVERE STORMS FOR AT LEAST A PERIOD
LATE THIS AFTERNOON INTO EARLY EVENING.

MODELS SUGGEST THAT FORCING FOR ASCENT ASSOCIATED WITH LOW-LEVEL
WARM ADVECTION MAY SUPPORT A RAPID INCREASE IN SEVERE STORM
DEVELOPMENT BY 20-22Z NEAR THE CENTRAL AND EASTERN KANSAS/OKLAHOMA
BORDER AREA. THIS MAY INITIALLY INCLUDE DISCRETE STORMS...BEFORE
GROWING UPSCALE...WHICH SHOULD TEND TO TRACK EASTWARD ALONG THE
FRONT INTO THE OZARK PLATEAU. ADDITIONAL SEVERE STORMS MAY FORM
SHORTLY THEREAFTER ACROSS PARTS OF WEST CENTRAL OKLAHOMA. IT
APPEARS THAT THIS LATTER ACTIVITY WILL OCCUR JUST AHEAD OF THE
SOUTHWARD SURGING COLD FRONT...AND STRONGER STORMS PROBABLY WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND LOCALLY STRONG WIND GUSTS.

AS LARGE-SCALE FORCING SUPPORTS INCREASINGLY WIDESPREAD THUNDERSTORM
ACTIVITY THROUGH MUCH OF THE INSTABILITY AXIS...WHILE THE SURFACE
COLD FRONT BEGINS TO SURGE SOUTHWARD AND TENDS TO UNDERCUT
CONVECTION...IT REMAINS UNCLEAR AT THE PRESENT TIME HOW LONG THE
SEVERE WEATHER POTENTIAL WILL CONTINUE INTO THE EVENING HOURS.

..KERR/MOSIER.. 03/25/2015

[Bobby821]

Will someone please tell channel 4 that we are NOT in a Moderate risk for storms today. Sheesh how can you equate an Enhanced risk with a Moderate. it is no wonder people are so ill informed on weather and do not take it serious when they should with this kind of forecasting.

[Soonerman12]

Bobby, the rating system is all kinds of jacked up. The only thing that matters is we are at risk for ALL modes of severe weather this afternoon and evening. Honestly, who cares the risk. People just need to remember to be aware. Being a person that chases storms I've seen this wayyy to many times. There will be days that are only forecasted as "slight" and we have a outbreak and days it is moderate and not a rain drop. Quit listening to local mets and pay attention to Venture, anon, myself ect. We don't use risk just give facts of what the satellite says and what chasers physically are seeing in the field.

[Soonerman12]

Looks like we could see a triple point set up in central OK today. Everyone please remember that severe weather is likely. People need to keep aware especially when storms first fire up, that'll be most likely time frame when discrete supercells will form. The more likely area to see this weather will be from a line from OKC to Tulsa to Joplin and NW Arkansas.

[LocoAko]

Will someone please tell channel 4 that we are NOT in a Moderate risk for storms today. Sheesh how can you equate an Enhanced risk with a Moderate. it is no wonder people are so ill informed on weather and do not take it serious when they should with this kind of forecasting.

Now we are. ... Wouldn't surprise me to see some very large hail reports today.



...SRN PLNS/OZARKS TO LWR OH VLY TODAY/TNGT...
WEAK LEE LOW NOW CENTERED OVER WRN PORTIONS OF THE TX PANHANDLE
SHOULD ELONGATE SLOWLY ENE ACROSS OK AND BECOME A BIT BETTER-DEFINED
TODAY AS LOW-LVL PRESSURE GRADIENT REGIONALLY TIGHTENS AHEAD OF
APPROACHING COLD FRONT. CONVERGENCE NEAR AND E OF THE LOW AND COLD
FRONT AND...TO A LESSER EXTENT...ALONG DRY LINE TRAILING SW FROM THE
LOW...SHOULD SERVE TO FOCUS STRONG TSTM DEVELOPMENT BY LATE AFTN
FROM CNTRL OK ENE INTO SE KS/SW MO. WITH TIME...STORMS SHOULD ALSO
DEVELOP EWD ALONG COLD FRONT ACROSS THE REMAINDER OF SRN MO...AND SW
ALONG DRY LINE INTO N TX.

INITIAL STORM DEVELOPMENT WILL BE DRIVEN LARGELY BY SFC HEATING AND
LOW-LVL UPLIFT...ALTHOUGH SOME DEGREE OF UPR-LVL FORCING MAY
ACCOMPANY LOW-AMPLITUDE DISTURBANCE MOVING E ACROSS NM. WARM SECTOR
MOISTURE WILL REMAIN COMPARATIVELY MODEST...WITH SFC DEWPOINTS
MAINLY AROUND 60 F AND PW OF 1.00-1.25 INCHES. NEVERTHELESS...GIVEN
500 MB TEMPS AOB MINUS 16C AND STRONG SFC HEATING...THIS SHOULD
YIELD 2000+ J/KG SBCAPE.

GIVEN THE DEGREE OF BUOYANCY...45-50 KT WSWLY MID-LVL FLOW ATOP 30+
KT SWLY 850 MB JET WILL BE MORE THAN ADEQUATE FOR STRONG SUPERCELLS
WITH VERY LARGE HAIL AND LOCALLY DMGG WIND. WHILE INCREASING DEGREE
OF LOW- AND MID-LVL FORCING SUGGEST THAT MUCH OF THE ACTIVITY WILL
FAIRLY QUICKLY EVOLVE INTO CLUSTERS/BROKEN LINES...SOME OPPORTUNITY
WILL EXIST FOR A FEW LONGER-LIVED DISCRETE STORMS...ESPECIALLY NE OF
SFC LOW AND NEAR DRY LINE/LOW INTERSECTION. THESE COULD YIELD A
COUPLE TORNADOES IN ADDITION TO VERY LARGE HAIL AND DMGG WIND.

AS THE COLD FRONT ACCELERATES SEWD THIS EVE AND OVERNIGHT...EXPECT
RESULTING SQUALL LINE/QLCS TO BECOME INCREASINGLY UNDERCUT IN THE
PLNS...WITH A DIMINISHING THOUGH STILL NON-ZERO THREAT FOR LOCALLY
DMGG WIND AND HAIL SWD INTO PARTS OF TX. A WIND THREAT
MAY...HOWEVER...CONTINUE LATER INTO THE NGT EWD ACROSS SRN MO AND
NRN AR INTO THE LWR OH VLY...WHERE STORMS WILL BE LESS LIKELY TO BE
UNDERCUT...AND A FEW BOWING SEGMENTS MAY EVOLVE.

[Bobby821]

Looks like we could see a triple point set up in central OK today. Everyone please remember that severe weather is likely. People need to keep aware especially when storms first fire up, that'll be most likely time frame when discrete supercells will form. The more likely area to see this weather will be from a line from OKC to Tulsa to Joplin and NW Arkansas.

So does this mean places like Moore and Norman and Chicashea will miss out on the major storms? hope not.

[LocoAko]

So does this mean places like Moore and Norman and Chicashea will miss out on the major storms? hope not.

Yeah, it'd be a real bummer to miss out on tennis ball sized hail during rush hour.

[Bobby821]

Yeah, it'd be a real bummer to miss out on tennis ball sized hail during rush hour.

These will most likely be occouring after or at the tail end of rush hour

[OKCMallen]

So does this mean places like Moore and Norman and Chicashea will miss out on the major storms? hope not.

Come on man. Don't put the bad juju out there like that.

[Anonymous.]

60F+ Dewpoints already pouring back into the state this morning. If you noticed the haze, you know it is severe weather time in OK.


Hail size could be pretty damaging with isolated supercells. Also I want to emphasize the flash flood threat, especially around C OK. We could have one of those boundaries that fires off cell after cell over the same area until the cold front really blasts by.


First severe risk for OKC this year, and we start with a Moderate.

[Soonerman12]

Bobby... The NWS Storm Prediction Center has now upgraded OKC to Tulsa to Joplin in the "moderate" risk area you referred to earlier... So maybe morgan was right lol Anyways, people in these areas PAY ATTENTION the SPC doesn't just issue this for no reason. This likely will become rapidly severe supercells this afternoon that WILL have a chance to produce tornadoes. Like I said earlier, triple point looks to set up in Central/East OK. I would say persons in OKC to Stillwater to Tulsa have the highest risk. I live in Tulsa, looks like it could be a long chase night.

[SOONER8693]

So does this mean places like Moore and Norman and Chicashea will miss out on the major storms? hope not.

Seriously? What is your deal? Not enough death and destruction in that area for you yet?

[venture]

Will go into details here in a few (just waking up)...

We are at a Moderate Risk now and yes, I will be in the chat room today because of it...

Weather Spotlight - Live Chat Room for Weather Event Coverage

[FighttheGoodFight]

Rain would be nice. I could use it to get my fertilizer soaked in. Tornados...no thanks

[venture]

Looking over the morning models...

This should start to fire off around 5PM today. NAM and HRRR have different opinions on where...

NAM



HRRR

[Soonerman12]

Venture... I'm having a hard time with really believing either of them.. I don't think the HRRR is positioned correctly with storms around Tulsa that early and I don't agree with NAM not really having much kick started by then. The only thing I do agree with is the positioning of the storms firing off on the NAM I just believe it will be blown up by then. Who knows, either way it'll be there no matter what.

[venture]

Venture... I'm having a hard time with really believing either of them.. I don't think the HRRR is positioned correctly with storms around Tulsa that early and I don't agree with NAM not really having much kick started by then. The only thing I do agree with is the positioning of the storms firing off on the NAM I just believe it will be blown up by then. Who knows, either way it'll be there no matter what.

HRRR is just firing the dryline, whereas the NAM waits for the front. Both are very possible today, we'll just have to watch. Main thing is Tulsa and NE OK won't get dryline play, so position of the front will be key for them up there.

[venture]

Moisture flooding back in pretty good...we'll need to see how much of this mixes out with daytime heating.