General Weather Discussion - April 2014

[Soonerman12]

Soonerdave... Also, Slight, moderate, and high refers to all types of Severe weather. I understand in a way the torcon does also, but for the most part torcon gives the casual observer the chances of a tornado happening within a 50 mile radius of whatever destination they choose (e.g. Eastern OK/Central OK). It helps people understand in a way what the chances of tornadoes are. Some people get confused with slight, moderate, and high cause that could mean different things. It's kind of like people not knowing the difference between watches and warnings if that makes since to you. I never said it was a perfect system though sir

[venture]

Wednesday's outlook changed slightly. Still a general 15% risk area over Central and Eastern OK with a hatched area from the Metro back to the north and northeast. Models last night still struggle to develop much in the way of any convection except for the isolated storm and SPC is picking up on that. Looks like risk will be limited to a decent cap much of the day and evening and it'll take a good push along the dryline to get things kicked off. There is a chance the cap wins and nothing happens, but I'm thinking we should still see one or two storms bust through. Any storm that makes it and busts through will likely be severe with all modes possible.

[LocoAko]

I do think torcon is more useful to the average viewer than KFOR's system no doubt. I believe they had an 8 on May 31, 2013.

EVERYONE was harping on the severe weather threat that day, not just TWC.

[crimsoncrazy]

How about rain amounts?

[venture]

How about rain amounts?

The isolated nature of storms will impact amounts that makes it pretty tough to even bother with amounts right now.

[Anonymous.]

Today could be a sleeper in SC OK. If something breaks through cap, almost a guaranteed supercell. N TX looks to have a better shot at this, but I am more worried about non-isolation down there.

Right now Wednesday looks like high bust potential in C OK. Dryline will have to be really mean to set something off before moving east enough. I agree with SPC's SLIGHT risk right now.


EDIT: I said Thursday, meant Wednesday.

[Soonerman12]

ANON... What do you think for Eastern OK? I noticed there was a pretty good bust potential in OKC area but it's looking like a higher potential for Wednesday and Thursday here in Eastern OK. It's looking like storms will fire off somewhere just North/Northeast of OKC tomorrow somewhere to the surface low... Do you concur? What do you think sir?

[Anonymous.]

Yea I would say E OK looks like really good shot at severe storms. Depending on where/if storms fire on dryline, the cap will have eroded enough by then that storms should be a good bet across much of NE into E OK. Storms could take on more a conglomerate structure or linear structure with emphasized wind threat as they evolve. But again, this depends on where they fire. It is tough for supercells to be sustained for a long period of time, especially heading into dark. Hail and tornados will be primary threat with supercells closest to dryline, if they fire.

Will know more tomorrow morning on location/timings/dewpoints.

[Soonerman12]

Yeah I notice that storms will most likely start dying off a little bit after dark due to the cap starting to build back in place. What about for Thursday? Computer models are having a little bit of a struggle placing locations. Some models have a moderate threat for severe storms/tornadoes just east of Tulsa and some have Tulsa smack dab in the middle. I would think the severe threat would be during the late morning hours Thursday possibly early afternoon unless the front completely stalls out. Some people are suggesting late afternoon early evening would be the threat Thursday.

[Soonerman12]

Man if these storms fire off near/just east of Enid there looks like a pretty decent chance of them being supercells around the pawnee/osage/Washington county areas with the surface low being in place. I would say IF there are supercells they would last just a little before bowing out and becoming more of a hail/straight line wind event.

[SoonerDave]

Soonerdave... Also, Slight, moderate, and high refers to all types of Severe weather. I understand in a way the torcon does also, but for the most part torcon gives the casual observer the chances of a tornado happening within a 50 mile radius of whatever destination they choose (e.g. Eastern OK/Central OK). It helps people understand in a way what the chances of tornadoes are. Some people get confused with slight, moderate, and high cause that could mean different things. It's kind of like people not knowing the difference between watches and warnings if that makes since to you. I never said it was a perfect system though sir

That's fine. We just disagree on its motives/utility. The notion is to simplify it over "slight/moderate/high", yet to understand their 1-10 semantics you have to go to their chart, and read what all the numbers mean. And driving folks to their site/charts/channel is, naturally, what it's all about.

Different strokes, I guess. Too much harem-scarem in my book, but that's just me.

[Soonerman12]

I agree with that aspect of it, they absolutely do some things to boost ratings no doubt about it.

[Jim Kyle]

Too much harem-scarem in my book, but that's just me.

It's a bit difficult for most of us to realize just how far the art of weather prediction has come in the last 70 years. We tend to forget that the whole theory of "fronts" only began during WW2, and the very first tornado forecast issued anywhere was in 1948, by the weather officer at Tinker AFB -- and it was accurate! Civilians didn't get such forecasts until later, and then they were very cautiously worded to prevent panic.

During the mid-50s, I was the assigned weather writer for The Oklahoman and kept very close contact with Tom Kyle, the man in charge of the NWS station at Will Rogers Field and who issued the first civilian tornado warning (turns out he's a distant cousin though neither of us knew it at the time). He loaned me a few of the standard weather textbooks used in training new meteorologists. The universal theme, then, was that the best predictor of what would happen on April 2, 2014, was the history of what DID happen on April 2, 2013, and the second best predictor was the average of what had happened on all preceding April 2s. None of this concern with highs, lows, and those new-fangled fronts.

Which is not to say that Tom actually followed that advice; it just shows how recently the art became backed up by science. He also taught me about the hook echo, which had been discovered in South Pacific typhoons during the war, but cautioned me not to make its existence public because it couldn't distinguish between rotation at 5,000 feet and that on the ground. He issued warnings only after spotters confirmed a funnel on the ground.

And spotters were an essential part of the system even that far back. I was an active ham radio operator at the time, and often went to the weather bureau office to man the base station when spotters were in the field. They chased for two reasons: to warn the public, and to get movies of the storms for the NWS labs to better understand what was going on. The fellows I dispatched went out in teams of two: a ham operator who communicated and drove, and a NWS cameraman.

[SoonerDave]

It's a bit difficult for most of us to realize just how far the art of weather prediction has come in the last 70 years. We tend to forget that the whole theory of "fronts" only began during WW2, and the very first tornado forecast issued anywhere was in 1948, by the weather officer at Tinker AFB -- and it was accurate! Civilians didn't get such forecasts until later, and then they were very cautiously worded to prevent panic.

During the mid-50s, I was the assigned weather writer for The Oklahoman and kept very close contact with Tom Kyle, the man in charge of the NWS station at Will Rogers Field and who issued the first civilian tornado warning (turns out he's a distant cousin though neither of us knew it at the time). He loaned me a few of the standard weather textbooks used in training new meteorologists. The universal theme, then, was that the best predictor of what would happen on April 2, 2014, was the history of what DID happen on April 2, 2013, and the second best predictor was the average of what had happened on all preceding April 2s. None of this concern with highs, lows, and those new-fangled fronts.

Which is not to say that Tom actually followed that advice; it just shows how recently the art became backed up by science. He also taught me about the hook echo, which had been discovered in South Pacific typhoons during the war, but cautioned me not to make its existence public because it couldn't distinguish between rotation at 5,000 feet and that on the ground. He issued warnings only after spotters confirmed a funnel on the ground.

And spotters were an essential part of the system even that far back. I was an active ham radio operator at the time, and often went to the weather bureau office to man the base station when spotters were in the field. They chased for two reasons: to warn the public, and to get movies of the storms for the NWS labs to better understand what was going on. The fellows I dispatched went out in teams of two: a ham operator who communicated and drove, and a NWS cameraman.

Awesome stuff, Jim! Thanks for sharing. I really thought about taking one of the spotter training sessions this year, but I just kept getting overcome by events...LOL

I remember listening to KTOK and they would sometimes relay warnings from ham operators.

And I love how the overarching theme was to avoid inciting a public panic.

[ou48A]

It's a bit difficult for most of us to realize just how far the art of weather prediction has come in the last 70 years. We tend to forget that the whole theory of "fronts" only began during WW2, and the very first tornado forecast issued anywhere was in 1948, by the weather officer at Tinker AFB -- and it was accurate! Civilians didn't get such forecasts until later, and then they were very cautiously worded to prevent panic.

During the mid-50s, I was the assigned weather writer for The Oklahoman and kept very close contact with Tom Kyle, the man in charge of the NWS station at Will Rogers Field and who issued the first civilian tornado warning (turns out he's a distant cousin though neither of us knew it at the time). He loaned me a few of the standard weather textbooks used in training new meteorologists. The universal theme, then, was that the best predictor of what would happen on April 2, 2014, was the history of what DID happen on April 2, 2013, and the second best predictor was the average of what had happened on all preceding April 2s. None of this concern with highs, lows, and those new-fangled fronts.

Which is not to say that Tom actually followed that advice; it just shows how recently the art became backed up by science. He also taught me about the hook echo, which had been discovered in South Pacific typhoons during the war, but cautioned me not to make its existence public because it couldn't distinguish between rotation at 5,000 feet and that on the ground. He issued warnings only after spotters confirmed a funnel on the ground.

And spotters were an essential part of the system even that far back. I was an active ham radio operator at the time, and often went to the weather bureau office to man the base station when spotters were in the field. They chased for two reasons: to warn the public, and to get movies of the storms for the NWS labs to better understand what was going on. The fellows I dispatched went out in teams of two: a ham operator who communicated and drove, and a NWS cameraman.

Great stuff......thanks
I believe we would all like to hear more..... perhaps on a separate thread

[venture]

Updated risk area for tomorrow...brings is much further south on the 30% and also the hatched area. Hatched are is roughly the OKC metro back to the east and north.



DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT TUE APR 01 2014

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS WED THRU WED NIGHT ACROSS PARTS
OF THE S CNTRL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY/OZARK
PLATEAU REGION...

...SYNOPSIS...
A BELT OF WESTERLIES EMERGING FROM THE MID LATITUDE PACIFIC WILL
REMAIN PROMINENT ACROSS MUCH OF THE U.S. THROUGH THIS PERIOD AND
BEYOND. WITHIN THIS REGIME...THE REMNANTS OF A GRADUALLY WEAKENING
MID-LEVEL CLOSED LOW /NOW DIGGING INTO THE CALIFORNIA COAST/ APPEAR
LIKELY TO TURN EASTWARD/EAST NORTHEASTWARD ACROSS THE FOUR CORNERS
STATES AND CENTRAL/SOUTHERN ROCKIES REGION WEDNESDAY THROUGH
WEDNESDAY NIGHT. IN ADVANCE OF THIS FEATURE... MID-LEVEL RIDGING
APPEARS LIKELY TO BUILD ACROSS THE LOWER PLAINS INTO THE
APPALACHIANS REGION...IN THE WAKE OF ANOTHER VIGOROUS SHORT WAVE
TROUGH...WHICH IS EXPECTED TO GRADUALLY TURN EAST SOUTHEAST OF THE
GREAT LAKES REGION THROUGH MUCH OF THE NORTHEAST.

IN ASSOCIATION WITH THE EASTERN IMPULSE...A SIGNIFICANT INTRUSION OF
COLD AIR HAS ALREADY OVERSPREAD MUCH OF THE UPPER MIDWEST AND MIDDLE
MISSISSIPPI VALLEY THROUGH THE SOUTH CENTRAL PLAINS. WHILE THE
FRONT ON THE LEADING EDGE OF THIS AIR MASS IS EXPECTED TO OVERSPREAD
MUCH OF THE OHIO VALLEY LATER TODAY AND TONIGHT...THE SLOWING
WESTERN FLANK IS EXPECTED TO EVENTUALLY STALL...BEFORE RETREATING
NORTHWARD THROUGH THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY
REGION. WEAK SURFACE PRESSURE FALLS ARE ALREADY OCCURRING ACROSS
THE CENTRAL HIGH PLAINS...BUT ONLY MODEST LEE SURFACE CYCLOGENESIS
IS FORECAST THROUGH WEDNESDAY NIGHT...AND IT REMAINS UNCERTAIN JUST
HOW QUICKLY /AND HOW FAR NORTH/ THE COLD CENTRAL PLAINS BOUNDARY
LAYER MODIFIES.

MODELS ARE SUGGESTIVE THAT A CONTINUING SOUTHERLY RETURN FLOW OFF A
MODIFYING WESTERN GULF OF MEXICO BOUNDARY LAYER WILL FINALLY ADVECT
SEASONABLY HIGH MOISTURE CONTENT INTO THE SOUTHERN PLAINS/OZARK
PLATEAU REGION BY LATE WEDNESDAY INTO WEDNESDAY NIGHT. BENEATH
RESIDUALLY STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH ELEVATED
MIXED LAYER AIR...THIS PROBABLY WILL CONTRIBUTE TO SIZABLE
CAPE...AND INCREASING CONVECTIVE POTENTIAL.

...S CNTRL PLAINS INTO MID MS VALLEY/OZARK PLATEAU...
CONSIDERABLE THUNDERSTORM ACTIVITY MAY BE ONGOING WEDNESDAY MORNING
WITHIN A LOWER/MID TROPOSPHERIC WARM ADVECTION REGIME... ABOVE THE
COLD SURFACE BASED AIR...ACROSS PARTS OF EASTERN KANSAS INTO WESTERN
MISSOURI. SOME SEVERE HAIL THREAT MAY LINGER WITH STRONGER ACTIVITY
AS IT DEVELOPS EASTWARD TOWARD THE OHIO VALLEY THROUGH THE DAY.

OTHERWISE...MID-LEVEL CAPPING BENEATH MID/UPPER RIDGING PROBABLY
WILL SUPPRESS CONVECTIVE DEVELOPMENT ACROSS AREAS TO THE SOUTH
THROUGH MUCH OF THE DAY. MOST GUIDANCE DOES APPEAR TO INDICATE THAT
SUBSTANTIVE BOUNDARY LAYER DESTABILIZATION IN THE PRESENCE OF AT
LEAST WEAK LOW-LEVEL WARM ADVECTION BENEATH DIFLUENT MID/UPPER FLOW
WILL CONTRIBUTE TO STORM INITIATION EITHER LATE WEDNESDAY AFTERNOON
OR...MORE LIKELY...EARLY WEDNESDAY EVENING. THIS SEEMS MOST
PROBABLE NEAR THE INTERSECTION OF THE RETREATING SURFACE FRONT AND
STRENGTHENING DRY LINE...ALTHOUGH UNCERTAINTY IS INCREASING
CONCERNING EXACTLY WHERE THIS WILL BE POSITIONED.

REGARDLESS...IN RESPONSE TO STRENGTHENING LARGE-SCALE FORCING FOR
ASCENT...AND SUFFICIENT SHEAR FOR ORGANIZED STORM DEVELOPMENT...
POTENTIAL APPEARS TO EXIST FOR INITIAL DISCRETE SUPERCELLS TO
CONSOLIDATE/GROW UPSCALE INTO A SEVERE MESOSCALE CONVECTIVE SYSTEM
BY LATE WEDNESDAY EVENING. BASED LARGELY ON THE ECMWF AND
NAM...THIS SEEMS MOST LIKELY ACROSS EASTERN OKLAHOMA AND ADJACENT
SOUTHEAST KANSAS.

..KERR.. 04/01/2014

[venture]

The short of the discussion above. Discrete supercells where convection initiates on the west side of this outlook area and it will turn into an MCS as it moves east of us.

[PennyQuilts]

Mcs?

[Charlie40]

Mesoscale Convective System = MCS

[venture]

Hrrr showing storms firing around 4pm or so just east of 44 in sw ok.

[OKCisOK4me]

^^thats fine by me

[PennyQuilts]

Mesoscale Convective System = MCS

Thank you.

A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones, and normally persists for several hours or more.

(shortened definition)

[Anonymous.]

Warm front surging north right now. Could see development along this line tonight. However, this low cloud deck has really kept instability down today. It is trying to burn off in S OK.

[Plutonic Panda]

Could it turn into a derecho?

[Anonymous.]

Could it turn into a derecho?

Huh?





MD out for SC OK. Large hail main threat. Temperatures down there are in the 80s with DP in the 60s.