General Weather Discussion - May 2015

[Anonymous.]

If convection and clouds from Friday evening linger into Saturday, it could hamper things. But like we saw yesterday, sometimes it doesn't matter and you get supercells in 68F rain-cooled air.

[SoonerBeerMan]

Also I know we've bashed them plenty in the last few weeks but I'd like to applaud the NWS yesterday. They seemed very very on point with their warnings and general info. All the warnings were coming out at a rapid pace in a timely manner and gave people plenty of time to seek shelter if the need warranted it.

Very good point!

[bradh]

That area around Valley Brook last night looked like a damn hurricane on radar, that was crazy.

[catch22]

That area around Valley Brook last night looked like a damn hurricane on radar, that was crazy.

The strippers reportedly have hail damage. So, business as usual for Valley Brook.

[RadicalModerate]

According to a News Ogle, K4, Gov. Fallin is reminding us to be "Weather Aware"

Dang. I wish I'da already considered that.

(side--not iso--bar): I recently encountered a "person of color" with a Florida tag on the car at the local Love's gas pumps. It was Saturday, exactly at Noon. The Sirens went off on a nearly cloudless day. He was so flustered--and looking around at the sky--that he had to ask me, "Wha'???!!!" All I could say was: "It's Oklahoma. And it's OK. Saturday, at noon they sound the sirens." He breathed a sigh of relief and said, 'Thanks . . . I couldn't make any sense out of all that." I resisted the urge to say, "It could have been worse . . . It might have been The Russians carrying out a Nuclear Strike." I figured that a noob to OK, from FLA, already had to deal with hurricanes and 'gators so I didn't want to increase his stress level.

This should probably be on a different thread regarding Storm Sirens . . .
Yet the specific location is difficult to Pintrest.

[jn1780]

SPC just added a huge moderate risk area from Western to west central Oklahoma for tomorrow. Enhanced area for most of the other areas.

SPC AC 071726

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT THU MAY 07 2015

VALID 081200Z - 091200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHWEST
TX...WESTERN OK AND SOUTHERN KS...

...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHERN
AND CENTRAL PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHERN
AND CENTRAL PLAINS...

...THERE IS A MRGL RISK OF SVR TSTMS FROM SW TX TO IL...

...THERE IS A MRGL RISK OF SVR TSTMS ALONG THE CAROLINA COAST...

...SUMMARY...
SEVERE THUNDERSTORMS WILL DEVELOP ACROSS THE SOUTHERN AND CENTRAL
GREAT PLAINS. VERY LARGE HAIL...DAMAGING WINDS...AND TORNADOES ARE
EXPECTED...ESPECIALLY ACROSS WESTERN OKLAHOMA.

...SOUTHERN/CENTRAL GREAT PLAINS...

LARGE-SCALE HEIGHT FALLS WILL SPREAD INTO THE DESERT SOUTHWEST
DURING THE DAY2 PERIOD AS STRONG UPPER LOW TRANSLATES INTO THE
4-CORNERS REGION LATE. DIFLUENT HIGH-LEVEL FLOW WILL SPREAD ACROSS
THE SRN/CNTRL PLAINS AHEAD OF THIS FEATURE WITH SUBSTANTIAL FLOW
EXPECTED TO OVERSPREAD A PRONOUNCED DRY LINE DURING PEAK HEATING.
STRONG SHEAR AND FAVORABLE HIGH-LEVEL VENTING SHOULD RESULT IN A
CONCENTRATED CORRIDOR OF SEVERE THUNDERSTORMS...ESPECIALLY ACROSS
WRN OK.

BOTH THE GFS AND NAM SUGGEST A WEAK MID-LEVEL SHORT-WAVE TROUGH WILL
EJECT ACROSS THE SRN HIGH PLAINS AFTER 18Z...TRANSLATING INTO WRN OK
BY 09/00Z. THIS FEATURE IS EXPECTED TO AID CONVECTIVE DEVELOPMENT
ALONG DRY LINE BY EARLY-MID AFTERNOON ACROSS THE HIGH
PLAINS...SPREADING/DEVELOPING EWD TOWARD THE I-35 CORRIDOR BY LATE
AFTERNOON. SHEAR PROFILES FAVOR SUPERCELLS AND BOUNDARY-LAYER
MOISTURE...ABSENT DAY1 CONVECTIVE DISRUPTION...SHOULD EASILY ADVANCE
NWD TOWARD SYNOPTIC BOUNDARY THAT SHOULD ORIENT ITSELF IN AN E-W
FASHION ACROSS SRN KS/SERN CO. IF MOISTURE/INSTABILITY RETURN TO
THE SYNOPTIC BOUNDARY...AS SUGGESTED BY LATEST NAM...ROBUST SEVERE
THUNDERSTORMS WILL DEVELOP ALONG A FAVORABLY SHEARED BOUNDARY THAT
COULD ENHANCE TORNADO POTENTIAL WITH ANY SUPERCELLS. EVEN
SO...DISCRETE WARM SECTOR SUPERCELLS ARE EXPECTED TO DEVELOP ACROSS
THE AFOREMENTIONED REGION OF NWRN TX...NWD TO THE SYNOPTIC FRONT
WITHIN AN ENVIRONMENT SEEMINGLY FAVORABLE FOR VERY LARGE
HAIL...TORNADOES...AND DAMAGING WINDS. FORECAST NAM SOUNDINGS
EXHIBIT PROFILES CHARACTERISTIC OF STORMS CAPABLE OF PRODUCING HAIL
IN EXCESS OF 2 INCHES AND PERHAPS EVEN A FEW STRONG TORNADOES.

SCT SUPERCELLS SHOULD DEVELOP/SPREAD NEWD TOWARD THE I-35 CORRIDOR
BY LATE AFTERNOON AS FOCUSED LLJ AIDS INFLOW. DURING THE
EVENING...SEVERE CLUSTERS SHOULD EVOLVE ALONG THE E-W SYNOPTIC FRONT
WHERE LLJ IMPINGES ON BOUNDARY.

[Anonymous.]

Altus storm is probably going to tornado soon. Looks like severe threat will likely remain along Red River corridor.

[corwin1968]

SPC just added a huge moderate risk area from Western to west central Oklahoma for tomorrow. Enhanced area for most of the other areas.

SPC AC 071726

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT THU MAY 07 2015

VALID 081200Z - 091200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHWEST
TX...WESTERN OK AND SOUTHERN KS...

...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHERN
AND CENTRAL PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHERN
AND CENTRAL PLAINS...

...THERE IS A MRGL RISK OF SVR TSTMS FROM SW TX TO IL...

...THERE IS A MRGL RISK OF SVR TSTMS ALONG THE CAROLINA COAST...

...SUMMARY...
SEVERE THUNDERSTORMS WILL DEVELOP ACROSS THE SOUTHERN AND CENTRAL
GREAT PLAINS. VERY LARGE HAIL...DAMAGING WINDS...AND TORNADOES ARE
EXPECTED...ESPECIALLY ACROSS WESTERN OKLAHOMA.

...SOUTHERN/CENTRAL GREAT PLAINS...

LARGE-SCALE HEIGHT FALLS WILL SPREAD INTO THE DESERT SOUTHWEST
DURING THE DAY2 PERIOD AS STRONG UPPER LOW TRANSLATES INTO THE
4-CORNERS REGION LATE. DIFLUENT HIGH-LEVEL FLOW WILL SPREAD ACROSS
THE SRN/CNTRL PLAINS AHEAD OF THIS FEATURE WITH SUBSTANTIAL FLOW
EXPECTED TO OVERSPREAD A PRONOUNCED DRY LINE DURING PEAK HEATING.
STRONG SHEAR AND FAVORABLE HIGH-LEVEL VENTING SHOULD RESULT IN A
CONCENTRATED CORRIDOR OF SEVERE THUNDERSTORMS...ESPECIALLY ACROSS
WRN OK.

BOTH THE GFS AND NAM SUGGEST A WEAK MID-LEVEL SHORT-WAVE TROUGH WILL
EJECT ACROSS THE SRN HIGH PLAINS AFTER 18Z...TRANSLATING INTO WRN OK
BY 09/00Z. THIS FEATURE IS EXPECTED TO AID CONVECTIVE DEVELOPMENT
ALONG DRY LINE BY EARLY-MID AFTERNOON ACROSS THE HIGH
PLAINS...SPREADING/DEVELOPING EWD TOWARD THE I-35 CORRIDOR BY LATE
AFTERNOON. SHEAR PROFILES FAVOR SUPERCELLS AND BOUNDARY-LAYER
MOISTURE...ABSENT DAY1 CONVECTIVE DISRUPTION...SHOULD EASILY ADVANCE
NWD TOWARD SYNOPTIC BOUNDARY THAT SHOULD ORIENT ITSELF IN AN E-W
FASHION ACROSS SRN KS/SERN CO. IF MOISTURE/INSTABILITY RETURN TO
THE SYNOPTIC BOUNDARY...AS SUGGESTED BY LATEST NAM...ROBUST SEVERE
THUNDERSTORMS WILL DEVELOP ALONG A FAVORABLY SHEARED BOUNDARY THAT
COULD ENHANCE TORNADO POTENTIAL WITH ANY SUPERCELLS. EVEN
SO...DISCRETE WARM SECTOR SUPERCELLS ARE EXPECTED TO DEVELOP ACROSS
THE AFOREMENTIONED REGION OF NWRN TX...NWD TO THE SYNOPTIC FRONT
WITHIN AN ENVIRONMENT SEEMINGLY FAVORABLE FOR VERY LARGE
HAIL...TORNADOES...AND DAMAGING WINDS. FORECAST NAM SOUNDINGS
EXHIBIT PROFILES CHARACTERISTIC OF STORMS CAPABLE OF PRODUCING HAIL
IN EXCESS OF 2 INCHES AND PERHAPS EVEN A FEW STRONG TORNADOES.

SCT SUPERCELLS SHOULD DEVELOP/SPREAD NEWD TOWARD THE I-35 CORRIDOR
BY LATE AFTERNOON AS FOCUSED LLJ AIDS INFLOW. DURING THE
EVENING...SEVERE CLUSTERS SHOULD EVOLVE ALONG THE E-W SYNOPTIC FRONT
WHERE LLJ IMPINGES ON BOUNDARY.

These weather threads are fascinating and are one of the few subjects I've encountered where what I'm reading might as well be in Medieval Gaelic.

Who are these bulletins intended for? Weather, aviation and emergency management types?

It makes me (sort of) want to dive in and learn more about the technical aspects of weather but it's a pretty intimidating subject!

[PennyQuilts]

Just getting away from all caps would be a huge improvement.

[Jim Kyle]

It makes me (sort of) want to dive in and learn more about the technical aspects of weather but it's a pretty intimidating subject!

It's not all that difficult, especially if you hang out here and follow some of the discussions. The Weather Bureau bulletins are filled with abbreviations that make them look much more arcane than they actually are once you figure out that WRN OK means Western Oklahoma, and GFS AND NAM" refer to two different computer forecasting programs that attempt to model the weather environment and by doing so, predict what's going to happen next.

Just think about the "texting" language that's so popular these days, eliminating keystrokes by dropping most vowels from words and leaving you to figure them out by context. That's pretty much what these official messages do, cutting down on keystrokes to get a maximum of information out in minimum time. And lots of it is now simply traditional jargon left over from the days not so horribly long ago when the best rapid-communication device available was the Teletype Model 33, running at a blazing 110-bit-per-second speed (today's Internet averages more than 3 million bits per second and "high-speed" goes up to 50 million and more).

From time to time, David posts tutorial messages to teach the rest of us how to read the more unfamiliar charts and tables, too.

EDIT: Some hints on the one you quoted: NEWD is northeastward and LLJ is, I think, Lower Level Jet (referring to the jet streams that influence weather quite heavily).

[jn1780]

Just getting away from all caps would be a huge improvement.

It may make sense to do it in all caps if these bulletins are automatically faxed out to different agencies. I imagine the all caps is a holdout from when everyone was using old style printers.

[LocoAko]

It may make sense to do it in all caps if these bulletins are automatically faxed out to different agencies. I imagine the all caps is a holdout from when everyone was using old style printers.

That's exactly it.

[corwin1968]

Most of the abbreviations are easy enough to figure out but it seems it could easily be made more readable. When I talked about learning more I was actually thinking about the actual mechanisms by which weather works. What different terms mean and how those interact to produce whatever they produce. I'm sure a lot of it is inexact but I'm guessing there are some basics that are very well understood. I aced an earth science class that included a quarter on meteorology but that was back in 1984!

Last night, driving home from dinner and standing the front yard, facing the North, was AWESOME! I love extreme weather and get a bit of an adrenaline dump from it, along with it being something of a "back to earth" or even spiritual/peaceful experience. I guess I was born in the perfect place for that!

[SoonerDave]

It's not all that difficult, especially if you hang out here and follow some of the discussions. The Weather Bureau bulletins are filled with abbreviations that make them look much more arcane than they actually are once you figure out that WRN OK means Western Oklahoma, and GFS AND NAM" refer to two different computer forecasting programs that attempt to model the weather environment and by doing so, predict what's going to happen next.

Just think about the "texting" language that's so popular these days, eliminating keystrokes by dropping most vowels from words and leaving you to figure them out by context. That's pretty much what these official messages do, cutting down on keystrokes to get a maximum of information out in minimum time. And lots of it is now simply traditional jargon left over from the days not so horribly long ago when the best rapid-communication device available was the Teletype Model 33, running at a blazing 110-bit-per-second speed (today's Internet averages more than 3 million bits per second and "high-speed" goes up to 50 million and more).

From time to time, David posts tutorial messages to teach the rest of us how to read the more unfamiliar charts and tables, too.

EDIT: Some hints on the one you quoted: NEWD is northeastward and LLJ is, I think, Lower Level Jet (referring to the jet streams that influence weather quite heavily).

You are absolutely spot-on there, Jim

It's a really bizarre way that being a software developer has helped me translate these forecasts in precisely the manner you describe. You take these bizarre contractions and abbreviations and almost say them, almost read them, mix in the context, and you can figure out what a lot of them mean. It's an entirely normal part of software development to create program code that consists of ways to store values in what are called "variables," and very often those variable names in code are contractions of what they represent. So, learning how those variable names get formed in the first place helped me greatly in reverse, taking the name and working backwards. It helped me to no end deciphering these forecasts back in the day when I took aeronautics back in HS and we had to learn how to read pilot weather briefings for the FAA exam. As a snarky bit of self aggrandizement, I annoyed the fire out of most of the guys in the class because I could just about read those weather briefings like plain text bwahahahaha.... Ah, the minor triumphs of high school LOL

SoonerDave (Not the "Dave" Jim was referencing in this post)

[bandnerd]

So what's the word on what appears to be a wall of water headed our way?

[Anonymous.]

Right now, nothing too serious. Will have to watch as these storms move into the more unstable environment across C OK, so far the cell east of Hobart is only showing weak signs of rotation. Watching closely.

[bradh]

so nothing serious, tornado wise. i'm more interested in rain forecast

[bandnerd]

Right now, nothing too serious. Will have to watch as these storms move into the more unstable environment across C OK, so far the cell east of Hobart is only showing weak signs of rotation. Watching closely.

What's the rainfall like? Flooding looks like a major concern considering how slowly the system is moving.

[venture]

NWS Norman ✔ @NWSNorman

NEW - OKC tornado that hit area around I-35/SE 44th rated at least EF2. Rating is still preliminary pending further analysis.

[Anonymous.]

Flooding is going to be big threat. Especially if storms redevelop after this main wave. Right now models are hinting at the possibility of generic rain/storms developing and training over I-40 corridor into tonight. We'll see though.

[Easy180]

Timeline for them to hit OKC?

[okatty]

Timeline for them to hit OKC?

Line appears to be just west of Hwy 81 (3PM) and moving at 25mph. Depending on where you are 330-4?

[Jim Kyle]

When I talked about learning more I was actually thinking about the actual mechanisms by which weather works. What different terms mean and how those interact to produce whatever they produce.

When Chan Guffey, city editor of The Oklahoman, dumped the Weather Beat onto my shoulders some 60 years ago, on my first trip out to the Weather Bureau office on the second floor of a hangar at the old Will Rogers Field I borrowed a couple of textbooks from the chief -- who, we discovered many years later, was a not-too-distant cousin of mine -- and from those, picked up the rudiments of meteorology as known at that time. It was nowhere near what we all take for granted today. The whole theory of "fronts" was only about a dozen years old!

One of those textbooks said, in total seriousness, that the most accurate way to forecast tomorrow's weather was to look up what had happened on the same day a year earlier. The general weather patterns were sufficiently cyclical that this method had a "better than even" chance of being accurate!

That same textbook went on to say that forecasters should remain in one area for most of their careers, since they would soon learn to "sense" the patterns for that area and their predictions would become more accurate.

And it was not until 1948 that anyone was able to predict, with any accuracy at all, the likelihood of a tornado. Two weather officers at Tinker had become fascinated by the storms, and found a pattern of temperature and humidity that seemed to be common to most of them. One spring day in 1948 they realized that that exact pattern was present, and convinced the commanding general to put the base on alert. That minimized the damage when the storm swept the flight line late in the afternoon.

Such forecasts quickly became the norm for the military, but civilian services still did not issue them for fear of panicking the populace. Finally, Tom Kyle decided that possible panic was acceptable if a warning could save lives, especially after the Woodward and Blackwell disasters, and issued a warning next time conditions warranted. Sure enough, the storm hit, and his warning was credited with drastically reducing the toll. Warnings became standard procedure.

Tom also showed me the notorious "hook echo" on their radar, but warned me NOT to publicize its existence -- again, for fear of panic. The hook had been discovered in the South Pacific during the late months of WW2 and was known to radar techs all over, but was not then --nor is it today--proof of a twister on the ground. It only shows you that dangerous circulation exists.

So don't be too leery of learning more about weather and its vagaries. Even the top pros are still learning a lot! And the more they learn, the more they discover we don't know.

[PennyQuilts]

Fascinating, Jim.

[NikonNurse]

Yesterday morning, the meteorologists were predicting isolated severe weather centered on western Oklahoma. What ended up happening was a major outbreak centered on OKC. It's hard to believe it was a slight risk day and OKC wasn't even included in that risk yesterday morning. I am extremely nervous about Saturday.

Do you know what it is about the H.E. Bailey Turnpike. Why do severe outbreaks so many times happen with supercells going up in SW OK, going up the turnpike into the OKC area impacting Moore?

Tornadoes don't like the price of traveling on that toll way, so they are being vindictive..........