New 00Z NAM for Sunday shows pretty significant cap in place over much of Oklahoma. Looks like show that day will be restricted to isolated activity along the dryline in the first western tier of counties.

New 00Z NAM for Sunday shows pretty significant cap in place over much of Oklahoma. Looks like show that day will be restricted to isolated activity along the dryline in the first western tier of counties.

What's it showing for Monday?

NAM doesn't go that far...only 84 hours.

New GFS has Monday being pretty significant and Tuesday is going to come down to how fast the dryline pushes through.

This is for Monday...

http://beta.wxcaster.com/skewts/GFS-test/096/SKT_GFS__KOUN.png

Nasty stuff being shown. Saw the 96h plot for OKC, where the GFS pops the EHI up to 7.7. Yikes.

Nasty stuff being shown. Saw the 96h plot for OKC, where the GFS pops the EHI up to 7.7. Yikes.

Seems to be shaping up to be a lock as a Moderate risk day right now, but I think overall coverage might keep it in the Slight category with a lot of strong wording.

SPC Day 3 Outlook

5% Risk area is over much of Western and Central OK.

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0214 AM CDT FRI APR 05 2013

VALID 071200Z - 081200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
AN UPPER-LEVEL TROUGH WILL AMPLIFY ACROSS THE WEST WITH A
QUASI-ZONAL FLOW REGIME CONTINUING E OF THE ROCKIES. A COUPLE OF
LOW-AMPLITUDE MID-LEVEL IMPULSES MAY EMANATE EWD ACROSS THE PLAINS.
AT THE SURFACE...A QUASI-STATIONARY FRONT SHOULD LIE ACROSS THE
MIDWEST...WITH WRN PORTION OF THIS BOUNDARY ADVANCING NWD AS A WARM
FRONT IN THE CNTRL PLAINS. DRYLINE WILL MIX ACROSS PARTS OF WRN TX
ON SUN AFTERNOON...WITH LESS CONFIDENT PLACEMENT OF POSITION WITH
NRN EXTENT.

...CNTRL/SRN PLAINS...
A SLIGHT RISK DELINEATION MAY BE WARRANTED FOR PARTS OF THE REGION
IN LATER OUTLOOKS...BUT BELOW-AVERAGE CONFIDENCE EXISTS WITH
WHERE/HOW CONVECTION SHOULD EVOLVE SUN AFTERNOON/NIGHT.

LOW-LEVEL MOISTURE WILL CONTINUE TO INCREASE BENEATH A STOUT
EML...YIELDING 50S SURFACE DEW POINTS ALONG/JUST AHEAD OF THE
DRYLINE BY SUN AFTERNOON. HOWEVER...GUIDANCE DIFFERS WITH POSITION
OF THE DRYLINE...LIKELY OWING TO PRONOUNCED VARIATION WITH THE
HANDLING OF LOW-AMPLITUDE SHORTWAVE IMPULSES IN THE LEE OF THE
CNTRL/SRN ROCKIES. THE POTENTIALLY MOST UNSTABLE ENVIRONMENT WOULD
PROBABLY BE CENTERED ACROSS PARTS OF WRN OK INTO N TX IMMEDIATELY
ALONG THE DRYLINE. HERE...ELONGATED WIND PROFILES WOULD SUPPORT A
RISK FOR SUPERCELLS PRIMARILY PRODUCING LARGE HAIL SHOULD CONVECTION
BE ABLE TO BREACH THE CAP. THIS THREAT WOULD LIKELY REMAIN WITHIN A
NARROW SPATIAL CORRIDOR GIVEN THE EXPECTATION OF STRONG MLCIN TO THE
E IN THE MOIST SECTOR. FARTHER N INTO KS...TSTM PROBABILITIES ARE
HIGHER ALONG THE SLOWLY ADVANCING WARM FRONT BUT MORE MARGINAL
BUOYANCY IS ANTICIPATED.

..GRAMS.. 04/05/2013

New Day 4-8 Outlook...here comes the strong wording.

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0354 AM CDT FRI APR 05 2013

VALID 081200Z - 131200Z

...DISCUSSION...
...SEVERE WEATHER APPEARS LIKELY EARLY NEXT WEEK FROM THE CNTRL/SRN
PLAINS TO THE MID/LOWER MS VALLEY...

WHILE RICH GULF MOISTURE HAS BECOME CONFINED TO THE SWRN PORTION OF
THE BASIN IN THE WAKE OF A COLD FRONT THAT HAS REACHED THE YUCATAN
PENINSULA...AIR MASS MODIFICATION WILL OCCUR THIS WEEKEND AND
ESPECIALLY EARLY NEXT WEEK AHEAD OF AN AMPLIFIED UPPER-LEVEL TROUGH
OVER THE WEST. THE WRN TROUGH WILL EJECT INTO THE CNTRL CONUS BY
MID-WEEK AS A POTENT MID-LEVEL JET STREAK ROUNDS THE BASE OF THE
TROUGH. BY THIS TIME...SEASONABLY RICH GULF MOISTURE WILL BE PRESENT
ALONG THE DRYLINE AND EVENTUAL COLD FRONT THAT WILL PUSH EWD TOWARDS
THE MS VALLEY. WITH SEVERAL DAYS OF MOISTURE RETURN OCCURRING
BENEATH A STOUT EML...A MODERATE TO STRONGLY UNSTABLE AIR MASS WILL
LIKELY DEVELOP.

DESPITE AVERAGE DIFFERENCES BETWEEN MODELS WITH REGARD TO
TIMING/PLACEMENT OF THE KEY SYNOPTIC FEATURES BY D5-6...INCREASING
FORCING FOR ASCENT ALONG WITH STEEP MID-LEVEL LAPSE RATES AND
STRENGTHENING DEEP-LAYER SHEAR SHOULD RENDER A SETUP FAVORABLE FOR
POTENTIALLY SIGNIFICANT AND WIDESPREAD SEVERE WEATHER DURING THIS
TIME FRAME. GREATEST DISCRETE SUPERCELL POTENTIAL WITH PRIMARILY
VERY LARGE HAIL AND TORNADOES SHOULD EXIST ON D5 AHEAD OF THE
DRYLINE. AS A PACIFIC COLD FRONT MERGES WITH THE DRYLINE...AN
EXTENSIVE SQUALL LINE SHOULD FORM AND DEVELOP EWD TOWARDS THE MS
VALLEY WITH PRIMARY RISKS BECOMING DAMAGING WINDS AND TORNADOES ON
D6. PRIOR TO D5...A LOCALIZED BUT ENHANCED RISK FOR VERY LARGE
HAIL/FEW TORNADOES SHOULD EXIST NEAR THE DRYLINE/WARM FRONT
INTERSECTION EXPECTED TO BE INVOF NWRN KS ON MON EVENING.

..GRAMS.. 04/05/2013

Venture, given that not everyone may be entirely familiar with the more technical info, I'm going to take a shot at offering a layman's phrasing on this bolded text. If I screw up too badly, please be gentle:

Original:

DESPITE AVERAGE DIFFERENCES BETWEEN MODELS WITH REGARD TO
TIMING/PLACEMENT OF THE KEY SYNOPTIC FEATURES BY D5-6...INCREASING
FORCING FOR ASCENT ALONG WITH STEEP MID-LEVEL LAPSE RATES AND
STRENGTHENING DEEP-LAYER SHEAR SHOULD RENDER A SETUP FAVORABLE FOR
POTENTIALLY SIGNIFICANT AND WIDESPREAD SEVERE WEATHER DURING THIS
TIME FRAME.

Rough translation:
Even though the computer simulations aren't in 100% agreement of the most important elements of the storm, by day 5 or 6 of this outlook, there will be considerable upward or "lifting" pressure ("forcing for ascent") in the atmosphere, considerable available atmospheric "energy" at the medium levels ("steep lapse rates"), and strong opposing air movement ("deep-layer shear"). These ingredients combine to allow for storms to form, rise quickly and forcefully (from the forcing/ascent and available energy), and rotate (from the shearing), all of which indicate a strong potential for severe storms.

So Tuesday is looking like more widespread activity taking place in central and eastern Oklahoma with more isolated stuff happening out west Monday? I see they only highlighten a small area in Kansas for day 4.

Dave - you are good. I'm taking the Spring off! ;)


So Tuesday is looking like more widespread activity taking place in central and eastern Oklahoma with more isolated stuff happening out west Monday? I see they only highlighten a small area in Kansas for day 4.

Yeah, but I always have to keep in mind these 4-8 day outlooks are different animals than the Day 1-3 outlooks. These are pretty much showing at minimum 30% risk areas, whereas Day 1 - 3 will go down to 5%. So what you see outlined on a Day 4-8 outlook is the more high end, widespread coverage. So what we may see for example with Monday. Right now on the Day 4 it has a little area in NW KS outlooked. When we get to tomorrow or Sunday, that area in NW KS will probably be a 30% area, but you'll see a 15% area cover all the way down into North Texas from I-35 back to the west. The entire area would probably fall under a Slight Risk with the wording KS being more widespread, OK/TX being more isolated.

It also is never out of the realm that we see a natural progression in how the outlooks will develop. A risked area on a Day 4-8 could be a Moderate risk area by the time it gets into the Day 1 or 2 outlooks. Just like a Moderate Risk on a day 3 outlook, if my memory isn't failing me completely, in a lot of cases translates to a High Risk by the time it falls into a Day 1.

So it can all be a bit confusing when looking at Day 4-8 products when we are so use to the classic Day 1 and 2 Outlooks (and the recently added day 3).

Dave - you are good. I'm taking the Spring off! ;)



Yeah, but I always have to keep in mind these 4-8 day outlooks are different animals than the Day 1-3 outlooks. These are pretty much showing at minimum 30% risk areas, whereas Day 1 - 3 will go down to 5%. So what you see outlined on a Day 4-8 outlook is the more high end, widespread coverage. So what we may see for example with Monday. Right now on the Day 4 it has a little area in NW KS outlooked. When we get to tomorrow or Sunday, that area in NW KS will probably be a 30% area, but you'll see a 15% area cover all the way down into North Texas from I-35 back to the west. The entire area would probably fall under a Slight Risk with the wording KS being more widespread, OK/TX being more isolated.

It also is never out of the realm that we see a natural progression in how the outlooks will develop. A risked area on a Day 4-8 could be a Moderate risk area by the time it gets into the Day 1 or 2 outlooks. Just like a Moderate Risk on a day 3 outlook, if my memory isn't failing me completely, in a lot of cases translates to a High Risk by the time it falls into a Day 1.

So it can all be a bit confusing when looking at Day 4-8 products when we are so use to the classic Day 1 and 2 Outlooks (and the recently added day 3).



You are correct, usually the "long-range" outlooks will show nothing. They seem to only use these products when they anticipate a heightened risk that they will issue in the upcoming 1-3. Barring major changes in the storm, this almost always results in at least a 'Moderate' risk area being issued for some part of the forecasted region, and 'Slight' over the general area.

It is kind of like when they issue Severe Thunderstorm Warnings for storms that are producing no severe weather (by definition) when they enter a more populated area. This is basically just covering all of their bases to 'be on the safe side'. I am, personally, a fan of this type of predicting.

With the heavy frost last night at my house I’m glad the only thing I have planted in my garden is potatoes.
So Ch. 9 says we might have another frost or freeze next week?

With the heavy frost last night at my house I’m glad the only thing I have planted in my garden is potatoes.
So Ch. 9 says we might have another frost or freeze next week?

Wednesday morning temps will dip down, but eh...nothing major.

So is this looking like a decent rain event or mainly severe tstorms?

No major changes to the outlook right now. Looks like significant, possibly tornadic, days on both Monday and Tuesday for the area.

The chat room will go live tomorrow afternoon: Live Chat ? Weather Spotlight (http://www.weatherspotlight.com/?page_id=40)

Feel free to bookmark it. It'll remain up through Wednesday.

Sunday Slight Risk - NW OK
http://www.spc.noaa.gov/products/outlook/day2otlk_0600.gif

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1236 AM CDT SAT APR 06 2013

VALID 071200Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF THE CNTRL/SRN
PLAINS...

...SYNOPSIS...
AN UPPER-LEVEL TROUGH WILL AMPLIFY ACROSS THE WEST WHILE A SERIES OF
SUBTLE/LOW-AMPLITUDE MID-LEVEL IMPULSES EMANATE FROM THE ROCKIES
ACROSS THE PLAINS WITHIN A QUASI-ZONAL FLOW REGIME. AT THE
SURFACE...A QUASI-STATIONARY FRONT SHOULD LIE ACROSS THE
MIDWEST...WITH WRN PORTION OF THIS BOUNDARY ATTEMPTING TO ADVANCE
NWD AS A WARM FRONT IN THE CNTRL PLAINS. DRYLINE WILL MIX INTO THE
TX BIG COUNTRY SUN AFTERNOON ARCING NWWD TO A LEE CYCLONE INVOF TX
PANHANDLE.

...CNTRL/SRN PLAINS...
LOW-LEVEL MOISTURE WILL CONTINUE TO INCREASE BENEATH A STOUT
EML...LIKELY YIELDING 50S SURFACE DEW POINTS ALONG THE
DRYLINE/QUASI-STATIONARY FRONTAL ZONE BY SUN LATE AFTERNOON.
GUIDANCE DOES INDICATE LOWER TO PERHAPS MIDDLE 60S SURFACE DEW
POINTS WILL DEVELOP AHEAD OF THE DRYLINE FROM CNTRL OK SWD TO THE
WRN GULF. ALTHOUGH THE PRESENCE OF A STRONG CAP WILL LIMIT THE DEPTH
OF THE PBL AND MIXING OF DRIER AIR ALOFT...MUCH OF THE GULF HAS
EXPERIENCED SUBSTANTIAL DRYING IN THE WAKE OF A RECENT COLD FRONT
PASSAGE. RICHER MOISTURE IS NOW CONFINED TO THE CARIBBEAN PER GOES
PW DATA...WITH ONLY A NARROW PLUME OF NEAR 60 SURFACE DEW POINTS
ALONG THE MEXICO GULF COAST. AS SUCH...SUSPECT THAT GUIDANCE IS
OVERLY AGGRESSIVE WITH THE AMPLITUDE OF LOW-LEVEL MOISTURE RETURN BY
SUN AFTERNOON.

DIURNAL TSTM DEVELOPMENT WILL LIKELY BE TIED TO A COUPLE OF SUBTLE
LOW-AMPLITUDE IMPULSES EMBEDDED WITHIN THE MODERATELY STRONG
MID-LEVEL FLOW REGIME AND INCREASING LOW-LEVEL WAA ALONG THE
QUASI-STATIONARY FRONT. MAJORITY OF GUIDANCE APPEAR TO KEY ON KS AS
THE MOST PROBABLE AREA OF CONVECTIVE DEVELOPMENT WHERE THE CAP WILL
BE WEAKER. THE NWRN PERIPHERY OF THE LOW-LEVEL MOISTURE PLUME INVOF
SWRN/CNTRL KS WOULD APPEAR MOST FAVORABLE FOR LARGE HAIL WITH A
STEEP MID-LEVEL LAPSE RATE/STRONG DEEP-LAYER SHEAR ENVIRONMENT. THIS
THREAT WILL BE INCREASINGLY CONDITIONAL WITH SRN EXTENT WITH ONLY A
NARROW SPATIAL CORRIDOR OF WEAKER MLCIN ALONG THE DRYLINE AND
PRONOUNCED CAPPING TO THE E.

Sunday appears to be a very conditional day when it comes to severe weather. A strong cap will be in place over much of Western Oklahoma along the dryline. The dryline though will feature a bulging feature on the southern end over it (over SW OK) which can help increase convergence and storm development chances.

The 12Z NAM indicates a stronger area of convergence in this zone with the 12Z GFS showing convergence all along the dryline. The GFS is also less extensive with its cap forecast having areas in NW and West Central OK with only a weak cap by afternoon. The GFS also has precip breaking out in the late afternoon across Western OK moving into Central sections by evening.

Current feeling right now is that cap will be stronger than what GFS hints, but maybe not as unbreakable as was NAM is putting for. The Dryline will be in play and both agree on positioning. Best chances for storm development will be over NW OK decreasing as your move South and East. Looking at the forecast soundings for Woodward, Enid, Norman, and Clinton show a breakable cap near Woodward becoming much tougher near the OKC area. Clinton is also still pretty stout. Wind profiles overall favor rotating storms so large hail and a tornado or two cannot be ruled out. Coverage does remain limited to one or two supercells, and also wouldn’t be shocked if storms try but fail to break though. Storm motions look reasonable moving E to ENE at around 20-25 mph.

http://www.weatherspotlight.com/screencap/outlooks/20130407_Sunday.png

Monday's outlook is a bit more difficult since GFS and NAM aren't completely on the same page. They agree on dryline placement and moisture return. However, NAM has a much stronger cap whereas GFS is much weaker over the area of greater instability. NAM also keeps more precip to a minimum where GFS has storms breaking out between 5PM and 7PM that evening. This forecast outlook area is a compromise between the two. If GFS would verify the risk area would extend a bit more to the south and east to I-35.


Not really much to add compared to the previous discussions. Storms that develop will be severe and profiles are favorable for rotating storms with large hail and tornadoes. Coverage will be better than Sunday, but might be limited in areas depending on where the cap holds.

http://www.weatherspotlight.com/screencap/outlooks/20130408_Monday.png

Peak at the setup for Tuesday which will be a two parter.

Afternoon / Evening dryline pushes into Central OK but not forecast to cross I-35. Moderate to high instability and relatively weaker capping will allow for storms to develop and push off to the east. All severe modes are possible on Tuesday.

http://www.weatherspotlight.com/screencap/outlooks/20130409_TuesdayAftn.png

Tuesday Night into Early Wednesday will see the cold front overtake the dryline and push through. Will likely see a squall line develop along the front as it pushes through.

http://www.weatherspotlight.com/screencap/outlooks/20130409_TuesdayNight.png

Pretty good run down from NWS Norman on the next few days. The TL: DR version - strong cap will limit overall storm coverage, anything that develops will be severe.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
301 PM CDT SAT APR 6 2013

.DISCUSSION...
SEVERE THUNDERSTORM POTENTIAL SUNDAY AFTERNOON THROUGH TUESDAY NIGHT REMAINS THE BIGGEST CONCERN.

TONIGHT INTO SUNDAY MORNING...THE AIR SHOULD REMAIN TOO CAPPED
FOR ANY THUNDERSTORMS TONIGHT...THOUGH CONFIDENCE IS NOT HIGH.
CANNOT COMPLETELY RULE OUT A STRAY STORM OR TWO NEAR THE RED RIVER
TONIGHT. ADDED MENTION FOR 20 PERCENT CHANCE OF STORMS NORTH OF
I-40 AND NEAR/EAST OF I-35 SUNDAY MORNING. IF STORMS DEVELOP...
HAIL...PERHAPS LARGE HAIL...WOULD BE THE MAIN HAZARD WITH DECENT
ELEVATED INSTABILITY. THERE IS A CHANCE FOR FOG DEVELOPMENT LATE
TONIGHT INTO SUNDAY MORNING NEAR I-44...BUT DID NOT MENTION DUE TO
LOW CONFIDENCE.

SUNDAY AFTERNOON AND EVENING...A FEW SEVERE STORMS MAY DEVELOP
NEAR A DRYLINE ACROSS WESTERN OR NORTHWEST OKLAHOMA. LARGE
HAIL...PERHAPS VERY LARGE HAIL UP TO THE SIZE OF BASEBALLS...
WOULD BE THE MAIN HAZARD. FAIRLY HIGH CLOUD BASES AND LACK OF
SIGNIFICANT LOW LEVEL WIND SHEAR MAY LIMIT THE CHANCES FOR
TORNADOES. ONLY KEPT 20 TO 30 PERCENT AS COVERAGE SHOULD REMAIN
ISOLATED AT BEST WITHOUT A GOOD TRIGGER FOR LIFT AND STRONG
CAPPING.

MONDAY AFTERNOON AND EVENING...SIMILAR TO SUNDAY...A FEW SEVERE
STORMS WITH MAINLY LARGE HAIL ARE POSSIBLE ACROSS WESTERN
OKLAHOMA. SEVERE STORM COVERAGE MAY BE A BIT BETTER DUE TO HIGHER
DEWPOINTS WHICH COMBINED WITH BETTER LOW LEVEL SHEAR...MAY ALLOW
FOR TORNADOES. HOWEVER...STRONG CAPPING SHOULD KEEP STORMS FROM
BEING WIDESPREAD.

THE MAIN SEVERE THREAT THROUGH MONDAY NIGHT SHOULD STAY WEST OF
THE OKLAHOMA CITY METRO AREA.

TUESDAY INTO TUESDAY NIGHT...PERHAPS A BETTER SHOT FOR SEVERE
STORMS WILL OCCUR ACROSS THE AREA...THOUGH CONFIDENCE IS LOW. A
FEW STORMS MAY DEVELOP ALONG A DRYLINE DURING THE AFTERNOON AND
EVENING HOURS WHICH COULD PRODUCE VERY LARGE HAIL AND TORNADOES IF
THEY CAN OVERCOME STRONG CAPPING. A LINE OF STORMS WILL LIKELY
DEVELOP ALONG AN APPROACHING COLD FRONT TUESDAY NIGHT WITH
ISOLATED SEVERE DAMAGING WIND AND HAIL REPORTS ALONG WITH PERHAPS
HEAVY RAIN AND LOCALIZED FLOODING. THE SLOWER 12Z ECMWF IS
PREFERRED...WHICH KEEPS RAIN LINGERING INTO WEDNESDAY.

WEDNESDAY THROUGH NEXT SATURDAY...RAIN WILL END ON WEDNESDAY...AND
THEN ALLOW FOR RATHER QUIET WEATHER CONDITIONS. BELOW AVERAGE
TEMPERATURES FOR THE MIDDLE OF THE WEEK WILL REBOUND TO NEAR OR
ABOVE AVERAGE BY NEXT WEEKEND.

MBS

Sounds pretty typical for an Oklahoma spring. Always riding that fine line between bust and outbreak. lol


"TUESDAY INTO TUESDAY NIGHT...PERHAPS A BETTER SHOT FOR SEVERE
STORMS WILL OCCUR ACROSS THE AREA...THOUGH CONFIDENCE IS LOW"

Translation: Anything can happen at this point. Ask us again later.

00Z NAM Update for tomorrow...

Northern half of my risk area (the white line) is the more probable. Southern half is less likely due to a stronger cap. It is near the bulge in the dryline so that can help with lift somewhat. NAM does develop some isolated storms that could move into Central OK before 10PM.

http://www.weatherspotlight.com/screencap/outlooks/20130407_Sunday_00Zupdate.png

Forecast Sounding from Clinton...
Pretty strong cap (3.7) noted but overall very unstable atmosphere. EHI and Helicity values are good for rotating storms. 1km helicity doesn't look bad at all either. LCL of 815 though tells me these will be pretty high based storms so that would limit tornadic threat and put the focus on very large hail.

http://www.stormchaser.niu.edu/chaser/tempgif/4671.GIF

I like the color coded geographical charts cause they're like 3rd grade and I think I can understand what they mean....

ON THE OTHER HAND...

the graphs with the lines running up and spiraling around don't do crap for me and make me wonder when I'm at work on Monday from 12-9, if I should be worried about my 2013 Hyundai being parked in the open when I have this feeling that it might be raptured by Mother Nature's fists of fury...aka...hail stones. Alas, I have no clue what the lines mean on the graph so I guess I'll just deal with the consequences...derp!

OKC, I think the best info there is right now just says there's a good potential for severe weather, but the variable is the "cap" in the atmosphere that prevents or limits those storms' development. It's just too close to call....the ingredients are too favorable to ignore the chance for severe storms, including hail, but the mitigating factor (cap) can't be ignored, either. Dicey call to be absolute either way.

Very little change to today's forecast. NAM shows storms firing this afternoon in NW OK and hints at them forming a small complex later this evening that would swing ESE over central OK. HRRR is mostly dry and keeps all storms north into KS. GFS hasn't ran yet, so we'll see what that says.

SPC has removed the slight risk for most of Western OK except for NW OK. Not unexpected as the cap is going to be strong and we'll likely only see a couple storms fire. If they do, they will be severe. I wouldn't be shocked if they put the slight risk back in place if it seems more probable that this would happen, but nothing to really read into yet. The story today and tomorrow as always been about the cap strength and if the dryline would provide enough lift to break it. There is also a weak warm front over Northern OK as well. Depending on how far north it goes, the intersection area of that and the dryline would hence the ability for storm development and also for a couple tornadoes.

Outlook map is pretty much what NWS Norman just put out, so at least most are on the same level of thinking with this.

http://www.weatherspotlight.com/screencap/outlooks/20130407_Sunday-2.png

Monday's outlooks looks pretty similar. NAM and GFS show storm development north of I-40 and west of I-35 in the afternoon. Storm motions would be ENE to NE at 25-35 mph. Forecast cap is going to be the bust maker on this forecast. Convergence is expected to be decent along the dryline, but may not be enough to break through or keep storms sustained. As storms move east the cap will increase so that may kill them off as they approach I-35. I highlighted the most probable area for storms tomorrow as it looks right now, but will need to be revisited tomorrow morning based on what we actually see outside. Main concerns tomorrow would be very large hail and tornadoes in any storm that develops.

http://www.weatherspotlight.com/screencap/outlooks/20130408_Monday-2.png

Here is the link again for the chat room: Live Chat ? Weather Spotlight (http://www.weatherspotlight.com/?page_id=40)

I'll be in and out while it remains quiet. Feel free to bookmark it as this will be the permanent spot for the chat room.

OKC, I think the best info there is right now just says there's a good potential for severe weather, but the variable is the "cap" in the atmosphere that prevents or limits those storms' development. It's just too close to call....the ingredients are too favorable to ignore the chance for severe storms, including hail, but the mitigating factor (cap) can't be ignored, either. Dicey call to be absolute either way.

Well, if the sky is going to be cloudy over the state, then it may be safe to assume not much of a severe nature will be able to break through the cap.

Latest HRRR run shows storms firing in NW OK by 6PM this evening with a large supercell moving over the northern Tier of counties through the evening.

http://rapidrefresh.noaa.gov/HRRR/from_jet/hrrr_jet/2013040714/t5/cref_t5sfc_f09.png

Tuesday's Risk area... this is currently a 30% hatched slight risk on the Day 3, so SPC may upgrade to moderate if conditions continue to look impressive. Models so development along the dryline around 4PM moving into Central OK in the early evenings.

http://www.weatherspotlight.com/screencap/outlooks/20130409_Tuesday-2.png

CIN pretty well gone according to SPC Mesoanalysis, not sure I really believe it though. However, looking at the 18Z special balloon sounding from Douglas, KS (just over the border), the cap is still hanging tough. HRR still tries to develop some cells over Northern OK early this evening, but doesn't look like the lift is there yet. SW OK is beautiful and clear, but I still have the chance down there at 10% or less right now.

http://climate.cod.edu/data/raob/KLMN/skewt/KLMN.skewt.20130407.18.gif

This is something I've been talking about. It is where the dryline is bulging out some in SW OK. There is higher convergence in this area.

http://www.spc.noaa.gov/products/md/mcd0394.gif

MESOSCALE DISCUSSION 0394
NWS STORM PREDICTION CENTER NORMAN OK
0626 PM CDT SUN APR 07 2013

AREAS AFFECTED...SW OK...NW TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 072326Z - 080100Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED SEVERE THREAT COULD DEVELOP ACROSS PARTS OF SW
OK AND NW TX OVER THE NEXT HOUR IF A THUNDERSTORM CAN INITIATE AND
PERSIST. AN ISOLATED THREAT FOR LARGE HAIL WOULD BE THE MAIN THREAT
EARLY THIS EVENING. WW ISSUANCE DOES NOT APPEAR LIKELY DUE TO THE
ISOLATED AND CONDITIONAL NATURE OF THE THREAT.

DISCUSSION...THE LATEST VISIBLE SATELLITE IMAGERY SHOWS AGITATED
CUMULUS JUST TO THE EAST OF CHILDRESS ALONG A WELL-DEFINED DRYLINE.
IN SPITE OF THE LACK OF LARGE-SCALE ASCENT AND CAPPING...STRONG SFC
HEATING TO NEAR 90 F AT CHILDRESS MAY ALLOW FOR ISOLATED CONVECTIVE
INITIATION. SFC DEWPOINTS TO THE EAST OF THE DRYLINE ARE IN THE
LOWER 60S F WITH MLCAPE VALUES ESTIMATED IN THE 1500 TO 2500 J/KG
RANGE. THIS COMBINED WITH 50 TO 55 KT OF DEEP LAYER SHEAR WOULD
SUPPORT SUPERCELL DEVELOPMENT. IN ADDITION TO THE INSTABILITY AND
SHEAR...MID-LEVEL LAPSE RATES ARE STEEP ESTIMATED TO BE NEAR 8.0
C/KM. THIS WOULD FAVOR LARGE HAIL AS THE MAIN THREAT IF A
THUNDERSTORM CAN DEVELOP AND PERSIST.

..BROYLES/HART.. 04/07/2013

Current Visible Sat showing agitated CU.

http://climate.cod.edu/data/satellite/1km/Oklahoma/current/Oklahoma.vis.gif

This is essentially our only hope right now to the SW. LOL

http://www.weatherspotlight.com/screencap/04072013-ama-706pm.png

One down...3 more days of precip chances to go. Monday looks like it may have a better shot at storm development with two focal areas both having different setups. Models favor NW OK with precip late tomorrow. Instability looks good in this area overall. The cap of course becomes in the issue. LCL looks pretty high so tornado threat tomorrow looks low overall unless we see some low level moisture improvement. The one area that has my attention is further south in SW OK. There is going to be more forcing there tomorrow and CIN is actually lower in that area. Much like today where this area had the better forcing overall (by forecast), we very well could see the same tomorrow with developing CU. Now if the forcing will be good enough to bust this thermonuclear cap, we'll have to wait and see.

http://www.weatherspotlight.com/screencap/outlooks/20130408_Monday-3.png

Tuesday and the interesting Wednesday forecast coming up.

Tuesday is definitely the day to watch out for right now. The setup looks pretty good for a decent amount of severe weather. Wind profiles aren't ideal for tornadic development due to the winds getting a bit more linear and not as much directional shear (SE to SW instead of WSW or W as we have now). Instability will be high and maximized along the dryline which is now forecast to not push through until evening (if at all). It very well could end up staying mostly stationary until the cold front overtakes it. I'm highlighting the most likely area for significant severe weather right now, but the risk area will go well into MO, AR, and TX. So it will be two phases to the severe weather on Tuesday. Initially will be isolated/scattered supercells along the dryline and ahead of it. These will push off to the ENE or NE at about 30-35 mph. These will have the chance for large hail and perhaps a few tornadoes. The next phase is with the cold front and a quickly developing squall line that will push through.

Depending on how things go, I wouldn't be shocked to see a moderate risk go out for some portion of C and E OK.

http://www.weatherspotlight.com/screencap/outlooks/20130409_Tuesday-3.png

After the front passes, we could see a wave of moderate precip come through. GFS and NAM are split on this. GFS keeps it in Western OK and NAM brings it through Central OK. The kicked? Pink isn't rain...

http://www.weatherspotlight.com/screencap/outlooks/20130410_Weds_snow.png

Some area could see a quick slushy accumulation of snow before its all said and done. I don't have much confidence that it'll happen, but might as well put it out there. It's been in the model solutions for a couple days now.

GFS Solution
http://www.twisterdata.com/data/models/gfs/3/maps/2013/04/08/00/GFS_3_2013040800_F66_SNOWIN_SURFACE.png

NAM Solution
http://www.twisterdata.com/data/models/nam/221/maps/2013/04/08/00/NAM_221_2013040800_F63_SNOWIN_SURFACE.png

Yeah. Winter isn't over yet. News 9 predicted snow earlier last week. I wonder if they are going to actually turn out to be right. We had a mild start to winter this year but it doesn't seem like it wants to end. This kind of reminds me of 2002 when there was highs in the 50s and lows near freezing as late as the first week of May. Coincidentally, that was an extremely quiet severe weather year.

My gut says today, a cell or two will fire up in W/SW OK late this afternoon, but it would have to be ideal conditions.

Tuesday PM still looks like the main show. Wednesday looks like a day of winter then back to beautiful spring weather.

Outlook for today is very conditional based on the ability for storms to break through the cap. So the map today is a little different. The shaded areas are those where convergence is forecast. On top of that you'll see the CAPE fields and also the dryline. There is a bit of a bump to the dryline this morning over SW OK, which helps to increase convergence just a bit. The dryline will flatten out a bit through the day, but this is probably what the models are picking up on. HRRR is also showing CIN vanishing over much of North Central and parts of SW OK today - hence the risk area. It keeps CIN relatively high over NW OK and SE of I-44. Should we have any chance for storms today I'm looking at these two areas as the best shot. HRRR CAPE forecasts for North Central OK are extremely high (and probably a bit over done). So should that instability be realized, that could be enough to get something up there. The other bet is for the SW part of the state. Much like yesterday, we'll probably see CU go up in this area. We had a couple weak echoes yesterday, but nothing could get established. We'll see how it works out today. Cap is really tough, and as is often the case with these setups you can have absolutely nothing or a monster storm if it can break through.

http://www.weatherspotlight.com/screencap/outlooks/20130408_Monday-4.png

I've come to the conclusion that the CAP is the springtime's answer to severe storm forecast uncertainty as the dryslot is to wintertime blizzard predictions :)

Slight risk is gone for Oklahoma today. Replaced with a 5% "See Text" outlook.

It feels so humid outside today. Is it supposed to be bad tomorrow or what?

nvm News9 upgraded the severe weather risk for OKC to Moderate


http://kwtv.images.worldnow.com/images/21910406_BG1.jpg

nvm News9 upgraded the severe weather risk for OKC to Moderate


Eh, its News 9. :-P LOL

Here is the SPC outlook...

http://www.spc.noaa.gov/products/outlook/day2probotlk_1730_any.gif

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT MON APR 08 2013

VALID 091200Z - 101200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/SW TX TO SRN
IA...

...SYNOPSIS...
SVR POTENTIAL DAY-2 WILL BE RELATED TO PROGRESSIVE/SYNOPTIC-SCALE
TROUGH IN MID-UPPER LEVELS...SHIFTING SLOWLY EWD FROM WRN TO CENTRAL
CONUS. MOISTURE CHANNEL IMAGERY AND 12Z RAOB DATA INDICATE
DEEPENING SHORTWAVE TROUGH OVER NV AND SERN CA...WHICH SHOULD EVOLVE
TO YIELD CLOSED 500-MB CYCLONE OVER UT THROUGH REMAINDER DAY-1.
DURING 09/12-09/00Z TIME FRAME...PRIMARY MID-UPPER CYCLONE IS FCST
TO DRIFT ACROSS SWRN CO FROM 4-CORNERS REGION...THEN MOVE SLOWLY
NEWD ACROSS CO THROUGH REMAINDER PERIOD. SEVERAL LOW-AMPLITUDE
VORTICITY PERTURBATIONS ARE EXPECTED TO MOVE NEWD FROM SYNOPTIC
TROUGH POSITION ACROSS SRN/CENTRAL HIGH PLAINS...WHILE BASAL SPEED
MAX ALOFT SHIFTS SLOWLY NEWD ACROSS OUTER SERN QUADRANT OF
CYCLONIC-FLOW REGIME. MAIN RIBBON OF 500-MB VORTICITY SHOULD REMAIN
ACROSS NWRN MEX THROUGH AT LEAST 10/06Z BEFORE FRAGMENTING AND
EJECTING...BASED ON STG CONSENSUS FROM LATEST AVBL RUNS OF
OPERATIONAL MODELS AND ECMWF/CMC. NET RESULT SHOULD BE SLGT
POSITIVE TILT TO MAIN SYNOPTIC TROUGH...POSITIONED DURING LATTER
HALF OF PERIOD FROM CENTRAL HIGH PLAINS THROUGH CO LOW TO NWRN MEX.

COMPLEX NATURE OF CYCLONE EVOLUTION ALOFT WILL BE REFLECTED AT SFC
TOO. HYBRID LEE-SIDE/FRONTAL-WAVE CYCLONE SHOULD CONSOLIDATE LATE
DAY-1 OVER ERN CO THEN MOVE EWD ACROSS KS THROUGH 10/00Z. AS THIS
OCCURS...ARCTIC COLD FRONT NOW LOCATED OVER ERN WY WILL MOVE SEWD
ACROSS REMAINDER CENTRAL HIGH PLAINS...REACHING FROM NERN KS FRONTAL
WAVE SWWD ACROSS NWRN OK AND TX PANHANDLE BY 10/00Z.
QUASISTATIONARY FRONT WILL EXTEND FROM LOW ENEWD OVER LOWER MI. PAC
COLD FRONT IS EXPECTED TO MOVE EWD FROM NM OVER SRN HIGH PLAINS
EARLY IN PERIOD...WITH 10/00Z POSITION FROM ARCTIC FRONTAL
INTERSECTION OVER WRN OK SWWD ACROSS W-CENTRAL TX TO DAVIS MTNS
REGION. DRYLINE SHOULD MIX EWD ACROSS W-CENTRAL TX AND WRN OK
DURING DAY...REACHING 10/00Z POSITION FROM EDWARDS PLATEAU/WRN HILL
COUNTRY REGION OF TX NWD ACROSS NW TX TO WRN OK INTERSECTION WITH
ARCTIC FRONT. ARCTIC FRONT WILL OVERTAKE BOTH PAC FRONT AND DRYLINE
FROM N-S THROUGH REMAINDER PERIOD.

BY 10/12Z...MAIN SFC LOW SHOULD BE MOVING EWD ACROSS NRN MO ALONG
QUASISTATIONARY FRONT...WHICH IS PROGGED TO EXTEND ENEWD OVER WRN
NY. ARCTIC FRONT WILL EXTEND SWWD ACROSS SERN OK...CENTRAL TX...AND
RIO GRANDE VALLEY BETWEEN LRD-DRT...HAVING FULLY OVERTAKEN PAC FRONT
AND DRYLINE.

...SRN PLAINS TO MO VALLEY REGION...
WIDELY SCATTERED TO ISOLATED TSTMS MAY DEVELOP INVOF DRYLINE AND
COLD FRONT DURING MID-LATE AFTERNOON...INCREASING IN COVERAGE
GREATLY AS FRONTAL FORCING IMPINGES UPON PROGRESSIVELY RICHER
LOW-LEVEL MOISTURE DURING EVENING/OVERNIGHT HOURS. LARGE HAIL IS
QUITE LIKELY...AND CONDITIONAL RISK EXISTS FOR AT LEAST A FEW
TORNADOES AND SERIAL CORRIDOR OF DAMAGING-WIND EVENTS. BROAD SWATH
OF SVR POTENTIAL STILL IS FCST IN ROUGHLY SAME AREA AS BEFORE...BUT
UNCERTAINTIES LINGER REGARDING PREFRONTAL TSTM COVERAGE...TIMING AND
MODE. AS SUCH...WILL MAINTAIN SIMILAR UNCONDITIONAL NUMERICAL
PROBABILITIES AS PRIOR OUTLOOK. SOME SMALL SUBSET OF THIS AREA
STILL MAY REQUIRE FUTURE CATEGORICAL UPGRADE AS MESOSCALE TRENDS
WARRANT.

OPERATIONAL MODELS HAVE BEEN TOO AGGRESSIVE IN MOISTENING BOUNDARY
LAYER ACROSS MUCH OF WARM SECTOR SO FAR...WHICH CONTINUES HISTORICAL
BIASES IN EARLY-STAGE RETURN-FLOW EVENTS. BY DAY-2...THAT BIAS
STILL IS APPARENT BUT NOT AS LARGE. INCREASING MATURITY OF UPSTREAM
MARINE MODIFICATION PROCESS AND PERSISTENCE OF INTERVENING
WAA/MOISTURE TRANSPORT REGIME SHOULD...IN EFFECT...ALLOW REALITY TO
CATCH UP TO PROGS BY MIDDLE OF PERIOD...THOUGH PROGGED DEW POINTS
MAY BE TOO MOIST OVER MO VALLEY. 60S F SFC DEW POINTS THEREFORE
SHOULD BE COMMON FROM CENTRAL TX TO IA BY AFTERNOON. LAPSE RATES
ALOFT WILL BE STEEPEST OVER SRN PLAINS...BUT STILL FAVORABLE INTO MO
VALLEY REGION. WHERE SUSTAINED DIABATIC SFC HEATING OCCURS...NET
RESULT SHOULD BE MLCAPE RANGING FROM AROUND 3000 J/KG OVER
CENTRAL/NRN TX TO AROUND 1000 J/KG INVOF IA QUASISTATIONARY FRONT.

FAVORABLE DEEP SHEAR WILL OVERSPREAD THIS SECTOR THROUGHOUT DAY AS
SYNOPTIC WAVE SIFTS SLOWLY EWD. HOWEVER...JUST ABOVE BOUNDARY
LAYER...FCST AFTN WIND SOUNDINGS ACROSS PRIMARY SVR CORRIDOR SHOW
SOME VEER-BACK TENDENCIES WITH HEIGHT. THIS APPEARS REASONABLE
GIVEN GEOMETRY OF MID-UPPER SYSTEM AND ASSUMPTION OF TYPICAL MASS
RESPONSE. SOME LLJ-RELATED REMOVAL OF THAT KINEMATIC WEAKNESS IS
EVIDENT IN TIME SERIES OF FCST SOUNDINGS...ESPECIALLY ACROSS
PORTIONS SRN OK AND N TX DURING EVENING. THAT AREA ALSO WILL BE
MORE STRONGLY CAPPED FOR LONGER PERIOD OF TIME...INDICATING HIGHER
PROBABILITY OF MAINTAINING DISCRETE STORM CHARACTER COMPARED TO
POTENTIALLY MESSIER STORM MODES ACROSS NRN OK AND KS/MO. AS
SUCH...POTENTIAL FOR SUSTAINED SUPERCELLS WITH SIGNIFICANT/DAMAGING
HAIL AND A FEW TORNADOES MAY BE GREATEST OVER SRN OK AND N TX PRIOR
TO LINEAR FORCING OF COLD FROPA. HOWEVER...AT LEAST ISOLATED
DAMAGING HAIL CANNOT BE RULED OUT FARTHER N INTO KS. LOW-LEVEL AND
DEEP SHEAR SHOULD SUPPORT POTENTIAL FOR SVR HAIL...WIND AND EITHER
EMBEDDED-SUPERCELLULAR OR QLCS TORNADOES THROUGHOUT NEAR-FRONTAL
WARM SECTOR BETWEEN CENTRAL OK AND SRN IA. BACKBUILDING ALONG OR
EVEN SLIGHTLY BEHIND COLD FRONT WILL EXPAND SVR POTENTIAL SWD WITH
TIME ACROSS CENTRAL/SW TX...BUT WITH MORE QUASI-LINEAR CHARACTER AS
MID-UPPER WINDS BECOME MORE PARALLEL TO BAND OF STRONGEST LOW-LEVEL
CONVECTIVE FORCING.

..EDWARDS.. 04/08/2013

nvm News9 upgraded the severe weather risk for OKC to Moderate


http://kwtv.images.worldnow.com/images/21910406_BG1.jpg

Who came up with that over there? That doesn't even make since. Aware, Ready, Action? What?

Who came up with that over there? That doesn't even make since. Aware, Ready, Action? What?

that is one reason why i don't watch Channel 9 during severe weather

Area forecast discussion
national weather service norman ok
257 pm cdt mon apr 8 2013

.discussion...
Main focus was on the next few days with severe weather... Fire
weather... Strong winds... And freezing temps the main concerns.

The strong cap continues to hold this afternoon across the area.
This will likely prevent any thunderstorm development late
aftn/evening. However... The strong sfc heating that is occurring
could bring a few locations to convective temperature so a storm or
two is not completely out of the question. If a storm does
develop... Wind shear and instability will be sufficient for it to
become severe.

Temperatures will be warm tonight with lows mainly in the 60s. Low-
level moisture will continue to spread northward overnight into
tuesday. Meanwhile... The upper low over nevada will continue to
move eastward. With this system approaching the area and moisture
increasing... Models suggest some drizzle could develop tues
morning. The models may be overdoing the moisture a little so will
keep a mention of drizzle out of the forecast for now.

Scattered to widespread shower/storms will be possible tues aftn
through wednesday morning. Severe weather will also be likely tues
aftn into the early morning hours on wednesday. A dryline is
expected to move into western portions of the fa tues aftn. This
boundary along with the approaching upper low and weakening cap
could provide enough lift for isolated to scattered thunderstorms to
develop tues aftn along the dryline... Some of which could become
supercells producing large hail... Damaging winds... And maybe even
some tornadoes. A strong cold front will then move across the region
tues evening/overnight with showers/storms becoming more widespread.
A squall line is expected to develop with the cold front as it moves
across the area producing some large hail although maybe not as big
as with the earlier supercells and damaging straight line winds.
Moderate to heavy rain will also be possible behind the front
tuesday night into wednesday.

Conditions behind the dryline will elevate fire wx concerns with
humidities aob 20 percent and winds around 20 mph expected in parts
of southwest ok and western north tx tues aftn/early evening. Will
issue a fire wx watch to cover this. Strong northerly winds will
also be likely behind the cold front tues night into wednesday with
a wind advisory likely needed across parts of the fa.

Colder air will move into the region behind the cold front. This
could lead to some snow in parts of northern/western ok late tues
night/wed morning before the precip ends but little to no
accumulations are expected. This cold air will also lead to freezing
temperatures in parts of western ok wednesday morning with low temps
aob freezing across a more widespread area thursday morning. A
freeze warning will likely be needed one or both of these days. Aftn
highs will also be cold wednesday and thursday with highs only in
the 40s and 50s. Temperatures are expected to begin to warm late
this week into the weekend with highs back into the 60s and 70s by
saturday. After thursday... Made no changes to the going forecast.

&&

Who came up with that over there? That doesn't even make since. Aware, Ready, Action? What?

I think they started to use that map during winter weather, where I can see it making more sense. They normally use a "Risk / Greatest Risk" map since apparently the SPC outlooks weren't good enough for them. We'll see how long it lasts once Payne has full control.


that is one reason why i don't watch Channel 9 during severe weather

They still have the best severe weather coverage typically, but we know you have a thing for KOCO. :) I can't say anything all that negative about them though. Damon at least is an aviation geek it seems, so that earns him points. :-P

i want some storms today but blame the cap

Mike Morgan is pumping up an ice storm for Wednesday morning.

Per latest imagery, a few towers trying to go up near Chilldress.

Little CIN and plenty of juice to play with down there. Some convergence right along the dryline as well. Not as much CU though as we saw yesterday out west, so we'll see what happens. Less activity today though makes tomorrow better as things come together - finally.

http://www.spc.noaa.gov/exper/mesoanalysis/s15/sbcp/sbcp.gif?1365458445693

Looks like CU all along the dryline now, with best area in that section of West Central OK/East Central TX PH that is looking the best on the updated graphic above.

hzbEixvGZdM

Looks like something could pop in W C OK, per dewpoints in this area, there is a very slight bulge in the dryline that could be just enough to set off a cell or two.

It looks like the cold weather is supposed to stick around through the weekend if we believe Mike Morgan.

Venture79, does this look to be winter's last hurrah or do long range models show cold weather returning after this week?

There was a cell trying near Cheyenne in Roger Mills County, but it has since gone poof.

Vis isn't all that promising out there...

http://climate.cod.edu/data/satellite/1km/Oklahoma/current/Oklahoma.vis.gif

Mike Morgan is pumping up an ice storm for Wednesday morning.

MM is definitely blowing the whistle early, but the NAM wants to make it happen over central OK:

http://wxcaster4.com/nam/CONUS1_NAM212_SFC_ACCUM-FZRN_48HR.gif

I'm noticing NAM has been trending to this 6"+ snowfall for days and GFS keeps the accumulating snow out west. So who knows who wins out in this one.

I love having the rain because I know we need it! But, I really done like the cold, hail and possible ice and snow they say is coming... :-(
Got to love Oklahoma weather!!!!!!!!!!!!