STORM2K

Some very interesting and strong wording from latest NWS Norman Office area discussion:

AFDOUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1037 AM CDT TUE JUN 7 2005

.UPDATE...
A FEW LIGHT ECHOES LINGERING AT THIS TIME OVER N CENTRAL OK...BUT THEY SHOULD DISSIPATE OR AT LEAST MOVE OUT OF THE CWA BY NOON. WILL DROP MENTION OF PRECIP FOR THIS AFTERNOON...EXCEPT FOR THE EXTREME W AS DRYLINE WILL BE QUITE A BIT CLOSER TO OUR W BORDER BY EARLY EVENING. CAP EXPECTED TO BE STRONGER THIS AFTERNOON...SO PROSPECTS FOR ANYTHING MORE THAN ISOLATED CONVECTION APPEAR SMALL. CURRENT TEMPS RUNNING A FEW DEGREES WARMER THAN 24 H AGO...THUS HAVE RAISED AFTERNOON HIGHS SLIGHTLY WHICH MESHES BETTER WITH NEIGHBORING GRIDS.

REGARDING LATE WEEK...HAVE A VERY STRONG FEELING THAT SOMETHING BIG IS BREWING. LOOKING AT PROGGED LONGWAVE PATTERN - WITHOUT GETTING BOGGED DOWN IN DETAILS - THE SETUP LOOKS ABOUT AS POTENT FOR WIDESPREAD/SIGNIFICANT SEVERE WX IN THE CENTRAL U.S. AS THIS FORECASTER HAS SEEN IN NEARLY 25 YEARS OF OPERATIONAL EXPERIENCE. MODELS HAVE BEEN CONSISTENT WITH UNSEASONABLY STRONG HEIGHT FALLS INTO THE SW LATE THIS WEEK. LATEST RUNS DEPICT NOSE OF A VERY STRONG UPPER JET /140 KT AT 300MB/ BLASTING SE ONTO THE W COAST BY SAT...WHICH SUPPORTS CONTINUING NEG HEIGHT ANOMALIES OUT W AND THUS KEEPING A VERY DEEP LONGWAVE TROF OVER THE W FOR JUNE...MOST LIKELY WITH A GENERAL NEGATIVE TILT AS DEPICTED BY A MAJORITY OF THE MED-RANGE MODELS. UNSEASONABLY STRONG MID/UPPER LEVEL FLOW THUS LIKELY AT LOW LATITUDES INTO S PLAINS. DETAILS...SUCH AS EFFECTS OF PROBABLE MCS ACTIVITY OR EVEN A POSSIBLE TROPICAL CYCLONE IN THE GULF AS SUGGESTED BY THE GFS...ARE MORE ELUSIVE AND REALLY ARE NOT AS CRUCIAL AT THIS POINT. SCREAMING MESSAGE IS THAT POTENTIAL WILL EXIST FOR 1 OR MORE SIGNIFICANT CENTRAL-U.S. SEVERE WX OUTBREAKS...BEGINNING AS EARLY AS THU BUT MORE LIKELY IN THE FRI-SAT-SUN PERIOD. PLAN TO HIT THIS HARD IN THE NOON HWO.

Wow...

That's some extremely strong wording... any of you more experience peeps out there wanna take a hit on this a bit. I avidly follow severe weather (watch the chaser forums) but honestly still find myself overwhelmed trying to figure out stateside stuff. All we keep getting out of the Chicago NWS is they are too uncertain to peg anything down... even for tomorrow.

Don't believe I've seen such strong wording before.......Wow! Guess we'll see.

Me either! And the other thing that is so unusual is that it is over a setup 3/4/5 days out. Anyone else find that strange?

The updated HWO had this to say....

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

THUNDERSTORM OUTLOOK...
THUNDERSTORM CHANCES...AND THE POTENTIAL FOR SEVERE WEATHER...WILL
INCREASE EACH DAY FROM WEDNESDAY THROUGH THE WEEKEND. CURRENT
FORECASTS INDICATE THAT THE GENERAL WEATHER PATTERN MAY SUPPORT THE
POTENTIAL FOR WIDESPREAD OR SIGNIFICANT SEVERE THUNDERSTORMS OVER
OKLAHOMA AND NORTH TEXAS LATE THIS WEEK...PERHAPS AS EARLY AS
THURSDAY OR FRIDAY BUT MORE LIKELY ON SATURDAY OR SUNDAY. THERE ARE
TOO MANY UNCERTAINTIES AT THIS TIME TO SAY WHICH DAY AND WHICH PARTS
OF THE AREA WILL HAVE THE GREATEST RISK. EMERGENCY MANAGERS AND
STORM SPOTTER GROUPS...AS WELL AS ALL INDIVIDUALS AND AGENCIES WITH
PLANS THAT WOULD BE AFFECTED MOST BY SEVERE WEATHER THIS WEEKEND...
ARE STRONGLY ENCOURAGED TO STAY UP TO DATE WITH THE LATEST WEATHER
INFORMATION THIS WEEK...AND TO BE PREPARED FOR AN INCREASING SEVERE
WEATHER POTENTIAL EACH DAY THROUGH SUNDAY.

Most interesting!

--snoopj

The developing U/A pattern over the West is similar to what happened about this same time in June in 1995 when VORTEX caught all of those biggies around Friona and Dimmitt in the TX Panhandle so a severe outbreak seems quite likely.

Steve

Aslkahuna wrote:The developing U/A pattern over the West is similar to what happened about this same time in June in 1995 when VORTEX caught all of those biggies around Friona and Dimmitt in the TX Panhandle so a severe outbreak seems quite likely.

Steve

Unless I am missing something, the was THEE outbreak of 1995. Otherwise, I remember that year being very hot compliments of a high pressure ridge that sat over the plains.

I would take the morning AFD with a grain of salt. The updated AFD for the afternoon didn't even make a mention of severe weather much less a setup not seen in 25 years.

However, indication are severe weather is certainly possible, and it could be an outbreak. I would HIGHLY doubt that it ends up being to the extent that the forecaster this morning was implying.

This is spreading fast. KC met got a tip on this through a fellow blogger. Take a look...http://blogs.scripps.com/kshb/weather/ He doesn't think its as good as 2003 or 2004 much less anything in the last 25 years. I don't know how good he is, so I will leave my comments there.

Keep in mind you have events like 1995 as Aslkahuna pointed out, and of course May 3, 1999. I don't see how anything could beat that. There are so many BIG outbreaks in the last 25 years that makes it incomprehensible to me to believe an outbreak bigger than those could be in store for the Central U.S.

I feel it was wrong to post such strong wording for an event AT LEAST 3 days out. The models this year have been pretty bad, especially at this time frame we're in now. Its still has me baffled at the amazing contrast between the morning and afternoon AFD. Just show the forecaster difference of opinion. I realize this guy has 25 years of experience, but I haven't read anything NEARLY that ominous elsewhere in the NWS and on other weather discussions through message boards, blogs, etc.

I'd definitely watch this system, but don't get your hopes up (if you're that crazy! ) or get too worried about it being something big. June '95 is in the back of my mind, but its too soon for me to even try to guess whether its going to be anywhere close to that.

Agreed. The wording was a bit strong. However, that aside, the overall synoptic setup does strongly favor a very active severe weather pattern for late this week, into the weekend. My eyes were drawn in particular to the 12Z GFS for Sunday in the central/southern Plains. Strong SW flow aloft overtop an extremely unstable airmass with backed surface winds from OK to NE ahead of an elongated surface low over western KS screams "outbreak". If the AFD had not mentioned "best setup in 25 years of forecasting", it actually isn't that bad of a discussion. The general setup strongly favors some sort of outbreak during that period. It's still too far out to pin down a day, or to pin down tornado potential. I do, however, note that the GFS, and now the Eta have been consistent in progging a very interesting setup over NW OK/TX panhandle for Friday ahead of the main trough, with strong veering winds, particularly in the low-levels. Flow then weakens a bit on Saturday, only to return with a vengeance on Sunday over a much larger area. I'll be paying very close attention indeed, and I'm already setting aside time for chasing this weekend.

I'll will be watching as well. Outbreak will be possible, so I would urge folks in the Plains to keep an eye on it. Don't look for a 25 year event though. Otherwise, as you said, the discussion is really a good one. I wish the afternoon AFD had more detail, that could be the whole center of debate really.

This guy's experience stands out to me though the more I think about it. He obviously has excellent pattern recognition. Hopefully he'll be writing more discussions through the remainder of the week. I'd be very interested in his thought process of this system as it evolves. Fortunately he put his ID at the end of the 1037 discussion, so I know where to look.

Thanks for the input... anyone else think they will be searching the net next Monday for a cure for looping radar stressed eyes? *winks*

Definitely going to be keeping an eye on this one for possible learning potential. Hope everyone keeps up the discussion over the next few days.

One thing to realize is the perosn who wrote that first AFD may not be the same person who wrote the next one. So that's most likely why you see a difference in opinion. The discussion is based on the particular forecast thoughts of the met who's writing the discussion at that time.

Check out the day 3 outlook. I do not recall ever seeing the moderate risk of storms being issued 3 days out.



DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0314 AM CDT WED JUN 08 2005

VALID 101200Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHEAST
NM...SOUTHEAST CO...SOUTHWEST KS...THE OK/TX PANHANDLES...AND WRN
OK...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
FROM WEST TX TO THE UPR MS VLY/GREAT LAKES...

...SYNOPSIS...
CONSIDERING THE LEVEL OF UNCERTAINTY AND COMPLEXITY INVOLVED IN THE
DAY 2 SEVERE WEATHER OUTLOOK...THE DAY 3 PERIOD...FRIDAY INTO
SATURDAY...PRESENTS A MORE CLASSIC AND PREDICTABLE SEVERE WEATHER
SETUP ACROSS THE SRN GREAT PLAINS. THERE IS A HIGH LEVEL OF
AGREEMENT AMONG A NUMBER OF MODELS THAT A POTENT AND PROGRESSIVE
SHORT WAVE TROUGH...CURRENTLY TAKING SHAPE ON THE NOSE OF A STRONG
NRN PACIFIC UPPER JET...WILL ROUND THE BASE OF THE WRN U.S. LARGE
SCALE TROUGH...AND EJECT NEWD ACROSS THE SRN ROCKIES BY LATE IN THE
DAY FRIDAY. THIS SCENARIO IS DEPICTED WITH REMARKABLE SIMILARITY IN
LATEST GFS...NAM...UKMET...ECMWF...AND CMC MODELS...WITH THE SHORT
WAVE TROUGH POSITIONED OVER SERN NM AT 72H...11/00Z...FRIDAY
EVENING.

ELSEWHERE...A BROAD UPPER RIDGE WILL PERSIST ACROSS THE WRN ATLANTIC
WHILE A DISTURBANCE OF TROPICAL ORIGIN IS FCST TO BE LOCATED OVER
THE ERN/CNTRL GULF OF MEXICO.

...SERN CO...TX/OK PANHANDLES...WRN OK...SWRN KS...
POTENTIAL WILL EXIST ACROSS THESE AREAS FOR WIDESPREAD SEVERE
WEATHER BEGINNING FRIDAY AFTERNOON AND CONTINUING INTO THE NIGHT.

GIVEN ANTECEDENT AIRMASS AND LIMITED AREAL EXTENT OF DEEP CONVECTION
OVER THE REGION THROUGH THURSDAY...AIR MASS AHEAD OF THE DRYLINE AND
DEEPENING LEE-LOW SHOULD BE MOIST AND STRONGLY UNSTABLE BY FRIDAY
AFTERNOON. LATEST GUIDANCE SUGGESTS THAT FORCING FOR ASCENT WILL
COMMENCE EARLY IN THE DAY BUT CAPPING SHOULD PREVENT WIDESPREAD
DEVELOPMENT TOO EARLY AND ALLOW FOR FURTHER DIURNAL HEATING AND LOW
LEVEL MOISTURE ADVECTION INTO THE REGION PRIOR TO STORM INITIATION.
STRONGEST FORCING AND INTENSIFYING MID LEVEL WIND FIELDS WITH THE
ADVANCING SHORT WAVE SHOULD ARRIVE OVER THE INSTABILITY AXIS BY LATE
AFTERNOON AND RESULT IN RAPID TO EXPLOSIVE TSTM/SUPERCELL
DEVELOPMENT IN THE MDT RISK AREA. FOCUS FOR STRONGER LOW LEVEL SRH
ACROSS THE REGION WILL EXIST ALONG POSSIBLE OUTFLOW BOUNDARY ACROSS
SRN KS/NRN OK...AS WELL AS NEAR SFC LOW AND DRYLINE INFLECTIONS. IN
ADDITION TO VERY LARGE HAIL AND DAMAGING WINDS...LATEST GUIDANCE
SUPPORTS THE POTENTIAL FOR LONG-LIVED SUPERCELLS WITH TORNADOES.

...MO VLY TO WRN GREAT LAKES....
QUASI-STATIONARY SYNOPTIC FRONTAL BOUNDARY SEGMENTED BY CONVECTIVE
OUTFLOWS WILL LIE ACROSS THESE AREAS AND PROVIDE A FOCUS FOR STRONG
TO SCATTERED SEVERE STORMS. GREATER CONCENTRATION OF STORMS WITH
SOME WIND/HAIL POTENTIAL MAY EXIST ACROSS MN INTO WI WHERE BOTH GFS
AND NAM DEPICT A POSSIBLE WAVE TRAVELING NEWD ALONG THE STALLED
FRONT.

..CARBIN.. 06/08/2005

Source: http://www.spc.noaa.gov/products/outlook/day3otlk.html

WELL!! *stares in stunned silence at the 3day mod risk* I think this is going to be shaping up to be a VERY interesting weekend.
And 35% prob! That's just ...WOW. Guess the models really have the attention of peeps at the NWS.

Christine[/quote]

Interesting...Moderates are not allowed on SPC day 3, policy dictates that. Looks like SPC has changed their rules again.

I haven't looked at much but what I'm reading throughout the boards is suggesting a less than impressive setup, especially for OK. It could be good for the Panhandle. Chasers on Stormtrack and TV guys on Medialine are both saying it doesn't scream an outbreak, especially a "25 year" event or whatever.

CONFIRMED:

*SPC is now allowed to issuse moderate risks on the day 3 outlook. Additionally, high risks are now issued on the day 2 outlooks.*

Norman's back today, mentioning severe, but definitely playing conservative. They have several concerns:


PATTERN FOR FRI-MON TIME PERIOD REMAINS FAVORABLE FOR SVR STORM
CHANCES SOMEWHERE IN THE PLAINS. HOWEVER..THERE ARE SEVERAL
CAVEATS TO WIDESPREAD HIGH-END SVR POTENTIAL IN THE OUN CWA.
FIRST.. ALTHOUGH MID/UPPER FLOW WILL GENERALLY INCREASE.. DEEP
LAYER SHEAR VECTORS REMAIN SOMEWHAT MARGINAL THE FARTHER S/E ONE
GOES ACROSS OK/NTEXAS..AND THIS CUD END UP BEING A LIMITING FACTOR
FOR HIGHLY ORGANIZED LONG-LIVED SUPERCELLS. IN ADDITION..
DEVELOPING TROPICAL SYSTEM PROGGED TO COME ASHORE NEAR NEW ORLEANS
OVER THE WEEKEND MAY END UP SEVERELY IMPACTING THE QUALITY AND/OR
DEPTH OF LOW LEVEL MOISTURE OVER OK/NTEXAS DUE TO PERIPHERAL
SUBSIDENCE EFFECTS..AND MAY ALSO HAVE ADDITIONAL EFFECTS ON
LOW/DEEP LAYER SHEAR AS WELL. FINALLY..AS IS COMMON FOR THE LATE
SPRING..THERE WILL BE POTENTIAL FOR LARGE SCALE TSTORM COMPLEX
OUTFLOW BOUNDARIES TO SEVERELY COMPLICATE THE SFC PATTERN EACH
NIGHT/MORNING. SINCE THESE FEATURES ARE RARELY FORECASTED WELL BY
THE SYNOPTIC SCALE MODELS..OBSERVATIONAL TRENDS ON EACH SUCCESSIVE
DAY WILL BE KEY TO PINPOINTING AREAS OF MAX THREATS.