Thursday might be a day to watch. GFS and ECMWF disagree on timing though.
GFS is slower with severe risk over Central OK, ECMWF pushes things off to the east faster with main threat possible in SE OK.
SPC Day 4-8 Discussion on the Weds/Thurs threat...
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0331 AM CDT FRI APR 18 2014
VALID 211200Z - 261200Z
...DISCUSSION...
EARLY IN THE MEDIUM-RANGE PERIOD BOTH THE GFS AND ECMWF ARE IN
GENERAL AGREEMENT REGARDING THE MOVEMENT OF LOW-LATITUDE SHORT-WAVE
TROUGH AS IT SHIFTS EAST OF THE SRN PLAINS INTO THE LOWER MS VALLEY.
25-35KT NW H5 FLOW ON BACK SIDE-BASE OF THIS FEATURE WILL ENHANCE
DEEP-LAYER SHEAR COINCIDENT WITH MODEST INSTABILITY. STRONG HEATING
WILL LIKELY DEVELOP ACROSS THE HILL COUNTRY OF TX AND DAYTIME
HEATING COULD PROVE INSTRUMENTAL IN A FEW SUPERCELLS IN THE WAKE OF
SHORT WAVE. GIVEN THAT THIS ACTIVITY WOULD EVOLVE WITHIN A BROADER
ZONE OF LESS THAN FAVORABLE LARGE-SCALE ASCENT...COVERAGE SHOULD BE
INADEQUATE TO WARRANT 30 PERCENT SEVERE PROBS DURING THE DAY4
PERIOD.
LATER IN THE WEEK MODEL SOLUTIONS BEGIN TO DIVERGE A BIT AS
LARGE-SCALE PATTERN CHANGES. ECMWF IS CONSIDERABLY FASTER THAN THE
GFS ALLOWING A STRONG SHORT-WAVE TROUGH TO TRANSLATE INTO THE
ROCKIES BY WEDNESDAY. DIFLUENT FLOW ALOFT AND STRENGTHENING SHEAR
PROFILES WOULD PROVE POTENTIALLY FAVORABLE FOR A PLAINS SEVERE
EVENT. HOWEVER...GFS DOES NOT EJECT THIS FEATURE UNTIL LATER
THURSDAY. EITHER OF THESE SOLUTIONS COULD GENERATE A POTENTIALLY
SIGNIFICANT SEVERE EVENT BUT TIMING DIFFERENCES PREVENT DELINEATING
AN ORGANIZED SEVERE THREAT THIS PERIOD.
..DARROW.. 04/18/2014
Looking at the model runs this evening. GFS has a big show over Central OK on Thursday. Euro has the big show in Western OK on Wednesday. Which one is right? Both have been sticking to their guns so we just have to see how each run progresses.
So are we looking at a potential PDS watch kind of a day? In addition, Payne has upper 90s forecasted for next weekend. Can we really see temperatures that hot in April?
Storm Outlook...
Saturday
Chance of a storm or two along the dryline, mainly out in TX. Otherwise dry for the main body.
Sunday
Couple have multiple chances of showers/storms on Sunday. Most likely will be Western OK. General rain early and then maybe some storms along the dryline later in the day. Things will slowly move east through the day/overnight. Severe risk is low, but some could get a bit grumpy.
Monday
Chance for some rain and storms remain, mainly the eastern half of OK. Not much in the way of severe weather.
Tuesday - quiet
Wednesday
Chance of storms late along the dryline in Western/Central OK. May not really fire until sunset or later. Best instability will be out west though, so severe potential might be pretty limited the further east any storms go.
Thursday
Chance of storms Central/Eastern OK by later afternoon along dryline/cold front. Similar to what we had recently. Timing is going to play into everything here on how fast the storm system moves through. Instability will be very high just ahead of the boundary coming through. Still to jumbled to pick a specific risk area.
Friday - Far SE OK some remaining storms and such.
Saturday - Quiet
Sunday
Very slight chance of a storm out west.
Short term severe risk...
Today, Sunday, and Monday look like days with very low severe risks. Storms are possible tomorrow over much of the state and then the eastern half on Monday. Instability just won't be there and the main ingredients will be down in Texas both days.
Rest of the week...
Tuesday - Quiet
Wednesday - SPC has a 30% risk area out on the Day 5 map for Western OK, and other areas of the high plains. We've been talking about it for awhile, but models are just crap from run to run and GFS and Euro never want to agree for more than a run. Wednesday appears to have CAPEs pushing near 2000 j/kg over W OK and CIN will decrease enough by late afternoon to allow for some isolated storms to form. Dryline should remain well out into the PHs, likely staying around or just east of I-27. Moisture looks good with dews into the low 60s possible. Moderate cap will exist though, which is why things should stay isolated. Tornado threat looks low with very elevated LCLs but the other indices show conditions would be favorable for severe storms with likely some very large hail.
Thursday - Chance for severe weather remains. GFS is up to speed with previous EMWCF runs having the main risk area to the east of I-35 and south of I-40. We'll see if this timing remains for a few more runs or if it will bounce around some more.
Friday - Slight chance for some lingering storms over the Red River counties east of I-35.
Saturday - Severe risk increases over the SW 1/2 of OK. GFS has a very unstable atmosphere ahead of the next system coming through and storms popping by late afternoon in SW OK. Setup looks good for all modes of severe weather, but this is a week out too. It'll change.
Sunday - Storm system start to move out into the Plains a bit more. Instability builds/remains over much of Oklahoma except for NE and far East Central OK. Precip forecast show widespread heavy rain, but again - we are really far out and confidence in thsi is slow. Like Saturday, ingredients are there for severe weather.
Extended Storm Outlook...
Tuesday 29th - Slight chance of storm Central & East. Rain North.
Wednesday 30th - Chance of rain, storm chances low.
Thursday May 1st - Dry - mostly.
Wednesday May 2nd - Dry.
Thursday May 3rd - Dry.
Friday May 4th - Chance of storms, statewide.
Now I will put the above with the level of confidence around 1%. Seriously. Regardless of it being so far out, the forecast has literally been changing run to run. So take it with a dump truck load of salt, if there is any left after winter, when looking at this forecast.
12Z Euro isn't all that far off from the GFS through the first half of this coming week. It builds instability back in on Friday much quicker and also fairly unstable on Saturday and Sunday as well. Chance of storms each day, but we'll worry about specifics if we see this continue to develop.
Climatologically speaking, we are heading into peak season. Things typically get busy from here through May. It has been a very quiet year so far and I expect it to increase and get back on track somewhat. Signs are there we are going to head into a much more active pattern soon - we'll see if it happens.
Hopefully it does. We need the rain... I just hope we don't have a quite season then have a cool wet summer.
Don't forget...we could still get some more snow. I am sure most of you remember March 29-30, 1951.
Models predicting more liquid over the next 2 days. Looks like potentially up to an inch over a large area of the state. Some of this will be in form of thunderstorms, though. So local amounts higher.
Next two days generally unstable as mentioned earlier this week.
00Z GFS definitely kicking things up pretty good for the next week or more. At least the chat room is setup for the most part 24 hrs a day now. LOL
I'm beat right now, worked all day, work again tomorrow morning. So I'll try to do a new outlook tomorrow evening when I get home.
Slight Risk today was extended north a tad into far SW OK. Main risk hail and wind.
Yea latest GFS pretty much gives a shot at precip. almost every day this week.
If clouds erode over SW OK by later today, could see a few storms try to make a show.
Nice precip bulb of moderate rain and embedded thunderstorms moving up into SW OK. Looks to be taking aim at SC OK. Maybe clip C OK if it continues to evolve north.
Looks like some purer thunderstorms popping in extreme SW/W OK.
Decent little meso in the storm moving into Harmon County. 2" hail reports coming from this storm.
Spotter confirmed tornado with the storm just across the border in Childress County.
Warning out finally...
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
555 PM CDT SUN APR 20 2014
THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHWESTERN HARMON COUNTY IN SOUTHWEST OKLAHOMA...
NORTHWESTERN HARDEMAN COUNTY IN NORTHERN TEXAS...
* UNTIL 630 PM CDT
* AT 555 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED 10 MILES NORTHEAST OF KIRKLAND...MOVING EAST AT
15 MPH.
HAZARD...TORNADO AND GOLF BALL SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED.
DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR. TREE
DAMAGE IS LIKELY.
4 Box image... Base Reflectivity, Base Velocity on the top...and then Max Hail size and NROT on the bottom.
Some monster hail possible with this thing.
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