The future of the season....

[samuel stone]

Yeah, wednesday looks great right now, and yes you can count on it changing between now and then. the main plus about wednesday is that the moisture return problems we will have sat-tues should be, for the most part dissolved.

 

[Stan Rose]

I have a feeling that if we can even get dewpoints in the low 50's up into eastern CO/western KS/western NE , there might be a decent chance of a severe weather outbreak over the western High Plains on Tuesday. There are no weather features forecast at this point that could halt or regress the moisture from marching north over the Heartland, so that's one positive aspect of this situation. It's still five days out, so we'll just have to keep our fingers crossed that the gulf moisture makes it far enough north in time and the forecasted flow pattern stays on track. B)
[/b]

I REALLY hope that happens, especially since its my day off, but the EC really has me worried. MOS is 97 degrees tomorrow for PUB--90 @#$%^ 7 degrees! It's the driest since 2002. The snow is virtually gone in the S mountains. It's bad, very baaaaad! :angry: If i were moisture, i'd be afraid of coming up here.

 

[Stan Rose]

This may be slightly off topic, but it does show how horribly the models are handling the BL right now. The 6 hour GFS forecast has dewpoints of 65-72 in Ern OK for right now. The 3 hour NAM forecast has dewpoints of 63-67 in Ern Oklahoma for right now. Current dewpoint Obs are 45-57 in Ern OK. Pretty scary. :unsure:

 

[joel ewing]

This may be slightly off topic, but it does show how horribly the models are handling the BL right now. The 6 hour GFS forecast has dewpoints of 65-72 in Ern OK for right now. The 3 hour NAM forecast has dewpoints of 63-67 in Ern Oklahoma for right now. Current dewpoint Obs are 45-57 in Ern OK. Pretty scary. :unsure:
[/b]

Courage in the face of adversity!! (The late, great Edna Mae Roten-h.s. english teacher / my frosh year / 1969). Ahhh...thanks once again, Edna.

 

[Mike Hollingshead]

This may be slightly off topic, but it does show how horribly the models are handling the BL right now. The 6 hour GFS forecast has dewpoints of 65-72 in Ern OK for right now. The 3 hour NAM forecast has dewpoints of 63-67 in Ern Oklahoma for right now. Current dewpoint Obs are 45-57 in Ern OK. Pretty scary. :unsure:
[/b]

The very off dew prog's(initiations in many cases) have been at it for awhile now.

 

[Stan Rose]

As I feared, the 00Z gfs is following the EC now and has banished the upper low on wed. just a big stinkin ridge now. the only positive sign is that it deepens the trough out west by the end of next week. Then again, it's been flopping so much lately you pretty much have to just close your eyes and hope for the best.

 

[Dan Robinson]

The big ? continues. Still a lot of inconsistency even now, four days from the possible start of the chaseable pattern. Getting dizzy just looking at each subsequent run. Wish at least Tuesday and Wednesday would become clearer, but still looks like a far northern Plains start. At least at the surface, by Thursday the dryline looks nice, juicy, sharp and full of bulges all the way into TX. If only the other layers of the cake looked as good. The way things have been going, by next week who knows.

 

[Dan Robinson]

Tuesday has entered the NAM horizon, so we finally have another 'second opinion' to add to the mix - and both it and the GFS paint a good picture for the 23rd and possibly the 24th. Both the 00Z NAM and the 00Z GFS show a large area of divergence in the middle and upper levels associated with the shortwave overspreading a large area including KS, NE and SD. At the same time, dewpoints of at least the mid to upper 60s (assuming a typical overforcast of moisture) show up along the KS-NE border, yielding CAPEs of up to 3500 j/kg. At the surface, good southeasterly winds should be widespread across this region ahead of a surface low in the MT-WY area.

The main negative continues to be the strong cap, with 700mb temps of 10 to 12C over the threat area. And of course, timing of the various features might be an issue. I know I'm getting into borderline forecast thread territory with this post, but Tuesday looks to be the best prospect yet for the actual return of the chase season. At least until the next model runs come out.

 

[Amos Magliocco]

Tuesday looks like a legit chase now after this morning's NAM. Beyond that, with the jet parked up in Montana and North Dakota, I don't know. Canada in late May? Anyway, I'll be happy with the one relatively clear chase day in NE/KS and worry about the rest later.

 

[Mike Hollingshead]

It's funny how the gfs showed Tuesday being the better looking day several runs ago and now that it is in the nam's range it still looks to be the day. I hope it doesn't change much because it looks good right now. If it stays like it is right now I'd probaby venture up to nw NE Monday for the hell of it and just drop sse for Tuesday. I like how Tuesday looks capped but with a strong wave coming in at peak heating. Please don't slow down(though if I was a betting man I'd bet it will).

 

[Mark Farnik]

For my area (High Plains of CO) best chance of severe wx looks to be on Monday afternoon and evening as the models are showing a nice batch of moisture advecting over the state from the s/sw during the day in advance of a mid latitude vorticy lobe the models forecast to come out of the Desert Southwest Sunday night and be crossing the northeastern corner during the evening hours on Monday. The Denver AFD has sheds more light on this situation:

QG OMEGA FIELDS
SHOW AN AREA OF MODERATE UPWARD VERTICAL VELOCITY OVER THE FCST
AREA BTWN 00Z-06Z/TUE. NAM ALSO INDICATES SBCAPE VALUES IN THE
2000-2800 J/KG RANGE ACROSS THE NERN COLORADO PLAINS WITH THE
HIGHEST VALUES NEAR THE NERN CORNER. STRONG TURNING WITH HEIGHT WILL
ALSO PRODUCE FAVORABLE HELICITY VALUES IN THIS AREA DURING EVENING
HOURS. COULD SEE AN OUTBREAK OF SEVERE WX SHOULD ALL THIS PAN OUT.[/b]

I think that if everything indeed pans out, we could see a fairly significant severe wx outbreak over the western High Plains, with the possibility of a few tornadoes given the forecast turning with height and helicity values. Of course, monday afternoon I am taking tests after school and then my little sister has a concert!! :angry: The first freaking good looking chase day of the year for my stomping grounds and I'm tied up! Grrrr.... I'd like to stab ol' Murphy in the eye. <_<

Monday actually could be a pretty decent day, if anyone feels like wandering this way and following the wave east for Tuesday and potentially Wedenesday's action. The Colorado Gang might want to take note of this as it would be a nice local chase.
I also apologize if this seems to much like a forecast thread.

 

[Jason Persoff]

On the upside, right now I'm in Vegas presenting at a medical conference (I love Vegas and I certainly don't mind getting paid to be here ) and arrive in CO tomorrow afternoon (presumably just in time for events this week, eh? Brief off-topic: Vegas is exceptionally family friendly and my kids and wife and I have a blast here with most family-friendly activities being FREE...very nice).

Back on topic: I think one of the more staggering pieces of information I would not have normally even factored in is the impact of the shortwave and longwave troughs shaping up this week. Since I've been here Wednesday, the daytime highs have been 99-102. On Monday, the high temp in Vegas will be 72. That's a staggering 30 degree temperature difference and may hint at the kind of penetration more polar air may have on the back of the trough. Pretty cool. Um, literally.

Now, to address Mark's comment above, I think the forecast guys in Boulder are awesome and I like seeing this kind of forecast. I'm always eager to see this kind of comment echoed in Goodland's AFD, which it's not.

AT THE SURFACE...WEAK LOW
PRESSURE WILL BE PRESENT EVERY DAY. EASTERLY SURFACE WIND WILL
PROVIDE SOME UPSLOPE LIFT AND CONVERGENCE NEAR THE TROUGH AXIS IN
EASTERN COLORADO. GOOD UPWARD VERTICAL VELOCITIES ARE INDICATED
EVERY AFTERNOON THROUGH MONDAY ALONG THIS SURFACE CONVERGENCE ZONE
AND SHIFT EAST INTO WESTERN KANSAS DURING THE EVENING. THERE IS
ALSO SOME ISENTROPIC UPGLIDE AT THE 300K SURFACE. HOWEVER...DUE TO
THE LACK OF STRONG FORCING WILL CONTINUE SLIGHT CHANCE POPS WITH
EXCEPTION OF SUNDAY NIGHT IN THE NORTHWEST ZONES WITH CHANCE POPS.
FORECAST SOUNDINGS STILL LOOK VERY DRY.[/b]

Hastings NE has a funny stream-of-consciousness AFD:

RESISTED TEMPTATION TO LACE DAYS 1 THROUGH 3 WITH SMALL
POPS. OKAY...FRONTAL BOUNDARY NEARBY AND SLOWLY EMERGING
MOISTURE TRENDS...BUT THIS PATTERN IS REMINISCENT OF THE
DOG DAYS OF MID/LATE SUMMER. HAVE KEPT A SMALL CHANCE FOR
LATE NIGHT STORMS IN THE SOUTH TONIGHT...WITH LLJ OVERRIDING
WEAK SURFACE BOUNDARY...BUT BELIEVE THIS WILL GENERALLY
BE SOUTH OF THE CWFA. KEPT THE SMALL RISK FOR THUNDERSTORMS
SUNDAY EVENING IN THE SOUTHWEST. AS MOISTURE POOLS NEAR
THE FRONT RANGE...ALL MODELS INDICATE SOME SORT OF STORM
COMPLEX WILL FIRE IN THE VICINITY OF NORTHEAST COLORADO.
TRICK THERE IS...IT WON`T GO ANYWHERE AS IT FORMS IN
THE RIDGE AXIS...WITH A STORM MOTION OF LESS THAN 10KTS.
SO...DON`T EXPECT IT TO WORK TOO FAR EAST AND HAVE LIMITED
COVERAGE. MONDAY LOOKS DRY...WITH INCREASING TEMPERATURES...
WINDS...AND MOISTURE.

IN THE LONGER TERM...SELDOM DOES THE MIDNIGHT SHIFT MAKE
CHANGES...BUT KANSAS OFFICE COORDINATION HAS LED TO ADDING A SMALL
CHANCE FOR THUNDERSTORMS LATE TUESDAY AND AND TUESDAY EVENING WITH
NEGATIVE TILT WAVE COMING INTO THE CENTRAL PLAINS. MOISTURE
BETTER...BUT THINGS COULD BE CAPPED SO COVERAGE VERY LIMITED
SPATIALLY AND TIME WISE. THIS GOES DECENTLY WITH SMALL POPS TO OUR
NORTH AND EAST AS WELL.[/b]

We'll see...All I know is Monday I'll be in the KS/NE/CO borders and will be moving eastward for Tuesday. Doubt I'll move way far east on Weds, but will see. Need to begin looking at GFS for the next part of the week. Thoughts?

 

[Jason Persoff]

Just got done looking at today's 12z GFS on the UCAR site. Is it just me or is there an amazing LLJ shaping up on the 144 and 156hr forecasts? There's southern flow STREAMING up to Canada (?). The 132hr forecast suggests that this feature will allow moisture to flow from the GOM upward over several days with Saturday developing a pretty amazing feature over the mid-west. Friday 500mb winds show a NW flow regime, and veering is fair. OK looks to have good sfc Tds (with the caveat mentioned throughout this thread that the GFS has been pretty generous with moisture) with a dryline punching through OK by 00z Sat. Theta-E in this area looks amazing too...

Biggest negative is the out-of-synch upper level support. But, we may be looking at high CAPE days with a dryline and plenty of moisture. Am I wrong here? Unfortunately forecast precip looks MCS-ish going into Friday and that could be bad (scouring of the air) or good (outflow boundaries). We'll see.

Reference the following (which will change with time as these links are to the most up-to-date GFS):

http://www.rap.ucar.edu/weather/model/gfs156hr_sfc_thet.gif
http://www.rap.ucar.edu/weather/model/gfs156hr_sfc_temp.gif
http://www.rap.ucar.edu/weather/model/gfs132hr_500_wnd.gif (sorta out of synch with other stuff)
http://www.rap.ucar.edu/weather/model/gfs156hr_500_wnd.gif (less upper support compared with jet which is up in MT)

/dodgesflames

From CPC for days 8+:

THE PERSISTENT LONGWAVE PATTERN FEATURING A WEAK 500-HPA TROUGH ALONG THE WEST COAST AND SOUTHWEST FLOW ALOFT INTO THE CENTRAL U.S. SHOULD LEAD TO CONVECTIVE DEVELOPMENT AND A HIGHER LIKELIHOOD OF ABOVE NORMAL PRECIPITATION OVER THE PLAINS AND MIDWEST.[/b]

 

[nickgrillo]

I'll quite likely be leaving early Monday for central Nebraska and then go from there. I think there is plenty of potential for Tuesday's setup, and like Mike H pointed out -- it's sure nice to see a warm layer (quite a strong capping inversion) atop a moist/unstable boundary layer -- with strong shortwave ascent passing through the region during peak heating. Deep, tropspheric veering will result in 0-6km shear quite supportive for organized supercells -- with a warming/moistening boundary layer contributing to at least 2500-3000 j/kg of sbCAPE by the mid-late afternoon.

There could also be a conditional setup developing further east on Wednesday -- but right now I'm focusing on what to do on Tuesday LOL

The GFS and ECMWF also bring in another nice upper trof (with the GFS progging plentiful low-level moisture to be spread out across the plains) into the central US by early next week. I may (quite likely) just stay out and wait the few "down" days rather than going back home after Wednesday

 

[Dan Robinson]

12Z ECMWF and GFS both say that Saturday-Tuesday next week could also be very nice.

Finally leaving tomorrow night after a long and stressful month of model watching. Never thought I'd see the day. Preliminary first stop of our trip will be Grand Island, NE. If all goes well, we should be there by Monday night, rested and ready for the return of chase season on Tuesday.