Monday, June 19, 2017

Long-range forecast, issued June 18, 2017

It's approaching midnight CDT, I have some free time so I'll do this again.

I can tell you that model runs, since yesterday's iteration fo this forecast, for the first few (potential) days of the trip showed craptacular chasing, with a reloading of the moisture and flow taking place.  If this should prove to be true, we would likely not leave on June 23, unless positioning required it.

Now, let's see what new guidance is suggesting for us.  As I'm typing this, I'm seeing the guidance I'm basing it on for the first time.  Just FYI.

Day 1 (June 23):
GFS: eastern NM
GEFS: eastern KS
GDPS: eastern CO
ECMWF: eastern CO/western KS
CFSv2: western KS

Day 2 (June 24):
GFS: central TX, central NM
GEFS: eastern OK/northwest AR
GDPS: western KS
ECMWF: southern OK
CFSv2: central NM

Day 3 (June 25):
GFS: central AB
GEFS: northeast NM
GDPS: southeast KS
ECMWF: maaaaaaaybe the southern TX panhandle
CFSv2: central AB

Day 4 (June 26):
GFS:  SK/MB border
GEFS: southwest KS
GDPS: southeast CO/eastern NM
ECMWF: central AB
CFSv2: southeast NM, western NE, central AB

Day 5 (June 27):
GFS: eastern SD, eastern NE
GEFS: eastern NE
GDPS: eastern CO
ECMWF: southeastern AB
CFSv2: eastern MT to western NE

Day 6 (June 28):
GFS: northeast NE to western WI
GEFS: eastern NE/western IA
GDPS: western KS
CFSv2:  western SD to western KS

Day 7 (June 29):
GFS: northern NE
GEFS: eastern NE/most of IA
CFSv2: western KS to northwest SD, northeast ND

Day 8 (June 30):
GFS: southeast SD/northeast NE
GEFS: eastern NE/western IA
CFSv2: central SD to TX panhandle

Day 9 (July 1):
GFS: northeast NE
GEFS: eastern NE to western WI
CFSv2: central OK

Day 10 (July 2):
GFS: northeast KS to southeast MN
GEFS: southern MN/northern IA
CFSv2: northern TX panhandle

So a couple of models take storms pretty far down south then fling the action into Alberta with an impressive upper trough.  If that were to happen we'd probably blow off the southern play.  A couple more like a lot of upslope in New Mexico and Colorado--perfect for really photogenic storms.  Yet more seem to key in on storms settling in for a few days in the central plains.  All of these are interesting scenarios, and the model spread thus makes it pretty much impossible to say which is more likely to happen.

It's funny.  Every year has its quirks.  The first few years, we were doing trips in July, which can be feast or famine, and we mostly had famine (relatively speaking).  Then we switched to earlier and we had some years with flow but no instability, instability with no flow, and then in 2015 we had a couple of good days, and one day in particular, where everything came together.  The models seem to be all over the place right now (as per usual) but the 2 things they're seeming to key in on is that, for at least some of our trip, there is likely to be a favourable juxtaposition of instability and shear.  The problem will be finding those areas and getting there.

Starting tomorrow, model solutions should start to converge on the most likely outcomes.  Decision time is still a few days away, and I honestly have no idea which way it's going to go--Friday departure or later.


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