NCEP long range

Mike Johnson

Anyone else notice the interesting forecasted pattern change late next week?

NCEP for example.

Mike
 
wheres my front porch chase.....that would be fantabulous
 
aha i just looked at NCEP and it was only out to 138 before that it was still in yesterday. im liking what im seeing, especially since its after this weekend. I got alot to do this weekend. I can't say for sure if i would head out this next week before the big trip. but might be tempting and all. I know there not forecasting rain in the good ole' mitten (MI) we need it though, grass fire threat is high. ill keep thy eye on it.

NCEP link is here

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/
 
Nick those soundings are still from last nights 00z. no biggy just thought i'd point out were looking at the 12z run's now. im not sure how RAP updates there charts but by the time some one looks they might be updated to 12z. or they do it like NCEP does in there seperate time slots, 12z, 18z, 00z, 06z. zzzzzzzzzzzzzzzzzzzzz this :lol:
 
I've been waiting for the 12Z GFS updates all damn morning - some computer chip somewhere is asleep. Waiting with baited breath for the new crystal ball prophecy......but there does appear to be a more active/progressive pattern for the middle of next week which will bear watching.

KR
 
I still have a feeling that it's going to be difficult to get Gulf moisture (true Gulf moisture, not this modified continental air that we've delt with on every other chase in the Plains so far this year)... The GFS was showing northerly-component winds all the way into or through (!) the Caribbean through early/mid next week. I suppose by mid-next week, we may be able to modify the continental air enough to support mid-upper 60s, but that's still to be determined...
 
Originally posted by Jeff Snyder
I still have a feeling that it's going to be difficult to get Gulf moisture (true Gulf moisture, not this modified continental air that we've delt with on every other chase in the Plains so far this year)... The GFS was showing northerly-component winds all the way into or through (!) the Caribbean through early/mid next week. I suppose by mid-next week, we may be able to modify the continental air enough to support mid-upper 60s, but that's still to be determined...

Jeff, help me out here if I am missing something. Just looking at the GFS (been watching this for several days in fact) Looks like tomorrow we start getting a genuine fetch of storm juice from the gulf and it just keeps right on coming through mid week when it looks like a front may be due in. Seeing a dryline sloshing back and forth across west Texas during the period and some disturbances (timing varies depending on where you look) coming across it.

Don't know if it would be enough to draw you OK folks out to west Texas, but I recognize this pattern as some cool chaseable days out here if I haven't missed something. Again, I am usually not much on the models. I am more of a "day 1" guy myself. :lol:
 
David, it is true that winds along the Texas Gulf coast turn southeasterly or on-shore, but trajectories show that the air air coming into the coast from the southeast is just recirculated continental air. In other words, it's air coming south from the eastern U.S., turning to the west in the Gulf, and coming ashore in TX. In the end, it's still continental air. In time, and with sunshine, evaporation will add moisture to the continental air (modifying it) and Tds will slowly recover. But this process is generally quite slow, and you still have a problem with shallow moisture depths. The 48hr forecast from the GFS shows the cold front from eastern Cuba to Honduras, sinking to a line from Puerto Rico to Panama by 72 hrs, which is rather remarkable.

So, looking at the 108hr forecast, it looks good for moisture return across the plains, but notice that, if you follow the winds, the air coming into TX is still air that is moving southward from the Canadian Atlantic coast, down off the East Coast of the US, across FL and the northern Gulf, then up into the plains. The true tropical air is shoved way the heck down to the low latitudes. This can be seen by looking at the 70 Td isodrosotherm, which sinks very far southward for this time of year... This tropical air does start to return northward by Tuesday of next week, as can be seen be the veering of the surface winds in the Caribbean, from northeasterly to easterly and southeasterly.

Again, there should be ample time to modify the continental air to get Tds into the mid-upper 60s perhaps, but you can see that the tropical air doesn't really start to return northward until Tuesday. For this time of year, though, mid-upper 60s is usually quite enough to build strong instability, so I'm not complaining too much, as long as we can get those mid-upper 60s (to get rid of these 1000-1500 CAPE setups with 15-20 degree dewpoint deficits).
 
Originally posted by The SnydeMOS
. This can be seen by looking at the 70 Td isodrosotherm, which sinks very far southward for this time of year... This tropical air does start to return northward by Tuesday of next week, as can be seen be the veering of the surface winds in the Caribbean, from northeasterly to easterly and southeasterly.

Just in time for zonal flow! :p

Gabe
 
Agreed with Jeff....

You can have as much southerly "flow" as possible for as long as you want prior to a system coming through (like it looks for next week's) - but the fetch is a PoS for the most part. Its not the fact that it's coming from the south that matters - it's the fact that you can follow the fetch back onshore between Louisiana and Florida that *REALLY* concerns me.

KR
 
For an example of favorable vs. unfavorable fetches, take a look at this graphic someone with no MS Paint talent whatsoever (me) put together:

http://www.stormskies.com/WindFetch01.bmp

The RED area signifies where I do NOT want my southerly flow coming from.
The YELLOW area indicates where I DO want to see my southerly flow coming from - where the optimum flow would come from for peak moisture return.

Obviously I did not shade the rest of the GoM because one is assuming that any air travelling into the Southern Plains would automatically be travelling over this region - no matter where it's fetch is from. What's IMPORTANT is the source region for your air.......to a reasonable degree.

Enjoy,

KR
 
Thought I'd bring this back to discuss the overall pattern this upcoming week and beyond. Looks like we will see severe weather every day across the S. Plains this week, and I think at least one of those will be a big day, if not more than one. Especially if there are remnant boundaries to play with on some days, which I think will come into play sooner or later this week to lead to some pretty nasty weather. But I'm also looking ahead to the last of this month, early next. Looks like the Subtropical Jet is zooming overhead by the 28th or 29th and there are some 500mb waves moving through every so often. Looks like the Southern Plains is in for an active season after all :)
 
Back
Top