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STORM CHASE -Model Watch Tour 3 !
Topic Started: May 16 2011, 02:08 PM (178 Views)
Supercell Ian
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Ian (IWO)

K folks, Friday is just around the corner now , and im half packed ! :)

Might aswell start a Model Watch now for MY trip.

Changeover day is Saturday 21st May with Sunday 22nd May being the 1st chase day.

Here's the latest ... If anyone can help update this would greatly appreciate it. Im not so good at rooting out model runs for the US.

NICK F of Net weather
" Sunday 21st looking good from 12z GFS at least, 500mb geopotential height/SLP chart for 00z Monday 23rd (18z CDT Sun 22nd) show falling heights from the trough over the Mountain West and a lee surface low over the central High Plains of KS/NE/CO:

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Exit of strong jet at 250mb over central/southern plains would create divergence aloft and thus convergence at the surface = storms:
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Add to this some good moisture return north and thus lots of CAPE:
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= severe storms on day 1?
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12z ECM maybe has a trough slightly further west over western USA with more in the way of ridging over southern and central Plains, but still scope for some moisture return over southern Plains, but would it be capped?:
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"
So hopefully the slightly more progressive GFS is right and the jet stream gets in the right positions for better winds aloft ... :)

So all i need to worry about now is getting into Dallas without any delays from STORMS ! ( how ironic would that be aye?! ha )


" When the atmosphere loses its state of equilibrium , its tries to return to this state, its this process that gives us the exciting phenomena of weather today." , By , me :)
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Supercell Ian
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Ian (IWO)

SPC starting to issue there forecasts.
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VALID 201200Z - 251200Z

...DISCUSSION...

GFS AND ECMWF AGREE THAT UPPER TROUGHING WILL EVENTUALLY SPREAD INTO
THE PLAINS/MS VALLEY...BUT TIMING DIFFERENCES BEGIN TO APPEAR DURING
THE MEDIUM RANGE PERIOD...AS EARLY AS DAY4. GIVEN THE RELUCTANCE OF
THE TROUGH TO ADVECT EWD...AND SHORT RANGE NAM GUIDANCE MORE IN LINE
WITH ECMWF...IT APPEARS THE GFS MAY BE TOO PROGRESSIVE WITH HEIGHT
FALLS ACROSS THE PLAINS INTO THE MID MS VALLEY DAY4. FOR THIS
REASON WILL INTRODUCE A RISK OF ORGANIZED SEVERE THUNDERSTORMS MORE
IN LINE WITH A DELAYED ECMWF. IT/S LIKELY THAT A MARITIME TROPICAL
BOUNDARY LAYER WILL HAVE RETURNED TO THE SRN PLAINS BY LATE WEEK
WITH AT LEAST MODERATE INSTABILITY IN PLACE PRIOR TO LARGE SCALE
FORCING/INTERACTION. IF TIMING OF UPPER TROUGH IS OPTIMIZED WITH
MINIMAL CONVECTIVE INTERFERENCE THEN A SIGNIFICANT SEVERE EVENT MAY
EVOLVE ACROSS THE ERN PLAINS...POSSIBLY EXTENDING INTO PORTIONS OF
THE MS VALLEY BY SATURDAY DEPENDING ON TROUGH PROGRESSION.

..DARROW.. 05/17/2011

" When the atmosphere loses its state of equilibrium , its tries to return to this state, its this process that gives us the exciting phenomena of weather today." , By , me :)
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