Transcript Discussion.ppt

Weather Discussion
2/17/15
Amazing: Hurricane Ridge
Freezing level above 12,000 ft
UIL 850 mb T stats
Tuesday AM: 11.2C
Winter Total Precip Near Normal
Temperature Above Normal
Alternative period of drought and
ARs: Ridge land
California
Reservoirs
Store the Water!
Compared to 76-77
76-77 was worse in terms of precipitation
But cooler in terms of temperature.
Why the
Difference?
Subtle shift E in
2014-15
Stronger
anomaly in 76-77
No One is Talking About El Nino Anymore!
Global Model Upgrade: January 14th
Increased resolution from roughly 26 to 13 km grid spacing
Better?
The Other Model Upgrade:
UW WRF
Major Upgrade to WRF modeling
system (Jan. 29, 0000 UTC run)
• Tested dozens of combinations of upgrades
and parameterizations for all seasons.
• Upgrade to new version of WRF (3.5.1 to
3.6.1)
• Moved from the NOAH to NOAH MP land
surface model. NOAH MP (multi-physics) has
much more sophisticated treatment of surface
and hydrological processes. Particularly
helpful when snow is on the ground.
NOAH MP Schematic
RAP Initialization
• We have been initializing with the GFS model
grids (1 or .5 degree resolution). Little
mesoscale detail, so model would have to spin
things up.
• Furthermore, we were using the grids from a
very different modeling system, again
resulting in spin-up issues.
Old
New
Big Differences over Puget Sound
Which is right?
Seattle Sand Point Soundings
Old
New
Inversion and fog was reported in area
New System Starts with much better
clouds
New
What is happening today?
The Forecast
Ridging without
End But With an
Omega Twist
• GFS long-term
forecast: here
• Regime shift
at end of the
month
The end