Transcript WeatherDsic.ppt

Weather Discussion
1/15/2013
Ship Tracks!
“These are "Type 1" shiptracks which form in (or persist into) a collapsed
boundary layer, a PBL highly scavenged of aerosols and very shallow, which
contains very "milky" cloud. The greatly increased aerosol loading (from
perhaps 10 /cm3 in the background to more like 200 /cm3 or more in the
shiptrack) invigorates the PBL by suppressing drizzle, which locally deepens it
and produces a stratocumulus cloud. “ Professor Rob Wood
Cold Wave Hits the SW!
Cold Hits Phoenix
Panic Hits LA!
Impressive Predictability
Cold Wave Due to Global Warming?
A quote from an unnamed climate
scientist at NCAR
• “In other words, the extreme cold is actually
related to the same phenomenon that leads
to extreme heat …A buckled jet stream, and
cold weather in the Southwest, happens just
about every winter, although not usually to
this extent, XXX said. However, more "extreme
blocking," along with unusual heat waves and
cold snaps, are more likely to be seen as a
result of climate change.”
West Pac Storm
Ryan Maue Comments
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From my database of NCEP CFSR cyclone tracks, this storm's relative low-latitude and 49 mb/24 hr maximum deepening rate puts it on the top of the
list of most rapid deepening North Pacific extratropical cyclones since 1979.
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Using a reference latitude of 45° for the "bomb calculation" and a storm average latitude of 34.5°N during the period of most rapid deepening, 49
mb / 24 hr equates to 2.55 bergeron. The minimum pressure is forecast to slowly deepen another several millibars to about 932 mb according to the
15/00z GFS forecast.
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I used the full-resolution (T574) surface pressure grids from NCEP GFS for the data points:
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1000 mb ... (13/12z)
994 mb ... (13/18z)
989 mb ... (14/00z)
978 mb ... (14/06z)
960 mb ... (14/12z)
946 mb ... (14/18z)
940 mb ... (15/00z)
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Runners-up for other most rapid deepeners (date of minimum pressure)
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2.33 ber:
2.27 ber:
2.25 ber:
2.23 ber:
2.18 ber:
Dec 21, 1995 (950 mb)
Mar 14, 1991 (952 mb)
Feb 28, 1987 (958 mb)
Feb 25, 1992 (961 mb)
Jan 15, 2011 (944 mb)
Predictability
7 Day Forecast!
Huge Waves
• Wavewatch III forecasts