RUC

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RUC RAOB TAMDAR SOUNDINGS
Ed Szoke NOAA Forecast Systems Laboratory

Joint collaboration with the Cooperative
Institute for Research in the Atmosphere,
Colorado State University, Fort Collins, CO
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TAMDAR soundings vs RAOBs some observations

• At the time of the last meeting...
• Found lots of variability in the TAMDAR soundings
• Often soundings close in time were not consistent
• Now...
• Much less variability
• Soundings tend to show good consistency
• And generally compare better to nearby raobs

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Overview

• Assessing TAMDAR data quality...quick review
• Compare TAMDAR soundings with each other
• Compare to a verifying raob sounding
• Concentrated on DTW and MSP and PIA
• Examining impact of TAMDAR on RUC forecasts
• Look at RUC forecast soundings with and without
  TAMDAR and compare to raobs
• Also compare RUC analyses
• Potential forecast value of TAMDAR soundings
• Consistency and potential usefulness of TAMDAR
  soundings...a brief case

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TAMDAR soundings vs RAOBs Weather at 1200 UTC
19 August 05
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TAMDAR soundings vs 1200 UTC 19 August 05 DTW
RAOB flights to ENE
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TAMDAR soundings vs 1200 UTC 19 August 05 DTW
RAOB flights to ENE
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TAMDAR soundings vs 1200 UTC 19 August 05 DTW
RAOB flights to ENE
Agreement is not as good but note TAMDARS are
heading NW and the raob would have headed to the
ene.
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TAMDAR soundings vs RAOBs DTW 1200 UTC 22
August 05
Quite a bit of lower level moisture over the
Upper Midwest.
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TAMDAR soundings vs DTW RAOB flights to the SE
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TAMDAR soundings vs DTW RAOB flights to the ENE
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TAMDAR soundings vs DTW RAOB flights to the NW
Note that the raob heads to the ESE
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TAMDAR soundings vs MSP RAOB flights to the E
Note the good consistency between TAMDARs 2 min
apart.
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TAMDAR soundings vs MSP RAOB flights to the
E-ENE
Not sure about the 1231 UTC TAMDAR flight...
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TAMDAR soundings vs MSP RAOB flights to the S
Excellent agreement on the height of the
inversion base.
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Next we will look at impact of TAMDAR on the RUC
- Examine RUC with (dev2) and without
(dev) TAMDAR - Using mainly DTW and MSP
locations - Look first at RUC analyses and
compare to raobs - Then see if impact is seen
in the forecasts by looking at mainly 3 and 6 h
forecasts and comparing to raobs.
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RUC analysis soundings vs RAOBs 18 August 2005
Surface map with radar for 1200 UTC.
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RUC analysis soundings vs DTW RAOB 18 August
2005
Comparison of RUC analyses for 1200 UTC with
(dev2) and without (dev) TAMDAR. Appears to be a
better match to the sounding when the TAMDAR data
was included.
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RUC analysis soundings vs MSP RAOB 1200 UTC 18
August 05
The same type of example from MSP could argue
that dev2 is a slightly better match to the raob.
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RUC forecast soundings vs RAOBs 0000 UTC 19 Aug
Comparison of RUC forecast soundings for Detroit
at 0000 UTC 3 h forecasts. -soundings are
different, but dev1 (w/o TAMDAR) may be closer
match to raob.
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RUC forecast soundings vs RAOBs 0000 UTC 19 Aug
Comparison of RUC forecast soundings for Detroit
at 0000 UTC 6 h forecasts.
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RUC forecast soundings vs RAOBs 0000 UTC 19 Aug
Comparison of RUC forecast soundings for Detroit
at 0000 UTC 9 h forecasts. -9 h is rather far
into the forecast but note differences do appear
between the forecasts...not clear which one is
better for this case.
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RUC forecast soundings vs RAOBs 0000 UTC 19 Aug
Comparison of RUC forecast soundings for Detroit
at 0000 UTC 12 h forecasts.
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RUC forecast soundings vs RAOBs 0000 UTC 23 Aug
05
Quite a bit of low level moisture MI-MN with
extensive low clouds over MI.
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RUC forecast soundings vs RAOBs 0000 UTC 23 Aug
05
TAMDAR data available for 2300-0100 UTC,
approximating what was available for the RUC 0000
UTC runs.
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RUC analyses with and without TAMDAR for 0000 UTC
23 Aug
Comparison with the Detroit 0000 UTC raob. RH
differences exist between the RUC analyses but
dev2 (with TAMDAR) does not look as good as dev1
(RUC analysis without TAMDAR) for this site.
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RUC analyses with and without TAMDAR for 0000 UTC
23 Aug
Comparison with the Minneapolis 0000 UTC raob.
This time dev2 (with TAMDAR) looks better at
lower levels.
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RUC analyses with and without TAMDAR for 0000 UTC
23 Aug
Comparison with the Davenport Iowa 0000 UTC raob.
Dev2 (with TAMDAR) temperature looks better at
and above 850 mb.
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RUC analyses with and without TAMDAR for 0000 UTC
23 Aug
Comparison with the Peoria Illinois 0000 UTC
raob. No improvement seen for this site, but
there are much fewer flights into PIA.
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RUC 6h forecasts with and without TAMDAR for 0000
UTC 23 Aug
Comparison of 6h RUC forecasts with the Detroit
0000 UTC raob. Mixed results, down low dev (w/o
TAMDAR) looks best with T, but above 850 mb dev2
(with TAMDAR) closely matches the raob in T and
Td.
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RUC 6h forecasts with and without TAMDAR for 0000
UTC 23 Aug
Comparison with the MSP 0000 UTC raob. Less
differences in the forecasts.
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RUC 6h forecasts with and without TAMDAR for 0000
UTC 23 Aug
Comparison with the Green Bay 0000 UTC raob.
Mixed...T better, RH not, for dev2 (with TAMDAR).
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RUC 6h forecasts with and without TAMDAR for 0000
UTC 23 Aug
Comparison with the Peoria 0000 UTC raob. Little
difference between the 2 forecasts aob 800 mb,
but better RH with dev2 above this level.
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RUC analyses with and without TAMDAR for 1200 UTC
23 Aug
Quiet weather aloft but still lots of low level
moisture, especially eastern WI through MI.
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RUC analyses with and without TAMDAR for 1200 UTC
23 Aug
TAMDAR flights before 1200 UTC.
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RUC analyses with and without TAMDAR for 1200 UTC
23 Aug
For Detroit. Not much difference down low, but
aob 750 mb dev2 RH better.
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RUC analyses with and without TAMDAR for 1200 UTC
23 Aug
MSP shown here...much better temperature for dev2
in the lowest 100 mb.
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RUC analyses with and without TAMDAR for 1200 UTC
23 Aug
Not true though at PIA, but again less TAMDAR
here.
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RUC analyses with and without TAMDAR for 0000 UTC
24 Aug
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RUC analyses with and without TAMDAR for 0000 UTC
24 Aug
The same type of example for 12z from MSP could
argue that dev2 is a better analysis.
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RUC analyses with and without TAMDAR for 0000 UTC
24 Aug
Analyses for Detroit.
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RUC analyses with and without TAMDAR for 0000 UTC
24 Aug
Analyses for MSP
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RUC forecasts without TAMDAR for Detroit for 0000
UTC 24 Aug
3 and 6 h forecasts for Detroit. Improvement
with time around 800 mb but not lower down.
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RUC forecasts with TAMDAR for Detroit for 0000
UTC 24 Aug
Dev2 forecasts more consistent.
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RUC forecasts without TAMDAR for MSP at 0000 UTC
24 Aug
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RUC forecasts with TAMDAR for MSP valid at 0000
UTC 24 Aug
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RUC forecasts with and without TAMDAR for 0000
UTC 24 Aug
Comparing the two 3-h forecasts. Note the great
match from dev2 for lower level T but dev is
better for Td.
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RUC analyses with and without TAMDAR for 1200 UTC
24 Aug
Still lots of lower level moisture around.
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TAMDAR availability for the 1200 UTC 24 Aug RUC
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RUC analyses with and without TAMDAR for 1200 UTC
24 Aug
Analyses for Detroit. Much better moisture down
low with TAMDAR.
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RUC analyses with and without TAMDAR for 1200 UTC
24 Aug
Analyses for MSP. Dev2 with TAMDAR captures the
low level inversion better.
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Case study of potential forecast value of TAMDAR
soundings -rapidly evolving environment in the
Dakotas leading to tornadoes
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Radar overview 1900 UTC
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Radar overview 2100 UTC
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Radar overview 2200 UTC
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Radar overview 2300 UTC
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TAMDAR availability area is at the western edge
of flights.
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BIS RAOBs the day starts with VERY shallow
moisture but increasing southerly flow above the
surface.
A lot happens before the next raob at 0000 UTC to
set up a supercell environment - what did TAMDAR
show?
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ABR RAOB with 1301 and 1326 UTC TAMDARs
Note the increase in moisture just after the
sounding launch and the increasing low level
southerly flow.
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ABR TAMDARs from 1533 to 1938 UTC.
This Aberdeen TAMDAR series of soundings nicely
shows the increasing depth of low-level moisture
even as the boundary layer warms.
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GFK TAMDARs from 1705 to 1913 UTC.
Grand Forks TAMDAR series of soundings also shows
the increasing depth of low-level moisture.
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GFK CAPE/CIN for TAMDARs from 1705 vs. 1913 UTC.
Considerably less inhibition and more CAPE in
just 2 h as shown by the TAMDAR soundings.
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Environmental variability within the spacing of
the raob network
Huge amount of variability on this day.
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Overall Summary

• TAMDAR quality has improved since our last
  meeting
• This allows forecasters to have more confidence
  in using the data
• Showing impact of TAMDAR on RUC forecasts is
  tricky
• But is fairly clear that one can see the impact
  on the analyses
• Would like to look more at lt 3 h forecasts
• It is easier to find examples of how TAMDAR data
  can aid operational forecasting and these can be
  quite dramatic
• Compared with smaller effects in NWP models.