ed szoke 1 april 12, 2005 tamdar project – april boulder meeting ed szoke* noaa forecast systems...

Ed Szoke 1April 12, 2005

TAMDAR Project – April Boulder Meeting

Ed Szoke* NOAA Forecast Systems Laboratory

*Joint collaboration with the Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO


Overview

• Assessing TAMDAR data quality• Method

• Compare TAMDAR soundings with each other• Compare to nearby ACARS soundings (for T)• Compare to a “verifying” raob sounding

• Concentrated on DTW and MSP• Also looked at MEM when CLASS soundings were

present


Example 1: 7 March 05/1200 UTC

● A look at some TAMDAR soundings

● A large variation in quality of this sounding sample● Some from MSP, some compared to CIMMS soundings in

MEM


Weather on 7 March: NW flow, scattered snow showersat 1100 UTC at MSP

•


TAMDAR soundings with raob comparison at MSP-sharp inversion

While there is quite a bit of variability (possibly the time differences could account for some of this), the sharp inversion is well

captured.


TAMDAR soundings with raob comparison at MSP

Raob is in green again. This set of soundings is not very good.


Weather on 7 March at MEM: SW low-level flow, scattered showers and thunderstorms at 1400 UTC


TAMDAR soundings with CLASS soundings at Memphis

One bad sounding but overall pretty good agreement especially with moisture.


TAMDAR soundings with CLASS soundings at Memphis

One bad sounding again, but also more variability in this group. But in terms of RH, the general character of the moisture seems to be captured.


Example 2: 9 March 05/1200 UTC

● A look at some ACARS soundings● Does a sample of ACARS soundings show good

agreement or is it more variable like some of the TAMDARs?


Weather on 9 March 05/1200 UTC Area of rain near Memphis


ACARS soundings out of Memphis

Very good agreement for this set close in time and space.


Another set of ACARS soundings out of Memphis

Good overall agreement for this set close in time and space.


ACARS compared to 2 TAMDAR soundings out of Memphis

Decent agreement except for the point around 820 mb for the 1346z sounding.


Example 3: 1 April 05/1200 UTC

● Good agreement at MSP and DTW where the weather was dry ● More variability though at MEM where there was some rain in the area.


Weather on 1 April 05/1200 UTC Wet near Memphis, dry MSP and DTW area


ACARS and TAMDAR soundings out of MSP

The general structure of the RH below 800 mb is captured in the TAMDAR soundings. Temperature agreement though is not that great.


ACARS and TAMDAR soundings out of MSP

Overall pretty good agreement.


TAMDAR soundings vs RAOB from DTW

All the TAMDARs do a very good job of showing the dry layer near 800 mb.



This set also resolves the dry layer.


TAMDAR and ACARS soundings soundings at Memphis

Rain in the area could be the cause of more disagreement among the soundings, but agreement is good aob 900 mb.


Example 4: 2 April case: more weather than the last example

•

Radar for DTW at 1200 UTC. Detroit at the nw edge of a major storm system to the east.



Something goes bad with the 1223z sounding, getting way too warm at 700 mb.


ACARS soundings vs RAOB from DTW

Some temperature problems appear to also be found in this set of ACARS soundings.


TAMDAR and ACARS soundings vs RAOB from DTW

Quite a bit of spread shown in this set.


Example 5: 4 April 05/1200 UTC

● End on a good note with good agreement

● Fair weather at MSP and DTW


Weather on 1 April 05/1200 UTC Wet near Memphis, dry MSP and DTW area


TAMDAR soundings vs RAOB from MSP

Excellent temperature agreement for the 1205z sounding with a distinct low level inversion.



Overall good agreement with both temperature and dew point.



Same with this set.



Good agreement with the DTW raob; key feature here is the dry layer beginning near 800 mb.



Good agreement, again the dry layer is well captured.



Same with this set.


Summary of TAMDAR comparisons

● From comparisons since late February…

● The number of questionable TAMDAR soundings appears to be less than in the early days of the project, likely a result of bad sensors being flagged.

● Examples demonstrated that the TAMDAR soundings are able to capture distinct dry and moist layers and sharp inversions.

● Overall, the quality appears in general to be good enough to be an important source of moisture data in the lower part of the atmosphere. Such information is very hard to get with any current sensors.

ed szoke 1 april 12, 2005 tamdar project – april boulder meeting ed szoke* noaa forecast systems...

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