1. TAMDAR Workshop 2006 – Boulder, Colorado 1 April 13, 2006 UPDATE ON TAMDAR IMPACT ON RUC FORECASTS & RECENT TAMDAR/RAOB COMPARISONS Ed Szoke,* Brian Jamison*, Bill Moninger, Stan Benjamin, Randy Collander*, and Tracy Smith* NOAA/ESRL Global Systems Division *Joint collaboration with the Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO

2. TAMDAR Workshop 2006 – Boulder, Colorado 2 April 13, 2006 Outline Using the high-resolution TAMDAR data available since 30 Mar 06... Examine impact on RUC forecasts Subjective evaluation concentrating on short-range precipitation forecasts Focus on 6-h accumulated precipitation forecasts ending at 0000 and 0600 UTC (but other fields also examined) For 1800 UTC runs compare forecast soundings with observed soundings Models used: identical RUC-20 km runs with and without TAMDAR Compare TAMDAR sounding quality and detail TAMDAR soundings compared to each other TAMDAR soundings compared to nearby RAOBs Emphasis on the kinds of sharp structures that can be resolved with the higher resolution TAMDAR data

3. TAMDAR Workshop 2006 – Boulder, Colorado 3 April 13, 2006 30 Mar 2100 UTC: Deepening storm with severe weather & ND snow System is at north/west edge of TAMDAR to within network (in WI/IL). In ND rain changing to snow. Will examine precipitation fields and CAPE and helicity.

4. TAMDAR Workshop 2006 – Boulder, Colorado 4 April 13, 2006 Display of the TAMDAR coverage from 2100 UTC 30 Mar to 0000 UTC 31 Mar

5. TAMDAR Workshop 2006 – Boulder, Colorado 5 April 13, 2006 TAMDAR/RAOB comparisons for 0000 UTC 31 Mar 06 – Minneapolis Good overall agreement with the sounding and all TAMDARs nicely resolve the dry layer centered at 800 mb

6. TAMDAR Workshop 2006 – Boulder, Colorado 6 April 13, 2006 TAMDAR/RAOB comparisons for 0000 UTC 31 Mar 06 – Minneapolis The most variability in this set is from the flight heading off to the southeast.

7. TAMDAR Workshop 2006 – Boulder, Colorado 7 April 13, 2006 AMDAR/RAOB comparisons for 0000 UTC 31 Mar 06 – Minneapolis For comparison to TAMDAR, here are a few AMDAR temperature profiles compared to the MSP RAOB

8. TAMDAR Workshop 2006 – Boulder, Colorado 8 April 13, 2006 TAMDAR/RAOB comparisons for 0000 UTC 31 Mar 06 – Peoria, Illinois Here we do see a difference between the ascent and descent soundings (that track in pretty much the same location and not far off in time), with a better match to the RAOB for the TAMDAR ascent.

9. TAMDAR Workshop 2006 – Boulder, Colorado 9 April 13, 2006 7 April 0000 UTC: Deepening storm with severe weather & R+ High risk severe wx day NE to eastern KS. Also heavy rains in band e-w across MSP. Will examine precipitation fields and CAPE and helicity.

10. TAMDAR Workshop 2006 – Boulder, Colorado 10 April 13, 2006 Comparison of 6-h RUC precipitation forecasts with and without TAMDAR for runs initialized at 1800 UTC on 6 April 06. Two main differences are highlighted: 1) In MN/nrn IA with more precip in TAMDAR run 2) More of a line of precip in eastern NE in the TAMDAR run Without TAMDARWith TAMDAR >0.25”>0.5”>1.0”>0.10”

11. TAMDAR Workshop 2006 – Boulder, Colorado 11 April 13, 2006 Observed 6h precipitation ending 0000 UTC 7 April 06 TAMDAR run looks better for having more precip near MSP. Similarly, in eastern KS more precip in the TAMDAR run is also better.

12. TAMDAR Workshop 2006 – Boulder, Colorado 12 April 13, 2006 Comparison of 6-h RUC CAPE and CIN forecasts with and without TAMDAR for runs initialized at 1800 UTC on 6 April 06. Not a lot of differences in the CAPE fields although more CIN across IL in the TAMDAR run. Without TAMDARWith TAMDAR

13. TAMDAR Workshop 2006 – Boulder, Colorado 13 April 13, 2006 Analyzed CAPE from the NAM valid 0000 UTC 7 April 06

14. TAMDAR Workshop 2006 – Boulder, Colorado 14 April 13, 2006 Comparison of 6-h RUC Helicity forecasts with and without TAMDAR for runs initialized at 1800 UTC on 6 April 06. A few differences are seen (northern IA, eastern KY). Analysis (next) perhaps favors TAMDAR run slightly.... Without TAMDAR With TAMDAR

15. TAMDAR Workshop 2006 – Boulder, Colorado 15 April 13, 2006 Analyzed SREH from the NAM valid 0000 UTC 7 April 06

16. TAMDAR Workshop 2006 – Boulder, Colorado 16 April 13, 2006 6 April 1800 UTC: S torm intensifying with severe weather developing Next we'll examine some TAMDAR/ RAOB comparisons for 1200 UTC and for the special soundings launched at 1800 UTC for MSP and LZK (Little Rock, AR).

17. TAMDAR Workshop 2006 – Boulder, Colorado 17 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 6 April 06 – Minneapolis Good agreement between the two descent TAMDARs

18. TAMDAR Workshop 2006 – Boulder, Colorado 18 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 6 April 06 – Minneapolis Same with this set

19. TAMDAR Workshop 2006 – Boulder, Colorado 19 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 6 April 06 – Minneapolis Also good agreement with a descent/ascent pair.

20. TAMDAR Workshop 2006 – Boulder, Colorado 20 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 6 April 06 – Minneapolis The main disagreement is found for the 2 TAMDARs heading south, but note these are ~80 min apart in time.

21. TAMDAR Workshop 2006 – Boulder, Colorado 21 April 13, 2006 TAMDAR/RAOB comparisons for Minneapolis: time series Nice depiction of the effect of sustained lift on the strong inversion centered near 850 mb.

22. TAMDAR Workshop 2006 – Boulder, Colorado 22 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 6 April 06 – Little Rock/Nashville Good overall agreement with the sounding and all TAMDARs.

23. TAMDAR Workshop 2006 – Boulder, Colorado 23 April 13, 2006 TAMDAR/RAOB comparisons for 1800 UTC 6 April 06 – Little Rock/Nashville Note how well the sharp inversion is resolved near 900 mb, and the very sharp dry layer above this.

24. TAMDAR Workshop 2006 – Boulder, Colorado 24 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 6 April 06 – Little Rock/Nashville Similar good resolution with this set of soundings a little while later.

25. TAMDAR Workshop 2006 – Boulder, Colorado 25 April 13, 2006 TAMDAR coverage for 1500-1800 UTC 6 April 06 Coverage doesn't go quite to Little Rock but is close.

26. TAMDAR Workshop 2006 – Boulder, Colorado 26 April 13, 2006 The next day: 7 April 2100 UTC - Severe weather moves into eastern/southern part of TAMDAR network Another high risk day, this time shifted east to western TN/KY. By 2100 UTC 4 tornado watch boxes were already in place.

27. TAMDAR Workshop 2006 – Boulder, Colorado 27 April 13, 2006 Southern TAMDAR coverage for 7 April 06 Jackson Little Rock BNA

28. TAMDAR Workshop 2006 – Boulder, Colorado 28 April 13, 2006 Comparison of 6-h RUC precipitation forecasts with and without TAMDAR for runs initialized at 1800 UTC on 7 April 06. More precipitation is produced by the run with TAMDAR across southern IN into OH. The run without TAMDAR has more precip in nw AL. Without TAMDAR With TAMDAR >0.25”>0.5”>1.0”>0.10”

29. TAMDAR Workshop 2006 – Boulder, Colorado 29 April 13, 2006 Observed 6h precipitation ending 0000 UTC 8 April 06 TAMDAR run looks better for having more precip in IN/OH

30. TAMDAR Workshop 2006 – Boulder, Colorado 30 April 13, 2006 TAMDAR/RAOB comparisons for 1200 UTC 7 Apr 06 – Jackson, MS Sharp dry layer above the inversion is really captured well.

31. TAMDAR Workshop 2006 – Boulder, Colorado 31 April 13, 2006 TAMDAR/RAOB comparisons for ~1500-1800 UTC 7 Apr 06 – Jackson, MS Sharp moisture changes between 700 to 750 mb are shown in special RAOBs and TAMDARs. Also, good agreement with the moisture profile down low.

32. TAMDAR Workshop 2006 – Boulder, Colorado 32 April 13, 2006 TAMDAR time series for Memphis leading up to initial tornadoes Nice time series showing both the removal of the early morning cap near 850 mb and then the development of a much more moist and unstable layer in the lowest 100 mb.

33. TAMDAR Workshop 2006 – Boulder, Colorado 33 April 13, 2006 Summary RUC forecasts with and without TAMDAR showed some differences Generally did not find cases as dramatic as those shown at AMS But the differences that were found usually favored the TAMDAR runs For other cases recently (not shown) differences were minor Sounding comparisons... Showed 3 different strong severe weather days Overall consistency between TAMDAR soundings is fairly good Higher resolution data is able to nicely capture very sharp moist/dry layers TAMDAR soundings continue to show value for forecast applications Nice Memphis time series leading up to the initial TN tornadoes last Friday