Simulated satellite imagery in AWIPS II

 

AWIPS II 4-panel display of the NSSL-WRF simulated satellite imagery, showing standard IR window (top left), WV (top right) and 10.35-12.3 micron channel difference.

CIRA and UW-CIMSS are providing the HWT and SPC with synthetic satellite data that is generated from the 4km NSSL-WRF.  This data is available for all GOES-R ABI IR bands and arrives locally by 7am.  This year we made a first effort at bringing the data into AWIPS II, which was successful thanks to Darrel Kingfield at NSSL.  The above image is a 4-panel display of the synthetic IR, WV and 10.35-12.3 micron channel difference, which was described in a previous blog post here.  I spoke with one of the forecasters in detail about the 10.25-12.3 micron channel difference and explained that GOES-R will be able to provide this, as well as other unique combinations of imagery such as RGBs, every 5 minutes over CONUS.  I discussed with her how we expect to combine imagery into unique products to help the forecasters use the ABI channels rather than simply sending all the bands to each forecast office.  The forecaster mentioned that she definitely wants to bring this simulated satellite imagery back to her office and I had her coordinate with the UW-CIMSS representative this week.

In addition, based on forecaster feedback from last year, CIRA provided us with a new color table to better distinguish areas where convective initiation might occur in the 10.35-12.3 micron channel difference imagery.  Forecasters have expressed approval for the new color table and have mentioned that it is easy to detect threat areas.

EWP: UW-CTC captures early afternoon convection

An unstable and weakly capped atmosphere has resulted in widespread convective development over southern Texas, northern Mexico into southern New Mexico late this morning and early this afternoon.  The UW-CTC product captured the vertical growth of these storms as inferred by the cloud-top cooling rates in the images below.  As was shown yesterday, the UW-CTC rates are providing good lead-time ahead of strong radar reflectivity.  The top panels are the GOES IR-window brightness temperatures (top left) and GOES visible reflectance (top right).  The bottom panels are the UW-CTC rates (bottom left) and El Paso, Texas 0.5 degree reflectivity (bottom right).  Unfortunately the timing of initiation was prior to the start of EWP so these hits have not been extensively evaluated by the forecasters on shift.  Perhaps later development in areas of thin cirrus clouds will provide more examples of the results of including the GOES optical depth retrievals in the UW-CTC algorithm.

 Figure 1. Valid 1715 UTC 08 May 2012.

 Figure 2. Valid 1745 UTC 08 May 2012.

  Figure 3. Valid 1815 UTC 08 May 2012.

EWP daily debrief 5/8

Today we had our first daily debrief with the EWP forecasters.  The forecasters were focused on the San Angelo and Austin, TX areas issuing severe thunderstorm warnings throughout the evening.  We discussed the previous day's activities and asked them a little about what they thought about the product performance during their warning operations...


SATCAST / UW-CTC
- The forecasters created a procedure called "Awesome CI" to complement last year's "Ultimate CI" (which we have made available to the forecasters in AWIPS II) that included the SATCAST product with the UW cloud-top cooling, along with OUN-WRF hourly theta-e and wind fields to combine both observed CI products with some model-based analysis fields... "Helped increase our situational awareness, which was a big plus."
- NWS Charleston forecaster mentioned both CI products back to home office and said they were very excited to look at them.
- "When the (SATCAST) data was coming in there was some positive responses to it... there were consecutive images where there were strong signals and it definitely increased my confidence."
- "With these products, even with training, experience is the key thing to get forecasters to use it."
- "It was nice having both the SATCAST and the CTC, where one is more sensitive and helping identify the area, the other helped key in on those really strong storms that I should be paying attention to."
- Would it have been helpful to see the feedback questions before going into operations to get an idea of what to look for?  "It might have helped direct us."
- "With the CTC, most of the signals were out in W TX and we weren't really looking at the radar, and those strong signals helped."

Nearcast
- Theta-e difference used extensively when storms were already mature... monitored what environment the storms were moving into... helpful in identifying intensification.
- "Could clearly see the boundary between the more stable air and unstable air."
- Couldn't get all the individual field levels in AWIPS II... was only able to get the difference.

Overall / Training
- Would be helpful to get some of the WES procedures built into AWIPS II.
- All these products would be helpful if someone was assisting the warning forecaster looking at these (and other) derived products.
-  Do you feel comfortable with the current training setup, do you want more time with the PIs or material on Monday?  "Getting us into that mindset prior to arrival with the WES case was very beneficial."

Nearcast in a warning environment

EWP forecasters are currently monitoring severe weather over southern TX and issuing experimental warnings for storms that have been producing severe hail.  One of the forecaster groups localized for the forecast office in Austin, TX has been monitoring GOES-13 IR with the UW-CIMSS differential theta-e product overlaid.  Their goal is to identify the near-storm environment that the currently severe storm is moving into to aid in the warning decision making process.  This provided a very good example how the Nearcast product maintains previous observations where new observations cannot be made due to cloud cover.  This can be useful in providing high-resolution observational data key to identifying localized regions of instability that cannot be obtained through other means.  In this case the forecasters decided to issue an experimental severe thunderstorm warning at 2228 UTC based on the current representation of the storm on radar and the Nearcast differential theta-e fields.

EWX Meso Update 2320 UTC

Forecaster comments from the EWP blog...

The first image below shows cloud top cooling rates at 1715Z.  Note the values of almost -35 K in the light blue over west central TX.    The second image below of IR satellite imagery at 1745Z, depicts the beginning phases of strong convection in the same region as the cloud top cooling noted 30 min before strong convection initiated.  The CIMSS cloud top cooling product correctly predicted the formation of a  complex of strong storms that later became severe during the late afternoon/early evening hours.

EWP: UW-CTC in areas of thin cirrus

The montage below demonstrates the improvement to the UW-CTC products to operate in areas of thin cirrus cloud cover during daytime hours.  This improvement was one of the largest deficiencies identified by forecasters in previous testbeds.  Diagnosing cloud-top cooling rates in presence of thin cirrus clouds is possible by inclusion of GOES daytime optical depth retrievals.   The UW-CTC rate at 2145 UTC 07 May 2012 was approximately -6 K / 15 min (lower left, figure 1); with further cooling of ~ -18 K / 15 min at 2215 UTC 07 May 2012 (lower left, figure 2).  By 2245 UTC the Dallas-Fort Worth radar indicated 50-55 dBZ composite reflectivity.  Another cell further west was not captured by the algorithm, possibly due to its position closer to colder anvil temperatures.

Figure 1. 

 Figure 2.

Figure 3.

EWX Meso Update 2230UTC

Forecaster comments from the EWP blog...

Issued a (experimental) warning on a cell for hail and wind based on radar trends and the fact that this storm was moving into a good environment.  The above image of radar reflectivity shows the storm moving southeast into a good theta-e environment depicted by the yellow axis on the above image.  The theta-e imagery is CIMSS-NRE Layer GOES Vertical Theta-e Diff Low-Mid Img

EM Discussion @ 21Z

Experimental Area Forecast Discussion (AFD) from EWP blog...

Location: Latest guidance supports continued development of strong to severe thunderstorms moving across McColloch, San Saba, Llano, San Saba and Mason counties.

Impacts:  primary impact will be large hail and damaging winds.  there is still potential for isolated tornadoes.

Met discussion:  OUNWRF showed evidence of moisture convergence on the h8/h7 wind and theta E H8-7 layer; MRMS Max hail size estimated 1.5″ hail;  UAH CI strength of signal showed 80-100 values over the areas of favorable moisture convergence; CI-CTC projected new development over Llano county.

EWP: UW-CTC over Texas

Over the past hour we have been evaluating the UW-CTC output with developing convection associated with an outflow boundary from a convective complex over Central Texas. 

Figure 1 shows the the GOES IR-window and visible observations at 1915 UTC 07 May 2012 (top) and the UW-CTC rate (bottom left) and associated SJT composite reflectivity (bottom right).

Figure 2 is the same as Figure 1, except valid ~2000 UTC 07 May 2012.

As can been seen in the images above, the UW-CTC rate at 1915 UTC (~ -15 K / 15 min) proceeded the development of a 56 dBZ composite reflectivity echo by 45 minutes.  Additionally this storm was producing a 0.80" radar-estimated maximum expected hail size by 2029 UTC.  This is one of hopefully, many examples, demonstrating how the quantitative measure of cloud top cooling rates can provide prognostic value of strong radar reflectivity and formation of near-severe hail.

EWP Underway: UW-CTC and Echo Top Heights

The EWP @ HWT is underway.  While we're currently getting spun up getting data displayed, etc., the first conversation related to UW-CTC (cloud-top cooling rate) was not warning related, but aviation related with a representative from the Houston CWSU.  The representative was interested in the validation study performed by UW/CIMSS of the UW-CTC to future NEXRAD 18, 30, and 50 dBZ echo top heights, especially over their Gulf of Mexico responsibility region as well as the Houston TRACON (terminal radar approach).  Since the results of the echo top height were not included in the HWT training, we'll provide the echo top height analysis to the Houston CWSU.

Justin
UW/CIMSS