Figure 3. Valid 2155 UTC 10 May 2012. The UAH CI Strength of Signal product continues to indicate rapid redevelopment on the tail end of the existing thunderstorm complex (top-left pane).
Sieglaff/CIMSS
Walker/UAH
Barnes/WFO OUN
Thursday, May 10, 2012
EWP: UAH SATCAST and UW-CTC Provides 40-50 minute lead time on EXPERIMENTAL Severe Warning
Thunderstorms continued to develop along an outflow boundary over southern Texas Thursday afternoon. The satellite-based convective support algorithms (UAH SATCAST and UW-CTC) captured the early growth of the latest thunderstorm along the outflow boundary. Shown in the figures below, SATCAST and UW-CTC provided 40-50 minutes of lead-time ahead of severe thunderstorm issuance and approximately 1 hour ahead of tornado warning issuance. Additionally golf ball size hail was reported with this storm 1.5 hours later.
Figure 1. Valid 2140 UTC 10 May 2012. The UAH CI Strength of Signal product detects early rapid growth on a newly developing storm in south Texas (top-left pane).
Figure 2. Valid 2145 UTC 10 May 2012. The UW-CTC algorithm identifies the same developing storm with cooling rates of approximately -12 K / 15 min (top-right pane).
Figure 4. Valid 2229 UTC 10 May 2012. The base reflectivity from KCRP with severe thunderstorm warning polygon issued by NWS forecasters at the EWP/HWT. This warning was later upgraded to a tornado waring at the EWP/HWT. **NOTE THIS IS AN EXPERIMENTAL WARNING**
Sieglaff/CIMSS
Walker/UAH
Barnes/WFO OUN
Sieglaff/CIMSS
Walker/UAH
Barnes/WFO OUN
BRO/CRP West Radar Analysis 2240Z
Forecaster comments from EWP blog...
CI continues to show promising results in terms of providing significant lead for strong/severe t-storms.
The first image below at 2115Z shows a strength of signal around 99 (red) in UAH-CI in the upper left pane for a developing storm west of Laredo.
The next image at 2125Z depicts -14C/15 min UW-CI (lower left) for the developing storm.
Radar imagery continued to show storm growth and the storm reached 50
to 55 dbz at 2208Z as shown in the upper right pane of the image
below. Also, MESH reached 1.18 inches at this time as well.
With these figures in mind, the lead time from initial CI detection
on UAH-CI was around 55 min. and the lead time from UW-CI was around 45
min. It would be great to put a product out conveying the possibility
of strong storms when we first see these CI signals with an actual
warning coming later.
CI continues to show promising results in terms of providing significant lead for strong/severe t-storms.
The first image below at 2115Z shows a strength of signal around 99 (red) in UAH-CI in the upper left pane for a developing storm west of Laredo.
BRO MESO Desk @ 2250Z
Forecaster comments from EWP blog...
We noticed a good comparison of the CTC at 2210Z occurring 18 minutes before the 1″ hail indication by MESH.
We noticed a good comparison of the CTC at 2210Z occurring 18 minutes before the 1″ hail indication by MESH.
BRO/CRP West Meso Desk @ 2220Z
Forecaster comments from EWP blog...
Focusing on the newly developed storms over Mexico and west of Laredo, the synthetic satellite appeared to capture the progression of these storms as they move east. Projections have these storms moving into Texas between 00Z-01Z. Latest radar trends may be a bit faster though.
Focusing on the newly developed storms over Mexico and west of Laredo, the synthetic satellite appeared to capture the progression of these storms as they move east. Projections have these storms moving into Texas between 00Z-01Z. Latest radar trends may be a bit faster though.
MESO Desk update @ 2150Z
Forecaster comments from the EWP blog...
These two nearCast screen captures depict the main axis of theta e/PW that was translating east of the BRO. Ample moisture remains over the eastern and southern parts of the BRO CWA and support thunderstorm development. Sadly, convection continues to be inhibited and is reflected on the 3DVAR sim. comp. reflectivity.
These two nearCast screen captures depict the main axis of theta e/PW that was translating east of the BRO. Ample moisture remains over the eastern and southern parts of the BRO CWA and support thunderstorm development. Sadly, convection continues to be inhibited and is reflected on the 3DVAR sim. comp. reflectivity.
Mexico! CTC shows a rapidly developing thunderstorm
Forecaster comments from the EWP blog...
Top image – IR Satellite with CTC rates of -40C/15 min (dark looking region) ~25 minutes before
+60 dBZ @ ~32Kft (bottom image) were observed.
+60 dBZ @ ~32Kft (bottom image) were observed.
BRO Meso Analysis with Nearcast/Sythetic WRF at 2030Z
Forecaster comments from the EWP blog...
The below image at 22Z depicts nearcast theta-e at 780 mb in the upper left pane, synthetic WRF IR in the upper right, nearcast theta-e at 500 mb in the lower left, and nearcast vertical theta-e difference in the bottom right.
Looking at the 780 mb theta-e, it shows areas in yellow of best moisture/instability predicted for this afternoon which matches up with storms predict in synthetic IR imagery. Because the 2 products derived off of different model projections are in decent agreement, this lends more confidence to this convective scenario for this afternoon.
The below image at 22Z depicts nearcast theta-e at 780 mb in the upper left pane, synthetic WRF IR in the upper right, nearcast theta-e at 500 mb in the lower left, and nearcast vertical theta-e difference in the bottom right.
Looking at the 780 mb theta-e, it shows areas in yellow of best moisture/instability predicted for this afternoon which matches up with storms predict in synthetic IR imagery. Because the 2 products derived off of different model projections are in decent agreement, this lends more confidence to this convective scenario for this afternoon.
BRO MESO Desk @ 20Z
Forecaster comments from EWP blog...
The following four screen captures depict several favored areas of UAH-CI strength of signal along the outflow boundaries that exist immediately north of CWA and north-south along a line from Los Angeles-Realitos-Encino-Raymondville. Knowing were the boundaries were located, UAH strength of signal allowed us to focus on the most favored areas between 20Z-21Z. (Synthetic Sat showed the most likely CI would take place between 20-21Z, particularly with storms along the Rio Grande. It didn’t capture any activity over the northern extent of the outflow boundary.)
The following four screen captures depict several favored areas of UAH-CI strength of signal along the outflow boundaries that exist immediately north of CWA and north-south along a line from Los Angeles-Realitos-Encino-Raymondville. Knowing were the boundaries were located, UAH strength of signal allowed us to focus on the most favored areas between 20Z-21Z. (Synthetic Sat showed the most likely CI would take place between 20-21Z, particularly with storms along the Rio Grande. It didn’t capture any activity over the northern extent of the outflow boundary.)
BRO Afternoon Forecast 1920Z
Forecaster comments from the EWP blog...
Synthetic WRF imagery was useful in making a convective forecast for Brownsville this afternoon. At 13Z, the synthetic WRF depicted two areas of convection over TX with the south complex near Brownsville being slightly displaced to the south in location. This convection was occurring in an area of high shear ahead of an upper level low progress slowly across the southwest U.S. (seen in synthetic and observed imagery).
13Z Synthetic:
13Z Observed IR/WV (top 2 panes):
At 19Z synthetic and observed IR/WV imagery matched up well with the
southern complex, but over did convection to the south of the northern
complex in TX. Over Brownsville area, visible satellite imagery
depicted a low broken cu field at 1914Z which matches low clouds in the
synthetic IR imagery.
19Z Synthetic:
19Z Observed IR/WV (top 2 panes):
1914Z Visible Sat:
Conclusion: The Synthetic WRF model seems to be doing an OK job
overall so far today with a few issues. However, it depicts the upper
low driving convection today as well as 2 distinct areas of convection
over TX.
For Brownsville area for the rest of the afternoon, synthetic images below predict convective initiation around 20Z with convection strengthening through the afternoon hours (22Z image), and then beginning to decrease in strength at 0Z.
20Z Synthetic:
22Z Synthetic:
0Z Synthetic:
Synthetic WRF imagery was useful in making a convective forecast for Brownsville this afternoon. At 13Z, the synthetic WRF depicted two areas of convection over TX with the south complex near Brownsville being slightly displaced to the south in location. This convection was occurring in an area of high shear ahead of an upper level low progress slowly across the southwest U.S. (seen in synthetic and observed imagery).
13Z Synthetic:
19Z Synthetic:
For Brownsville area for the rest of the afternoon, synthetic images below predict convective initiation around 20Z with convection strengthening through the afternoon hours (22Z image), and then beginning to decrease in strength at 0Z.
20Z Synthetic:
BRO MESO desk @ 1834Z
Forecaster comments from EWP blog...
A few towering cu were present across BRO. CTC centriods were present in LaSalle county (CRP) an immediately south of Starr county. In fact, the LaSalle county CTC also showed a high strength of signal on the UAH-CI.
A few towering cu were present across BRO. CTC centriods were present in LaSalle county (CRP) an immediately south of Starr county. In fact, the LaSalle county CTC also showed a high strength of signal on the UAH-CI.
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