In light of rapid development of convection in MN, we decided to shorten the debrief in order to start operations as soon as possible. We will include more in depth feedback in tomorrow's thorough weekly debrief. Our forecasting teams will begin the day localized over Minneapolis, Sioux Falls and Hastings, and will likely shift around throughout the day. Stay tuned!
SATCAST / UW Cloud-top Cooling
- "The left-most storm in Dallas was captured well by the cloud-top cooling... it got to -21 C / 15 mins and 30 minutes later it had severe hail."
- "We had that one storm that developed over Mexico and it had -37 C / 15 mins and it gave a lead time of over an hour and really kept going after that... that really demonstrated the utility of those products... we couldn't use radar over there and we basically had to go with the cooling rate."
- "In Sioux Falls, the CTC on the splitting supercell gave an hour to hour and 15 minute lead time... that is a product that could be very useful in the field."
- "In ABQ we had the opposite, the terrain really kept firing stuff that showed up on the CTC but nothing became of it."
- "We got a signal of about -12.5 C / 15 mins and that gave us about a 15-20 minute lead time... otherwise, most of them under -16 C / 15 mins gave us false alarms, but anything greater than that was good."
Simulated Satellite
- "It did a very good job of timing the convection and location in NM... then we switched up to Sioux Falls and the timing was good as well, but the location was off by about 120 miles... Even if you only know the timing is good, you can tell people that you're confident something is going to happen and that's huge."
Thursday, June 14, 2012
Wednesday, June 13, 2012
FSD – WRF Simulated imagery off on location but good on timing
Forecaster comments from EWP blog...
After seeing the CIRA/CIMSS sim imagery do very well in ABQ, we switched to FSD where the sim imagery indicated deep convection developing between 2100-2200z, but the location of the convection was about 130mi ese of where convection developed in Tripp and Lyman counties in central SD.
WRF Simulated IR 10.4 valid at 13 Jun 2100z:
GOES IR 2100z:
GOES IR 2130z:
CTC 2132z in Tripp and Lyman Co:
GOES IR 2144z:
CTC 2144z in Tripp and Lyman Co:
WRF Simulated IR 10.4 valid at 13 Jun 2200z:
GOES IR 2200z:
GOES IR 2230z:
WRF Simulated IR 10.4 valid at 13 Jun 2300z:
GOES IR 2300z:
WRF Simulated IR 10.4 valid at 14 Jun 0000z:
GOES IR 14 June 0014z:
After seeing the CIRA/CIMSS sim imagery do very well in ABQ, we switched to FSD where the sim imagery indicated deep convection developing between 2100-2200z, but the location of the convection was about 130mi ese of where convection developed in Tripp and Lyman counties in central SD.
WRF Simulated IR 10.4 valid at 13 Jun 2100z:
FWD: ABQ We Have Left The Building
Forecaster comments from EWP blog...
Switched domains to the FWD CWA. Ongoing supercell were producing hail over 2″ inches in diameter across eastern Dallas county. KFWS radar showing new supercell developing over the western portion of the county. Cloud top cooling product showed tops of >-21 degrees Celsius. Issued a severe thunderstorm warning based off both 88D reflectivity and cloud top cooling. Have since got reports of ping pong ball size hail.
KFWS radar at 2335z (warning issued on both storms):
Cloud top cooling product about 30 minutes before:
Switched domains to the FWD CWA. Ongoing supercell were producing hail over 2″ inches in diameter across eastern Dallas county. KFWS radar showing new supercell developing over the western portion of the county. Cloud top cooling product showed tops of >-21 degrees Celsius. Issued a severe thunderstorm warning based off both 88D reflectivity and cloud top cooling. Have since got reports of ping pong ball size hail.
KFWS radar at 2335z (warning issued on both storms):
CTC wins again
Forecaster comments from EWP blog...
CTC on the Lyman/Buffalo County Storm peaked at around -21C/15min at 2145z. Just got a severe report at around 2247 of 1.75 inch hail with the storm in Lynam County so it looks like about a big hit for CTC.
CTC on the Lyman/Buffalo County Storm peaked at around -21C/15min at 2145z. Just got a severe report at around 2247 of 1.75 inch hail with the storm in Lynam County so it looks like about a big hit for CTC.
ABQ North: Perhaps a Breakthrough
Forecaster comments from EWP blog...
Updraft in north central Colfax county may actually push the
severe limits. 40 dbz is reaching higher into the cloud (we are reaching
here). The visible cloud presentation has become more intriguing.
Lightning has also been detected with this thunderstorms for the first
time today.
Cloud top cooling product has shown -11 degrees C, well below our
severe threshold, but it is a start.. However, MESH is still
underwhelming despite the slight increase. We are still not confident in
much activity making off the higher elevations, and the latest run of
the OUN WRF continues to support our forecast.
Cloud-top cooling product:
MESH at the same time (look closely, it's there):
It’s getting bigger. MESH at 2214z is now up to 0.40″.
and as I write this, the temporary strengthening ceased. Now onto storms in the southern ABQ CWA.
Cloud-top cooling product:
ABQ South is now FSD ALL
Forecaster comments from EWP blog...
We abandoned ship and moved way north to look at the development in SD. Good looking cell moving into Bruce County however the MESH is only up to 0.79. Will continue to monitor since this storm is in an area of 2000-2500 j/kg SBCAPE. Below is an image of the CIMSS CAPE and RUC13 SBCAPE (contour).
We abandoned ship and moved way north to look at the development in SD. Good looking cell moving into Bruce County however the MESH is only up to 0.79. Will continue to monitor since this storm is in an area of 2000-2500 j/kg SBCAPE. Below is an image of the CIMSS CAPE and RUC13 SBCAPE (contour).
ABQ: Comparison of NEARCAST and RAP CAPE
Forecaster comments from EWP blog...
While waiting for convection to become surface-based, we overlaid CIMSS NEARCAST 780-500MB CAPE with RAP 850-700MB CAPE. As I mentioned in a post yesterday, I realize that these two CAPEs were not meant to be compared together as they are computed and sampled differently. But FWIW, I did the comparison at 2200 UTC and was surprised how well they compared.
The axis of CAPE in the RAP from NW of Roswell to the NE corner of NM
seems suspicious, given the density of surface observations (see image).
Other than that feature, the comparison seems generally good. Perhaps
the RAP uses satellite estimates of theta-e or CAPE already. Something
to research.
While waiting for convection to become surface-based, we overlaid CIMSS NEARCAST 780-500MB CAPE with RAP 850-700MB CAPE. As I mentioned in a post yesterday, I realize that these two CAPEs were not meant to be compared together as they are computed and sampled differently. But FWIW, I did the comparison at 2200 UTC and was surprised how well they compared.
Third MAF Warning…Jeff Davis County
Forecaster comments from EWP blog...
Another strengthening storm developing over the northern slopes of the
Davis Mts. The UAH-CI gave us a 75 several minutes ahead of the
development…
2130z Update on Lincoln County Storm
Forecaster comments from EWP blog...
Looks like the Lincoln County storm/shower is starting to diminish. Interestingly, the CTC product showed -25c but again, it was over the higher terrain. Today, it seems like whenever anything develops on the higher terrain, it moves off into the lower elevations and dies out. Suspect the storms still cannot realize that reservoir of SBCAPE to the east.
Looks like the Lincoln County storm/shower is starting to diminish. Interestingly, the CTC product showed -25c but again, it was over the higher terrain. Today, it seems like whenever anything develops on the higher terrain, it moves off into the lower elevations and dies out. Suspect the storms still cannot realize that reservoir of SBCAPE to the east.
MAF Second Warning for Persidio County
Forecaster comments from EWP blog...
Issued our second EXPERIMENTAL Severe Thunderstorm Warning for Persidio County.
Storm is showing strongest Cloud Top Cooling rates observed at 2202 UTC today around
-37C/15 min. This cell is over northern Mexico way out towards the
edge of the KMAF NexRad coverage…with 40 dBZ echo at 35 thousand feet.
We will see how this one pans out as it get closer in on the radar
coverage as it moves towards the Davis Mts. Here is the corresponding CI
imagery 15 minutes earlier at 2145 UTC…
Update… KMAF Echo Top shows storm west of the Rio Grande has increased to
54 kft at 2220z. This gave around 30 minute lead time before increase.
Update… storm over Mexico northwest of Candelaria intensified to over 64
dBZ at 2311z. The strong CTC signature gave a lead time of a little over
an hour for this intense storm.
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