Zoomerang poll results (http://www.zoomerang.com/Shared/SharedResultsSurveyResultsPage.aspx?ID=L26GZV2Q6QZG) also include UWCI comments from forecasters:
|
Yes
|
40 |
71% |
|||||
No
|
16 |
29% |
|||||
Total |
56 |
100% |
On average, how many minutes elapsed between radar detection of a 35 dBZ echo and the UW CI/CTC rate nowcast? (please indicate which came first)
1 NA
2 UWCI product was not
available today.
3 Radar usually detected 35 dBZ echoes first,
about 5 minutes before the nowcast.
4 10-15 min., CI signal before
echo
5 In using this dataset, was looking across eastern CO and
wrn KS. Most of the area was delineated with cloud mask.
6 N/A
7
around 30 to 45 minutes between the UW flag and the echo
8 N/A
9
N/A...UW CI did not predict CI today.
10 Only CI was edges of
cirrus with no convective development.
11 No CI detetected except
for a few false alerts due to cirrus, and no convection occured...so
good fcst of null event!
12 very little if any. edge if cirrus was
flagged as ci which did not materialize.
13 For the echoes that
came up very fast, lead time was short 5-10 minutes, and echoes were
fairly obvious on satellite.
14 Only a few detections, but seemed
like about 30 min.
15 About 15 minutes from nowcast to radar
detection.
16 Did not pay enough attention today.
17 10 minutes
(estimated) lead time on the UW CI versus the 35 dBZ. This was on
real-time KTLX and KVNX data, but was intensely interrogated.
18
N/A - did not play that close attention.
19 Not sure.
20 45
minutes to one hour
21 UW CI/CTC first, 10 to 15 minutes lead
time.
22 The UW CI/CTC products preceded the onset of detectable
convection by about 15 minutes.
23 CI came about 10-20 minutes
after satellite CI detection, with much longer lead times south of
the Red River.
24 Less than 10 minutes. UW CI/CTC came first. Due
to the explosive growth, -13C/15 min to -22/15 min (for a 5 minute
interval) the initial storm convection indication would have only
provided a 5 to 10 minute lead time before >35 dBZ echoes were
indicated.
25 I don't remember!
26 Based on our assessment
during the morning portion of the day shift with convection across
the SE, the CI did not do very well today with very little if any
lead time. IN fact, in some cases negative lead times. Perhaps an
issue with the resolution of the satellite data this morning.
27
15 minutes.
28 not sure...we need to look more closely during next
session
29 Not sure about the 35 dBZ echo... as was comparing it
with first-echo... although I did notice that it had negative lead
times with first echo... but some positive lead time with development
of 35 dBZ.
30 I was not able to get this detailed with my analysis
of these products. I was mainly trying to familiarize myself with the
products, their displays, and interpreting their ouput.
31 Had no
radar echoes.
32 CTC rate (accum) product -- indication ~ 20 min
before 35 dbz return
33 Less than 30 minutes.
34 Perhaps 30
to 45 minutes from CI hit to echo.
35 30 to 45 minutes between
nowcast and 35 dbz echo.
36 They were basically simultaneous for
the one significant storm that developed. This cell progressed from
cu-congestus to severe thunderstorm in a matter of minutes.
37 In
one case north of the CWA... CI preceded the echo by around 30
minutes.
38 UW CTC product seemed to precede first (of this event)
35 dbz echo ~ 30 min.
39 generally 15 minutes or less... uncapped
and unstable airmass.
40 30 minutes from nowcast to echo.
On average, how many minutes between the first lightning flash and UW CI / CTC rate nowcast? (please indicate which came first and whether it was cloud-to-ground or total lightning data when available)
1 NA
2 UWCI product was not
available today.
3 Lightning usually occurred 45 minutes to an
hour after the CI nowcast.
4 15-30 min., total lightning data was
shown before cloud-to-ground confirmation.
5 Did not see any
lightning as of this typing.
6 N/A
7 N/A
8 N/A...UW CI did
not predict CI today.
9 ditto #18.
10 See comment above
11
none.
12 For fast developing storms it was about 30 minutes for CG
detection.
13 Did not notice. NLDN CG data was not coming in
reliably.
14 About 45-60 minutes from nowcast to total lightning
detection.
15 Did not pay enough attention today.
16 Not
Evaluated.
17 less than 20 minutes. UW CI came first.
18 Note
sure.
19 N/A
20 In general 5 to 15 minutes.
21 Unknown
22
I wasn't watching this too close. I know there was pretty good lead
time (30-45 minutes?) between CI signature and first lightning flash
for the first storm near Sayer, OK.
23 Not evaluated properly...no
comment.
24 Made notes on this one!!! It was about 45 minutes
before the first flash was detected when the first CI/CTC indicators
arrived.
25 None.
26 Not evaluated sufficiently to
provide an exact number of minutes.
27 not sure...we need to look
more closely during next session
28 Didn't take notice of the time
interval. Need a little cheat sheet of the sorts of things you want
us to look at prior to the case.
29 Same as above.
30 Also had
no lightning.
31 CTC rate (accum) product -- indication ~ 10 min
before 35 dbz return
32 Around an hour.
33 Probably 30 to 45
minutes to first CG (no LMA data available in domain today).
34
Roughly 30 to 45 minutes between nowcast and first CG (no LMA
available)
35 About an hour until the first CG.
36 Don't know.
37 not noted
38 Didn't catch lightning interval. Sat down and
started with warning shortly there after.
39 30 to 45 minutes from
nowcast to first CG (was beyond LMA range).
Please list some of the strengths and weaknesses of the UW CI / CTC rate nowcast performance on this day.
1 NA
2 UWCI product was not
available today.
3 CI was very good at pinpointing areas of
convective initiation and convection that would eventually produce
lightning, but was a little slow at detecting the initial 35 dBZ
echoes.
4 Noticed that there were times when CI was fairly
sporadic (scan-to-scan) and hard to use due to rapid growth of
convection. The CTC was helpful in development of convection south of
OKC when main activity had been seen well north of OKC.
5 In this
situation, the masking did limit the number of false alarms.
6 UI
CTC did not do well at all forecasting convective initiation in the
Mid Atlantic. The presence of cirrus per ice mask mostly prevented
this.
7 The product did a good job at pegging areas to watch for
precip development. The weakness is that you can't look at the exact
area it highlights and expect to see rain from that particular cloud.
It is more of an attention grabber to watch a particular
area/region.
8 It successfully did NOT detect convective
initiation, as it did not occur. So that in and of itself is a
success. Cirrus contamination did occur, which I would hope would be
an area of focus to improve the algorithm in these circumstances.
Maybe use multi-sensors.
9 Cirrus obscured potential convective
development areas...a known issue.
10 Seem to indicate CI on edges
of cirrus or where cirrus was thin and moved over areas of cumulus.
The ice cloud mask did keep the CI algorithm from trying to detect
much over Oklahoma.
11 Accurately indicated no convection was
initiating on dryline.
12 cloud masking was again somewhat of a
problem. UW data did have problems with detecting ci along dryline
all afternoon.
13 Anvils covered our domain after very quick storm
initiation, so alot of the additional CI was in the ice cloud mask.
It did detect the CI correctly though when it wasn't covered, it was
just a short window. The overshooting top product did work well too,
it was just at this point in time I was so engrossed in radar
analysis, it didn't change my observation of the OT on satellite.
14
Did well with initial convection, then very poorly as expected once
anvil cirrus developed. Would have liked to see it perform better
when very thin cirrus is overhead.
15 Did not pay enough attention
today.
16 Not enough evaluation time on the UW CI or CTC rate
nowcast to determine any weakness or strengths. Familiarization of
product suite was primary focus.
17 Ability to let one know cells
that one need to pay attention to in the very near short term.
18
Did have a lower FAR than U AL Huntsville CI product.
19 It is
conservative, but in general it seems to have a low FAR and good POD.
HOwever, it is challenged in this rapidly developing storm
environment. This application definitely has potential particularly
with very high res satellite data. The UAH CI in contrast had a very
high POD but also very high FAR.
20 Did a good job overall, no
complaints.
21 Didn't provide too much lead time with explosive CI
early on. Did better later on.
22 Explosive rate of convective
development limited potential for extensive lead time for this
product. Ran into some CI detections along differential boundaries on
dryline south of I40. Also there appeared to be a false detection
along the northern end of a dust blown debris behind dryline and
capped cumulus elements along and behind the dryline convection.
23
The algorithm wasn't consistent; in some areas it did very well with
predicting initiation while in others it didn't predict anything at
all and then storms developed.
24 Overall performance was of
little utility.
25 Very little CTC to evaluate its positive value
for forecast/warning forecast operations in this particular event.
26
Too early to tell yet at least concerning the 35 dBZ echo.
27 I
have limited experience using this product operationally. My initial
impression is that the output from the CI products often lags
operator-identified convective initiation as interpreted from radar
data. However, this may be a reflection of the type of convective
environment that was in place (strongly unstable, generally
uncapped/unsheared environment- suggesting "explosive"
development).
28 The CI was very conservative in identifying
potential convective elements (maybe had only a couple all day)...
and this turned out to be a positive factor given the lack of
convection. It did well with the 'null' case.
29 CTC rate (accum)
product was only product that was non-null during this convectively
limited event
30 The CI product had a 0 FAR, but a relatively low
POD (probably around 0.50). Although I call this a weakenss, it does
provide some value, as it indicates that "triggering" of
the CI product essentially guarantees convective development.
31
Predictions proved reliable with few false alarms.
32 Very useful
tool, although a slight cool bias was noted.
33 Once again, the
CI FAR was very low. The algorithm appears to be properly
discriminating in identifying the most significant updrafts. Again,
the CI "triggered" for the most signficant storm very
shortly before 50 dBz developed in radar data. This was probably a
consequence of the environment.
34 Did identify some areas that
eventually convected.
35 UW CTC accum product was useful for
highlighting the initial convective cell
36 With convection
already ongoing... don't remember there being that many
identifications.
37 Tended to be cold as it missed a couple of
storms, but when it did nowcast development confidence was high that
one would develop.
Based on your cumulative experience, how would you envision using a satellite-based convection initiation nowcast product (note: includes both UWCI and UAH SatCast) within day-to-day operations?
1 It seems overall it would improve
some situational awareness to some degree. I believe these will be
the most useful at night and in weakly sheared environments where
multiple growing/decaying towers exist and these parameters (cooling
tops) would give a better conceptual model of what is evolving.
2
Satellite-based CI nowcast products might provide a good "reality
check" and improved SA.
3 I would use such a product to try
to hone in on those cells that are more important to track.
4 With
the case today, I struggle to see the usefulness of the CI products
in the day-to-day opperations, mainly because the FAR looks to be
VERY high. Again, I'm anxious to see if there is more usefulness in a
day that is more cut and dry...but at that point does it still have
more usefulness than the satelite data itself does? I'm not sure. I
do think it is a great concept though, it would be nice to utilize
for summer air-mass thunderstorms to help identify which cumulus
cloud will spark a storm.
5 I would keep it running in the
background, overlaid on a visible satellite loop.
6 I forsee using
CI nowcast products in day to day operations as a situational
awareness tool. Or possibly in an environment where isolated cells
are common in weak flow/summer environments.
7 As a situational
awarness product to help identify locations where convection may
first initiate
8 Using it as a temporal tool, seeing with time
areas of enhanced cu fields, and looking for trends or regions to
hone in on.
9 Weakly sheared environments and initial CI with
focusing on a spatial and temporal scale, but not a yes-no
decision.
10 Useful for gaining/maintaining SA.
11 As a
situational awareness tool to watch for developing convection.
12
I probably would only use it on days that are relatively clear prior
to CI. However, the example today increased my confidence in the
algorithm in those situations.
13 I would envision using the CI
data as a situational awareness data set. Especially on the first
initiations of the day. Where is the area to watch. This could be
especially useful in an environment when there is a lot of cu
developing, but it is not certain where the first storm will develop.
Taking the individual cells out of the mix and looking at it as a
group of objects, and then assessing what is the trend in the data.
Is this area having more red hits than another. If so this is an area
that is a place I want to watch, despite whether each cell that is
tracked is red or blue or what. Looking at the trends of the region.
I see this being very useful in the day-to-day operations.
14
Oftentimes in the Northeast, I find that I can anticipate areas of CI
as weall as the automated products by watching cloud buildups on vis
satellite imagery. Would use the CI product to maintain SA if radar
is already active. However, I think the nearcasting model could prove
very useful when storms are developing under a cirrus shield, but did
not use it in today's training.
15 Situational awareness of
expected convective development. Issuance of NOWcasts and Mesoscale
AFDs indicating the CAP is weakening or has been eroded, and then
compare with short term models to see how well they are initializing
or simulating the event.
16 This could be used for operational
staffing "spin-up" prior to warning operations. Could also
be used in short-term forecast discussions and graphicasts to
indicate most likely areas for convective initiation.
17 Would be
great to use when preparing/monitoring for initiation and help with
timing of warning operations.
18 I think would really need to be
situation nearly cloud-free to begin with and fairly strongly forced
(by frontal boundaries or terrain). Need to evaluate more.
19
Would probably use it earlier in the day before initial storms have
developed, and not so much in areas stabilized by earlier convection
and/or where large scale lift is not as focused.
20 I think it is
great leading up to convective initiation, or when storms are more
isolated, like in a previous DRT simulation. You can then issue NOWs
for the onset of storms in your CWA. I am eager to pay more attention
tomorrow when storms have not already begun.
21 I believe the UAH
product can be used in an operational environment to help draw
attention to areas to watch for storm development. But the product
flags once and then doesn't flag that area again...which makes it too
noisy. A probalistic forecast would likely enhance the use of this
product.
22 As a SA tool to focus my attention. It gets noisy in
active storm situations.
23 Would use it in the future for
anticipating initial development of convection. Not sure how well it
would perform in subsequent rounds of convection where atmosphere may
have already been overturned by earlier convection.
24 When
anticipating convection, it is a good tool to use when organizing and
planning convective operations.
25 Still not sure yet, since do
far this week has had mixed success and plenty of false triggers.
Certianly don;t think I would use it on it's onw, and really need to
overaly with satellige imagery (VIS mainly).
26 monitoring ci can
help with situational awareness and used for highlighting possible
development in nowcasts and graphicasts.
27 I will admit I like CI
products when nothing is going on yet, and would be useful at drawing
our attention to slower developing convective development. As soon as
storms begin to fire, I found myself quickly switching to radar
analysis, MRMS and 3dvar monitioring. Satellite CI products combined
with ensemble CI products would be useful.
28 Not sure how much in
it's current state it would help identify specific locations on
impending CI that one would not already notice with higih res VIS
imagery, but would like more time to evaluate in more widespread
airmass convection and with terrain.
29 Its performance is
uneven...some days does very well and others not. Would still use it
before initial CI as a situational awareness safety net.
30 Could
use it to determine when to bring up the Skywarn network, when to
shift operations to a "severe mode", and as an SA tool
during an event to anticipate where new convection will form.
31 I
would immediately utilize the CI Nowcast product to make decisions on
1) prioritizing short-term convective focus for radar/warning
operations, 2) issuance/updating of mesoscale discussions, and 3)
updates to short term public products for different sectors of the
public (fire weather, aviation, hydrology, etc).
32 N/A - like
more time into the week before providing this feedback.
33
Pre-convective environment.
34 I would use it when/if it becomes
available.
35 visualisation overlaid to sat is useful
36
Helping one focus on main areas that need immediate attention. It
certainly helped us today stay ahead of the development.
37 I
would use it as an SA tool before CI and during the event. I could
see these products being used by the mesoanalyst.
38 Perhaps an
algorithm that trips an alarm at a warning forecaster's workstation
when CI is first detected in/near a CWA...it's time to begin warning
operations mode!
39 Even in explosive convective environments,
there is still is a least a short lead time and the nowcasts can
provide focus for the forecasters to identify potential storms for
further interrogation.
40 I would use it before storm initiation
to help in situational awareness for where storms may or may not
develop. It would also help out in early prediction of where to focus
41 Reserve it's use to relatively "clean atmosphere"
events without much cumulus/stratocumulus or anvil clouds around.
42
I envision a product like this increasing in utility when very high
resolution (both in space and time) satellite data is made available
to WFOs. The main utility would be in helping with the very short
term forecasts by helping forecasters focus on areas mostly to be of
immediate concern.
43 Would use it for short term forecast (1-2
hour) convective initiation forecasts and nowcasts.
44 (with
limited experience with these products)...would expect increased
forecast confidence with regard to locations of convective
initiation
45 Perhaps to help get a timing on the initiation of
convection... especially when have a pretty good cap.
46 I think
it could be a valuable now/near-casting tool in certain environments,
especially those in which the atmosphere is capped and there is
uncertainty as to whether CIN can be removed/ overcome.
47 For
short-term public forecasts, aviation forecasts at TAF sites and at
cornerposts for arrivals into DFW. Also for transitioning into
warning operations.
48 Having experienced a null case event...
would lean towards the Cimms due to a smaller 'false alarm' rate...
but curious to see how each performs in a more active situation. In
operations, would likely monitor output until storms got going.
49
I envision using a combination of these products to assist temporal
and spatial forecasts of CI.
50 See response in 23.
51 I would
use the satellite-based CI tools in concert with numerical model
output to refine timing in aviation, public, and fire weather
forecasts.
52 For updates to public and aviation forecasts,
tactical decisions for airport ground operations, and for WFO
decisions on transitioning into warning operations.
53 The UAH-CI
is too liberal, the UW-CI a little too conservative in identifying
CI. Being aware of these limitations, using the two in conjunction
can be useful to convective analysis and forecasting.
54 Useful
monitoring tool prior to convection... and even after radar
operations begin... provided there is someone available to look at
it.
55 would use this...together with other satelltie CI products
56 expect I would use all available CI products...in the context
of their individual strengths/weaknesses
57 monitoring cu fields
to determine which clumps may be more significant. With its
relatively low false alarm rate... expect several of the hits to
verify.
58 Sat-based nowcasts have a definite role in assisting
forecasters in anticipating development. I suspected this prior to
coming to EWP, but I leave convinced of this fact.
Comments on UWCI from the HWT blog: (http://goesrhwt.blogspot.com/2011/06/ewp-end-of-week-debrief-10-june.html)
Convective Initiation
-
(Thursday event - N.E.) Cloud-top cooling products seemed to work in
diagnosing the strength of storms on the southwest edge of the line
that were newly developing.
- Even though CI didn't always
occur... false hits were useful in identifying clouds trying to break
the cap.
- Forecasters not interested in seeing a binary
yes/no output.
- "There were instances where similar
looking clumps of Cu that one would flag for CI but the other
wouldn't... so I wasn't sure how to interpret that other than maybe
this area was more conducive to further development."
-
There are lots of products that provide you lead time on CI, the real
question would be on the consistency of the output.
- "I
would definitely look at this in my WFO... especially the
cooling-tops product gave me a lot of information on the relative
strengths of the storms."
- "If both groups could
work together and come up with a probabilistic product that combined
the strengths of the UAH and the UWCI products, that would be very
useful."
- "I think from a purely public forecast
perspective, especially this time of year where we get convection
every day, it would help you identify when exactly CI will occur."
-
Would be very valuable for nocturnal CI.
Comments on UWCI from HWT Blog: (http://goesrhwt.blogspot.com/2011/06/daily-debrief-9-june.html)
Convective Initiation
-
UWCI triggered CI occurring right as the appearance of a 50 dBZ echo
on radar... it was so unstable that it didn't really have much of a
chance.
- "I liked the cooling cloud tops product... gave
you some awareness of what storms you should pay attention to during
warning ops and which ones were strongest."
- "I
found it useful this week and look forward to that era when we can
get those increased temporal refresh rates. This would be very
useful."
- In a more dynamic situation this could be very
useful.
We asked the forecasters if they had a preference
to see more or less signal (more vs less FAR)...
- "I
like looking at them both side by side... you can come up with a poor
man's ensemble for CI because we know the limitations of both."
-
"There may actually be a benefit of some false hits because it
may be telling you that the cap is strong... it can give you a sense
of what's going to happen in the short-term."
Comments on UWCI from HWT blog: (http://goesrhwt.blogspot.com/2011/05/end-of-week-debrief-27-may.html)
Convective Initiation
-
(26 May event) CI did not so well over AL/TN... high FAR, low POD in
morning... Forecaster theorized this may have something to do with
the less dramatic temperature differences between the surface and
clouds during the morning hours.
- CI did much better during
rapid scan.
- The UAH version was much more agressive that the
UW version.
- Having a probabilistic approach versus a yes/no
would help.
- Forecaster used the UW CTC/CI product to issue a
severe weather statement... ended up putting a warning on it
afterwards.
- This could be important for not just severe
weather... the CI products could be very useful for the onset of
lightning as sort of a proxy for the growth of a certain dBZ
threshold above say a -10 C level if it had faster updates.
-
"I'm assuming that performance should improve pretty
dramatically once you get the rapid updates with the next-generation
satellites, but now I guess it would work best in a clean environment
in the plains. I could also see the probabilities a good way to
go."
- Maybe contouring SATCAST probabilities would be a
good.
- "Based on what it's designed to do, I can see
this working in a typical summer afternoon in Florida, not just over
the plains."
- Could help identify waterspout candidates
because they're harder to see on radar.
- For non-severe
faster moving systems it may be useful in detecting regions of heavy
rain.
- Would be a good idea to get west coast offices to look
at these things since they rely heavily on satellite data because of
a lack of surface observations.
More comments from HWT Blog: (http://goesrhwt.blogspot.com/2011/05/ewp-forecaster-debrief-26-may.html)
Convective Initiation
-
We were seeing 10-15 minute lead times from the UAH CI product along
the dryline prior to any echoes above 35 dBZ on radar. The UWCI was
much more conservative and missed a few instances of CI, but it had
less false alarms and similar lead times when it did trigger for
CI.
- UAH CI did show some signals after initiation behind the
dryline, but nothing really continued to grow. However, forecaster
mentioned how this would be very useful in warning operations to help
increase situational awareness for future development when you may be
focusing primarily on the first storms.
- Forecaster mentioned
how he was watching the UAH CI this morning over the SE and it was
giving negative lead times and UWCI was not flagging anything at all.
However, he did want to emphasize that on Tuesday GOES-E was in
rapid-scan operations and was not this morning, so that could be why
the lead times were so poor.
More from HWT: (http://goesrhwt.blogspot.com/2011/05/convective-initiation-along-sw-ok.html)
Forecaster comments reposted from
EWP blog...
Convective inititation occured along the
southwest OK dryline. According to UAHCI and CIMMS CI products, had
about 10-15 minute lead time for storm near Altus. 30 minute lead
time from UAHCI and 20 mintue lead time from CIMMS CI for storm near
Sayer.
Horizontal convective rolls east of sw OK dryline
suggest storms may form in the warm sector too…maybe!
Pablo,
Rudoph, and Bobby
More: (http://goesrhwt.blogspot.com/2011/05/ewp-end-of-week-debrief-20-may.html)
Convective Initiation
-
The CIMSS product had pretty good lead time before we actually
started seeing lightning of about 45 minutes to 1 hour, only about 15
minute lead time over 35 dBZ echo.
- Later in the events
everything became cloud masked.
- Mostly masked with the CIMSS
stuff, but UAH was not and we were expecting CI behind the initial
line, but nothing went and there were no CI nowcasts made, so that
was very good that we weren't getting false alarms.
- There
were times when they would have 30 minute lead-times on radar echos,
and other times there were no lead-times during the same event.
-
I would like to spend some time looking at those products in more my
type of environments, like weak shear.
- A probabilistic
approach might be more useful than a simple yes/no output. I like the
idea of having pre-CI through CI ongoing information.
- "I
tended to look at the UAH one more because it was giving me more
detections."
- "I found having the masking overlaid
was very important... there were times where the CIMSS wasn't showing
something but the UAH was and it helped me get an idea of why."
More (http://goesrhwt.blogspot.com/2011/05/oklahoma-ci-18-may-2011.html)
Forecaster comments reposted from
EWP blog...
"2330Z Update: UAH CI indicating possible
development across Garvin and McClain counties. There does appear to
be an HCR in this location but we believe that the edge of thin
cirrus clouds are causing algorithm to detect cloud cooling that is
not real. Looks like we are going to move operational area to eastern
Colorado where there is a lone supercell. kbrown
2230Z Update:
Got a hit off of the UAH CI over southern Comanche county where there
are weak echoes aloft (15-20dbz). These echoes are associated with a
wildfire plume, however.
2140Z: Brief UAH CI detected across
north-central Oklahoma in cloud streets (1832Z), but no subsequent
echoes were detected.
Although there has been several hours of
cu/tcu formation near and east of dryline, CI algorithms have not
detected CI across OUN domain. From 20Z to 2115Z this is actually a
good thing since no echoes have developed (good case of low false
alarm). Before the CIMSS CI became contaminated with Ice Cloud Mask,
there were a few hits for CI on leading edge of incoming cirrus
across northwest Oklahoma between 19Z to 20Z. No echoes were
subsequently detected.
Isolated CI hits from the UAH algorithm
did accurately depict some elevated echoes over the OK/AR border but
no lightning occurred. Leadtime for echoes was 15 to 30 minutes."
More (http://goesrhwt.blogspot.com/2011/05/potentially-missed-ci-target-but-with.html)
As we have seen over the past couple
years during the Spring Experiment, the bane of the satellite
community's existence has struck again. It's 2100 UTC and that means
we have another 30 minute gap in satellite data right during
initiation period... so any updates in the imagery and the CI
products will have to wait until after 2115 UTC, and our last image
was at 2045 UTC. During that period the cirrus is likely to move over
the area, inhibiting any of the CI products from detecting the clouds
underneath... We will continue to monitor the area, however it seems
like we may have just missed our target.
However, there is a
silver lining to this event. Forecasters have been watching the CI
products constantly over the past couple hours and have noticed no
false alarms over the area of developing cu field for either of the
CI products. There were a few false alarms with the cirrus
overrunning the surface causing false cooling with the UWCI, as well
as a couple false alarms with some of the stratus area in eastern CO
with the SATCAST (UAH CI) product. The forecasters mentioned that the
fact that these CI products were showing no signals over the cu field
of interest provided them with increased confidence that CI was NOT
occurring. Increased confidence is a good thing, whether it leads to
exciting weather or not.
More (http://goesrhwt.blogspot.com/2011/05/ci-over-va.html)
Widespread cumulus fields forming across central eastern VA and UAHCI products capturing this much better than CIMSS in this case, which is a very moist, weakly unstable, but uncapped environment (almost tropical). While most new CI IDs are very scattered to isold in nature, now beginning to see some banding or clustering, which actually matches very well with at least one 4km WRF (12Z run for SPC…see second image above), and will be watching to see if the IDing of this banding of CI zones within otherwise wideapread cu field helps to identify where stronger storms could soon be forming in this kind of environment.
More: (http://goesrhwt.blogspot.com/2011/05/friday-13-may-debrief-finally.html)
UWCI / OTTC
- Was not coming
in correctly all week, so was not demonstrated within AWIPS.
-
Forecasters were not comfortable offering further comments based
solely on informal demonstrations with visiting PI since they were
not able to use the products within AWIPS.
More: (http://goesrhwt.blogspot.com/2010/06/ewp-weekly-debrief_18.html)
UWCI
I asked about the lead
times from the surveys... 15-30 mins the general consensus?
"Hard
to be sure because we were arriving at the HWT after convection was
developing."
"Getting in there around noon would get
more accurate results."
"The case event was already
initiated when I got there."
"Struggling giving
up screen space during severe weather" (from survey)... is there
a display you think would help?
"Having an additional
head would help. We were only provided with two screens so it changed
our strategy."
"Would be useful for the mesoanalyst
position at the WFO."
"4-panel devoted to those products
works well."
I asked the forecasters if they were ok with
more signals if that meant giving up some FAR...
"I would
like earlier signals, like a probability signal... which part of my
CWA is going to have the best chance... Some kind of signal before
there's aggitated clouds would be helpful."
I asked the
forecasters whether they preferred the CI or the cloud-top
cooling...
"I used them both... kind of liked them both
simultaneously."
"It was hard because it seemed it was
50/50 on detecting things so I lost a lot of confidence in using the
product, but I did like the cloud-top cooling a little better because
it seemed to do better."
I asked the forecasters if they
preferred the accumulated of instantaneous fields...
"I stuck
with the instantaneous for the most part, I don't think I even looked
at the accumulated to be honest."
"I tended to look at
the instantaneous."
Would you see a benefit in having
a cloud-top cooling track?
"Yes... an overshooting top
track would be very useful as well."
More: (http://goesrhwt.blogspot.com/2010/06/ewp-real-time-iop-ci-feedback.html)
We noticed an area of obvious convective development that was not detected by the UWCI product on the WV/VA border at 1915 UTC and the forecaster asked me to explain why no CI nowcast was made. Looking at the IR, you could see significant cooling occurring from 1832 and 1915 UTC (see above), but still no signals were seen. Jordan Gerth and I looked at the cloud typing output to see if we could draw any conclusions from that to determine what was going on (see below). Most of the area was covered by cloud types identified as 'water' or 'mixed phase'. However, there were a few spots of 'cirrus' classification over WV nearby where the CI nowcast should have been made. It seemed on visible and IR satellite that this may not have been the case, but this is hard to determine for sure. Jordan suggested that because there were these spots nearby that they may have been contaminating the spatial tests required by the algorithm to flag an area as filtered cloud-top cooling, and thus not allow for a CI nowcast to be made. This may be a fluke case where nothing can be done, but it may be useful to examine this in more detail to see if something can be improved.
More : (http://goesrhwt.blogspot.com/2010/06/ewp-weekly-debrief.html)
UWCI
This week was
plagued by cirrus... can't remove it so we need to communicate well
the limitations of the product. Forecasters were mentioning that they
were constantly referring to the cloud type web page and suggested
providing this into AWIPS. Will severely limit the applicability.
"If it's a good day to use it, the forecasters will use
it... Most useful prior to development... right now things have to
start developing before we issue products, this gives us some
additional lead time."
Forecasters mentioned that the
product would be useful in nighttime operations... possibly get more
lead time... At night, stuff fires so quickly... perhaps providing a
CI alarm in AWIPS would help situational awareness. Forecasters
suggested providing a nighttime WES case for training. Lee is going
to distribute web site and explain how to use it so they can look at
it anytime.
Expressed interest in CI accumulated to follow CI
signals through time in case they missed a scan.
Limitations
in sensor scan time noted.
Forecasters mentioned the interest
in providing more signals. they saw a lot of cases where CI was
obvious but was not captured by the product. I asked if they were ok
with the idea to sacrifice FAR for more detections...
"More
times I expected to see something and didn't happened more often than
not... not useful if things aren't showing where I expected to see
it."
"Could you build different thresholds? Could you
build one that was not so strict?"
"What about
probabilistic detection? Then you can set your own
threshold."
"Concerned about FAR getting too high
because then it'll stop getting used."
There was a
request for using additional bands... "You guys know the best
bands to use... If you can get more information from other bands, go
for it"
I asked if they saw the UWCI product being a
precursor to lightning...
"Did not specifically check."
"I
was more correlating the 35-40 dBZ"
During an event with
a strong cap, the UWCI/CTC showed signals but no development occurred
(or continued to occur)... perhaps provide a case of this in
training.
From yesterday's IOP over Boulder, CO area... cell
showed CI at 22:30 UTC... at 22:58 UTC a 30-40 dBZ occurred...
showing 28 min lead time. Similar results were seen throughout the
week.
A forecaster asked is testing on simulated satellite
imagery planned? Yes, but currently the computation time is expensive
so 5 min data would be rough.
Forecaster requested that it
would be nice if the UWCI automatically loaded with satellite imagery
in AWIPS.
More: (http://goesrhwt.blogspot.com/2010/05/ewp-week-2-debrief.html)
UWCI and Cloud-top Cooling
-
Forecasters wondering how well it will work in the Northeast... so
often cirrus is in the area... Saw very few signals for yesterdays
case.
- A little ahead of total lightning with yesterday's case...
not like case event when it occurred at same time
- Cloud-top
cooling more valuable for situational awareness than CI
- "Wonder
if this type of product would be useful in something like guardian or
alert type software, because not all people will be looking at it all
the time."
- "Would be neat to look at if it saved all
the locations where CI was occurring... would like to have the 60-min
accumulated.. make it more like the hail tracks" (mentioned this
was available)
- "I was watching a storm over Amarillo with
60+ dBZ after CI and there was no CG... I was waiting for lightning
to happen because that's what we were told the research used to
verify it... You can't use CG as a discriminator... you need total
lightning."
More :(http://goesrhwt.blogspot.com/2010/05/ewp-daily-briefing-debrief.html)
UWCI and CTC
CI vs
CTC... bias towards one?... Liked CTC better... picked up about
15 minutes before radar and better discriminated areas of interest...
showed more signal than CI.
Are you ok with more false
alarms?... "As long as forecasters are trained, false alarms
are not a problem. Even with CI itself... make it less stringent. I
can tell if cirrus is over top of it. I know why you're doing it, but
maybe you don't have to go as far."
"Is the anyway
to have the CI continue to track a vertically developing cloud to see
if the development continues?" (This is under development within
WDSSII)
Forecaster mentioned that he used the UW-CIMSS CI
phone application this morning... He had good impressions and would
like to see that sort of display in AWIPS (similar to the "OVERALL"
discussion)
More: (http://goesrhwt.blogspot.com/2010/05/may-21-ewp-friday-debrief-overview.html)
REGARDING UWCI AND CTC
-
In marginal cases when we're not sure whether storms will go it may
be more useful
- Nighttime when no visible is around it is
definitely more useful
- In winter nighttime snow events, low top
convection close to radar not detected... cooling tops earlier might
give clue of snow showers occurring... also upslope snow showers,
where mountains inhibit radar reflectivities would be a good thing to
see
- Didn't have enough time with the products to determine if CI
or CTC more useful
- Was slower than radar constantly
- They
realize that the products are meant for better temporal and spatial
resolutions, but hard to see it's use when not available
- Just
because cloud top is cooling, it may not be the dominant storm... may
not be n the favorable location or on right side of boundary... using
any algorithm without paying any attention to the environment is not
proper use of the data in forecasting operations... need to combine
and/or base the products on environmental information
- The
cases this week were slam dunk, so CI was pretty sure to happen...
not so useful then
- During May 19 case over OUN... initially
watched for CI on southern storms... once one went, they monitored
radar... may be useful in detecting first storm of the day
- "Not
a lot of meteorologists are gonna have confidence on just one case...
need to see more than that"
More: (http://goesrhwt.blogspot.com/2010/05/ewp-daily-briefing-5202010.html)
In the case of multiple towers
with equal weak reflectivities on radar, would CI detection over one
and not the other add value to your forecast?
"It's
plausible. If that's the way it play out. It would be hard to
objective analyze that all the time."
"It does have
utility in determining which storm will be the dominant
storm."
"Depends on the environment."
When visible satellite is not
available, is it (CI detections) even more useful? (this was
simulated in yesterday's IOP for one forecaster)
"Yes,
absolutely" (also agreed by the other forecasters in theory)
Feedback that is embedded within the report:
Hazardous Weather Testbed – Final Evaluation
In general, forecasters found that the UWCI products are a useful tool to help them increase situational awareness prior to warning operations during severe weather days. One particular comment from the online survey echoed the UWCI potential:
“Areal descriptions of convective initiation described by UWCI could be added to short term forecasts, or even significant weather advisories/warnings if quick development is expected.”
Forecasters also noticed lead-times on their subjective interpretation of convective initiation based on signals from radar generally of about 5 to 30 minutes. There were occasions where the UWCI had negative lead-times, but this was usually due to cirrus contamination, satellite scan time limitations or varied definitions of “convective initiation” by the forecasters. When comparing UWCI to the first occurrence of CG lightning detected by the NLDN, forecasters found that UWCI lead times extended, often to 60 minutes. However, there were occasions where convection would develop and radar reflectivities would reach in excess of 55 dBZ, but no CG lightning would be detected, so determining a lead time was difficult and forecasters became confused on how they were supposed to evaluate the product. . . . .
There were several instances where UWCI showed no signals where convective development occurred, or showed signals where no convective development occurred over cirrus-free areas. One comment captured from the online survey may help explain the situations where this occurred most often:
“In this situation, there was a fairly strong CAP. Because of that, there were several instances when the UWCI product indicated CI, yet no storm developed. Or, perhaps a small storm would develop but it would quickly dissipate due to the CAP. There were also several times in which the UWCI product did not indicate CI, yet it did develop. This appeared to be in areas that were not covered by cirrus.”
Forecasters mentioned that “it was also nice to see the actual values of cloud top cooling” since it provides them with a more physical interpretation of what is going on with the developing convection. Also, forecasters mentioned that the cooling rate product provided more signal than the more stringent convective initiation nowcast, which, as mentioned above, missed some instances of initiation due to various reasons. The forecasters requested that a cloud-top cooling rate track be provided. Similar to those produced by NSSL within the Warning Decision Support System – Integrated Information (WDSS-II) to produce rotation and hail tracks, cooling rate tracks would be very useful in determining cloud-top trends. This would allow forecasters to determine whether the convective storm growth is weakening, strengthening or remaining constant over 30 to 60 minute periods.