HMT Event Log
Date: Nov
30-Dec. 2 2005
Note takers: Jorgensen, Showell, Van Cooten
|
Time (UTC) |
Event |
|
2104 |
Begin testing scans as precip is increasing to SW |
|
2230 |
Begin recording data as echo to SW is increasing in
intensity and precip starting to fall in the American River Basin |
|
2300 |
Light rain (RW-) started at SMART-R location |
|
2344 |
Banded precip lines from SW to NW max dbz to about 40 dbz |
|
|
|
|
0055 |
Rain increasing 207 degrees to 35 degrees at elevation of 2
degrees. RW- at site |
|
0058 |
Rain gone at 12 degrees |
|
0115 |
About same R- Elevation 3 degrees at site |
|
0116 |
Elevation 15 degrees. Nice band on scan. TRW- at site 0016
with Lightning overhead; 10 km 46-50 dbZ 251 degrees |
|
0123 |
19.5 degrees good echo N of site. 46-50 DbZ - Only heard
thunder one time End T @ 0117. Only one LTG - 4 degree good cell 360 degree
to 75 degree,\. Moving NE. RW-
End 0132 at site |
|
0142 |
Good Echo 19 degree azimuth on 10 degree elevation scan |
|
0145 |
On 3 degree scan from azimuth 319 degrees to 10 degrees at
range from 10 to 25 KM echo has 50 DbZ return. Echo at
azimuth 330 on 12.5 degree scan. No rain at site |
|
0148 |
RW- started heavier than before almost moderate rain |
|
0150 |
RW- again |
|
0200 |
19.5 degrees very little echo 18 Dbz return. 360 degree
through 180 degrees no echo at .1, .5, .9 (1.4 see tree line) 46 degree echo
line 330 degree thourgh 71 degree
at a range of 10 to 25 km. Echo gone at 10 degree scan. RW- ended. Everything weakening on
scans from .1 degree through 19.5 degree |
|
0217 |
RW -- 218
degree azimuth at 19 degree beam elevation; small 30 DbZ echo |
|
0222 |
RW- 46 DbZ
overhead at 19 degree bem elevation |
|
0227 |
Very weak echoes .1 degree through 19.1 degree beam
elevations; RW –. Weather Radio announced wind advisory for area |
|
0244 |
Every level weak RW- at site |
|
0255 |
R--- |
|
0257 |
4 degree through 8 degree beam elevation @ 220 through 310
degree azimuth. Area weak but appears to be on increase 18-25 DbZ 10 km wide |
|
0302 |
Area from 216-346 degree zimuth becoming very broad. 4 to 6
degree beam elevation with area of 20 km wide . 50-100 km out. R ended.
Leading edge of 25 km out 230-65 degree azimuths. Good echo at 19.5 degree
elevation |
|
0312 |
Some embedded 55 Dbz echoes from 300 to 320 azimuths at
range 60 km, Might be ground clutter. |
|
0315 |
At 5 degree beam elevation still 30 degree DbZ from azimuth
193 through 81 degrees. Stronger at 19.6 degree elevation almost completely
wrapping around |
|
0318 |
100 km range from azimuths 270-310 degrees echoes increasing
|
|
0330 |
- 0.9
degree beam elevation 55 Dbz echo at azimuth 271 degrees. At 1.8 degree beam
elevation embedded moderateshowers. From azimuth 220 to 360 degree at range
of 25 km out to 100 km moving East. Still good rain at 12.5 degree beam
elevtion |
|
0343 |
RW - |
|
0344 |
RW- |
|
0355 |
Area from range 0 to 25 km weaken in low beam elevations.
Still Looks good at bem elevations from 3 to 6 degrees at range 2 to 50 km |
|
0358 |
From Azimuth 199 to 269 degrees at 15 km range there is a 45
DbZ echo moving east from 246 degrees. |
|
0421 |
From Azimuth 195 to 75 degrees at range 10 km an echo of 45
Dbz from 5 degrees to 19.6 dgreee beam elevation |
|
0449 |
0.9 degree beam elevation not much to see. Embedded showers
west 40 dbZ . 1.8 degree beam elevation about the same |
|
0450 |
Area has decreased 25 km to 50 km all sectors |
|
0454 |
0.9 beam elevation most echoes gone except ground clutter to
WNW. 2 degree elevation some showers out to 25 km from azimuths 230 to 0
degrees |
|
0458 |
- Moderate Rain
Began. Good radar echo over site. 45 DbZ in beam elevations from 4 degrees to
19.5 degrees moving NE. RW Ended and RW- began |
|
|
|
|
0551 (12/1/05) |
Edited VCP12 scan to 14 tilts in 4 Min 18 Sec to Match NWS
Sites |
|
0600 (12/1/05) |
Modified VCP scan to run every 5 minutes |
|
|
|
|
0622 |
5.1 beam elevation shows echo redevelopment NW-SW |
|
0645 |
0.9 degree elevation from azimuth 214 to 315 degrees solid
area of rain with embedded 30-38 dbz echoes |
|
0650 |
Rain picking up at site to R moderate |
|
0652 |
Echo which produced R moderate at site now at azimuth 0 to
2 degrees with a 34 to 38 DbZ return on the 5.1 elevation scan. |
|
0656 |
on 1.8 to 2.4 beam elevations at 298 degree zimuth 34-38
dBz embedded in rain area. For
5.1 and 8.1 degree beam elevation for azimuths 355 to 30 degrees 54 dbz
embedded |
|
0707 |
at 4 degree beam elevation from 17 to 57 degree azimuths
54-58 Dbz returns |
|
0721 |
1.8 degree beam elevation – DbZ picking up in
selected cells. 34-38 DbZ in several cells along the 240 degree radial |
|
0744 |
34-38 dbZ just SW of origin point at 19.6 beam elevation |
|
0747 |
42-46 DbZ at 1.8 and 2.4 degree beam elevation in call at
271 degrees and range less than 5 km |
|
0749 |
Rain Picked up at site |
|
0751 |
Almost feels like squalls with very strong gusts an wind
driven rain |
|
0752 |
Moderate rain continues |
|
0755 |
Rain Diminishes |
|
0806 |
Radar echo coverage increases from azimuths 313 to 62
degrees with 2.4 through 4.8 beam elevations showing 38-42 DbZ |
|
0811 |
Beam elevation 1.8 to 5.1 have an echo at 356 degres of 50
to 54 DbZ; 1.5 to 3.1 Degrees
have an echo at 231 azimuth of 46 to 50 Dbz; Cell intensities increasing.
NOAA Weather Radio with 8Z obs indicate wind gusts increasing. |
|
0931 |
Areal coverage and ntensity from azimuth 210 to 60 degrees
increasing |
|
1026 |
Light Rain begin |
|
1036 |
Moderate Rain in squall |
|
1041 |
Radar scans showing distinct radials |
|
1042 |
Heavy rain with gusts |
|
1044 |
Moderate rain |
|
1048 |
Heavy rainfall with gusts |
|
1053 |
Rain ends |
|
1119 |
Scan shows large area of 90 to 160 with embedded echoes |
|
1212 |
Echo at 240 through 300 degree azimuth at 20 mile range
has an intense return through th 15.1 elevation scan |
|
1223 |
Same echo at 6 degree elevation angle has a return of 58
dBz |
|
1227 |
on scans from 3.2 to 12.6 from azimuth 350 to 10 degrees
and range of 2 to 10 km the echo has a 58 dBz return |
|
1227 |
Moderate rain began with strong winds |
|
1236 |
Rain ended |
|
1247 |
Strong wind gusts |
|
1253 |
Wind gust shook trailer |
|
1258 |
Moderate rain began with gusty winds |
|
1300 |
Strong gusty winds with wind driven rain |
|
1305 |
Very heavy rain with strong gusts that shook trailer |
|
1313 |
Moderate rain with strong gusty winds continuing |
|
1323 |
Very strong series of gusts ; three gusts rocked the truck very hard |
|
1330 |
Strong winds and heavy rain continue |
|
|
|
|
1530 |
Jorgensen taking over from VanCooten |
|
1525 |
Switching to FFT processing from PPP also speeded up the
antenna a bit from 19.5 to 21.1 deg/s to complete VCP within 4 min 18 sec to
better match NWS & ETL scanning |
|
1526 |
Bright band ring at 20 km at 15 deg elevation sw |
|
1527 |
Moderate rain at site |
|
1605 |
Rain has stopped at site |
|
1614 |
Sfc wind has really picked up here at the site. Probably
>30 knots or so |
|
1628 |
Light rain falling again at the site |
|
1747 |
Echoes to the west are weakening significantly |
|
1807 |
Echoes building back to the west again. Now moderate rain
here at the site. Apparently a bright band to about 45 dbz overhead. See a
ring 10 km in diameter centered on site at 14 deg elevation angle |
|
1842 |
Echo extent to the west has really increased in the last
half hour. Now nearly continuous from the site to 100 km rang |
|
1856 |
Area from SW to W from 50 km to 100 km range has huge mass
of echo approaching 50 dbz on 1 degree elev scan |
|
1933 |
Forecasters indicate 8-9 Z ending for precip tonight |
|
2056 |
Moderate rain now at the site. Very extensive stratiform
echo on the PPI out to 100 km particularly to the SW |
|
2143 |
Echoes seem to be weakening to the west. Highest
reflectivity at upper tilts now seems to be N and E of the site. West edge of
precip seems to be only ~10 km to the west |
|
2246 |
Echoes to the west intensifying again – light rain
still at site |
|
0057 |
Heavy precip at site, upper 50s dbz |
|
|
|
|
0116 |
Range 50 km with azimuth of 220 degrees; 3.1 elevation scan shows a kidney bean shaped echo. The 8.1 elevation scan shows a chain of concavely curved echoes with 42 dBz returns. The 15.6 elevation scan shows a 42-46 dBz bow shaped echo heading toward radar from 250 degrees |
|
0150 |
Raindrop size increased at site; Checked for small hail from the way it sounded on truck; could not confirm small ice pellets |
|
0151 |
Intense echo at azimuth 268 degrees and range of 100 km. 0.9 degree through 1.8 degree beam elevation scans showed 58 dBz |
|
0200 |
Intense echo from azimuth 260 to 268 degrees at range of 80 km moving from 260 degrees . 58 to 60 dBz through 1.8 scan |
|
0205 |
0.9 degree elevation scan shows intensity decreased on averge 5 dbZ. Continuing to move along the 270 degree radial. Now at 75 KM range |
|
0211 |
echo diminishing |
|
0220 |
Echo elongated from 260 to 270 degree azimuth with alignment from twooÕclock to seven oÕclock . 0.9 degree scan has dBz back up to 58-60 dBz in NE quad of echo |
|
0225 |
Dbz in echo has decreased once again on average of 5 dBz in scans below 2.4 |
|
0225 |
Heavy rain at site. Sounds like some small ice pellets |
|
0230 |
0.9 and 1.3 degree elevation scans along the 270 degree azimuth at range of 70 km show echo has increased since last scan and core of 58 dBz returns has increased n depth |
|
0235 |
DbZ has decreased once again and the areal coverage of the echo is smaller |
|
0253 |
Very heavy rain |
|
0256 |
End of very heavy rain and now moderate rain again |
|
0309 |
Very strong wind gusts on passenger side of truck; Heavy rain began and once agin sounded like some small ice pellets were hitting the truck with the rain |
|
0321 |
Possible attenuation; Heavy rain and wind gusts ongoing during this volume scan where returns from the precipitation area along the 270 degree radial dropped on the average 10 dBz |
|
0322 |
Gusts and rain diminish |
|
0335 |
Gusts Picked up ; Band of rainfall moving along the 270 degree azimuth has now evolved into embedded cells along the axis of the rainband. The 0.9 and 1.3 elevation scan show 54-58 dBz returns in three distinct cells in the azimuths from 270 to 320 degrees at a range of 47 degrees |
|
0345 |
A cell first developed on the 340 UTC scan. At 345 UTC this cell at 265 azimuth at a range of 25 km on the 1.3 and 1.8 elevation scans returned 54-58 dBz. This cell was ahead and SE of the persistent rain band with embedded cells now located at a range of 35 km and azimuths 275 to 300 |
|
0348 |
Large raindrops at site |
|
0356 |
On the .9 elevation scan at 300 degree azimuth and range 40 km a cell returned 59 dBz |
|
0455 |
Spoke with Dave Kingsmill about status of rain area and outlook. Said front was near Auburn and was beginning to climb the Sierras so precip should return to a more stratiform pattern and then post frontal begin to diminish. Thinking about closing project in the early morning hours of Friday. Dave Kingsmill will call back at 07 Z |
|
0612 |
Series of strong wind gusts |
|
|
|
|
0800 |
Midnight PST – echoes over basin dissipating and
moving out. Light echoes <25 dbz to ENE |
|
0804 |
End of data collection |
|
|
|
|
|
|
|
|
|
|
|
|