HMT-West 2008: Project Status

Active field operations for HMT-West 2008 have ended and daily conference calls will be discontinued. Unattended sensors will continue to operate, although if they malfunction, they will not be repaired. The plan at present is to remove much of the remaining ESRL instrumentation during April and May. However, some surface sites, particularly those with soil moisture sensors, and the Truckee profiler, will remain in place long term.

Many thanks to the forecasters, engineers, instrument operators and coordinators, chief scientists, program managers and other key individuals that made HMT-West 2008 a success.

Dave Kingsmill

Posted by Status Editor at 7:02 PM | Permalink

Except for a few scattered clouds near the Sierra crest, clear skies dominate the American River Basin today. The forecast indicates that a couple of precipitation systems may brush by extreme northern California during the upcoming week, but it is very unlikely that anything more than a few tenths of an inch of precipitation will fall within our domain. Moreover, the precipitation that falls will likely be associated with snow levels at or below 5000 feet (i.e., likely snow at our Blue Canyon radar site). We do not anticipate IOP operations this week.

On Monday (17 March), if the forecast continues to indicate low to zero probability of an IOP-worthy precipitation event within our domain for next week (i.e., week of 17 March), we will terminate HMT-West 2008 project operations for the season. Under this scenario, Monday 17 March would be our last daily teleconference of the season.

No instrument status issues to report at this time

Kingsmill

Posted by Status Editor at 6:23 PM | Permalink

Cold and showery conditions persist across the American River Basin today. Over the last 24 h, about 0.8 inches of liquid equivalent has fallen at Blue Canyon , with about seven inches of new snow. Skies should start clearing out later today, with sunny conditions prevailing over the next few days. The forecast for the precipitation event we have been following for the Tuesday-Wednesday time period indicates that precipitation will likely get no further south than extreme northern California. Another quick-moving system may get farther south and impact our domain in the Thursday-Friday time period, but it looks fairly cold (i.e., snow level below 5000 feet) and would likely not drop a lot of precipitation given its progressive nature. IOP operations are not anticipated in the next 5 days.

On Monday (17 March), if the forecast continues to indicate low to zero probability of an IOP-worthy precipitation event within our domain for next week (i.e., week of 17 March), we will terminate HMT-West 2008 project operations for the season. Under this scenario, Monday 17 March would be our last daily teleconference of the season.

No instrument status issues to report at this time

Kingsmill

Posted by Status Editor at 7:34 PM | Permalink

Conditions are still showery over the American River Basin today, but temperatures have cooled, with snow levels likely around 3000-4000 ft. This pattern is forecast to persist over the next 24-36 hours, with temperatures cooling a bit more. Thereafter, a dry pattern is forecast to be in place into the early part of next week. Our next (and probably last) opportunity for an IOP-worthy precipitation event is probably in the Tuesday to Thursday period of next week (18-20 March). At this point, model guidance indicates that this event will produce no more than minor amounts of precipitation within our domain. However, there is a reasonably well-defined (yet modest) moisture plume associated with this system and snow levels would possibly be above Blue Canyon. Therefore, this system warrants our attention, at least for a few more forecast cycles.

On Monday (17 March), if the forecast continues to indicate low to zero probability of an IOP-worthy precipitation event within our domain for next week (i.e., week of 17 March), we will terminate HMT-West 2008 project operations for the season. Under this scenario, Monday 17 March would be our last daily teleconference of the season.

Instrument status:

Data from the Big Bend (BBD) field site is not being telemetered to Boulder. The problem is likely related to a faulty modem that will not be repaired until at least the week of 24 March. Even with this problem, it is believed that instruments are operating normally and data is being archived on-site.

Kingsmill

Posted by Status Editor at 7:40 PM | Permalink

Cool and showery conditions exist over the American River Basin today. Since about midnight local time, 0.5 to 1 inches of rain has fallen in the ARB, with snow levels around 6000-7000 feet. Colder air is forecast to filter in later this afternoon into tonight, which should lower the snow levels to around 4000-5000 feet. After the current system exits, a much colder system starts impacting our domain Friday night. Precipitation amounts from this cold-core system should be smaller than the present system and snow levels much lower, probably around 3000 feet. IOP operations will not be initiated for this event. After the weekend, the next opportunity for precipitation in our domain appears to be toward the middle part of next week. More on this in the next few days.

No instrument status issues to report at this time

Kingsmill

Posted by Status Editor at 7:19 PM | Permalink

The dry conditions that have been in place over the American River Basin over the last several days are forecast to end tonight, with rain and snow showers likely to occur overnight and into Thursday. Precipitation accumulations are expected to be in the 0.5 to 1 inch range, with snow levels starting out around 6000 feet and lowering to around 4000-5000 feet. Given the limited precipitation amounts and likelihood of snow occurring at the Blue Canyon radar site, an IOP for this event will not be initiated. Looking toward the weekend, another round of precipitation is forecast to occur. Amounts will again be on the small side and snow levels will be quite low, probably around 3000 feet. It is not anticipated that IOP operations will be initiated for this activity.

Miscellaneous:

• The operations summary for IOP7 has been posted to the Operations Summary blog

Instrument status:

• The communication problem with the Alta field site has been repaired and data will soon be displayed again on the web.

Kingsmill

Posted by Status Editor at 7:09 PM | Permalink

Weather: interesting disturbance coming in Thu-Fri time frame, but not the kind of meteorology we're looking for. Too cold, not enough precipitation.

IOP status: stand down UFN

Equipment: Alta s-band radar has a comms problem. The wide-area network is supposed to be upgraded sometime soon at both STO and RNO; should help ALPS workstation performance.

Paul "IOP Killer" Schultz, GSD
303 497-6997

Posted by Status Editor at 8:25 PM | Permalink

Weather: weak system goes through today/tonight, another on Thursday, and an aggressive trough setting up for the weekend, but that brings only cold-core dynamics and convective showers with low snow levels.

IOP status: nothing UFN.

Equipment status: we always like it when Dave White says "Nothing to report."

Paul Schultz, GSD
303 497-6997

Posted by Status Editor at 7:38 PM | Permalink

Weather: nothing more than light showers tonight/tomorrow, maybe a tenth or two Mon-Tue (10-11March).

IOP status: down UFN

Equipment: AWIPS/ALPS upgrades planned for Tuesday; please inform Woody Roberts or myself if there are any concerns.

Paul Schultz, GSD
303 497-6997

Posted by Status Editor at 7:44 PM | Permalink

Weather: only showers associated with the current short wave making its way into the area. The next disturbance, scheduled for Monday, seems to be losing punch and too far north.

IOP status: stand down UFN

Equipment issues: a hot plate gage was fixed, everything else working fine.

Paul Schultz, GSD
303 497-6997

Posted by Status Editor at 9:30 PM | Permalink