Wasatch Weather Weenies

The lack of progress on improve the air quality along the Wasatch Front is deeply disturbing.  Excuses and foot dragging seem to be the modis operandi  of the day. Yesterday, the Salt Lake Tribune reported that many Utah business leaders sent a signed letter to Governor Herbert asking him to propose "bold strategies for addressing air pollution in Utah" and urging the Division of Air Quality "to propose a wide array of strong and ambitious proposals as part the Serious SIP it submits for public comment this fall."  The "Serious SIP" refers to the Strategic Implementation Plan for reducing air pollution in the Salt Lake Valley, as required by the EPA.  The full letter is included with the Tribune article, available here . The article notes that Bryce Bird, director of the Utah Division of Air Quality, said that " truly innovative air quality solutions that hold promise for Utah are difficult to come by ." While I agree that there is no quick...

Imagine the western U.S. equivalent of Hurricane/Tropical Storm Harvey. Rain nearly nonstop in California for 6 weeks.  Runoff turning the Central Valley into an inland sea.  Sacramento buried under 10 feet of water.  Damages of more than a half-trillion dollars. Now that would be a climate catastrophe right? Except, it already happened. During December. In 1861. Granted, the damages were not more than a half-trillion dollars.  That's merely the lower estimate of storm damage if it happened today.  But in December 1861, a megaflood in California killed thousands of people and 800,000 cattle.  A catastrophe by any standards, and it happened before significant global warming. Source: USGS, Ingram (2013) I write this to emphasize caution in interpreting the causes and contributors to the severity of floods produced by Harvey during and following the immediate aftermath of the storm.  The meteorology and hydrology of extreme events is m...

Houston and the surrounding area are absolutely snake bit.  Tropical Storm Harvey now sits over the Gulf of Mexico just south of Galveston.  Although the precipitation area has broken up some, Houston and environs remain in one of the main shields. It's been absolutely unbelievable how that area has been a magnet to precipitation for this event.  Such a shame. It ain't over yet.  We all want this thing to be over, but Harvey will continue to float around SE Texas and western Louisiana through tomorrow.  The National Weather Service is calling for 2-3 inches today and another 2-3 inches tomorrow for the Houston area.  These numbers are lower than seen earlier this week, but are going to slow the recovery.  Let's hope that the stronger bands and precipitation regions spare the area. Perhaps I'll write more later, but right now I've reached a point of numbness.

Now Tropical Storm Harvey now holds the record for the longest time remaining a named storm (i.e., with at least tropical-storm-force winds) after landfall in Texas.   At present, it is having a significant impact not only on Texas, but also southwest Louisiana, where the brunt of Harvey's randbands are currently moving onshore.   Harvey is currently moving slowly southeastward and back over water.  It is expected to remain offshore through Tuesday, before making another landfall, somewhere along the northeast Texas Gulf Coast.  Although some strengthening is possible, Harvey is not expected to regain hurricane status prior to landfall.   Nevertheless, it really isn't the wind, but the precipitation and flooding, that is the main issue with Harvey, and unfortunately he's going to continue to be a problem for Texas and Louisiana for the next few days (and longer in terms of recovery).  Beyond that, Harvey is expected to move slowly up th...

There is no historical analog for the impacts of Hurricane Harvey.  The precipitation numbers being pumped out by our forecast models a couple of days ago were jaw dropping and beyond comprehension.  Unfortunately, those forecasts are coming to fruition.   The numbers on the map below are 24-hour precipitation totals from the Texas Mesonet that I believe are since 7 AM CDT yesterday.  A significant swath of the area from northeast of San Antonio through the Houston area received more than 6 inches of precipitation.  Multiple stations in the Houston area reported more than 10 inches of rain, with a maximum of 18.02".   Source: Texas Mesonet Major flooding is occurring along streams and rivers across the region.   Source: NWS The National Weather Service Houston/Galveston forecast office has a graphic showing points that are forecast to reach major or record flooding stages, emphasizing that the impacts are "unknown and beyond anything...

Last night I kept an eye on the radar and surface observations in Texas as Harvey made landfall.  The image below shows the situation at 0135 UTC when the eye was just beginning to move over the barrier islands. At that time, it was clear that Corpus Christi would be spared the worst of the winds.  Although they still had a miserable night, the eyewall, indicated above by the ring of high (yellow) radar reflectivity, where the strongest winds are concentrated, would pass just to their northeast. Additionally, the right side of the eyewall was moving over Matagorda Island State Park and the Aransas National Wildlife Refuge, areas that are relatively undeveloped. However, it was also clear that Rockport was spending a remarkably long time in the slow-moving eyewall.  I have never been through a hurricane, but colleagues who have spent time on the ground in or near the eyewall describe it as a terrifying experience.  The minutes must have ticked by like hour...

This is a blog focused on mountain weather, but sometimes our attention does wander, today to Hurricane Harvey and its impacts on the Gulf Coast. First a little context.  It has been 4323 days since the last major (category 3 or higher) hurricane landfall on the Gulf or East Coast of the US.  This is by far the longest major hurricane "drought" since the mid 1800s.  It has been a good run, but one that may be ending today or tomorrow. Hurricane Harvey is currently lurking off the Texas Gulf Coast.  Some perspective on the scale and significance of the storm is provided by a continental US sateltite and radar perspective.  Precipitation associated with Harvey essentially spans the entire Texas Gulf Coast, with associated cirrus clouds covering a broader region that is, well, approximately the size of Texas. Zooming in, one can see Harvey's eye quite well, with a classic spiraling rainband pattern. The latest advisory issued by the National Hurricane...

With 8 days left to go in meteorological summer (June to August) this summer is in a dead heat with 2013 for the hottest summer on record at the Salt Lake City International Airport with an average temperature of 80.8ºF. Source: NOAA Regional Climate Centers This summer had a pretty good lead through early August, thanks to all of the pain and suffering from late June through most of July, but we've given some of that lead back this month.  Granted, August hasn't seemed to bad, but it's still above average for temperature.  Everything is relative. Forecasts call for a high-amplitude ridge to build in over the weekend and dominate our weather over the next several days.  This mean highs in the mid 90s beginning tomorrow and lows near 70 at the airport (give or take a few degrees). The average temperature for the entire summer in 2013 was 80.8ºF, which is right where we are at so far this summer.  Basically, we need to close out the last 8 days of August w...

A tip of the hat to the astronomers for getting yesterday's forecast right.  It was a great day for science.  Much thanks from the weather guessers. And, speaking of the weather, keep your fingers crossed that we see some hydrometeors today.  We have a weak monsoon surge pushing in from the south, with moisture on the increase.  The NAM analysis and forecast loop below shows cloud cover and precipitable water values on the increase overnight and today for northern Utah. The HRRR forecast for later today shows scattered showers and thunderstorms across northern Utah and Nevada. The chaotic nature of atmospheric convection prevents us from precisely predicting the location and intensity of those showers, but let's hope they deliver.  A bit of rain later today and evening would be greatly welcomed.

Note: Post has been updated to correct location of site with 10ºF temperature fall. Before. Source: CIRA  After. Source: CIRA Incoming solar radiation (Salt Lake area sites). Source: Alex Jacques, MesoWest, University of Utah Temperature (Salt Lake area sites). Source: Alex Jacques, MesoWest, University of Utah Temperature at Peters Sinks (notorious cold spot in Bear River Range) site in the Bear River Range.  Fall of about 10ºF, although it's unclear if we're at the bottom yet (probably close). Source: Utah State University, MesoWest

Morning has broken and things are looking good along the path of totality over the western U.S.  It's early for a visible loop, but as can be seen below, a band of mid and upper-level clouds is slowly but surely exiting the totality path area of far western Wyoming and Idaho.   Here's a look at the GOES-16 geocolor imagery from CIRA at 13:32 UTC (7:32 AM) and it looks pretty good too.  There are some thin patchy clouds over portions of the Idaho panhandle and western Montana moving southward that are just barely discernible in the imagery.    Source: CIRA You couldn't ask for a better forecast from the operational HRRR than the one below, valid about a half hour after totality.  No clouds predicted along the entire track from Wyoming to the Pacific Coast.  Source: ESRL That forecast might be a bit optimistic as there may be a few high clouds around over Idaho and the remnants of the cloud band evident that is over southern Idaho...

" Eclipse viewing is about synoptic possibilities,  but succeeding or failing based on unresolved cloud processes"  – Slight paraphrasing of quote about storm chasing from meteorologist Chuck Doswell Model forecasts have trended in the "right" direction since our post on outlooks for the eclipse on Friday.  At that time, the models, such as the NAM below, alled for a short-wave trough to be over Idaho at eclipse time, with at least partial cloud cover over portions of Idaho and Wyoming. As I write this, the latest (0600 UTC) NAM forecast calls for that short-wave trough to be both further east and weaker, with the Pacific coast ridge also shifted further east.  Much of Oregon is still in a prime spot for lack of cloud cover, but the situation, at least synoptically, is better for Idaho and the Jackson area than one would have anticipated from the forecasts on Friday. If we look at time-height sections, however, there remains one concern to give me a...

As I write this, we are now about 3 days from the 2017 Eclipse and the ultimate test of transportation and communications infrastructure in rural areas of Idaho and Wyoming, where the vast majority of Utahns and University of Utah students hope to view the eclipse (Question: Will anybody attend class on the first day of the semester, which is also Monday?). The large-scale forecast for Monday seems to be stabilizing, but I still consider highly specific cloud forecasts to be difficult given the weak large-scale forcing.  A high-amplitude ridge parked over our area would be a godsend for forecasters, but that's not what we're looking at for Monday. Instead, the GFS calls for a weak upper-level shortwave trough to sweep across Idaho and Wyoming from 1200–1800 UTC (0600–1200 MDT), and be accompanied by some mid- and high-level clouds.  A short-wave ridge further west builds along the Pacific Northwest coast. Eclipse time is approximately 1721 UTC (1121 MDT) in Redmon...