Dr. Rob Carver's WunderBlog

The odds of a White Christmas

Fri, 18 Dec 2009 05:30:00 GMT

The odds of a White ChristmasThis time of the year, meteorologists are often asked if there will be snow on Christmas Day, known as a White Christmas. In this blog entry we won't be looking at specific forecasts for December 25, 2009, but we will be looking at how often White Christmases have occurred over the past thirty years. To do this, we'll use a database of weather observations gathered at airports around the world from 1979 to 2008. For the purposes of t...
Read More

Ida, Nicaragua, and Rain

Sat, 7 Nov 2009 09:51:00 GMT

Hi everybody,When Ida made landfall along the Nicaraguan coast, the main threat mentioned in NHC's discussions was flooding due to excessive rain. Now that Ida is back over the ocean again, it's worth reviewing how much rain did fall. Right now, all that is easily accessible on the internet are satellite-derived precipitation estimates. CMORPH is one such estimate, produced at NOAA's Climate Prediction Center. This estimates uses multiple satellite datasets to e...
Read More

Snow for the Appalachians and Rain for the East Coast

Thu, 15 Oct 2009 07:33:00 GMT

It's weekends like this that make me glad I'm not in Happy Valley (State College, PA). It's only October, but the NWS has issued a Winter Winter Advisory covering most of central PA from Happy Valley to the Allegheny Plateau from Thurs. night into Saturday morning. What's going on? Well, it's a bit complicated. A low forming off the Carolina coastline is expected to move NE while deepening and producing a wide shield of rain. As the low moves past the Chesapeake...
Read More

Storm update from Wunderground's SF office

Tue, 13 Oct 2009 23:35:00 GMT

As of 4pm PDT, it looks like the worst of the rain will be ending soon for the SF Bay region. It's a bit early to tabulate the results across the region, but I will note that the Personal Weather Station located on top of our building had recorded a total of pi (3.14) inches of precipitation so far today. From a meteorological perspective, the winds with this storm haven't been anything unusual for a Pacific storm. At least for the Bay Region, rain seems to be th...
Read More

California is going to get a little wet

Mon, 12 Oct 2009 07:26:00 GMT

Here's a tip, when the local NWS office helpfully lists the one day and two day precipitation records in their forecast discussion, get out your rain gear.What's going on? Well, the remnants of Super typhoon Melor are about to make landfall along the northern CA coastline Monday night. For Northern CA, the NWS is forecasting 2-3 inches of rain along the Bay, 4-6 inches of rain for the Santa Cruz and Sierra foothills, and several feet of snow in the Sierra Nevada ...
Read More