Friday, December 21, 2012

Northern FL Freeze: 22 December 2012

Hard freezes that extend deep into the FL Peninsula are a high-impact event because of the impact they can have on the citrus crop and the FL economy. The NWS WFO from Tallahassee has been using the analog impact guidance over the last few days. In fact, they mentioned it in the long-term section of their AFD 3 days before the upcoming event.

A Look Back: 25 December 2011

Note: The following blog post on the multi-day snow event across West Texas last December 2011 was written by NWS Forecaster, Jeff Vitale from the Weather Service Forecast Office in Lubbock, TX. If you have an interesting event to share, please contact the CIPS Analog Guidance developers.

Wednesday, December 19, 2012

Midwest Snowstorm: 19-21 December 2012 (Update)

Over the last couple days model output has honed in on a storm track in the last 24 hours. This allowed the NWS to issue winter storm and blizzard warnings across a large portion of the Central U.S.

Monday, December 17, 2012

Potential Impacts Midwest Snowstorm: 20-21 December 2012

For the last couple days, model output and the Analog Guidance has been advertising a high-impact event across the Midwest on December 20th and 21st. Although the track of the model output has varied (see graphic below from the Milwaukee, WI NWS Forecast Office issued this morning), what has been consistent is that a strong area of low pressure will develop over the Southern Plains and track north-northeastward into the Great Lakes.

Thursday, December 13, 2012

Special 132-h East Coast Analog Run: 19 December 2012

What a difference 24 hours makes. Yesterday morning's (20121212/1200) 12Z GFS 156-h forecast had a sub 984-mb surface low just southeast of New York City (top image below). This morning's (20121213/1200) 12Z GFS 132-h forecast (bottom image below) had a weaker 1004-mb surface low. For the most part, this was due to a slower and weaker midlevel trough. Although the surface low does deepen considerably in the next 12-24 h of forecasts as

Using the Analog Guidance in the Forecast Process

This post should be a complete reference guide when a user would like information about utilizing the analog guidance as an impact-based tool for the upcoming forecast. The ideas here are based on NWS forecaster feedback and experience in using the guidance over the past 4 years.

Wednesday, December 12, 2012

Special 156-h East Coast Analog Run: 19 December 2012

If the 156-h forecast from the GFS 20121212/1200 model run is close to verifying, the most similar historical events indicate that from Binghamton to Albany, NY through interior New England would most likely have a white Christmas. Although timing of the system between the GFS and the consistent (as of late) European model during this period differ, there is support from the GEFS members that this threat is very credible. Fields between the top 15