Day 273: 72-Hour Rainfall Totals
Above are the estimated rainfall totals for the past 72 hours ending at 3 UTC (10 PM CDT) tonight. These are some impressive rainfall totals! No wonder there has been flooding!
Day 272: Eastern North Carolina Flooding
This certainly has been the year of the flood, or so it seems.
Wilmington, NC (far southeast North Carolina) has just set their all-time 4-day precipitation record. The record was 19.06″ which occurred with Hurricane Floyd in 1999. As of 10:45 PM EDT, Wilmington, NC had received 19.09″ of rain with heavy rain still falling. As you can see with the radar image above, the heavy rain will continue for the near future…
If you are traveling in eastern North Carolina, remember: “Turn Around; Don’t Drown”.
Day 271: Tropical Depression #16 (Nicole?)
Yesterday (Monday) was a wild weather day. Los Angeles set their all time record high temperature of 113F; records date back to 1877! Wilmington, North Carolina set their all time record 24 hour precipitation total…(in excess of 10″, but I don’t know the exact value). Also, tropical depression #16 developed south of Cuba.
As indicated in the official forecast from the National Hurricane Center (NHC) above, tropical depression #16 is forecast to develop into Tropical Storm Nicole during the day tomorrow. Again, the official forecast is above. A series of model forecasts (of track) can be found below.
In any event, tropical storm Nicole (if it develops) won’t last very long. It will be ingested into a broad baroclinic zone associated downstream of a long-wave trough over the eastern United States. In layman’s terms, it will transition from a true tropical cyclone to something more typical of the northern United States — an extratropical cyclone. In any event, deep tropical moisture, broad baroclinic zone, and prolonged resonance time all point toward a heavy rain event in areas that just saw a heavy rain event. Expect widespread flooding to continue.
Day 270: Urban Heat Island Effect and Lake Effect in a High Resolution Model
Under certain atmospheric conditions, typically clear skies and calm winds, the overnight low temperature at a given location is often affected by non meteorological conditions. The more urban an area, the warmer the overnight low temperature will be (given the aforementioned quiescent conditions). This is known as the Urban Heat Island Effect. Also, because water heats and cools slower than the air temperature, proximity to large bodies of water also play a significant role in the overnight low temperatures (once again, under quiescent conditions).
What’s amazing is that our numerical weather prediction models are being run at spatial scales that can now capture these trends. Above (and annotated below) is the forecast low temperatures for the southern plains tomorrow morning from the NSSL Weather and Forecast Model (WRF). (It’s a 36 hour forecast, valid at 12 UTC, or 7 AM, Tuesday.) This model is run using a spatial grid length of 4 kilometers in the horizontal direction. If you look carefully at the forecast, you can see what appear to be spurious areas of warmer low temperatures than the general pattern of low temperatures. These areas are not spurious, but actually the model forecasting Urban Heat Island or Lake effects on low temperatures. Overnight low temperatures near the lakes will be highly dependent on what the lake temperature is. Warmer lakes result in warmer overnight lows.
Urban areas are circled and labeled in red, whereas the lake effects are circled in yellow.
Day 269: High Pressure Dominates
This evening’s surface chart depicts a large high pressure in control of much of the United States. This comes in the wake of the upper level low that is mentioned last night and the night before. An exception to this is along the east coast were a stalled surface front and area of low pressure are causing widespread showers and thunderstorms.
Programming note: Tomorrow begins the WxChallenge, a collegiate forecast challenge. I hope to resume more substantive posting as this begins.
Day 268: Developing Closed Low
Last night’s blog post highlighted the cooler weather that was on the way for the southern plains. Tonight’s image is a water vapor satellite imagery of the short-wave trough (yellow circle)that is undergoing a closing-off / potentially cutting-off process.
Also, note the two jet streaks (black circle) over Kansas. The atmospheric response to these jet streaks will aid the deepening of the trough over the next 12-24 hours.
Day 267: Autumn-like Weather On the Way
The times are a changing…Above are the forecast high temperatures for Sunday afternoon from the Global Forecast System (GFS) model. Notice the upper 50s over southwest Missouri! Below are the forecast low temperatures for Monday morning. Notice the 40s! I hope this sticks around!!!
About Patrick
Patrick Marsh is a Ph.D. student at the University of Oklahoma's School of Meteorology. He earned a Bachelors of Science in Mathematics and Physics (cum laude) from the University of Arkansas in 2005 and a Masters of Science in Meteorology in 2007. In addition to working on his doctorate, Patrick serves as the National Severe Storms Laboratory Liaison to the Hazardous Weather Testbed where his research interests lie in working with operational forecasters, data mining, data visualization, and all things high-impact weather. For more about Patrick's work, check out his complete CV!
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