Scott A. Minnick, NOAA-National Weather Service, Wakefield, VA; scott.minnick@noaa.gov, www.weather.gov
A warm and wet end to July has transitioned to a cool and wet start to August. Through the 15th, rainfall across the state is already 1 to 3 inches above the normal for the month. Average temperatures are running 1 to 2 degrees below normal. Based on the latest guidance, the cool trend will be short lived as guidance indicates a return to more seasonable temperatures through the latter half of August. The Climate Prediction Center’s 8 to 14 day outlook calls for increased probabilities for above normal temperatures. Guidance does indicate that the above normal rainfall trend will persist through the end of the month, with CPC calling for increased probabilities of above normal precipitation. As we move into meteorological fall next month, the forecast becomes more challenging. ENSO neutral conditions, meaning neither El Niño nor La Niña, leave us with no strong climate indicator heading into the fall months. This means the climate trends are tied to more short term climate drivers. However, these indicators are difficult to forecast outside of a few weeks. As the higher latitudes begin to cool, this results in more opportunities to get cooler air filtering into the eastern portion of the nation. Long term guidance and recent trends indicate that the cooler air will generally stay over Canada, leaving Delaware in an area of increased probabilities for above normal temperatures. Fall is typically the driest season of the year, so uncertainty increases. CPC calls for equal chances for above, below, or near-normal rainfall. Which of course, a tropical system can impact quickly.
Speaking of the tropics, the National Hurricane Center has revised the original hurricane outlook based on the already active season. With now Hurricane Gert lifting well offshore, that brings us to 7 named storms. The revised forecast calls for 14 to 19 names storms. As we move into the peak of the season in September, always be prepared for possible impacts from a tropical system.
