Office of the Delaware State Climatologist

June 19th EF0 tornado confirmed near Greenwood, DE.

Prior to Monday's tornado in Sussex County, NWS Philadelphia Tornado Database shows that 59 tornadoes have been recorded for Delaware from 1954 to 2012. [http://innovation.srh.noaa.gov/tors/index.php?cw=phi] That's an average of about 1 tornado per year.

Weather service confirms tornado hit Greenwood Weather Service survey teams and DEMA confirmed Monday night's storm included a small tornado around Greenwood.

December 2016 was the sixth month with temperatures appreciably above Delaware's normal statewide temperature. Even though Delaware experienced above normal temperatures during December 2016, it was still 11.5°F cooler than the extreme warmth experienced across the State during December 2015.

December 2016 was the third month in a row with below normal precipitation for the state.

Check out our December 2016 climate update for more information: http://climate.udel.edu/news/december-2016-climate-update

Warm Conditions Persist Across Delaware During December 2016 | Office of the Delaware State Climatologist Preliminary data indicates that the statewide average temperature in December was 39.3°F, 1.2°F above the 1981-2010 normal of 38.1°F (Figure 1). December was the sixth month in a row with temperatures appreciably above normal across the First State. Even though Delaware experienced above normal temp...

Although Delaware experienced drier than normal conditions in both October and November 2016, the fall 2016 statewide precipitation average still exceeds the September-October-November 1981-2010 Climate Normals by 2.46 inches. This can be attributed to the deluge that occurred in Sussex County on September 29th where portions of eastern Sussex County received more than 12” of precipitation.

Meanwhile, Northern Delaware saw drier than normal conditions. =)

Read more of our summary on temperatures and precipitation for fall 2016: http://climate.udel.edu/news/fall-2016-climate-update

Very Warm, and Moist Conditions Characterize the 2016 Autumn Season Across Delaware | Office of the Delaware State Climatologist Preliminary data indicates that temperatures were significantly above the 30-year normal during the autumn season. The statewide mean autumn temperature of 60.3°F was 2.7°F above the 1981-2010 mean value of 57.6°F (Figure 1). Autumn 2016 was tied with the 2005 season as the 2nd warmest autumn since…

As the year comes to a close, we took some time to reflect on November 2016 in Delaware. We found that November was the fifth month in a row with temperatures appreciably above normal across the state and the 8th driest November since records began in 1895.

Read more in our November 2016 climate update: http://climate.udel.edu/news/november-2016-climate-update

Very Dry, Warm Conditions Persist Across Delaware During November 2016 | Office of the Delaware State Climatologist

Did you know that October 2016 was the 12th warmest October on record for Delaware since records began in 1895?

Learn more about how October measured up in our October Climate Update: http://climate.udel.edu/news/october-2016-climate-update.

October 2016 Brings Warm and Dry Conditions Across the First State | Office of the Delaware State Climatologist

Our September Climate Update is now posted. Read more about how September stacks up to the 1981-2010 Normals. (Hint: Think warm and wet conditions!) http://climate.udel.edu/news/september-2016-climate-update

September 2016 Brings Very Warm and Very Wet Conditions to Delaware | Office of the Delaware State Climatologist

With average temperatures in June, warm temperatures in July, and the warmest August on record, it's not such a surprise to see that Delaware's summer 2016 ranks as the 4th warmest summer on record.
Read our summer 2016 climate update here: http://climate.udel.edu/news/very-warm-temperatures-and-near-normal-precipitation-characterize-2016-summer-season-across-del

Very Warm Temperatures and Near Normal Precipitation Characterize the 2016 Summer Season Across Delaware | Office of the Delaware State Climatologist Preliminary data indicates that summer 2016 ranked as the 4th warmest summer season since records began in 1895. The statewide mean summer temperature of 76.6°F was 2.1°F above the 1981-2010 mean value of 74.5°F (Figure 1). Delaware’s four warmest summer seasons have all occurred since 2010.

Our August climate update has been posted.: http://climate.udel.edu/news/august-2016-very-warm-and-dry-across-delaware

August 2016 ranks as the warmest August since records began in 1895 and statewide precipitation was nearly 1 inch less than the 1981-2010 normal precipitation for August.

August 2016 Very Warm and Dry Across Delaware | Office of the Delaware State Climatologist Preliminary data indicates that the statewide average temperature in August was 78.7°F, 3.8°F above the 1981-2010 normal of 74.9°F (Figure 1). August 2016 ranks as the warmest August since records began in 1895. August’s extreme warmth follows the 5th warmest August on record. The Wilmington/New Cas...

Delaware's July statewide temperature was 3 degrees F warmer than the 1981-2010 normal July temperature. Meanwhile the state experienced generally wetter conditions than normal. For more details, please check out our recent climate update for July 2016: http://climate.udel.edu/news/july-2016-climate-update

Hot and Moist Conditions Prevail Across Delaware During July 2016 | Office of the Delaware State Climatologist

Great post about a heat burst that occurred in Sussex County on Monday evening!

You can read more about heat bursts from the Norman, OK NWS Weather Forecast Office: http://www.crh.noaa.gov/oun/?n=heatburst_info.

When you run a network of weather stations, which we often refer to as a mesonet, you see LOTS of data...all the time. While looking through the data is part of the job, we're particularly intrigued when we have thunderstorms move through our network like what we saw late Monday evening. Every once in awhile, we get lucky and see something unusual. As we reviewed data from Monday night, we noticed something very peculiar that we don't see very often around here in the air temperature data at Harbeson: a 7 degree F increase in air temperature in 15 minutes following a pretty nice downpour (see graphs of small temperature spikes around 2300 hours at both Harbeson and Stockley in eastern Sussex County, DE). Most of the time when it rains this time of year, we expect it to cool us down, not INCREASE the temperature. So why would the air temperature increase at Harbeson? It's due to a lesser known phenomenon (at least for those of us in the Eastern U.S.) called a heat burst. A heat burst can occur when a thunderstorm begins to decay (or die) and dry air is pulled in from aloft. As that dry air gets pulled in, it cools and becomes denser than the air around it. As the thunderstorm starts to run out of energy, this dense pocket of cool, dry air begins to descend, warming as it goes, before finally reaching the ground. In the most extreme cases, heat bursts can increase surface temperatures by 20-30 degrees in only a few minutes and are sometimes associated with strong winds. For our decaying thunderstorms Monday night in Sussex County, this wasn't the an extreme event and thankfully we didn't see the strong, gusty winds with this heat burst. But it was still a nice "treat" for us weather geeks who enjoy a rarity like this. Heat bursts are most common in the Great Plains in the United States and most often occur at night, particularly during late Spring/early Summer. So at least this event matched the seasonal climatology pretty well. Heat bursts aren't unprecedented on Delmarva though. A much stronger heat burst (temperature increase of 13 degrees F) occurred near Salisbury, MD on April 26, 2009. While the heat burst on May 2nd was much smaller, it was still interesting to see it happen in not one but 2 DEOS stations as the storm died out crossing Sussex County. Not many systems can detect a heat burst like that.

Yesterday brought record warmth across Delaware. While the record high for the state for March 9th wasn't broken (82 °F set in 2000 in Milford), it did set a record at the Wilmington New Castle County Airport which saw a high of 81 °F.

The previous record for March 9th at the airport was 74 °F set in 1964 and tied in 2000 and the normal high temperature for this date is 50 °F.

http://climate.udel.edu/news/record-warmth-yesterday

Record Warmth in Delaware Yesterday | Office of the Delaware State Climatologist Yesterday brought record warmth across Delaware. While the record high for the state for March 9th wasn't broken (82 °F set in 2000 in Milford), it did set a record at the Wilmington New Castle County Airport which saw a high of 81 °F.

With a cold start to 2015, which included the 6th coldest February on record for Delaware, the First State ended the year with a record-breaking warm December. Read more about Delaware's above normal temperatures and precipitation in our Annual Climate Update for 2015.

http://climate.udel.edu/news/2015-annual-climate-update

Temperature and Precipitation Both Above Normal Across Delaware During 2015 | Office of the...