By WBOC Chief Meteorologist Dan Satterfield
We ended November with just a little rain on Delmarva, but we really needed a good soaking. More rain is coming next week, so we have another shot at catching up a bit. The map above shows that the least rainfall in the last 30 days has been over Sussex County in Delaware, and Wicomico County in Maryland. This very dry ground has made forecasting temperatures rather difficult. The daytime temps. are warmer than expected and night-time temps. are colder than expected, because the dry ground heats up and cools off more quickly than the moist soil to our north and west.
The numerical weather models are run with soil moisture information, but the data is often not of sufficient quality and the model physics is not as good as it could be. Forecasters therefore must notice (and adjust) for this when making a forecast, and we have indeed been doing just that for a few weeks now. This is a good example of how giving a numerical weather model a very accurate starting point is critical to getting the best forecast.
Rainfall data for Salisbury shows a 6.54 inch deficit for Meteorological Fall from Sep- Nov.
CLIMATE NORMAL PERIOD 1981 TO 2010 WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST VALUE (LST) VALUE VALUE FROM YEAR NORMAL .................................................................. TEMPERATURE (F) YESTERDAY MAXIMUM 73 129 PM 74 1993 53 20 55 MINIMUM 61 754 AM 14 1976 34 27 44 AVERAGE 67 44 23 50 PRECIPITATION (IN) YESTERDAY 0.14 1.70 1985 0.12 0.02 0.06 MONTH TO DATE 0.54 3.43 -2.89 3.26 SINCE SEP 1 17.44 10.90 6.54 9.49 SINCE JAN 1 51.50 41.97 9.53 46.88