The Delmarva region is expected to see several rounds of rain as a series of weather systems move through the area from late Friday into Sunday morning. While the rain will be spread out over time, confidence is high that most locations will see wet conditions at some point during the weekend.
The first round of rain arrives late Friday into Friday night as a weakening cold front crosses the region. This front is associated with an area of low pressure moving from the Great Lakes toward eastern Canada. Because the front is weakening as it approaches Delmarva, it is not expected to bring much of a temperature drop or colder air. Rain during this period should generally be light to moderate.
A stronger system moves in on Saturday as a slow moving trough dives south from Canada into the Great Lakes. This will help develop a new area of low pressure over the Lower Mississippi Valley that tracks northeast toward the Mid Atlantic. A warm front is expected to lift through Delmarva Saturday morning, placing the region in a warmer and more humid air mass. Temperatures are forecast to rise into the 60s, which is mild for this time of year, though still a few degrees shy of daily records.
Heavier rain is expected later Saturday into Saturday night as a cold front moves through the region. There may be enough instability in the atmosphere for a rumble of thunder, but severe weather is not expected. After the initial front moves offshore Saturday night, scattered showers may linger until a secondary cold front passes through on Sunday morning.
Once the secondary front clears the area, winds will increase, but the chance of wind gusts reaching advisory levels remains low. Overall, rainfall will be spread out over a 36 to 48 hour period with breaks between rounds.
Forecast confidence is high that rain will occur, but exact rainfall totals remain uncertain. Most guidance suggests at least a half inch of rain, with some models indicating localized totals between 1.5 and 2 inches. The probability of receiving one inch or more of rain sits around 30 to 50 percent, while the chance of exceeding two inches is low.
Despite the potential for moderate rainfall, flooding concerns remain minimal. The rain will fall gradually rather than all at once, and recent mild temperatures should have eliminated any lingering ice in creeks or rivers, allowing water to drain efficiently.
More confidence in rainfall totals is expected as the weekend approaches, but residents across Delmarva should be prepared for several periods of rain from Friday afternoon through Sunday morning.
