The image above (courtesy NOAA) shows sea surface temperature departure from average (anomalies) indicating weak La Nina conditions across the Equatorial Pacific. Notice the blue colors off the western coast of South America stretching westward along the equator indicative of cooler than average sea surface temperatures.
Wrath of Sally to Pass Through Tidewater of Virginia and Carolinas
Afternoon showers will develop across the DC Metropolitan Area on Thursday, eventually transitioning into a steady light rain during the overnight and continuing through predawn Friday. The showers will come to an end on Friday morning as a cold front slides southward through the Washington Area. The threat of severe thunderstorms will remain well south of our area across the eastern Carolinas and Tidewater of Virginia.
Feeling Like October
Just how low will the mercury go this weekend into early next week?
A cold front will cross the Washington region late tonight ushering in lower humidity and cooler temperatures for the early to middle portion of the upcoming work week. The latest European forecast models depict the potential for the remnants of Sally to impact our region during the later portion of the week. Should this threat materialize, the threat for heavy rain and tornadoes would increase Thursday night into Friday.
More Heavy Rain?
The latest European Forecast model (images below, courtesy Pivotal Weather) show heavy rain moving through the Washington Area Thursday night into the day on Friday. Depending upon how quickly the remnants move through, the threat of widespread flooding may not materialize.
Wind Shear & Tornado Threat
The next image shows bulk wind shear (wind shear is defined as winds that change speed and direction with height) increasing as the remnants of Sally potentially move through the Mid-Atlantic Thursday into Friday. The threat from tornadoes would be relatively high for our area if wind shear values above 45 knots were to materialize as shown in the model image below. If the track of Sally’s remnants were to shift further south, the threat for tornadoes would decrease… stay tuned.