Aug 10, 2016

Prolonged Wet Spell Still Likely

Much needed rain fall occurred across parts of the Northeast States on Wednesday morning helping to begin to ease the dry and drought conditions across parts of the region. Nonetheless a severe drought continues for most of the Northeast. Areas of west-central and western New York State as well as a good portion of Southern New England remain in moderate or severe drought as shown in the image below.


From the US Drought monitoring service here is the discussion regarding the Northeast's drought:

"Moderate to heavy rains, locally exceeding 5 inches, fell on areas from southwestern New England southward and eastward into the mid-Atlantic and through the central Appalachians. These rains removed dryness and drought from most of West Virginia and in the mid-Atlantic south of the Mason-Dixon line, but only scattered improvement was noted elsewhere. In eastern and northern New England, where only light rain fell, severe drought expanded through most of Massachusetts, and moderate drought covered the rest of southern New England. Rainfall deficits for the past 90 days range from 4 to 9 inches in much of this region. In addition, long-term rainfall shortages remain entrenched, with accumulated shortfalls over the past 2 years of 12 to 24 inches observed from central New England southward into northeastern Pennsylvania. Temperatures averaged a few degrees above normal this past week, exacerbating conditions."

However there is going to be a definite pattern change as it relates to our dearth of rainfall. As I mentioned in my update A Drippy Looking Long Range, the next 7 days upcoming will feature frequent bouts of  showery rains and thunderstorms with any shower or storm capable of producing torrential rain. Even though it has been dry and the rain will be absorbed by the ground, there is the chance that too much rain could fall in a short time period (like 2 hours or less) resulting in the threat for flash flooding. Definitely something to keep an eye on.  

Weather data is coming into agreement on both what periods during the next 7 days will be the rainiest and how much rainfall is possible.  For Eastern NY State and Western New England (our neck of the woods) the best chance for widespread rain  will be from Thursday into next Monday. The best chance for getting soaked will be during the afternoon hours right up through early night (10 PM or so). The exception to this will be this Saturday August 13th when the rain could start earlier and will probably continue well into the early morning hours of Sunday before it diminishes from NW to SE as Sunday moves on. This same weather data continues to indicate that precipitable water values over the next 5 days will be  near +3 standard deviations (SD) above  normal with values rising to near +4 SD on Saturday. These high deviations above normal strongly favor heavy rain. And once again several features will come together in time and place to efficiently make the heavy rain happen..

Here is the 7 DAY TOTAL AMOUNT of rain expected. (Forecast is from the Weather Prediction Center) It is for the 168 hour period from 8 AM Wed 10 Aug through next Wednesday, 8 AM 17 August:

The forecast map indicates a widespread 1.5-2 inch rain fall for us with more than a few locations getting 3 to even locally near 4". Keep in mind this the total expected rainfall for the next 7 days . BUT as for our region goes, I think that most of this heavy rain will occur in the Friday through Sunday morning period, with Saturday seeing the most rain.