Area forecast discussion 
National Weather Service Gray ME 
707 PM EDT Monday Oct 20 2014 


Synopsis... 
low pressure over the eastern Great Lakes will move to the 
southeast tonight and Tuesday and will intensify south of Long 
Island Tuesday night....bringing an extended period of rain to 
the area. Low pressure will meander off the southern New England 
coast Wednesday through Friday before drifting off to the 
northeast on Saturday. A cold front will cross the area Sunday 
followed by a ridge of high pressure for Monday. 


&& 


Near term /until 6 am Tuesday morning/... 
7pm update: tweaked evening sky grids to reflect more cloud cover. 
Input latest observation data and temperatures/dewpoints look on track. No other 
changes at this time. 


Previous disc: 
weak 500mb ridging between closed low exiting the Maritimes to 
the NE...and deepen trough over the ph valley will allow for a mainly 
dry night...although this will allow for more stagnant surface flow 
overnight...as the middle levels become more srly toward daybreak. Look 
for the onshore to develop stratocu...especially over the coastal 
plain and in the southeast upslope areas. High and middle clouds will move 
in from the west in advance of the system to our west..which 
begins to close off by morning. There will be a slight chance of a 
very light shower toward daybreak. Temperatures will drop off quickly 
this evening...as clear skies hold until a round midnight...but 
once the clouds move in...temperatures will remain steady through the latter 
part of the night....with lows middle to upper 30s north and 40 to 45 
elsewhere. 


&& 


Short term /6 am Tuesday morning through Tuesday night/... 
surface flow remains generally weak...and will likely see a bit of a 
cold air damming situation with NE winds inland...and a more east 
flow near the coast...with a coastal front developing. This 
combined with middle level warm air advection...will produce a steady rain by 
afternoon on the coastal plain and into the foothills. In the mountains 
and points north...will be more showery into the afternoon as the 
downslope helps dry things a bit...but even here the warm air advection will 
produce steady rain by late in the day. Highs will work their way 
into the upper 40s north to meteorological impact statement 50s on the coast...as the the marine 
air works in. 


Tuesday will see a mainly steady light rain continue overnight as 
warm/moist air advection continues. The winds will gradually pick 
overnight as the surface low begin to form S of Long Island New York...but 
the heaviest rain and breeziest conditions will hold off until 
Wednesday. Mins will drop back into the 40s Tuesday night. 


&& 


Long term /Wednesday through Monday/... 
the models are in general agreement on the long wave pattern 
well into next week. We begin the period with a closed low near 
the Delaware-Maryland-Virginia. The upper low will slowly meander northeast along 
the coastline through Friday night before exiting into the 
Maritimes on Saturday. At the surface...low pressure will be 
situated just offshore and drift slowly northeast through the middle 
Atlantic and New England coastal waters Wednesday through Friday 
before exiting the region by Saturday. We'll see bands of rain 
pinwheeling in off the Atlantic Wednesday through Friday...with 
the heaviest rain likely falling Wednesday and Thursday. Quantitative precipitation forecast 
amounts on the order of 2 to 4 inches are likely across the 
forecast area with localized 5 inch totals possible across the 
western Maine mountains. On Saturday...some lingering clouds and 
widely scattered showers mainly across the higher 
terrain...despite weak ridging behind the upper low. More 
unsettled weather for Saturday night and Sunday as a quick moving 
shortwave drives another cold front across the area. A ridge of 
high pressure follows for Monday. 


&& 


Aviation /23z Monday through Saturday/... 
short term...VFR should hold through much of tonight...with gradually 
deteriorating conds beginning toward daybreak as onshore flow 
moves stratus and rain inland on Wednesday...by Wednesday afternoon should see 
coastal areas down to IFR...with inland areas following by Tuesday 
evening. 


Long term... 


Wednesday - Friday...IFR in rain and fog. NE surface wind gusting to 25 knots. 


Sat...scattered MVFR possible in showers. 


&& 


Marine... 
short term...winds/seas continue to diminish overnight and into 
Tuesday morning. Will see east flow begin to pick up Tuesday 
afternoon and especially Tuesday night...with Small Craft Advisory seas/winds expected 
by midnight...and building to gales by Wednesday morning. 


Long term... 


Wednesday - Thursday...gale force winds are likely. 


Friday...small craft conditions are likely. 


&& 


Hydrology... 
main Stem rivers will need to be monitored closely middle to late week. 
Most small rivers and streams will likely have sharp rises as 
well. The heaviest rainfall is expected to be over south-central 
Maine and the northeast facing higher terrain. Again...mostly 2-3 inches 
quantitative precipitation forecast with localized amounts approaching 5 inches. 


&& 


Tides/coastal flooding... 
coastal flooding is a possibility as the system makes a loop over 
Long Island New York on Thursday. Wave run up tools indicating 
some beach erosion and splash over across much of our 
coastline. Near shore waves could top out in the 10 to 15 foot 
range. 


&& 


Gyx watches/warnings/advisories... 
ME...none. 
New Hampshire...none. 
Marine...gale watch from late Tuesday night through Thursday morning 
for anz150>154. 


&& 


$$ 



National Weather Service Glossary of Abbreviations
Back to forecast page
Non-Expanded Version (with abbreviations)

Units: English | Metric

Find the Weather for any City, State or Zipcode, or Country:

U.S. State List | Severe Weather | Tropical Storms | Ski Conditions
United States | Canada | Central America | South America | Asia | Europe | Australia | Africa | Islands

Weather Underground Copyright© 2014
Weather Underground, Inc.

Questions or Comments? Contact Us