Area forecast discussion 
National Weather Service Taunton Massachusetts 
248 am EDT sun may 26 2013 


Synopsis... 
low pressure in the Gulf of Maine will slowly move northeastward 
tonight. Some improvement is likely Sunday as this low departs 
into northern New England. Mainly dry weather is anticipated with 
moderating temperatures Monday into Tuesday. A warm front will move 
through Wednesday bringing some showers and thunder. Expect warm 
and muggy conditions by the end of the work week. 


&& 


Near term /through today/... 
continuing to monitor temperatures this morning. Received reports 
of light snowfall...some of which managed to accumulate a few 
tenths. Middle-level low has was centered over Boston early this 
morning...with the surface low pressure centered over the Gulf of 
Maine southeast of Wiscasset Maine. 


26/00z guidance is in excellent agreement with the location and 
timing of their synoptic features. As such used a general model 
blend for the timing in moving these lows away from southern New 
England. The notable exception to the overall good agreement was 
the low-level temperature fields in the GFS. The GFS has a 
spurious pocket of significantly warmer air at both 925 mb and 850 
mb. As such ignored the mav temperature guidance for today. High 
temperatures will once again be 10-15 degrees below normal. 


Coverage of showers has already decreased this morning...and 
expecting this trend to continue early this morning. Showers end 
from south to north through this morning. Northwest winds increase 
with gusts up to 35 miles per hour possible today. 


&& 


Short term /tonight through 6 PM Monday/... 
tonight...should see clearing skies as high pressure starts to 
build into southern New England. Winds will stay up enough to 
prevent optimal radiational cooling until late tonight. 
Temperatures will be well below normal once again...with patchy 
frost possible. 


Middle-level trough shifts east Monday...but cyclonic flow still 
aloft as a surface high pressure arrives. Limited moisture around 
850 mb should support some diurnal cloud development...but not 
deep enough for any showers. Monday should be a dry day with at 
worst partly cloudy skies. 


Of more concern are the temperatures. 26/00z mav guidance 
continues to advertise highs in the middle-upper 70s pvd-bdl and low 
70s bos. Meanwhile while model temperatures at 850 mb and 925 mb 
support only support values of 65-70. 26/00z met guidance is 
lower...and favored. 


&& 


Long term /Monday night through Saturday/... 
big picture...upper low over the northeast USA migrates northeast 
through the Maritimes. Upper high pressure over the plains shifts 
east for the latter half of the week. Pacific upper low digs over 
The Rockies midweek...then ejects through the northern plains by 
next weekend. 


Model preferences...upper contour fields are similar for much of 
the week. Minor differences in handling the ejecting Pacific low 
upstream late week. We used blends of HPC/gmos and GFS/European model (ecmwf) data 
as available. 


The dailies... 


Monday night-Tuesday...clear skies and light winds Monday 
night...dewpoints 35-40. Could be some frost in the Berkshires and 
Monadnocks but elsewhere temperatures should bottom out in the upper 30s 
to middle 40s. 


High pressure overhead Tuesday with temperatures aloft warming...values 
around 9-10c support maximum temperatures 75-80. Cooler at the coast as the 
light flow will allow for developing sea breezes. 


Wednesday...upper ridge will push warming temperatures into the region. 
Warm front representing the leading edge of this warmer air moves 
across New England late Wednesday/Wednesday night. This will 
generate some showers...and stability parameters support potential 
for thunder as well. 


Thursday through Saturday...very warm air aloft with 850 mb temperatures 
around 16c. Dewpoints are expected in the low to middle 60s. Mixing 
should support maximum temperatures in the middle and upper 80s...dewpoints 
point to humid air with night mins in the 60s. Shower potential 
looks low Thursday and Friday. An approaching cold front may bring 
a chance of showers Saturday especially north of the Mass Pike. 
But the strength of the upper ridge may keep this front to our 
north and preclude showers. So the precipitation forecast is low confidence 
by next Saturday. 


&& 


Aviation /06z Sunday through Thursday/... 
forecaster confidence levels... 


Low...less than 30 percent. 
Moderate...30 to 60 percent. 
High...greater than 60 percent. 


Overview... 


Through 12z...VFR visibilities dominate across southern New 
England. VFR ceilings nudging north through the CT River 
Valley...with MVFR conditions elsewhere. 


Today...high confidence in trends...moderate confidence in timing. 
Precipitation tapers off from S-north with VFR conditions everywhere 
by middle afternoon. 


Tonight and Monday...high confidence. VFR. 


Kbos terminal...moderate confidence in taf. 


Kbdl terminal...moderate confidence in taf. 


Outlook...Monday night through Thursday... 


Monday night through Thursday...generally VFR. Early morning IFR 
possible in fog and low clouds. Local MVFR ceilings/visibilities in 
showers/thunderstorms Wednesday and Wednesday night. Sea breezes at the 
coast Tuesday. 


&& 


Marine... 
forecaster confidence levels... 


Low...less than 30 percent. 
Moderate...30 to 60 percent. 
High...greater than 60 percent. 


Marginal gale-force wind gusts still possible across the outer 
south coastal waters early this morning...but becoming less likely 
with time. Currently planning on downgrading the gale warnings to 
small craft advisories with the morning forecast unless some 
information comes in which changes my mind. 


Expecting Small Craft Advisory conditions to continue into tonight 
for most waters. Conditions should continue to improve from 
northwest to southeast across the waters tonight into Memorial 
Day. 


Outlook...Monday night through Thursday... 


Monday night through Wednesday...winds and seas below small craft 
thresholds. South winds may gust near 25 knots nearshore of the 
cape and islands Wednesday afternoon. 


Thursday...southwest winds gusting near 25 knots nearshore of the 
cape and islands. The southwest wind will build seas with 5-6 foot 
values on the outer waters...possibly on Rhode Island and Block Island sounds 
as well. 


&& 


Climate... 
several climate records could be reached over the weekend. While 
Boston...Providence...and Worcester were several degrees over 
their record low maximum temperature this afternoon...Hartford has 
tied its record low maximum of 48 so far. If their temperature GOES up 
even a degree the record set in 1967 will hold. However...think 
theres a good chance that we will tie that record in Hartford. 


Tonight...the forecast low at Worcester...34 degrees...would break 
the current record low of 35 degrees set in 1992. The forecast 
lows at Providence...Hartford...and Boston are within 2-3 degrees 
of the previous records /see below/. 


Hartford - forecast low - 39 record low - 36 (1992) 
Providence - forecast low - 38 record low - 35 (1972) 
Boston - forecast low - 41 record low - 39 (1882) 


&& 


Box watches/warnings/advisories... 
CT...none. 
Massachusetts...none. 
New Hampshire...none. 
Rhode Island...none. 
Marine...Small Craft Advisory until 4 am EDT Monday for anz232>235-237- 
250-254. 
Small Craft Advisory from 2 PM this afternoon to 4 am EDT 
Monday for anz230-231-251. 
Small Craft Advisory until 9 PM EDT this evening for anz236. 
Gale Warning until 7 am EDT this morning for anz255-256. 


&& 


$$ 
Synopsis...Belk/wtb 
near term...Belk 
short term...Belk 
long term...wtb 
aviation...Belk/wtb 
marine...Belk/wtb 
climate...rlg