Weather

707 
fxus61 kbox 070958 
afdbox 


Area forecast discussion 
National Weather Service Taunton Massachusetts 
558 am EDT sun Sep 7 2008 


Synopsis... 
the remnants of Hanna will move through the Gulf of Maine...away from 
southern New England. Weak high pressure builds over New England later 
today through early Tuesday bringing warm dry weather. An approaching 
cold front Tuesday will bring a period of scattered showers/thunderstorms 
followed by dry seasonable weather Wednesday and Thursday. 


&& 


Near term /until 6 PM this evening/... 
with Hanna pulling away from the coast...all showers should come to 
an end this morning. Gusty northwest winds will diminish quickly this 
morning as the high builds in. Clearing skies will allow solar mixing 
during the afternoon. 850 mb temperatures 12-14c midday will cool a little 
to 11-12c late. Full mixing with this air should support maximum temperatures in 
the low to middle 80s most places...the upper 70s elsewhere. 


&& 


Short term /6 PM this evening through 6 PM Monday/... 
high pressure remains in control through the night and Monday. This 
will mean dry more comfortable weather with dew points in the upper 
40s and 50s. Radiational cooling tonight will allow min temperatures in the 
upper 40s and 50s. Daytime heating and mixing Monday with 850 mb 
temperatures 10-12c should support maximum temperatures around 80. 


&& 


Long term /Monday night through Saturday/... 
Monday night...high pressure will gradually move offshore. 
Temperatures will fall to around 50 in the interior to around 60 
along the coast. 


Tuesday...an upper level trough and accompanying low pressure system 
will pull a cold front through southern New England Tuesday afternoon. 
Scattered showers and thunderstorms will likely accompany the front 
as it moves through. At this point...the timing of the front 
coincides with a strong low level jet...which will result in high 
amounts of shear. If this scenario verifies...severe thunderstorms 
will be possible with the frontal passage with damaging winds the 
greatest threat. Will stick with chance probability of precipitation in the grids and 
mention thunder but at this point will leave mention of severe out 
of the grids and limit that mention to the severe weather potential statement. High temperatures 
will be slightly above normal prior to the front moving through. 


Wednesday and Thursday...high pressure builds back into the area 
behind the front. Dry...more autumn-like weather is expected...with 
high temperatures slightly below normal. 


Friday and Saturday...another series of fronts could move through 
southern New England. This far out there is little agreement amongst 
the models. Some say a warm front Friday and cold front Saturday. 
Others say a cold front Friday and still others say a warm front 
that will miss southern New England on Friday and a cold front on 
Saturday. Will only make small adjustments to the grids for these 
days since the picture is so unclear. 


&& 


Aviation /10z Sunday through Thursday/... 
06z tafs bring improving conditions to MVFR 09z-12z as Hanna tracks 
off east Massachusetts coast near Plymouth...then to VFR by 15z as low clouds scour 
out. 


Core of strongest winds heading off Cape Cod as of 0530z and winds 
will diminish as Hanna tracks across Rhode Island and southeast Massachusetts through 09z. Winds 
shift to north behind storm with 30kt gusts likely...then gradient will 
maintain 25kt gusts into early afternoon. 


Clear tonight with west winds 10kt or less. 


Outlook...Sunday night through Thursday 


Sunday night through Monday night...VFR. 


Tuesday...mainly VFR...then MVFR in showers and thunderstorms as a 
front moves through southern New England. 


Wednesday through Friday...VFR. 


&& 


Marine... 
VAD wind profiles at box-enx-gyx show 30-35 knots in the surface to 5000 
foot layer. Mixing along with the cyclonic flow aloft will mean a 
lingering period this morning of sustained or frequent gusts around 
the gale threshold. We will transition to a few hours of morning gales 
on the eastern waters...and small craft advisories on the remaining 
waters. As the surface center moves farther away we will see the winds 
diminish to below 25 knots. 


High seas will linger through the morning...then slowly subside this 
afternoon through Monday. Seas will drop below 5 feet by Monday 
morning on the inner waters...but 5 foot seas will linger on the 
outer waters through Monday afternoon. 


The high seas with long period swell will mean a high risk of rip 
currents along the South Coast beaches. A high surf advisory will be 
issued for these locations for today. 


Outlook...Monday night through Thursday... 


Monday night...winds and seas below small craft criteria. 


Tuesday...small craft criteria likely as upper level trough and cold 
front move through the waters. 


Wednesday through Friday...winds and waves will fall below small 
craft criteria by Wednesday afternoon and remain that way through 
Friday. 


&& 


Hydrology... 
issued Flood Warning for North Nashua River at Fitchburg where latest 
nerfc forecast brings river just over its 6.5 feet flood stage through 
daybreak. Other smaller rivers have shown sharp rises due to 
torrential rainfall...but are expected to remain within their banks. 
We continue to keep an eye on Pawtuxet River at Cranston Rhode Island where 
minor flooding is possible later today. 


Flood warnings also remain in effect for most of area for significant 
urban flooding. We anticipate these will be allowed to expire on 
schedule early this morning. Flood Watch will probably be allowed to 
expire as well since renewed flooding is not expected. 


&& 


Box watches/warnings/advisories... 
CT...none. 
Massachusetts...high surf advisory until 8 PM EDT this evening for maz020-023- 
024. 
New Hampshire...none. 
Rhode Island...high surf advisory until 8 PM EDT this evening for riz006>008. 
Marine...Gale Warning until 8 am EDT this morning for anz231>233-250- 
254-255. 
Small Craft Advisory until 11 am EDT this morning for anz230- 
234-236. 
Small Craft Advisory until 5 am EDT Monday for anz235-237. 


&& 


$$ 
Synopsis...wtb/rlg 
near term...wtb 
short term...wtb 
long term...rlg 
aviation...rlg/jwd 
marine...wtb/rlg 
hydrology...jwd