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fxus61 kakq 062007 
afdakq 


Area forecast discussion 
National Weather Service Wakefield Virginia 
407 PM EDT Sat Sep 6 2008 


Synopsis... 
Tropical Storm Hanna will continue to move rapidly northeast 
across the Delaware-Maryland-Virginia early this evening...then across the New 
England coast late tonight through midday Sunday. High pressure 
builds into the middle Atlantic region Sunday and Monday...while a 
cold front approaches from the northwest on Tuesday. The front 
will gradually drop south through the middle Atlantic area Tuesday 
night and Wednesday. 


&& 


Near term /until 6 PM this evening/... 
latest surface analysis shows the center of Hanna over lower Maryland... 
continuing to move quickly neward. All tropical related headlines 
over inland areas (tropical storm winds and flash flood watches) 
have been dropped per the latest trends...though for a few hours 
at least will expect the tropical storm warnings to continue along 
the coasts (based on the latest land and buoy obs). 


Have scaled back probability of precipitation and rain amounts quite a bit across the bulk 
of the region (all except lower Maryland eastern shore)...as the center of 
Hanna is about ready to clear our forecast area. Downsloping northwest flow 
no doubt accelerating the drying on the backside of Hanna...and 
thus have reflected these trends in the latest forecasts. 


Total rain amounts thus far have ranged from 1 to 3 inches east of 
I-95 (lcly higher amounts across portions of lower Maryland eastern shore)... 
with amounts between 2 to 4 inches over most areas west of I-95. Pockets 
of 5-7" amounts were noted over portions of the eastern Virginia Piedmont...with 
radar estimates near 8" over far western Prince Edward County. 


Clearing conditions overnight will likely lead to areas of fog... 
especially considering the amount of standing water...though the 
extent and density will depend heavily whether or not surface winds 
will decouple or not. For now...will have areas of fog mentioned... 
allowing later shifts to evaluate based on ob trends this evening. 


&& 


Short term /6 PM this evening through Tuesday night/... 
high pressure builds in behind Hanna Sunday and Monday. Lingering 
tropical airmass results in a mostly sunny day with highs in the 
mid to upper 80s and lows in the 60s...xcpt for sby where improving 
radiational cooling conditions may drop min temperatures into the upper 
50s Monday morning. Will have to be mindful of possible diurnal 
development across eastern Virginia/NC along sea/Bay breeze convergent zone 
for both Monday and Tuesday...as is hinted by both the GFS/NAM. At this 
point...given the degree of anticyclonic flow and relative lack of 
low level instby/thermodynamics...have refrained from including rain 
chances in the forecasts. 


Please consult the latest tropical storm local statement from National Weather Service 
Wakefield (hlsakq) for the latest information on T.S. Hanna. 


&& 


Long term /Wednesday through Saturday/... 
GFS/European model (ecmwf) remain in decent agreement and continue to show the cold 
front stalling across the Carolinas on Wednesday as the middle level flow 
flattens out. Will have 30% chances of precipitation across the south tapered 
to dry forecast north. With north-northeast flow highs should remain in the upper 
70s. 


Difficult forecast Thursday/Fri/Sat as eventual track of Ike will be the 
dominant feature. Overall best chances for showers would be SW zones 
west/ low level Ely flow as weak warm advection begins to move back in 
the low/middle levels from the SW. Keeping 20-30% chances in forecast both 
Friday and Sat but will be subject to changes as track of Ike becomes 
more certain. Temperatures near average for Sep. 


&& 


Aviation /20z Saturday through Thursday/... 
Hanna continues to move across the region...the center of circulation 
is now approaching ches Bay from the middle Virginia peninsula. An area of 
moderate to heavy rainfall is across the southern Delaware-Maryland-Virginia 
peninsula just upstream of the center of circulation. Expect mainly 
MVFR AVN conds for the rest of the afternoon over Mainland Virginia/NE 
NC with only light to moderate bands of showers. The Eastern Shore 
(incl sby) will experience widespread IFR conds through 20z. AVN 
conds improve across the area after about 20z with the center of 
Hanna NE of the area. 


Gusty winds to around 40 knots still along all coastal areas from NE 
NC to the Eastern Shore. Winds will gradually drop off as Hanna 
pulls away late the afternoon and evening. Precipitation tapers off from 
SW to NE beginning now for southern Virginia and ending by 00z or so tonight 
for the Eastern Shore. Expect widespread fog Sat night/morning 
after winds die down and again Sun night/morning with plenty of 
residual moisture in place following the heavy rains. 


VFR conds during the day Sunday with downsloping winds and building 
high pressure. VFR also during the day Monday. Chance of precipitation 
increases through the day Tuesday ahead of approaching cold front. 


&& 


Marine... 
as of 3 PM...center of ts Hanna now into the ches Bay/apprchg Maryland Eastern 
Shore...continuing to move north-northeast. With the initial afternoon forecast package will 
continue with tropical storm warnings for entire akq marine 
area...however west/ conference call west/ TPC/hurricane ctr from 4 to 5 
PM some headlines may may be dropped and will update the forecast again 
after 5 PM. 


Strongest winds through the Erly eveng hours will be over the NE sections 
particularly the northern coastal waters where some gusts around 50 knots will 
be possible...more like 40-45 kts elsewhere. Winds rapidly decrease 
later during the eveng and overngt. 


Coastal flooding issues generally have been minor (low end moderate at 
most) thus far and with winds already shifting to west...do not 
expect conditions to get any worse (although will need to monitor Maryland 
zones adjacent to the Bay through the next high tide cycle). 




Much lighter winds generally 20 kts or less after midnight and into 
Sunday morning. Weak high pressure takes control sun/Mon...then flow 
turns back to south-southwest ahead of next cold front Tuesday...with a Small Craft Advisory surge 
possible later Tuesday into Wednesday depending on how much cold air can make 
it this far south. 


All marine interests should continue to monitor the latest forecasts 
from the National Hurricane Center for information on Hanna. 


&& 


Akq watches/warnings/advisories... 
Maryland...Tropical Storm Warning for mdz021>025. 
Flash Flood Watch until 8 PM EDT this evening for mdz021>023. 
NC...Tropical Storm Warning for ncz015>017-030>032-102. 
Virginia...Tropical Storm Warning for vaz075-077-078-084>086-089>091- 
093>100. 
Marine...Tropical Storm Warning for anz630>633-650-652-654-656-658-670. 
&& 


$$ 
Synopsis...bkh 
near term...bkh 
short term...bkh 
long term...lkb 
aviation...baj 
marine...lkb 

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