Area Forecast Discussion


145 
FXUS61 KAKQ 172101
AFDAKQ
Area Forecast Discussion
National Weather Service Wakefield VA
401 PM EST Sat Feb 17 2018
.SYNOPSIS...
Low pressure skirts across southern Virginia and North Carolina
late this afternoon and intensifies off the Delmarva coast this
evening, bringing widespread rain to the region. High pressure 
returns Sunday with mostly sunny skies and seasonable temperatures.
A warm front lifts north through the area Monday and Monday 
night. High pressure becomes anchored off the southeast coast 
Tuesday and Wednesday bringing a return to well above normal 
temperatures.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Latest analysis indicates sfc low pressure over SW VA with high
pressure centered across SE New England. Rain has overspread
most of the CWA, but except across the north has been light so
far. Due to column cooling/wet bulb effects, temperatures over
the far N/NW have dropped into the mid 30s, but with sfc dew pts
at 32-33 F not expecting much more of a drop. Thus, just a
little sleet/snow possibly mixed in across Fluvanna/Louisa/Caroline
into early evening but should be no accumulation with just wet 
roads. Elsewhere, all rain continuing into evening as sfc low 
pressure pushes east off the coast and intensifies off the
delmarva...then heads out to sea by Sun morning. Will have high
PoPs (65-80% W to 80-100% E) this evening...decreasing NW-SE 
after midnight. Lows in lower 30s NW to the upper 30s/lower 40s
SE. QPF amounts to avg 0.25 to 0.50" N to 0.15 to 0.30" S. 
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Sfc high pressure builds over the region Sunday for a dry/mostly
sunny day. Highs mainly from the mid to upper 50s west of Ches
Bay (warmest south central VA), with cooler conditions, mainly 
in the in the upper 40s/lower 50s close to the coast with light
onshore flow. Models bring next system and a return of moisture
back from the SW by Mon. Mostly clear Sun evening with 
increasing clouds overnight from SW to NE. Lows mainly 35-40F 
though readings may actually rise a bit after midnight across
the west. A slight chance for rain late west of I-95. With the 
sfc high well off the mid- Atlc/New england coast on Mon, 
overrunning moisture pushes across the local area with mainly 
cloudy skies and a light E/SE flow. Best forcing remains off to 
our NW however, so not necessarily looking at a lot of QPF. Will
carry PoPs to 40-50% most areas for now. Not a true CAD setup, 
but a lot of clouds and shallow mixing will keep it cool for 
much of the day, especially across the Piedmont. Late day highs 
will avg 50-55F W/NW to the mid 60s far SE. Increasing SW flow 
Mon night as upper ridge axis begins to amplify/build off the SE
coast.Models indicate some continued light QPF amounts Mon 
night, but there is little forcing for precipitation so will 
genly keep PoPs capped at just 20%. Milder with little drop in 
temperatures due to the SW flow, lows ranging from the upper 40s
to mid 50s. Area will be firmly in the warm sector on Tue, with
strong upper ridge centered over the Gulf Stream off the SE 
coast. GFS/NAM depict a lot of low level moisture across the 
area so skies may start of mostly cloudy. Suspect the SW low 
level flow and 850mb temperatures rising to +10 to +12 C will be
sufficient to scour out the low level clouds by late morning 
and allow for a partly sunny day. Highs expected into the 70s 
except for locally cooler conditions at the immediate coast.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A strong +2 st dev 500mb ridge will be located over the 
Subtropical wrn Atlantic Wednesday bringing very warm temperatures. 
Lows Tuesday night/Wednesday morning are forecast to be in the mid 
50s to around 60F, followed by highs Wednesday in the upper 60s/low 
70s over the Ern Shore, and at least mid/upper 70s elsewhere. There 
is the potential for low 80s over SE VA/NE NC. A weak shortwave 
trough is progged to rotate around the ridge Wednesday, and this 
could result in some more clouds and low PoPs (20-30%) over the 
Piedmont. The ridge slowly breaks down Wednesday night into 
Thursday, but remains strong. Therefore, a cold front to the NW will 
have slow progress reaching the Mid-Atlantic. PoPs Wednesday night 
will range from 20-30% S to 30-40% N, then ~30% S to 50-60% N 
Thursday. Lows Wednesday night will mainly be in the 50s, with the 
potential for wide ranging highs Thursday possibly around 60F/low 
60s N to the 70s SE depending on where the cold front reaches. Upper 
level ridging will continue to prevail but gradually weaken off the 
Southeast coast later next week into next Weekend with well above 
normal temperatures continuing. There remains some uncertainty with 
the cold front, with the general consensus for the front to be into 
NC Friday with highs in the 50s to low 60s, and then lifting back N 
as a warm front with highs in the 60s to around 70F by Saturday. 
Forecast PoPs are mainly 20-30% Thursday night through Saturday.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MVFR/VFR cigs through 21-22Z, radar/satellite trends have 
slowed down the arrival of heavier precipitation and appear to 
be pushing it off to the north at least for awhile. Still
anticipate flight restrictions deteriorating to IFR between 
22-00Z at most terminals as showers begin to overspread the 
region. There could be a brief period of light mix/sleet NW of
KRIC late this aftn/early evening but overall mainly just rain
at main terminals. Easterly winds diminish for a few hrs this
evening then gradually shift to the NW from 05-10Z/Sun. Turning
drier w/ VFR conditions returning Sunday. Winds on Sun will be
fairly light underneath sfc high pressure, except for NNE winds
10-15kt at KORF/KECG through 18Z. 
Another round of rain showers and flight restrictions/lower 
cigs are possible by Monday and possibly lasting through Mon
night/tue morning with low stratus. Expect VFR/warm SSW flow to
prevail Tue after the early am clouds scour out. A cold front 
approaches from the NW on Wednesday but expect VFR conditions 
to prevail.
&&
.MARINE...
Latest sfc analysis shows high pressure off the New England coast 
with weak low pressure off the Carolina coast. Seas remain close to 
5 ft over far southern coastal wtrs this aftn, but with a slight 
downward trend expected and this being quite marginal will not hoist 
any headlines. The aforementioned low slides NE along the coast 
tonight and strengthens. A brief period of SCA criteria winds is 
psbl over the wtrs, but with this expected to last less than a few 
hours, will maintain previous thinking that a MWS or SMW will likely 
be best suited to handle this. Pressure gradient then slackens into 
Sun, with sub-SCA conditions expected to continue through at least 
the middle of next week. NNE winds late Sun veer around to the ESE 
Sun night as a surface high slides offshore, becoming southerly Mon 
night into Tue as a warm front lifts north across the waters. SSW 
flow persists into midweek, with seas remaining 2-4 ft.
&&
.CLIMATE...
ECG set a record high at 81 F Fri 2/16. Another round of record
highs will possibly be challenged Tue 2/20 and Wed 2/21:
* Record highs:
 
* Date: Tue 2/20   Wed 2/21
* RIC:  77 (1930)  75 (1930)
* ORF:  77 (1991)  79 (2014)
* SBY:  75 (1930)  75 (1943)
* ECG:  78 (1991)  77 (2014)
&&
.EQUIPMENT...
KAKQ radar will be down UFN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ
AVIATION...LKB
MARINE...MAS
CLIMATE...
EQUIPMENT...