Scientific Forecaster Discussion
fxus61 kakq 231046
Area forecast discussion
National Weather Service Wakefield Virginia
646 am EDT Mon Apr 23 2018
high pressure remains centered just off the northeast and mid
Atlantic coast today. Low pressure will track northeast up
and along the East Coast Tuesday through Wednesday.
Near term /until 6 PM this evening/...
as of 350 am EDT Monday...
Latest sfc analysis shows ~1030 mb high pressure centered just
offshore with ~1007 mb low pressure over Tennessee. The high remains
just offshore today allowing for a mainly dry day as the low
stays put over the southeast states. Some light rain is psbl over far
SW areas by mid aftn (20-30%) with no pops for the remainder of
the fa during the daytime period. High temps range from near 60
along the coast to the upr 60s inland.
Short term /6 PM this evening through Wednesday/...
as of 350 am EDT Monday...
Rain overspreads the fa tonight except for the lwr MD ern shore
where it may take until 12z Tue morning to reach. Pops ramp up
to categorical south of i64 tonight/Tuesday morning, with high
end chc to likely pops to the north. Lows tonight upr 40s NW to
mid 50s se. Tue looks breezy and wet, courtesy of strong
(albeit slightly weakening) onshore flow and upper forcing.
Still appears enough lift/moisture for periods of moderate to
heavy rainfall. Event total qpf 1-2". Highs Tue upr 50s NW to
mid 60s se.
Drier, albeit with lingering clouds for Wednesday. Slightly
warmer with some peeks of sun likely. Still enough remnant low
to mid level moisture for a few showers, so will maintain chc
shower wording. Highs in the upr 60s to mid 70s.
Long term /Wednesday night through Sunday/...
as of 355 PM EDT Sunday...
A fast moving shortwave is forecast to track from Georgia to ern
North Carolina Thursday-Friday am. 22/12z GFS has 999mb sfc
low pressure centered over southeast Virginia at 12z Friday with around 1 inch of
quantitative precipitation forecast over much of the County Warning Area. The most recent 12z European model (ecmwf) has a much weaker
low pressure system centered around 150 miles to the southeast
with less than a quarter inch of quantitative precipitation forecast confined to southeast Virginia/NE NC.
Kept pops between 25-35% with the highest values in the
southeastern County Warning Area given the differences between the guidance.
Highs in the upper 60s on the ern shore/low 70s elsewhere Thu-Fri.
A more potent mid-level shortwave is still forecast to track over
the northeastern US Friday into the weekend. This will set the stage
for another chance of rain late Friday-Saturday as a cold front
passes through the region. Once again, there are differences between
the guidance regarding the strength and timing of the storm system.
Therefore, have carried slight chc/chance pops from Friday
through 00z Saturday. Highs in the mid-upper 60s Saturday
warming to around 70 on Sunday. Lows in the mid 40s to around 50
Aviation /12z Monday through Friday/...
as of 1 am EDT Monday...
VFR to start off the 12z taf period with bkn to ovc high and
mid level cloudiness ahead of the system apprchg from the SW. Se
winds aob 5 kt this morning increase to 10-15 kt this aftn.
Cloud deck will eventually lower late this afternoon and evening
as rain approaches from the SW. As rain chances increase
overnight, expect cigs to lower into the MVFR range towards the
end of the taf period, especially over ric/ecg.
expect conditions to deteriorate from SW to NE Tue morning as a
large area of rain approaches the County Warning Area. This will result in
flight restrictions throughout the day Tuesday at all terminals.
Restrictions will likely last through ~12z Wed before
conditions slowly improve during the day.
East winds increase to between 15-20 kt (gusts to ~25 kt) at
orf/phf/sby/ecg during Tue and last through 00z Wed. Slightly
lower winds (e at 10-15 kt) expected at ric during this
timeframe. Winds decrease after 00z Wed and turn to the SW by
as of 400 am EDT Monday...
High pressure centered off the Delmarva will drift offshore
today resulting in a continued southeast flow of 5-15 kt. Waves/seas
will persist between 1- 2 ft for most of today. Seas and waves
will likely build some late this afternoon to a solid 2 ft
across the Lower Bay and up to 3 ft over the coastal waters
south of Cape Charles as winds increase to 15 kt late this
Winds and waves increase significantly overnight tonight into
Tue and scas are already in effect for this period. Low
pressure over Tennessee will slowly push east with a secondary
low developing along the Carolina coast Tuesday. This will
result in increasing onshore flow from the southeast. Winds increase
quickly to 15-25kt mid morning Tuesday increasing more through
the afternoon. Rain will limit deep mixing which should help to
limit winds to 30 kt or less, however, during the period of
strongest pressure falls late Tue afternoon into Tue evening
some winds gusts to 35 kt are possible across the Lower Bay and
coastal waters from Cape Charles south. Seas and waves will
build quickly in the onshore flow with seas 5-9 ft off the
coast and 4-6 ft waves in the mouth of the Bay (2-4ft elsewhere
in the bay).
Broad low pressure lifts north of the region during Wednesday
with south-southwest winds 5-15kt becoming northwest in the wake of the low Wed
night into thurs morning. Seas over the coastal waters may
remain elevated (greater than 5 ft) through Wed. After a brief
lull midweek the next low pressure system then impacts the
Marine...Small Craft Advisory from 8 am to 8 PM EDT Tuesday for
Small Craft Advisory from 8 am Tuesday to 8 am EDT Wednesday
Small Craft Advisory from 8 am Tuesday to midnight EDT Tuesday
night for anz630-631-633.
Small Craft Advisory from 8 am Tuesday to 8 PM EDT Wednesday
Small Craft Advisory from 2 am Tuesday to 8 PM EDT Wednesday