Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 270743

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
343 AM EDT Thu Oct 27 2016

.SYNOPSIS...A cold front will cross the area this evening. High
pressure then builds over the area tonight through Friday night.
A secondary cold front crosses the area Sunday afternoon. High
pressure builds again Sunday night into the middle of next week.


.NEAR TERM /THROUGH TONIGHT/...Low pressure is located over northern
IN/OH this morning. A warm front is across the Ohio Valley while
high pressure continues to move off the Mid-Atlantic coast early
this morning. Strong warm air advection aloft is occurring this
morning across the Ohio Valley and NY/PA. Most of the
precipitation is in vicinity of the nose of warm air. Although the
best forcing is further north...showers are expected across the
Mid-Atlantic region today. High pressure will continue to move
eastward and the sfc warm front will move through the Mid-Atlantic
region by afternoon. This will cause temps to rise into the U50s
across the north and low/mid 60s further south. Winds will
increase this afternoon as the pressure gradient tightens ahead of
an advancing cold front. S winds 10-15 mph with gusts up to 25mph
are expected today.

The cold front will cross the Mid-Atlantic region late this
afternoon/early evening from west to east. Showers are likely along
and ahead of the front. Steepening lapse rates may produce some
instability today. A stronger shower or weak thunderstorm can not be
ruled out mainly along the front. Rainfall amounts will average 0.1
to 0.25 with the highest amounts near the MD/PA border.

The cold front should be east of the region tonight and NW winds
will begin to advect in cool and dry conditions. Winds are expected
to increase after midnight tonight with 10-20mph with gusts up to


moves into the region Friday however a pressure gradient will
still be present. Breezy conditions will continue through most of
the afternoon with NW winds 10-15mph and gusts up to 25 mph. Temps
will range from the U50s/L60s north to mid 60s south. High
pressure moves briefly over head Friday night before shifting
south by Saturday. Partly sunny conditions expected Saturday with
temps climbing into the 70s in most locations. A cold front
approaches the region from the north Sat night.


.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Recent runs have shown
frontal passage for Sun has been pushed back until late in the
day. This will allow for temps to climb into the low 80s across
Charlottesville and Fredericksburg with mid to upper 70s elsewhere.
Scattered showers will be possible along and behind the front over
northern and northwestern areas Sun afternoon with precip chances
decreasing as you move south. Front pushes south of the area after
06Z Mon with showers ending. Cooler wx Mon as high pres builds in.

Ampliflying mid-upper level ridge over the southeast U.S. into the
mid Atlc states early next week will help rebound temps quickly
with mid 70s to low 80s expected. Rain chances may increase toward
the end of next week.


11-14Z as scattered showers form across southern PA/northern MD
this morning. VFR conditions expected elsewhere as a warm front
moves northward today. S winds will increase by this afternoon
with gusts up to 25 kts expected. A cold front will cross the
terminals from west to east this afternoon and evening. Winds will
likely diminish slightly after the frontal passage, however, NW
winds will increase late tonight through Friday. Gusts up to 25
kts can not be ruled out after midnight tonight. Winds will
diminish late Friday afternoon.

A cdfnt will cross the area Sun afternoon with winds shifting to
NW and then N Sun night.


.MARINE...Southerly winds will increase ahead of a cold front this
morning. SCA begins at this morning for the southern MD waters
then expands at 10am for all waters with southerly channeling of
20 to 25 knots.

Likely showers late Thursday afternoon/evening associated with the
cold front. Strong gusts and special marine warnings possible
with the showers. Wind shifts W then NW behind the cold front
Thursday night with gusts around 25 kt into Friday morning.
Tranquil Friday evening under high pressure. SCA is in effect for
all waters through Friday afternoon.

Southwesterly winds ahead of an approaching cold front Saturday will
likely result in Small Craft Advisory level wind gusts over the

Small craft advzy conditions possible Sun into Mon behind fropa.


MARINE...Small Craft Advisory from 10 AM this morning to 6 PM EDT
     Friday for ANZ530>532-535-536-538>542.
     Small Craft Advisory from 6 AM this morning to 6 PM EDT Friday
     for ANZ533-534-537-543.


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