arlwx

The latest from LWX:

.NEAR TERM /THROUGH TONIGHT/...
Forecast is largely on track this morning as surface low moves
eastward from Tennessee and redevelops along the North Carolina
coastline before moving east-northeastward and out to sea
tonight. At the same time, the upper level trough will close off
this afternoon and track overhead this evening.

Widespread light to moderate snow is being observed this morning
with generally 2-4" already reported across the area as of 3 AM.
Continued light to moderate snow, with occasional heavier
bursts, is expected through today for much of the region as
isentropic lift and upper level forcing persist through the day,
with a couple exceptions. Drier air will work into portions of
northern/western MD and eastern WV after sunrise, and this will
curtail snow amounts/intensity. Additionally, warmer air will
push northward into portions of central VA and southern MD,
introducing sleet/rain/freezing rain to that region heading into
Sunday morning. Between these areas the most significant
amounts are expected to occur. Models are also indicating that a
deformation band may occur again late this afternoon and
evening as the upper level low traverses, and this is currently
progged to occur near the I-95 corridor, with the localized
highest amounts likely where this sets up.

Total snowfall amounts expected to range from 6-10" across the DC
metro area and across much of northern VA, tapering to 4-7" north
towards the PA/MD border where drier air will cut down on amounts,
and 4-8" towards southern MD and central VA near
Spotsylvania/Orange/Albemarle where mixing occurs. In these
areas, a light glaze to up to a tenth of an inch of ice is
also forecast.

Snow will then taper off and end during the overnight hours.

Highs today generally 28-35F, with lows tonight in the 20s.

&&
 

As for headlines, did upgrade the advisory to a warning for the
northern Shenandoah Valley and the Washington Metropolitan area.
Am concerned that east-west oriented banding may cause locally
higher amounts across these areas. Frontogenetical forcing
increases as the low passes by to the south late tonight into
Sunday morning, and looking at the 00z nam bufkit, did notice
the Eqivalent Potential Temperatures nearly neutral with height
for a period between 06 and 12z along with slightly negative EPV
and Frontogenetical forcing that lines up, suggesting that CSI
banding is possible. Elsewhere, left the headlines from the
previous forecast. Still looking at a most likely of 2-5 inches
across northern Maryland, the eastern Panhandle of West Virginia
and the Baltimore Metropolitan areas, with 4-7 inches
elsewhere. Do want to point out that there is still uncertainty
regarding the placement and location of any banding
precipitation and also with the track of the low. Any slight
change in either direction will have an impact on snowfall
totals. Having that been said, there will be impact from snow
across the entire CWA tonight into Sunday.
 

VDOT plows already onboard in SW VA.

http://vdotplows.org/

And the latest AFD from LWX.

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Low pressure will track through the Gulf Coast States Saturday
into Saturday evening before transferring its energy to a
coastal low off the North and South Carolina Coast by Sunday
morning. The low will move off the Mid-Atlantic Coast Sunday and
high pressure will return for Sunday night. The closed upper-
level low associated with this system will get sheared apart as
it runs into a strong confluence zone, with shortwave energy and
jet maxes passing through Saturday into Sunday.

For Saturday...High pressure will remain over New England while
the surface ridge axis extends down through the Mid-Atlantic.
The low and mid-level flow will back to the southwest, causing
relatively warmer and more moist air to overrun the surface cold
air in plac. At the same time, shortwave energy well ahead of
the upper-level low will pass through the area. The overrunning
and shortwave energy should be enough to cause snow to break out
over much of the area, first across the Potomac Highlands and
Shenanodah Valley Saturday morning and across the rest of the
area Saturday afternoon. Temperatures will remain below freezing
or drop below freezing after precipitation begins, so
accumulating snow is likely.

The same pattern will persist for Saturday night with low
pressure transferring its energy to a coastal low as it passes
by to the south. Overrunning and shortwave energy will continue
to bring snow across the area with accumulation likely. The coastal low will will move out to sea Sunday and high pressure will wedge down from the north. This will cause snow to gradually end from north to south. Details are still a little uncertain at this time. Latest 00z guidance shows that the best chance for additional snow accumulation will be south of Interstate 66 and US 50. High pressure will continue to wedge into the area Sunday night. Most areas across the northern and central CWA should turn out
dry, but a little light snow or flurries cannot be ruled out
across central Virginia into southern Maryland where leftover
moisture will be tough to scour out.

As for accumulations, it does appear that snowfall rates will be
on the light to perhaps occasionally moderate side. This is
because the primary forcing mechanism appears to be overrunning.
Strong frontogentical forcing appears that it will remain to our
south, closer to the low. Therefore, latest thinking for most
likely snow amounts are around 2-4 inches near the Washington
and Baltimore Metropolitan areas into northern and central
Maryland as well as northern Virginia. Farther south and west, 4
to 8 inches are most likely at this time. The reason for the
higher amounts is that moisture will be a bit deeper closer to
the low and farther from the drier air associated with the high.
A Winter Storm Watch is in effect for these areas (Potomac
Highlands into central Virginia and extreme southern Maryland).
Most likely forecast do have amounts below temporal criteria for
a warning, (5" in 12 hours and 7" in 24 hours), but still
several inches of snow are likely at this point. Also, there is
still some uncertainty with the low track Sunday morning. Some
outlying guidance suggest that heavier snow is still possible
across these areas. Therefore, a Watch has been issued.

 

WSWs up to the SW and S of DC.

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
337 AM EST Fri Jan 11 2019

MDZ017-VAZ036>040-050-051-056-057-111645-
/O.NEW.KLWX.WS.A.0002.190112T1700Z-190113T1700Z/
St. Marys-Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-
Culpeper-Spotsylvania-King George-
337 AM EST Fri Jan 11 2019

...WINTER STORM WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SUNDAY MORNING...

* WHAT...Significant snow possible. Snowfall accumulations of 5 or
  more inches possible.

* WHERE...Portions of central Virginia, the Virginia Piedmont and
  extreme southern Maryland.

* WHEN...From Saturday afternoon through Sunday morning. The
  steadiest snow is most likely late Saturday afternoon into
  Sunday morning.

* ADDITIONAL DETAILS...Travel may be difficult due to snow covered
  and slippery roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

&&

$$

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
337 AM EST Fri Jan 11 2019

VAZ025>027-029-030-503-504-507-508-WVZ055-505-506-111645-
/O.NEW.KLWX.WS.A.0002.190112T1500Z-190113T1700Z/
Augusta-Rockingham-Shenandoah-Page-Warren-Western Highland-
Eastern Highland-Northern Virginia Blue Ridge-
Central Virginia Blue Ridge-Hardy-Western Pendleton-
Eastern Pendleton-
337 AM EST Fri Jan 11 2019

...WINTER STORM WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
SUNDAY MORNING...

* WHAT...Significant snow possible. Snowfall accumulations of 5 or
  more inches possible.

* WHERE...Portions of the Potomac Highlands in eastern West
  Virginia and Virginia as well as the central Shenandoah Valley.

* WHEN...From Saturday morning through Sunday morning. The
  steadiest snow is most likely Saturday afternoon through Sunday
  morning.

* ADDITIONAL DETAILS...Travel may be difficult due to snow covered
  and slippery roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

The latest from LWX

LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The system we`ve been watching for this weekend appears at the
moment that it will come in 3 phases.

1) Mid/upper jet induced band of (mainly light) snow is likely
Saturday afternoon and evening. This is due to a coupled 250 hPa jet
structure (left exit against right entrance). 850-700 hPa frontal
forcing and mid-level cyclonic vorticity advection pivot across the
area in tandem with this upper jet couplet. This should result in
decent lift and widespread light snow, with embedded moderately
heavy bands possible depending on exactly where the best
juxtaposition and moisture all line up together. General thinking
right now is an advisory level event, with potentially near warning
in any heavier bands or perhaps terrain enhanced areas of snowfall.

2) Surface low develops ahead of southern stream shortwave energy
Sunday east of NC and moves offshore. Where exactly this low
develops and tracks off the coast will determine how far north and
west its precipitation (snow) shield gets. Right now, a track near
Cape Hatteras would suggest southern MD, but the orientation of the
mid-level wave and PVA could draw snow a bit further north toward
the I-95 corridor. Amounts for this wave are more uncertain, but
accumulating snow appears most likely south of the I-70 corridor.

3) Trailing/strung out 500 hPa northern stream wave moves across
Monday. With dry advection in the low levels, any precipitation
would be reliant on lingering mid-level moisture and lift with the
upper low. Isolated snow showers are possible, with the highest
chances over the Allegheny Front.

After the weekend system, high pressure follows for the first part
of next week. Another stout shortwave/clipper-like system approaches
during the middle of the week bringing the next chance of
precipitation. Temperatures look marginally cold at this point, and
precipitation would likely be scattered/showery given current setup.

Thereafter, a significant change in the upper wave pattern over
NAmer seems imminent, with longwave troughing and more persistent
cold possibly encroaching on the eastern CONUS beginning late next
week.
 

Other forecasts:

The Blue Ridge near I-66:

The latest from LWX:

LONG TERM /SATURDAY THROUGH TUESDAY/...
Strong/cold high pressure to the north and developing low pressure
to the south near the Gulf Coast may spell trouble for the Mid-
Atlantic this weekend. 500 hPa pattern is a little convoluted. A
ridge over the western CONUS will be in a favorable place (anchored
near 120 W which usually results in downstream trough amplification
and coastal low track close enough to the Mid-Atlantic to bring
substantial precipitation), but the ridge will be undercut by an
incoming trough over southern CA. To what extent the ridge is
diluted remains in question and is arguably the biggest single
cause of spread in the latest guidance, but virtually everything now
shows measurable snowfall across most of the area.

Due to the more drawn out mid/upper height pattern (as opposed to a
compact and deepening upper low approaching the coast),
precipitation may ultimately be in an extended/lighter form, with
the best chance for any heavier rates possibly coming Sunday morning
(subject to change at this time range, of course).

After the system exits, troughing will linger over New England with
northwest flow keeping temperatures on the colder side through the
middle part of next week.
 

The current forecast for DCA:

The latest from LWX:

.LONG TERM /FRIDAY THROUGH MONDAY/...

Very strong high pressure (1040+ mb) builds in from the Arctic

across southeastern Canada toward New England Friday into

Saturday. Meanwhile, amplifying (but narrow) ridge over the

Rockies forces downstream height falls as two shortwaves begin

to interact crossing the Central Plains states. This will cause

low pressure to develop over the Gulf Coast and track east-

northeastward. Guidance has been very consistently trending more

amplified over the last couple days, so will maintain high end

chance PoPs (for snow given cold air in place) Saturday night

through Sunday. GFS/GEFS is by far the most aggressive guidance

(along with the 0z operational CMC), but ECMWF holding out that

an upper low coming ashore of southern CA over the weekend will

undercut the ridging over the Rockies, causing less downstream

amplification and phasing. Regardless, nearly all guidance

including the 0z ECMWF as well as virtually every ensemble

member has at least some measurable snowfall, they just differ

(and quite significantly) on finer scale details and amounts.

The latest from NWS:

(snip)

.LONG TERM /THURSDAY THROUGH SUNDAY/...
It will be blustery on Thu with the local area in between deep low
pressure over the Canadian Maritimes and high pressure over the
north central U.S. Wind chill values will be in the 20s all day.
High pressure then builds over the region Thu night through Fri
night keeping cold and dry conditions. For next weekend, the global
models show the potential for a winter storm to impact the mid
Atlantic and Northeast coasts with the GFS showing more phasing and
a sfc low track closer to the coast and farther north than the rest
of the global models (ECMWF, UKMET and Canadian) which show a more
suppressed and less developed sfc system and track farther offshore.
At this time, Sat and Sat night appear the best time frame for any
precip with snow the most likely p-type given strong upper
confluence and sfc high pressure over the Northeast and southern
Ontario and Quebec regions.

(snip)

The 00z GFS 9s trying to troll me for the latter half of MLK weekend.

But I'll wait until a week out to hunt for my flamethrower.

As today is the last day of fall...

My warminista parody of White Christmas:

I’m dreaming of a mud solstice

Just like the ones I often know

Where the gutters glisten

and children listen

but can’t hear anyone forecast snow

I’m dreaming of a mud solstice

With every card I’m writing down

May your days be o’ercast and brown

May all you turn around, don’t drown.

From the latest LWX discussion:

.NEAR TERM /THROUGH TONIGHT/...
Latest surface analysis places surface low pressure near the
Louisiana/Arkansas border, with high pressure already pushing
into the western Atlantic. High clouds are slowly thickening
across the region, but precipitation is still several hours
away. Temperatures have therefore dropped to near or below
freezing, but believe they should generally rise back above
freezing before precipitation arrives later this morning, even
in the southern Shenandoah Valley. That said, have left a
chance of freezing rain in the forecast across that area, while
the rest of the region should be solidly rain. Latest guidance
has increased the speed of rain`s arrival, with rain likely to
affect the entire CWA by the evening rush. Highs will be in the
40s in most of the region thanks to the increased cloud cover
and the arrival of the rain.

First push of warm advection and extremely moist air ahead of
the main low occurs tonight, so flood watch remains in effect.
PW`s get quite high for December and the low level jet is pretty
strong, so potential for some heavier rain is certainly present,
but guidance is not exactly in great agreement regarding how
heavy the rain will be tonight. However, enough models show the
heavy rain signal such that there is no reason to take it out,
especially considering the extremely wet weather we`ve had all
year. Now that it is the cold season, the soil is even less
capable of absorbing significant rainfall, and without active
vegetation, runoff is significantly higher, so it will not take
as much rain to get flooding. Temps will likely be steady or
slowly rise overnight.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Rain likely tapers to showers on Saturday as the initial wave
moves east, but with the high PW air mass still in place,
heavier rain can still occur with showers through the day, so
the flood watch continues through the day. Some guidance is
hinting at a secondary burst of heavier rain Saturday night as
the upper low approaches and coastal low redevelopment occurs
just to our southeast, so its possible the flood watch may end
up getting extended into Sunday. With the surface system passing
east and winds becoming northerly by Sunday, Saturday will
likely be the warmest day just behind the initial push of
southerly winds, with a cooling trend Saturday night and temps
probably not changing much on Sunday. With the upper low finally
pulling east of us Sunday night, the chance of precip will
finally decline dramatically, so quickly taper pops by then.
Temps will also cool more, and whatever shower activity remains
could change to snow, most likely over the higher elevations,
but this doesn`t look like it will amount to much. Lows Sunday
night will drop back into the 30s.
(snip)

From here, global model solutions differ in the amplitude of an
upper trough crossing the Great Lakes Thursday and Thursday
night. GFS is much less amplified, and brings a cold front
through the area Thursday night with limited moisture. The ECMWF
on the other hand is significantly more amplified, stretching
the base of the upper trough all the way to the northern Gulf.
This allows for a surface low to develop along the Gulf Coast
states and tap into the Gulf moisture. This would bring much
more precipitation to the region as low pressure tracks up the
east coast Thursday night, with rain being the favored ptype.
Will carry middle of the road chance POPs Thursday and Thursday
night for now with near normal temperatures prevailing.

 

Updated flood watches from LWX

Flood Watch
National Weather Service Baltimore MD/Washington DC
429 AM EST Fri Dec 14 2018

DCZ001-MDZ004>006-011-013-014-016>018-503>508-VAZ036>040-050>057-
501-502-505-506-142000-
/O.CON.KLWX.FA.A.0008.181214T2300Z-181215T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
District of Columbia-Frederick MD-Carroll-Northern Baltimore-
Southern Baltimore-Prince Georges-Anne Arundel-Charles-St. Marys-
Calvert-Northwest Montgomery-Central and Southeast Montgomery-
Northwest Howard-Central and Southeast Howard-Northwest Harford-
Southeast Harford-Nelson-Albemarle-Greene-Madison-Rappahannock-
Orange-Culpeper-Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-Northern Fauquier-Southern Fauquier-Western Loudoun-
Eastern Loudoun-
Including the cities of Washington, Frederick, Ballenger Creek,
Eldersburg, Westminster, Reisterstown, Cockeysville, Baltimore,
Bowie, Suitland-Silver Hill, Clinton, College Park, Greenbelt,
Laurel, Camp Springs, Glen Burnie, Annapolis, Severn, South Gate,
Severna Park, Arnold, Odenton, St. Charles, Waldorf,
Lexington Park, California, Chesapeake Beach, Huntingtown,
Dunkirk, North Beach, Lusby, Prince Frederick, Germantown,
Damascus, Bethesda, Rockville, Gaithersburg, Silver Spring,
Lisbon, Columbia, Ellicott City, Jarrettsville, Aberdeen,
Lovingston, Charlottesville, Stanardsville, Madison, Orange,
Gordonsville, Culpeper, Dale City, Manassas, Woodbridge,
Lake Ridge, Montclair, Reston, Herndon, Annandale, Centreville,
Chantilly, McLean, Franconia, Arlington, Alexandria,
Falls Church, Falmouth, Fredericksburg, Dahlgren, Warrenton,
Turnbull, Purcellville, Leesburg, Ashburn, and Sterling
429 AM EST Fri Dec 14 2018

...FLOOD WATCH REMAINS IN EFFECT FROM THIS EVENING THROUGH
SATURDAY AFTERNOON...

The Flood Watch continues for

* Portions of Maryland, The District of Columbia, and Virginia,
  including the following areas, in Maryland, Anne Arundel,
  Calvert, Carroll, Central and Southeast Howard, Central and
  Southeast Montgomery, Charles, Frederick MD, Northern
  Baltimore, Northwest Harford, Northwest Howard, Northwest
  Montgomery, Prince Georges, Southeast Harford, Southern
  Baltimore, and St. Marys. The District of Columbia. In
  Virginia, Albemarle, Arlington/Falls Church/Alexandria,
  Culpeper, Eastern Loudoun, Fairfax, Greene, King George,
  Madison, Nelson, Northern Fauquier, Orange, Prince
  William/Manassas/Manassas Park, Rappahannock, Southern
  Fauquier, Spotsylvania, Stafford, and Western Loudoun.

* From this evening through Saturday afternoon

* Moderate rainfall is expected with locally heavy rain
  possible. Rainfall amounts around 1 to 2 inches are most
  likely with locally higher amounts around 3 inches possible.
  Runoff from the rainfall may cause creeks and streams to rise
  out of their banks as well as the potential for flooding in
  urban areas.

Flood Watch
National Weather Service Baltimore MD/Washington DC
429 AM EST Fri Dec 14 2018

MDZ003-VAZ025>031-507-508-WVZ050>053-055-142000-
/O.CON.KLWX.FA.A.0008.181214T2300Z-181215T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington-Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-
Clarke-Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-
Including the cities of Hagerstown, Staunton, Waynesboro,
Stuarts Draft, Harrisonburg, Strasburg, Woodstock, Mount Jackson,
New Market, Winchester, Luray, Shenandoah, Stanley, Front Royal,
Berryville, Big Meadows, Wintergreen, Romney, Paw Paw,
Martinsburg, Charles Town, Shepherdstown, and Moorefield
429 AM EST Fri Dec 14 2018

...FLOOD WATCH REMAINS IN EFFECT FROM THIS EVENING THROUGH
SATURDAY AFTERNOON...

The Flood Watch continues for

* Portions of north central Maryland, Virginia, and West
  Virginia, including the following areas, in north central
  Maryland, Washington. In Virginia, Augusta, Central Virginia
  Blue Ridge, Clarke, Frederick VA, Northern Virginia Blue
  Ridge, Page, Rockingham, Shenandoah, and Warren. In West
  Virginia, Berkeley, Hampshire, Hardy, Jefferson, and Morgan.

* From this evening through Saturday afternoon

* Moderate rainfall is expected with locally heavy rain possible.
  Rainfall amounts of 1 to 2 inches are most likely with locally
  higher amounts of 3 inches possible. Runoff from the rainfall
  combined with melted snow may cause creeks and streams to rise
  out of their banks as well as the potential for flooding in
  urban areas.

http://vdotplows.org/

Covering all of VA except for NOVA, Hampton Roads and the Eastern Shore.

As much as I had a snicker about the "deck" jokes...

Pictures of disks may be abounding.

For those who will be still alive.

Yes, I was car-free in my college days and had maintenance men (in that day) shovel and salt the walks.

And dug myself out repeatedly in 1996 and later.

But from the tone on this forum, I'm not certain some appreciate that some want s*** to NOT show up.

((Just put a s*** fence around me and DCA, and you can have all of that you want.))

Who stole the fuel for my flamethrower?

Seriously, 1.7 inches of "coating" in Arlington VA about 10 minutes ago.

Even Elkins is at 33F.

5 minutes ago, DSF said:

Baltimore City just announced they are opening on time. Hope they made the right call, because it's a disaster in this city when they're wrong. 

It might be.

6 am update:

DCA 38

BWI 35

IAD 34 with ice pellets

OH NO!!

Where's my flamethrower to defend DCA with???  It's got to be somewhere around here...

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
316 AM EST Wed Nov 14 2018

VAZ025-503-504-508-141630-
/O.CON.KLWX.WS.A.0006.181115T0600Z-181116T0600Z/
Augusta-Western Highland-Eastern Highland-
Central Virginia Blue Ridge-
316 AM EST Wed Nov 14 2018

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
LATE THURSDAY NIGHT...

* WHAT...Heavy mixed wintry precipitation possible. Total ice
  accumulations of one quarter inch or greater are possible.
  Total snow and sleet accumulation of several inches is also
  possible.

* WHERE...Augusta, Western Highland and Eastern Highland
  Counties, along with the Central Virginia Blue Ridge.

* WHEN...From late Wednesday night through late Thursday night.

* ADDITIONAL DETAILS...Slippery road conditions are possible.
  Scattered power outages and tree damage are possible due to
  the ice. The hazardous conditions could impact the morning and
  evening commutes on Thursday. Any ice accumulation on paved
  surfaces including driveways, sidewalks, and parking lots,
  could also create hazardous conditions for those venturing out
  on foot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

&&

$$

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
316 AM EST Wed Nov 14 2018

MDZ003-VAZ031-WVZ052-053-141630-
/O.EXA.KLWX.WS.A.0006.181115T0900Z-181116T1100Z/
Washington-Clarke-Berkeley-Jefferson-
316 AM EST Wed Nov 14 2018

...WINTER STORM WATCH IN EFFECT FROM LATE TONIGHT THROUGH LATE
THURSDAY NIGHT...

* WHAT...Heavy mixed wintry precipitation possible. Total ice
  accumulations of one quarter inch or greater are possible.
  Total snow and sleet accumulation of several inches is also
  possible.

* WHERE...Portions of western Maryland, western Virginia and
  eastern West Virginia.

* WHEN...From late Wednesday night through late Thursday night.

* ADDITIONAL DETAILS...Slippery road conditions are possible.
  Scattered power outages and tree damage are possible due to
  the ice. The hazardous conditions could impact the morning and
  evening commutes on Thursday. Any ice accumulation on paved
  surfaces including driveways, sidewalks, and parking lots,
  could also create hazardous conditions for those venturing out
  on foot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

&&

$$

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
316 AM EST Wed Nov 14 2018

MDZ501-502-VAZ026>030-507-WVZ050-051-055-501>506-141630-
/O.CON.KLWX.WS.A.0006.181115T0900Z-181116T1100Z/
Extreme Western Allegany-Central and Eastern Allegany-Rockingham-
Shenandoah-Frederick VA-Page-Warren-Northern Virginia Blue Ridge-
Hampshire-Morgan-Hardy-Western Grant-Eastern Grant-
Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
316 AM EST Wed Nov 14 2018

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
LATE THURSDAY NIGHT...

* WHAT...Heavy mixed wintry precipitation possible. Total ice
  accumulations of one quarter inch or greater are possible.
  Total snow and sleet accumulation of several inches is also
  possible.

* WHERE...Portions of western Maryland, western Virginia and
  eastern West Virginia.

* WHEN...From late Wednesday night through late Thursday night.

* ADDITIONAL DETAILS...Slippery road conditions are possible.
  Scattered power outages and tree damage are possible due to
  the ice. The hazardous conditions could impact the morning and
  evening commutes on Thursday. Any ice accumulation on paved
  surfaces including driveways, sidewalks, and parking lots,
  could also create hazardous conditions for those venturing out
  on foot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

Watches now up west of the Blue Ridge.

DCA hit 32 as of 3 am on the 11th.

On ‎11‎/‎8‎/‎2018 at 3:31 AM, arlwx said:

The actual date would be the 11th.

NWS is calling for RIC to hit it. It's warmed up to 31F at DCA, so close call.

What a switch since 11 Oct.

Update:  NWS is calling for 30F for DCA and 27F for RIC.

Freeze warning now posted for DCA, downtown Baltimore, and the Chesapeake Bay.

URGENT - WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
307 AM EST Sat Nov 10 2018


DCZ001-MDZ011-013-014-016>018-507-508-VAZ054-057-101615-
/O.CON.KLWX.FZ.W.0009.181111T0300Z-181111T1400Z/
District of Columbia-Southern Baltimore-Prince Georges-
Anne Arundel-Charles-St. Marys-Calvert-Northwest Harford-
Southeast Harford-Arlington/Falls Church/Alexandria-King George-
Including the cities of Washington, Baltimore, Bowie,
Suitland-Silver Hill, Clinton, College Park, Greenbelt, Laurel,
Camp Springs, Glen Burnie, Annapolis, Severn, South Gate,
Severna Park, Arnold, Odenton, St. Charles, Waldorf,
Lexington Park, California, Chesapeake Beach, Huntingtown,
Dunkirk, North Beach, Lusby, Prince Frederick, Jarrettsville,
Aberdeen, Arlington, Alexandria, Falls Church, and Dahlgren
307 AM EST Sat Nov 10 2018

...FREEZE WARNING REMAINS IN EFFECT FROM 10 PM THIS EVENING TO
9 AM EST SUNDAY...

* TEMPERATURES...As low as 30.

* IMPACTS...Freezing temperatures could kill sensitive
  vegetation and damage unprotected outdoor plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Freeze Warning means sub-freezing temperatures are imminent or
highly likely. These conditions will kill crops and other
sensitive vegetation.