Tag Archives: miller a

February 12-13, 2014: Observations (Pax)

Event Updates:

As of 3:30 PM on 2/13, there is approximately 1.5″ of snow/sleet on the majority of surfaces in Church Hill. Temperature continues to slowly fall and is hovering at 34 degrees Fahrenheit. Rain has changed to sleet and now snow.

Radar from afternoon of 2/13/2014

Radar from evening of 2/12/2014
Radar from evening of 2/12/2014

Church Hill Storm Observation Summary:
* Place – Time: Church Hill, (2/13/2014)
* Temperature: 25-37, During Event
* Winter Weather Watch/Warning/Advisory: Warning
* Closings: Chesterfield Government Closed on 2/13/14
* Road Conditions: All roads covered during event, primary roads cleared by the morning of 2/13. However, secondary roads were still partially snow covered.
* Precipitation Description: Snow, sleet, freezing rain and rain. Initial snow was very fine and powdery snowflakes. Event transitioned from snow to sleet near 11 PM on 2/12. Sleet changed to freezing rain by 1:00 AM on 2/13/14. Rain and Drizzle followed during the early morning hours until 2 PM on 2/13/14. Sleet and the sleet to snow transitioned back into Richmond by 3:30 PM.
* Total Precipitation: 5.75″ (4.25” of snow on 2/12, 1.5″ of snow on 2/13). Approximately 0.25″ of sleet. Minor accumulations of freezing rain. 3.7″ inches of snow was reported at the airport on 2/12, 2.1″ inches of snow was reported at the airport on 2/12 for a total of 5.8″. Snowfall totals were heavier towards the peidmont and mountains in western Virginia (6-21” was common).
* Comments: Snow began near 4 PM at the Chesterfield Courthouse on 2/12/14. Nearly .75″ had accumulated by 5:30 PM when I left work. My commute home took nearly an hour, which is about twice as long as it normally takes. Heavy snow occurred for about an hour between 9-10 PM when about an inch of snow fell. The precipitation quickly transitioned to sleet. Freezing rain then set in late in the evening after I went to bed. As the storm wrapped up on 2/13, drizzle changed to a brief round of heavy sleet and rain with two loud rumbles of thunder. An hour later, the second round of precipatation hit with moderate to heavy snowfall. The snow tapered off by 7 PM dropping another 1.5″ of snow.

Snowfall Totals:

NWS Updated Snowfall Map for 2/12-2/13
NWS Updated Snowfall Map for 2/12-2/13

Videos:

NWS Special Weather Statement:

Special Weather Statement

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WAKEFIELD VA
358 PM EST THU FEB 13 2014

VAZ063-070>072-080>083-132230-
HANOVER-CHESTERFIELD-HENRICO-KING WILLIAM-DINWIDDIE-PRINCE GEORGE-
CHARLES CITY-NEW KENT-
INCLUDING THE CITIES OF...ASHLAND...COLONIAL HEIGHTS...RICHMOND...
PETERSBURG...HOPEWELL
358 PM EST THU FEB 13 2014

...A BAND OF MODERATE TO HEAVY SNOW TO MOVE ACROSS THE INTERSTATE 95
CORRIDOR THROUGH 530 PM...

A BAND OF MODERATE TO HEAVY SNOW WILL MOVE ACROSS THE INTERSTATE
95 CORRIDOR FROM THE TRI-CITIES TO RICHMOND THRU 530 PM. THE SNOW
WILL COME DOWN HARD ENOUGH TO REDUCE THE VISIBILITY TO AROUND ONE
QUARTER MILE AND QUICKLY COVER ROAD SURFACES. A COATING TO UP TO ONE
INCH OF SNOW IS POSSIBLE WITH THIS BAND OF SNOW. MOTORISTS SHOULD
USE CAUTION AND SLOW DOWN IF TRAVELING LATE THIS AFTERNOON. BE
PREPARED FOR POOR VISIBILITIES AND SLIPPERY ROAD CONDITIONS.

$$

JM

February 12-13, 2014: Winter Storm Warning

Late evening update on the latest snowfall forecast from the NWS and their text on the Winter Storm Warning:

NWS Snowfall Forecast, Evening of 2/11/14.
NWS Snowfall Forecast, Evening of 2/11/14.

Winter Storm Warning Text:

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE WAKEFIELD VA
551 PM EST TUE FEB 11 2014

VAZ065-066-070-071-079-080-121200-
/O.CON.KAKQ.WS.W.0003.140212T1800Z-140214T0000Z/
MECKLENBURG-LUNENBURG-CHESTERFIELD-HENRICO-BRUNSWICK-DINWIDDIE-
INCLUDING THE CITIES OF...SOUTH HILL...COLONIAL HEIGHTS...
RICHMOND...LAWRENCEVILLE
551 PM EST TUE FEB 11 2014

...WINTER STORM WARNING REMAINS IN EFFECT FROM 1 PM WEDNESDAY TO
7 PM EST THURSDAY...

A WINTER STORM WARNING REMAINS IN EFFECT FROM 1 PM WEDNESDAY TO
7 PM EST THURSDAY.

* LOCATIONS...PORTIONS OF CENTRAL VIRGINIA.

* TIMING...WEDNESDAY AFTERNOON THROUGH THURSDAY EVENING.

* HAZARDS...SNOW AND SLEET...POSSIBLY MIXED WITH FREEZING RAIN
  OVER SOUTHERN SECTIONS. A CHANGEOVER TO PLAIN RAIN IS POSSIBLE
  FOR A BRIEF PERIOD ALONG THE INTERSTATE 95 CORRIDOR EARLY
  THURSDAY.

* ACCUMULATIONS...SNOW ACCUMULATIONS OF 4 TO 8 INCHES...WITH THE
  HEAVIEST ACCUMULATIONS EXPECTED WEST OF INTERSTATE 95. A TRACE
  TO A TENTH OF AN INCH OF ICE ACCUMULATION IS ALSO POSSIBLE.

* IMPACTS...SNOW AND ICE CAN LEAD TO SLICK AND HAZARDOUS TRAVEL
  CONDITIONS AS IT ACCUMULATES ON ROADWAYS. THE SNOW IS EXPECTED
  TO BE HEAVY AND WET...AND MAY WEIGH DOWN ON TREE LIMBS AND
  POWER LINES. SPORADIC POWER OUTAGES ARE POSSIBLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS SIGNIFICANT AMOUNTS OF SNOW...
SLEET...AND ICE ARE EXPECTED OR OCCURRING. STRONG WINDS ARE ALSO
POSSIBLE.  THIS WILL MAKE TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

&&

$$

February 12-13, 2014: Heavy Snow from Miller A?

Another 24 hours has passed and models still trending towards a complex weather system impacting the area tomorrow into Thursday morning. Below are some graphics on the storm system. In addition, language for the winter storm watch is also posted.

NWS Forecast from morning of 2/11/14,.
NWS Forecast from morning of 2/11/14,.
NWS Forecast from the morning of  2/11/14.
NWS Forecast from the morning of 2/11/14.

 

NWS Forecast Discussion:

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/…

— Changed Discussion —

SIGNIFICANT WINTER STORM PRIMED TO IMPACT THE REGION LATE

WEDNESDAY THROUGH THE DAY THURSDAY…

 

OVERVIEW…

MODELS HAVE COME INTO GOOD AGREEMENT AS AFOREMENTIONED NRN AND SRN

STREAM ENERGY WL PHASE INTO A POTENT SHORTWAVE OVER THE GULF STATES

WED/WED NIGHT. CLOUDS WILL INCREASE LATE TONIGHT AND EARLY WED AS

THE SYSTEM APPROACHES FROM THE SOUTH. CYCLOGENESIS IS EXPECTED TO

OCCUR OVER THE NERN GULF WED PM, AS AMPLIFYING FLOW BEGINS TO LIFT

MOISTURE NWD. SFC HIGH PRESSURE TO THE NORTH WILL BEGIN TO

RETREAT…BUT WILL REMAIN RIDGED DOWN ACROSS NORTH CENTRAL VA.

STRONG SPEED MAX WILL EMERGE FROM THE BASE OF THE SHORTWAVE…FURTHER

ENHANCING THE FLOW OVER THE SE, WHICH WILL SERVE TO EJECT THE

SHORTWAVE NE. A WINTER STORM WATCH REMAINS IN EFFECT FOR THE CWA

WITH THE EXCEPTION OF THE SOUTHERN TIDEWATER AND NE NC. IF CURRENT

TRENDS HOLD WITH 12Z SUITE, UPGRADES TO WARNINGS/ADVISORIES WOULD

BE NEEDED TODAY OR THIS EVENING. MANY FACETS TO THIS EVENT…WHICH

BREAK DOWN AS FOLLOWS:

 

PRECIPITATION…

MODEL CONSENSUS HAS SLOWED ONSET OF PCPN BY A FEW HOURS, BUT

GIVEN THAT WAA PRECIP/OVERRUNNING IS OFTEN REALIZED QUICKER THAN

MODELS INDICATE, DID NOT CHANGE ONSET TIMING FROM PREVIOUS

FORECAST. MODELS IN GENERAL AGREEMENT WITH THE TRACK OF THE SFC

LOW…LIFTING IT ALONG THE SE COAST LATE WED TO JUST OFFSHORE LATE

WED NIGHT-EARLY THURS MORNING. 11/00Z ECMWF TRACKS THE LOW ALONG

THE SE COASTAL PLAIN AND INTO SE VA/NE NC THU MORNING.

 

CHC POP WED MORNING/AFTN RAMP UP TO CATEGORICAL POPS WED AFTN/NIGHT

AS THE POTENT SHORTWAVE AND STRONG WINDS ALOFT PROVIDE DYNAMICAL

FORCING FOR ASCENT (STRONG AGEOSTROPHIC LIFT) OVER THE MID-

ATLANTIC. STRONG HEIGHT FALLS WILL ALSO PRODUCE STRONG Q-VECTOR

CONVERGENCE/FRONTOGENETIC FORCING OVER THE REGION (STRONGEST

BETWEEN H6-7). THIS RESULTS IN PERIODS OF MODERATE PRECIP

UNDERNEATH THIS BANDING. PRECIP WILL BEGIN AS ALL SNOW FOR ALL BUT

FAR SE WHERE TEMPS WILL BE WARM ENOUGH FOR RAIN…POSSIBLY A BRIEF

PERIOD OF SLEET AS LAYER MOISTENING ENSUES. THE PERIOD OF HEAVIEST

SNOWFALL LOOKS TO BE WED EVENING INTO EARLY THU MORNING. SFC LOW

APPROACHES COASTAL PLAIN FROM THE SOUTH, AND WARM AIR MOVING IN

ALOFT SHOULD START MIXING IN SOME SLEET, EVENTUALLY CHANGING THE

SNOW OVER TO SLEET OR R/ZR PER BUFR SOUNDINGS. PRECIP WILL BEGIN

TO TRANSITION TO ALL RAIN OVER THE SE…BUT REMAIN ALL SNOW OVER

THE PIEDMONT. A MIXED BAG OF PRECIP FROM SOUTH CENTRAL VA INTO

EAST-CENTRAL VA (MAINLY I-95 EAST) AS A WARM NOSE WARMS TEMPS TO

~2-4C BTWN 950 AND 850MB. THIS WILL PRODUCE PERIODS OF

SNOW/SLEET/RAIN/FREEZING RAIN. STILL TOO EARLY TO IRON OUT EXACT

PTYPES IN THIS TRANSITION ZONE…BUT IT SEEMS VERY POSSIBLE THAT

THERE COULD BE ACCUMULATING ICE ON TOP OF SEVERAL INCHES OF SNOW

OVER CNTRL VA. DRY AIR WILL BEGIN TO PUNCH INTO THE SE AS THE LOW

LOCATES JUST OFF THE VA COAST THU MORNING, WHICH WILL EVENTUALLY

TURN INTO JUST LGT RA/DZ ACROSS THE SE AS MOISTURE ALOFT SLACKENS.

MEANWHILE, MOISTURE AXIS WILL LOCATE FROM THE PIEDMONT INTO NRN VA

AND THE MD ERN SHORE. MODELS INDICATE STRONG DYNAMICS IN THIS

MOISTURE AXIS WITH STRONG LIFT IN THE SNOW GROWTH LEVEL. MODEL GEO

POT VORT IS ALSO NEGATIVE IN THIS REGION…WHICH ALSO PORTENDS TO

POSSIBLY ENHANCING BANDING BEHIND THE DEPARTING LOW. WILL MAINTAIN

LIKELY POPS ACROSS THE REGION THURS AFTERNOON AS THE PV ANOMALY

CATCHES UP WITH THE LOW. THIS WILL CAUSE THE LOW TO OCCLUDE AND

SLOW ITS FORWARD PROGRESS. WILL NEED TO MONITOR THIS AREA AS TEMPS

MAY BE WARM ENOUGH FOR RAIN…BUT DYNAMIC COOLING MAY TRANSITION

IT BACK TO SNOW BEFORE PCPN TAPERS OFF.

 

TEMPERATURE…

OBVIOUSLY DEPENDANT ON EXACT TRACK. USED A BLENDED SOLUTION FROM THE

ECMWF/CMC/NAM (BLENDED IN THAT ORDER) FOR TEMPS/THICKNESSES.

OPERATIONAL ECMWF WAS A SHADE EAST IN THIS LAST 00Z RUN…AND HENCE

THE FORECAST HAS SHIFTED THE MIXED PRECIP AXIS FARTHER WEST. HIGHS

WED GENERALLY IN THE L30S INLAND…TO U30S IMMEDIATE COAST. LOWS WED

NIGHT IN THE 20S NW TO MID 30S SE. IGNORED NUMERICAL GUIDANCE FOR

MAXIMA ON THU FORECAST AS THEY ARE TYPICALLY TOO HIGH IN ONGOING

PCPN. UNDERCUT GUIDANCE AND KEPT HIGHS IN THE MID 30S INLAND…TO

LOW 40S COASTAL AREAS.

 

QPF/SNOWFALL TOTALS…

GENERALLY ACCEPTED WPC GUIDANCE FOR QPF AMOUNTS, THOUGH DID MIX IN A

BLEND OF AFOREMENTIONED MODEL GUIDANCE. QPF RANGE FROM ONE INCH NW

TO AN INCH AND THREE QUARTERS SE.

 

SNOWFALL AMOUNTS WILL RANGE FROM 10-14 INCHES OVER THE PIEDMONT

(ALL SNOW) TO 5-10 INCHES ALONG THE I-95 CORRIDOR…WITH 3-5″ FOR

THE NRN NECK/PENINSULA…WESTERN TIDEWATER AND INTR NE NC (LOWER

AMOUNTS IN CNTRL VA DUE TO WINTRY MIX). LITTLE…IF ANY

ACCUMULATION IN S/E TIDEWATER. IN MARYLAND, HIGHEST TOTALS WILL BE

IN USUAL SPOTS N/W OF 50 IN WICOMICO/DORCHESTER COUNTIES…WITH

MIXING RESULTING IN LOWER TOTALS ALONG AND EAST OF 13. PLEASE

REFER TO SNOWFALL GRAPHICS FOR MORE INFO.

— End Changed Discussion —

Winter Storm Watch:

URGENT – WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE WAKEFIELD VA
1026 AM EST TUE FEB 11 2014

NCZ012-VAZ065-066-070-071-079>081-087>089-092-093-112330-
/O.CON.KAKQ.WS.A.0003.140212T1700Z-140213T2300Z/
NORTHAMPTON NC-MECKLENBURG-LUNENBURG-CHESTERFIELD-HENRICO-
BRUNSWICK-DINWIDDIE-PRINCE GEORGE-GREENSVILLE-SUSSEX-SURRY-
SOUTHAMPTON-ISLE OF WIGHT-
INCLUDING THE CITIES OF…MARGARETTSVILLE…SOUTH HILL…
COLONIAL HEIGHTS…RICHMOND…LAWRENCEVILLE…PETERSBURG…
HOPEWELL…EMPORIA…WAKEFIELD…FRANKLIN
1026 AM EST TUE FEB 11 2014

…WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY AFTERNOON
THROUGH THURSDAY AFTERNOON…

A WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY AFTERNOON
THROUGH THURSDAY AFTERNOON.

* LOCATIONS…PORTIONS OF CENTRAL AND EASTERN VIRGINIA.

* TIMING…LATE WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON.

* HAZARDS…HEAVY SNOW AND SLEET…POSSIBLY MIXED WITH FREEZING
  RAIN OVER EASTERN SECTIONS. A CHANGEOVER TO RAIN IS
  ANTICIPATED OVER EASTERNMOST SECTIONS OF THE WATCH AREA LATE
  WEDNESDAY NIGHT

* ACCUMULATIONS…THE POTENTIAL FOR 6 OR MORE INCHES OF SNOW…
  WITH HEAVIEST ACCUMULATIONS EXPECTED MAINLY ALONG AND WEST OF
  I- 95. A LIGHT ACCUMULATION OF ICE WILL ALSO BE POSSIBLE.

* IMPACTS…SNOW AND SLEET CAN LEAD TO SLICK AND HAZARDOUS
  TRAVEL CONDITIONS AS IT ACCUMULATES ON ROADWAYS. THE SNOW IS
  EXPECTED TO BE HEAVY AND WET…AND MAY WEIGH DOWN ON TREE
  LIMBS AND POWER LINES. SPORADIC POWER OUTAGES ARE POSSIBLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW…SLEET…OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

February 12-13, 2014: Forecast for Heavy Snow to Mix?

Chance of more than 8" of snow on Day 3, NWS
Chance of more than 8″ of snow on Day 3, NWS

The Eurpoean Weather model has been showing hints of a winter storm since last Thursday (2/6) for the middle of this week. As we are within 48 hours of the storm, several more weather models are on board with a significant storm scenario for Central Virginia. While it is still early to issue snowfall forecasts, certain models have pegged Richmond for as much as 6″ to 25″ of snow. A wide range that can vary based on the track and intensity of the storm.

NAM 12Z 84-Hour Snowfall Accumulation
NAM 12Z 84-Hour Snowfall Accumulation

The NAM model above is likely overdone in snow totals since it is projecting totals for the later hours of its run (shown for the novelity factor only).

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE WAKEFIELD VA
410 PM EST MON FEB 10 2014

NCZ012-VAZ065-066-070-071-079>081-087>089-092-093-111200-
/O.NEW.KAKQ.WS.A.0003.140212T1700Z-140213T2300Z/
NORTHAMPTON NC-MECKLENBURG-LUNENBURG-CHESTERFIELD-HENRICO-
BRUNSWICK-DINWIDDIE-PRINCE GEORGE-GREENSVILLE-SUSSEX-SURRY-
SOUTHAMPTON-ISLE OF WIGHT-
INCLUDING THE CITIES OF...MARGARETTSVILLE...SOUTH HILL...
COLONIAL HEIGHTS...RICHMOND...LAWRENCEVILLE...PETERSBURG...
HOPEWELL...EMPORIA...WAKEFIELD...FRANKLIN
410 PM EST MON FEB 10 2014

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THURSDAY AFTERNOON...

THE NATIONAL WEATHER SERVICE IN WAKEFIELD HAS ISSUED A WINTER
STORM WATCH...WHICH IS IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THURSDAY AFTERNOON.

* LOCATIONS...PORTIONS OF CENTRAL AND EASTERN VIRGINIA.

* TIMING...WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON.

* HAZARDS...SNOW AND SLEET...POSSIBLY MIXED WITH FREEZING RAIN.
  MUCH OF THIS AREA WILL CHANGE TO MAINLY RAIN ON THURSDAY.

* ACCUMULATIONS...THE POTENTIAL FOR 4 OR MORE INCHES OF
  SNOW...ALONG WITH A LIGHT ACCUMULATION OF ICE.

* IMPACTS...SNOW AND SLEET CAN LEAD TO SLICK AND HAZARDOUS TRAVEL
  CONDITIONS AS IT ACCUMULATES ON ROADWAYS. THE SNOW IS EXPECTED TO
  BE HEAVY AND WET...AND MAY WEIGH DOWN ON TREE LIMBS AND POWER
  LINES. SPORADIC POWER OUTAGES ARE POSSIBLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.