000
FGUS71 KRNK 071248
ESFRNK
NCC005-009-033-157-169-171-189-193-197-VAC005-009-011-017-019-021-
023-029-031-035-037-045-063-067-071-077-083-089-121-141-143-155-
161-163-173-185-197-530-580-590-640-678-680-690-750-770-775-
WVC025-055-063-089-141300-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
748 AM EST FRI FEB 7 2020

...WINTER/SPRING FLOOD OUTLOOK...NUMBER 2

...RIVER FLOOD POTENTIAL HIGH WITH CURRENT FLOODING AND FORECAST
RAINFALL...

EACH WINTER AND EARLY SPRING, THE NATIONAL WEATHER SERVICE OFFICE
IN BLACKSBURG ISSUES A SERIES OF ROUTINE FLOOD POTENTIAL 
OUTLOOKS. THESE OUTLOOKS ESTIMATE THE POTENTIAL FOR RIVER
FLOODING (NOT FLASH FLOODING) ACROSS THE BLACKSBURG OFFICE`S 
HYDROLOGIC SERVICE AREA (HSA). THE HSA INCLUDES 40 COUNTIES 
COVERING PARTS OF SOUTHWEST VIRGINIA, FAR NORTHWEST NORTH CAROLINA
AND FAR SOUTHEAST WEST VIRGINIA. MAJOR RIVER BASINS IN THE HSA 
INCLUDE ALL OR PARTS OF THE NEW, GREENBRIER, TENNESSEE, JAMES, 
ROANOKE, DAN, AND YADKIN. THIS OUTLOOK IS BASED ON THE CURRENT 
ASSESSMENT OF HYDROMETEOROLOGICAL FACTORS WHICH CONTRIBUTE TO 
RIVER FLOODING. THESE FACTORS INCLUDE, BUT ARE NOT LIMITED TO, 
RECENT PRECIPITATION, SOIL MOISTURE, SNOW COVER AND SNOW WATER 
EQUIVALENT, STREAM FLOWS, RIVER ICE AND EXPECTED FUTURE WEATHER 
CONDITIONS.

IN THIS PART OF THE SOUTHERN APPALACHIAN AND MID-ATLANTIC REGION,
HEAVY RAINFALL IS THE PRIMARY FACTOR THAT LEADS TO RIVER 
FLOODING. HEAVY RAINFALL CAN RAPIDLY CAUSE RIVER FLOODING AT ANY 
TIME OF THE YEAR, EVEN WHEN OVERALL RIVER FLOOD POTENTIAL IS 
CONSIDERED LOW. SNOWMELT CAN CONTRIBUTE TO THE FLOODING AS IT DID
DRAMATICALLY IN JANUARY 1996, WHEN RAIN ON TOP OF RAPID SNOWMELT 
PRODUCED RECORD FLOODING THROUGHOUT PARTS OF THE MID-ATLANTIC 
REGION, INCLUDING THE GREENBRIER RIVER.

FLOOD POTENTIAL OUTLOOK:
FOR THE BLACKSBURG HSA, THE RIVER FLOOD POTENTIAL IS HIGH FOR THE
NEXT TWO WEEKS (THROUGH FEBRUARY 20TH) BASED PRIMARILY ON CURRENT
CONDITIONS AND THE POTENTIAL FOR ADDITIONAL HEAVY RAIN NEXT WEEK.

CURRENT FLOODING: 
THERE IS WIDESPREAD FLOODING OR NEAR-FLOOD CONDITIONS ACROSS THE
ENTIRE HSA DUE TO THE VERY HEAVY RAINS OVER THE PAST 48 HOURS.
STAGES ARE NEARING OR PAST CREST ON THE FASTER-RESPONDING RIVERS
BUT CRESTS ARE 1 TO 2 DAYS OUT ON SOME OF THE LARGER RIVERS.

RECENT PRECIPITATION: 
THE FIRST WEEK OF FEBRUARY HAS BEEN EXTREMELY WET WITH FLOODING
RAINFALL OVER THE PAST FEW DAYS OF APPROXIMATELY 3 TO 6 INCHES
ACROSS THE AREA. NUMEROUS DAILY RAINFALL RECORDS HAVE OCCURRED
OVER THE PAST TWO DAYS.

JANUARY PRECIPITATION WAS SLIGHTLY ABOVE AVERAGE WITH 3.77 INCHES
ACROSS THE COOP NETWORK VERSUS THE JANUARY MEAN OF 3.32 INCHES OR
118 PERCENT OF NORMAL. AMOUNTS RANGED FROM A LOW OF 1.93 INCHES AT
PRINCETON IN MERCER COUNTY, WV TO A MAXIMUM OF 6.85 AT BOONE 1 SE
IN WATAUGA COUNTY, NC. DECEMBER PRECIPITATION WAS ALSO SLIGHTLY 
ABOVE AVERAGE AT 3.92 INCHES VENUS THE LONG-TERM MEAN OF 3.32 
INCHES OR 118 PERCENT OF NORMAL. NOVEMBER WAS SLIGHTLY DRIER 
ACROSS THE REGION WITH MEAN PRECIPITATION OF 2.59 INCHES OR 76 
PERCENT OF THE NORMAL MEAN OF 3.42 INCHES.

DROUGHT:
NO DROUGHT CONDITIONS ARE CURRENTLY OBSERVED OR EXPECTED TO
DEVELOP THROUGH FEBRUARY 20TH WITHIN THE HSA.

PLEASE VISIT THE WWW.DROUGHTMONITOR.UNL.EDU/ FOR ACCESS TO THE 
DROUGHT MAPS AND ADDITIONAL INFORMATION.

SNOW COVER: 
SNOW COVER IS HYDROLOGICALLY INSIGNIFICANT WITH RAIN CHANGING TO
SNOW OVER JUST THE PAST FEW HOURS.

PLEASE VISIT WWW.NOHRSC.NOAA.GOV FOR DETAILED INFORMATION ON SNOW
COVER AND SNOW WATER EQUIVALENT.

RIVER ICE: 
THERE IS NO RIVER ICE ANYWHERE IN THE HSA AT THIS TIME.

STREAMFLOW:
USGS REAL-TIME AVERAGE STREAMFLOWS AT 7, 14 AND 28-DAY DURATIONS
ARE ALL INDICATING WELL ABOVE NORMAL FLOWS WITH NEARLY EVERY
GAGING STATION AT RECORD FLOWS FOR THIS DATE FOR DAILY FLOWS THIS
MORNING, FEBRUARY 7TH.

FOR MORE DETAILED INFORMATION ON STREAMFLOW CONDITIONS SEE THE 
USGS WATERWATCH WEBSITE: HTTPS://WATERWATCH.USGS.GOV

SOIL MOISTURE: 
SOIL MOISTURE ANALYSES FROM THE CLIMATE PREDICTION CENTER (CPC)
INDICATE NEAR-NORMAL SOIL MOISTURE AS OF FEBRUARY 5TH BUT DOES NOT
REFLECT THE RECENT RAINFALL WHICH HAS LIKELY PUSHED VALUES TO WELL
ABOVE NORMAL.

FOR ADDITIONAL SOIL MOISTURE INFORMATION SEE: 
HTTP://WWW.CPC.NCEP.NOAA.GOV

RESERVOIRS: 
MAJOR WATER SUPPLY RESERVOIRS INCLUDING JOHN H. KERR, W. KERR
SCOTT, PHILPOTT LAKE, LAKE MOOMAW, SMITH MOUNTAIN LAKE, AND THE
WESTERN VA WATER AUTHORITY RESERVOIRS NEAR ROANOKE ARE ALL AT FULL
CAPACITY OR IN FLOOD CONTROL OPERATIONS.

FUTURE WEATHER CONDITIONS: 
QUANTITATIVE PRECIPITATION FORECASTS (QPF) FROM THE WEATHER
PREDICTION CENTER (WPC) OVER THE NEXT 7 DAYS (THROUGH 7 AM FRIDAY
FEBRUARY 14TH) INDICATE RAINFALL AMOUNTS RANGING FROM 1 TO 2
INCHES ACROSS THE AREA WITH THE HIGHEST OVER THE SOUTHER CWA.
MOST OF THIS PRECIPITATION WILL FALL AS RAIN.

WPC QPF IS UPDATED FREQUENTLY AND IS AVAILABLE AT: 
WWW.WPC.NCEP.NOAA.GOV/#PAGE=QPF

THE LONGER TERM OUTLOOKS FOR THE 6 TO 10 AND 8 TO 14 DAY PERIODS 
THROUGH FEBRUARY 20TH INDICATE INCREASED PROBABILITIES FOR BOTH 
TEMPERATURES AND PRECIPITATION TO BE ABOVE NORMAL ACROSS THE HSA.

PROBABILISTIC/ENSEMBLE RIVER FORECASTS: 
THE METEOROLOGICAL MODEL ENSEMBLE RIVER FORECASTS (MMEFS) FROM THE
GEFS AND NAEFS ENSEMBLES VALID THROUGH ABOUT FEBRUARY 13 INDICATE
SOME RIVERS MAY RISE BACK TO NEAR FLOOD STAGE BY LATE IN THE 
PERIOD IN RESPONSE TO ANTICIPATED RAINFALL.

ENSEMBLE RIVER FORECASTS (MMEFS) ARE AVAILABLE AT: 
WWW.WEATHER.GOV/ERH/MMEFS

SUMMARY:
THE RIVER FLOOD POTENTIAL IS WELL ABOVE NORMAL THROUGH THE OUTLOOK
PERIOD, BASED ON CURRENT FLOOD CONDITIONS AND FORECASTS FOR
ADDITIONAL.


$$

PC

  US Dept of Commerce
  National Oceanic and Atmospheric Administration
  National Weather Service
  1325 East West Highway
  Silver Spring, MD 20910
  Page Author: NWSChat Administration Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy  
Freedom of Information Act (FOIA)  
About Us  
Career Opportunities