Alert archive / North Carolina / River Flood Warnings in 2018

River Flood Warning 64, NWS Raleigh, NC

December 21, 2018Alamance County, North Carolina

NWS Raleigh, NC issued this river flood warning at Dec 21, 2018, 2:40 AM EST for Alamance County, North Carolina. It took effect at Dec 21, 2018, 3:05 AM EST. It was in force for 10 hr.

The area

The outline as issued.

The facts

Issued
Dec 21, 2018, 2:40 AM EST (07:40 UTC)
In effect from
Dec 21, 2018, 3:05 AM EST
Expired
Dec 21, 2018, 12:44 PM EST
In force
10 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
Minor

County Alamance County, NC

The radar

The Raleigh/Durham radar (KRAX), 95 km from the middle of the area, began a volume at 07:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The river

Written for the forecast point Haw River at Haw River (HAWN7). The gauge peaked at 18.78 ft at Dec 21, 2018, 6:00 AM EST.

actionminormoderate510152012/2112/22
Action stage
16 ft
Minor stage
18 ft
Moderate stage
23 ft
Major stage
27 ft

This gauge today: stage, forecast and historic crests

Stage from the USGS instantaneous record for site 02096500, one reading an hour, from a day before the product to a day after it ended. Flood stages are today's.

The text

As transmitted.

992 
WGUS42 KRAH 210740
FLWRAH


BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Raleigh, NC
240 AM EST Fri Dec 21 2018



...The National Weather Service in Raleigh has issued a
Flood Warning for the following rivers in North Carolina...

  Haw River At Haw River affecting Alamance County


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Safety message. If you encounter deep water while driving, do not 
attempt to drive through. Turn around, dont drown.

&&

NCC001-211939-
/O.NEW.KRAH.FL.W.0064.181221T0805Z-181222T0300Z/
/HAWN7.1.ER.181221T0805Z.181221T1200Z.181221T1500Z.NO/
240 AM EST Fri Dec 21 2018

The National Weather Service in Raleigh has issued a 

* Flood Warning for 
  The Haw River At Haw River.
* until this evening, or until the warning is cancelled.
* At  2:16 AM Friday the stage was 17.8 feet.
* Flood stage is 18.0 feet.
* Minor flooding is forecast.
* Forecast...The river is expected to rise above flood stage by early
  this morning and continue to rise to near 18.9 feet by this 
  morning.The river will fall below flood stage by late this morning.
* Impact...At 18.0 feet, Overflow begins on both banks at the water 
  treatment plant. 

&&

The following are the latest observations and 7 AM forecast stages
for the next several days.


                 FLD  OBSERVED                FORECAST 7 AM
LOCATION         STG  STG  DAY TIME    Sat   Sun   Mon   Tue   Wed

Haw River
 Haw River        18  17.8 Fri 02 AM  15.0  11.6   9.2   7.5      


&&

LAT...LON 3624 7953 3613 7934 3590 7918 3585 7930
          3604 7944 3613 7954         

$$
2 follow-up statements
318 
WGUS82 KRAH 211429
FLSRAH


Flood Statement 
National Weather Service Raleigh, NC
929 AM EST Fri Dec 21 2018

...The Flood Warning continues for the following rivers in North 
Carolina...

  Haw River At Haw River affecting Alamance County

  Haw River Near Bynum affecting Chatham County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Safety message. If you encounter deep water while driving, do not 
attempt to drive through. Turn around, dont drown.

&&

NCC001-220229-
/O.EXT.KRAH.FL.W.0064.000000T0000Z-181222T0916Z/
/HAWN7.1.ER.181221T0739Z.181221T1131Z.181221T2116Z.NO/
929 AM EST Fri Dec 21 2018

The Flood Warning continues for
  the Haw River At Haw River.
* At  9:16 AM Friday the stage was 18.4 feet.
* Flood stage is 18.0 feet.
* Minor flooding is occurring and Minor flooding is forecast.
* Impact...At 20.0 feet, There is significant overflow on the right 
  bank opposite the water treatment plant.
* Impact...At 18.0 feet, Overflow begins on both banks at the water 
  treatment plant. 

&&

The following are the latest observations and 7 AM forecast stages
for the next several days.


                 FLD  OBSERVED                FORECAST 7 AM
LOCATION         STG  STG  DAY TIME    Sat   Sun   Mon   Tue   Wed

Haw River
 Haw River        18  18.4 Fri 09 AM  15.6  11.7   9.2   7.5   6.2


&&

LAT...LON 3624 7953 3613 7934 3590 7918 3585 7930
          3604 7944 3613 7954         

$$

NCC037-220229-
/O.EXT.KRAH.FL.W.0063.000000T0000Z-181222T2308Z/
/BYNN7.1.ER.181221T0552Z.181221T1800Z.181222T1108Z.NO/
929 AM EST Fri Dec 21 2018

The Flood Warning continues for
  the Haw River Near Bynum.
* At  9:01 AM Friday the stage was 12.4 feet.
* Flood stage is 11.0 feet.
* Minor flooding is occurring and Minor flooding is forecast.
* Forecast...The river will continue rising to near 12.5 feet by this
  afternoon. The river will fall below flood stage tomorrow morning.
* Impact...At 11.0 feet, The river widens up to 400 feet across. It 
  floods pasturelands on the right bank and woodlands on the left.

&&

The following are the latest observations and 7 AM forecast stages
for the next several days.


                 FLD  OBSERVED                FORECAST 7 AM
LOCATION         STG  STG  DAY TIME    Sat   Sun   Mon   Tue   Wed

Haw River
 Bynum            11  12.4 Fri 09 AM  10.9   9.0   7.7   6.9   6.4


&&

LAT...LON 3590 7918 3582 7911 3576 7905 3569 7916
          3585 7930                   

$$
759 
WGUS82 KRAH 211744
FLSRAH


Flood Statement 
National Weather Service Raleigh, NC
1244 PM EST Fri Dec 21 2018

...The Flood Warning is cancelled for the following rivers in North 
Carolina...

  Haw River At Haw River affecting Alamance County


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Safety message. If you encounter deep water while driving, do not 
attempt to drive through. Turn around, dont drown.

&&

NCC001-211814-
/O.CAN.KRAH.FL.W.0064.000000T0000Z-181222T0916Z/
/HAWN7.1.ER.181221T0739Z.181221T1131Z.181221T1608Z.NO/
1244 PM EST Fri Dec 21 2018

The Flood Warning is cancelled for
  the Haw River At Haw River.
* At 12:31 PM Friday the stage was 17.7 feet.
* Flood stage is 18.0 feet.
* The river fell below flood stage at 11:08 AM Friday.
* Forecast...The river will continue to fall to 14.8 feet by tomorrow
  morning.
* Impact...At 18.0 feet, Overflow begins on both banks at the water 
  treatment plant. 

&&

The following are the latest observations and 7 AM forecast stages
for the next several days.


                 FLD  OBSERVED                FORECAST 7 AM
LOCATION         STG  STG  DAY TIME    Sat   Sun   Mon   Tue   Wed

Haw River
 Haw River        18  17.7 Fri 01 PM  14.8  11.7   9.2   7.5   6.2


&&

LAT...LON 3624 7953 3613 7934 3590 7918 3585 7930
          3604 7944 3613 7954         

$$

What forecasters said that day

The local office's own words before this river flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Raleigh, NC wrote its last area forecast discussion before this river flood warning went out at Dec 21, 12:55 AM EST, 1 hour 45 minutes earlier.

Area forecast discussion, Dec 21, 12:55 AM EST, 1 hour 45 minutes before
Area Forecast Discussion
National Weather Service Raleigh NC
1255 AM EST Fri Dec 21 2018

.SYNOPSIS...
A storm system will continue to track northeast through central
North Carolina through Friday bringing unsettled conditions to our
area. This storm system will move off the East Coast Saturday,
allowing high pressure to build over the Southeast U.S. Saturday
night through Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1020 PM Thursday...

Not much change to previous forecast, still adjusting temperatures
based on the northwestward progression of the warm front and the
convective showers lifting through portions of central NC.

The aforementioned warm front is slowly continuing to drift
northwestward, bisecting the Triad as of 01Z and through Winston-
Salem as of 03Z. Temperatures rise significantly in the wake of the
fropa, with increases of 5-10 degrees or more in the span of a few
hours. Along and east of US-1 temperatures are generally in the mid
60s, with low 60s between US-1 and I-85 and low to mid 50s at points
northwest of there. The overall coverage of precipitation continues
to decrease, however the intensity of some of the showers has
increased. While the best chance for any severe weather remains
along the coast, there is still a slight chance for some isolated
strong winds over central NC. The chance best chance will be over
the next couple of hours, after that the chances wane.

There are several surface lows over Southeast and Mid-Atlantic
regions, however the closest was over WV/VA as of 02Z. As the low
lifts northeast overnight, expect some decrease in both coverage and
intensity of rain across the area. Another low, currently over
AL/GA, will slowly lift northeastward toward the area overnight. The
primary surface low, cold front and upper level low will remain west
of the mountains tonight, but will bee an issue Friday.

Temperatures should be topping out in the next couple of hours,
slowly decreasing thereafter. With temperatures currently in the low
to mid 60s across much of the area, only expect them to bottom out a
category or two lower, mid 50s to low 60s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 300 PM Thursday...

The upper trough axis will maintain its slight negative tilt as it
moves over the Eastern US, its axis shifting overhead and just to
our ENE Fri night. DPVA/height falls aloft along with still-potent
upper divergence and elevated PW (150% of normal) will necessitate
good chance to likely pops for showers, although the loss of
Atlantic inflow as deep layer winds veer to SSW and the reduced PW
and retreat of the highest dewpoints to our NNE should trim coverage
and intensity Fri as compared to today's rainfall. Have decreased
POPs/QPF slightly, slowly shifting SW to NE in tandem with passage
of the 850-500 mb trough axis. Winds will remain southerly to begin
the day, especially across the central Piedmont, where gusts higher
than 30kts possible as some mixing is allowed on Friday. Further
veering of low and mid level winds to W and NW in the wake of the
low will bring in drier air late Fri night, and will end pops
shortly after midnight with a trend toward clearing skies W to E.
Highs 56-67 (NW to SE), followed by lows in the upper 30s to lower
40s with the onset of cold air advection overnight.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 300 PM Thursday...

Saturday morning an upper level trough axis will be heading east
with surface high pressure located over the Gulf of Mexico.
Highs from around 50 degrees with lows in the lower 30s looks
likely with no precipitation in the forecast. During the day
Sunday a shortwave will head east out of the central United
States and move across central North Carolina. The front looks
to cross the zones Sunday evening and appears to be weak.
Saturated theta-e compaction is very weak and a pre-frontal
trough exists which will limit surface convergence. Monday into
Tuesday surface high pressure will move overhead with more dry
weather and near normal temperatures.

Towards the end of the extended models diverge with the general
idea being a closed low over the southwestern United States and
heights slowly rising over North Carolina. As this occurs
another cold front will move across the area with the next
system rapidly approaching the area Thursday.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
As of 1255 AM Friday...

Aviation conditions will remain mostly MVFR through the rest of the
nighttime hours, but with brief periods of both IFR cigs (as
scattered lower clouds become broken at times) and VFR cigs (as
holes develop in the MVFR cloud deck, revealing higher clouds
above). The greatest chance of IFR cigs will be at INT, close to the
westward-drifting warm frontal zone. Vsbys across the area will be
mostly VFR but will periodically become MVFR, primarily within
scattered showers that persist over the region. Winds will remain
from the SSE and S with infrequent gusts to around 15 kts.

After daybreak, cigs will begin to lift slowly and break up,
occurring first at RWI/FAY during the mid to late morning, when we
may even see a period of VFR conditions. MVFR cigs will linger
longer at RDU/INT/GSO, although enough holes may develop in the MVFR
cloud deck to flip to VFR at these locations after 17z. Showers will
gradually dwindle from S to N during the morning, as low pressure
tracks northward over the S Appalachians while slightly drier air
moves into central NC from the S. But the risk of showers will
remain through the day, especially at INT/GSO, as a strong upper
level low crosses the region. MVFR conditions are expected with
these showers. As the surface low continues moving northward over
the Central Appalachians and drags a cold front through central NC,
we'll see a trend to high-confidence VFR conditions late afternoon,
persisting through tonight as blustery winds from the S shift around
to westerly, bringing in drier air.

Looking beyond 06z Sat, VFR conditions should dominate late tonight
through Christmas Day as high pressure extend over the region,
although a brief period of MVFR cigs is possible Sun night with a
quickly passing upper level disturbance. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

SYNOPSIS...JM
NEAR TERM...KC
SHORT TERM...JM/ Hartfield
LONG TERM...Haines
AVIATION...Hartfield
Hazardous weather outlook, Dec 20, 11:29 PM EST, 3 hours 11 minutes before
Hazardous Weather Outlook...UPDATED
National Weather Service Raleigh NC
1129 PM EST Thu Dec 20 2018

NCZ007>011-021>028-038>043-073>078-083>086-088-089-211030-
Person-Granville-Vance-Warren-Halifax-Forsyth-Guilford-Alamance-
Orange-Durham-Franklin-Nash-Edgecombe-Davidson-Randolph-Chatham-Wake-
Johnston-Wilson-Stanly-Montgomery-Moore-Lee-Harnett-Wayne-Anson-
Richmond-Scotland-Hoke-Cumberland-Sampson-
1129 PM EST Thu Dec 20 2018

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Overnight.

Periods of moderate to briefly heavy rainfall will occur overnight.
This additional rainfall on an already saturated ground will quickly
run off, leading to rain swollen creeks and streams as well as minor
street flooding.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

The office that day

Everything else NWS Raleigh, NC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 20, 10:37 PM ESTRiver Flood WarningRAHAnson, Stanly13 hr
Dec 21, 12:10 AM ESTRiver Flood WarningRAHChatham30 hr
Dec 21, 9:35 AM ESTWind AdvisoryRAHCumberland, Edgecombe, Franklin, Halifax, Harnett, Hoke and 7 more10 hr
Dec 21, 11:01 AM ESTRiver Flood WarningRAHDavidson, Davie27 hr
Dec 21, 2:59 PM ESTSpecial Weather StatementRAHChatham61 min
Dec 21, 3:10 PM ESTSpecial Weather StatementRAHLee65 min
Dec 21, 3:18 PM ESTSpecial Weather StatementRAHPerson57 min
Dec 21, 3:25 PM ESTSpecial Weather StatementRAHAlamance50 min
Dec 21, 3:44 PM ESTRiver Flood WarningRAHHalifax, Northampton26 days
Dec 21, 4:08 PM ESTSpecial Weather StatementRAHJohnston, Nash52 min
Dec 21, 4:18 PM ESTSpecial Weather StatementRAHAlamance57 min
Dec 21, 5:06 PM ESTSpecial Weather StatementRAHEdgecombe, Halifax54 min

Nearby

River Flood Warnings in North Carolina, 2018Every river flood warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive; the gauge from the NWS water service and the USGS.