Alert archive / North Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 1849

August 3, 2004Carteret County, North Carolina

The Storm Prediction Center issued this mesoscale discussion at Aug 3, 2004, 5:35 AM EDT for Carteret County, North Carolina. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 3, 2004, 5:35 AM EDT (09:35 UTC)
Expired
Aug 3, 2004, 10:30 AM EDT
In force
5 hr
Issued by
the Storm Prediction Center

County Carteret County, NC

The radar

The Morehead City radar (KMHX), 78 km from the middle of the area, began a volume at 09:36 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 nearest sounding before it

Newport, NC (KMHX), launched 00:00Z, 9.6 hours before the alert went out and 78 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Newport, NC at 00:00Z on 2004-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1945 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Newport, NC at 00:00Z on 2004-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1945 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
668 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

050 
ACUS11 KWNS 030936
SWOMCD
SPC MCD 030935 
NCZ000-031430-

MESOSCALE DISCUSSION 1849
NWS STORM PREDICTION CENTER NORMAN OK
0435 AM CDT TUE AUG 03 2004

AREAS AFFECTED...EXTREME ERN NC -- MHX-HAT AREA INCLUDING SRN OUTER
BANKS AND CAPE LOOKOUT

CONCERNING...TC TORNADO POTENTIAL...HEAVY RAINFALL 

VALID 030935Z - 031430Z

POTENTIAL FOR MINI-SUPERCELLS AND BRIEF TORNADOES SHOULD REMAIN
MAINLY OVER WATER -- BUT MAY ALSO SPREAD NEWD FROM CAPE FEAR AREA
ACROSS OCRACOKE TO NEAR CAPE HATTERAS AS INNER BANDS OF HURRICANE
ALEX CROSS AREA.  BECAUSE OF ISOLATED NATURE OF THREAT AND VERY
SMALL LAND AREA INVOLVED...WW NOT ANTICIPATED ATTM. 

TIME SERIES OF VWP FROM ILM/MHX SHOWS INCREASE IN 0-1 AND 0-3 KM
HODOGRAPH SIZE OVER PAST FEW HOURS...AS SFC FLOW BACKS AND WINDS
INCREASE THROUGHOUT BOUNDARY LAYER.  GREAT MAJORITY OF ZONE WHERE
FAVORABLE SHEAR IS JUXTAPOSED WITH AT LEAST MARGINAL BUOYANCY WILL
REMAIN OFFSHORE.  HOWEVER...NWRN PORTION OF THIS REGIME SHOULD
SPREAD ONTO SRN OUTER BANKS THROUGH 10-11Z AND NEWD THEREAFTER. 
MAXIMIZED CONVERGENCE WITHIN INNER BANDS SHOULD HELP TO MAINTAIN
CONVECTIVE LIFT.  RELATIVELY LONG-LIVED/ISOLATED/DISTINCT CELLS WILL
NOT BE VERY COMMON IN DENSE PRECIP FIELD OF INNER BAND
REGION...HOWEVER ANY DISCRETE CELLS THAT FORM WITHIN THESE BANDS MAY
ROTATE FOR AN HOUR OR TWO...MOVING NWWD THEN WWD BEFORE DISSIPATING
N OF EYE.  MEANWHILE...CONVERGENCE/LIFT IN THIS REGIME COMBINED WITH
TROPICAL WARM-CLOUD PRECIP PROCESSES SHOULD RESULT IN 2-3 INCH/HOUR
RAIN RATES FROM HEAVIER CORES...SOME OF WHICH WILL TRAIN ALONG AXES
OF SPIRAL BANDS.

REF NHC ADVISORIES UNDER WMO HEADER WTNT21 KNHC FOR LATEST WARNINGS
AND TRACK/INTENSITY GUIDANCE ON ALEX.

..EDWARDS.. 08/03/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MHX...

34687687 34937654 35187598 35297560 35297550 35247551
35207555 35097578 34867610 34567649

Nearby

Mesoscale Discussions in North Carolina, 2004Every mesoscale discussion in 2004

Sources

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