000
FLUS74 KOUN 311044
AWUOUN

AREA WEATHER UPDATE
NATIONAL WEATHER SERVICE NORMAN OK
443 AM CST WED JAN 31 2007 

...WARNING DECISION UPDATE...

THIS WARNING DECISION UPDATE CONCERNS WESTERN...CENTRAL AND NORTHERN 
OKLAHOMA AND WESTERN NORTH TEXAS.

WE MAY NEED A SNOW ADVISORY LATER THIS MORNING... BUT WE ARE 
HOLDING OFF ON HEADLINES AT THIS TIME DUE TO UNCERTAINTIES REGARDING 
WHERE AND WHEN THE HEAVIER SNOW BANDS MAY SET UP. WE PREFER TO COVER 
THE DEVELOPING SITUATION WITH SHORT-TERM FORECASTS AND THE HWO AT 
PRESENT. SPECIAL WEATHER STATEMENT WILL LIKELY BE UPDATED LATER THIS 
MORNING TO PROVIDE MORE INFO ON SUBSEQUENT SNOW EVENTS AND ARRIVAL 
OF MUCH COLDER AIR.  

SHORT-TERM MODEL QPFS /NAM-GFS-RUC/FOCUS ON NW-NCENTRAL OK AND 
ADJACENT TX PANHANDLE AND S KS IN DEPICTING 0.1-0.2" WATER 
EQUIVALENT TOTALS AND CORRESPONDING 1-2 INCH SNOWFALL THROUGH 18Z 
ACROSS N OK. NAM AND GFS PLACE A SECOND BAND MUCH FARTHER S ACROSS N 
TX ROUGHLY FROM ABI TO PRX. RUC IS THE ONLY ONE AT PRESENT 
INDICATING HEAVIER AMOUNTS IN BETWEEN - IN THE .15-.25 RANGE ACROSS 
SW-CENTRAL OK. RADAR TRENDS SUPPORT THE IDEA OF HEAVIER WSW-TO-ENE 
BANDS EVENTUALLY... BUT CURRENTLY DO NOT PROVIDE MUCH HELP IN 
PINNING DOWN THE LOCATIONS. HENCE OUR DILEMMA.

ONCE EVAPORATION/WETBULBING ALLOWS MORE OF THE EXISTING ECHOES TO 
REACH THE GROUND... WE MAY BE ABLE TO NAIL DOWN THE MORE LIKELY 
CORRIDOR/S OF 2+ ACCUMULATIONS. IF NECESSARY WE WILL INITIATE 
ADVISORIES AT THIS TIME. MEANWHILE THINK IT BEST TO WAIT UNTIL WE 
SEE THE WHITES OF THEIR EYES (LITERALLY?). 

SE PART OF OUR CWA MAY WARM TO SLIGHTLY ABOVE FREEZING THIS 
MORNING... AND PRECIP COULD START AS RAIN BASED ON LATEST MODEL 
FORECAST SOUNDINGS. ANY PRECIP SHOULD CHANGE VERY QUICKLY OVER TO 
FROZEN SHORTLY AFTER INITIATING DUE TO EVAPORATIONAL COOLING. 

$$

BRANICK

NOTE: THIS PRODUCT IS MEANT TO INCREASE INFORMATION EXCHANGE ON THE 
STORM SCALE.

TERMS DEFINED:

Z = REFLECTIVITY
V = VELOCITY (GROUND- OR STORM-RELATIVE)
VOLUMETRIC Z = REFLECTIVITY AT LOW, MID AND HIGH LEVELS 

VIL = VERTICALLY INTEGRATED LIQUID
TDA = ALGORITHM TO DETECT STRONG CYCLONIC SHEAR
POSH = PROBABILITY OF SEVERE HAIL ALGORITHM
SCIT = STORM CELL IDENTIFICATION AND TRACKING
MESH = MAXIMUM EXPECTED HAIL SIZE

TBS = THREE-BODY SCATTER = REFLECTIVITY FLARE SIGNATURE FROM HAIL
AP = ANOMALOUS PROPAGATION
MESO = MESOCYCLONE
RFD = REAR FLANK DOWNDRAFT
BWER = BOUNDED WEAK ECHO REGION
MT = MAX STORM TOP
TVS = TORNADIC VORTEX SIGNATURE
LP = LOW PRECIPITATION SUPERCELL
HP = HIGH PRECIPITATION SUPERCELL
GIANT HAIL = HAIL 2 INCHES OR GREATER

RDA = WSR-88D RADAR SITE
VCP = VOLUME COVERAGE PATTERN OF WSR-88D
TDWR = TERMINAL DOPPLER RADAR (LOCATED IN NORTHWEST NORMAN)
POLARIMETRIC RADAR/DUAL POL=SEE: WWW.NSSL.NOAA.GOV/~SCHUUR/RADAR.HTML
ZDR = DIFFERENTIAL REFLECTIVITY
KDP = DIFFERENTIAL PHASE
HCA = POLARIMETRIC HYDROMETEOR CLASSIFICATION ALGORITHM

$$