MESOSCALE PRECIPITATION DISCUSSION 0710
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 AM EST SUN DEC 27 2015
 
AREAS AFFECTED...CENTRAL/NORTHEAST TX...EASTERN
OK...CENTRAL/NORTHERN AR...SOUTHERN MO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 270900Z - 271500Z
 
SUMMARY...VERY HEAVY RAINS ARE EXPECTED TO FOCUS OVER THE REGION
THROUGH THE MORNING HOURS WHICH WILL RESULT IN AN ELEVATED RISK OF
SIGNIFICANT FLASH FLOODING.

DISCUSSION...A STRONG MID LEVEL CLOSED LOW CENTER WILL BE EJECTING
GRADUALLY ACROSS FAR NORTHERN MEXICO AND THEN EAST ACROSS WEST
TEXAS THROUGH THE MORNING HOURS...AND DOWNSTREAM OF THIS THERE
WILL BE AN AXIS OF STRONG LARGE SCALE ASCENT THAT WILL BE
INTERACTING WITH A STRONG FRONTAL ZONE THAT IS GRADUALLY SETTLING
SOUTH THROUGH EASTERN TX AND INTO THE LOWER MS VALLEY REGION. THE
HEIGHT FALLS ARE ALREADY GENERATING SURFACE LOW PRESSURE OVER THE
RIO GRANDE VALLEY AND A CONSENSUS OF THE GUIDANCE SHOWS THIS
DEEPENING THIS MORNING WHICH WILL ENHANCE THE LOW LEVEL SOUTHERLY
TRANSPORT OF DEEP MOISTURE AND INSTABILITY FROM THE GULF OF MEXICO.

THE LATEST BLENDED-TPW PRODUCT AND GPS-DERIVED TPW DATA SHOWS A
POOL OF 1.5 INCH PWS POOLING OVER THE LOWER MS VALLEY AND
ESSENTIALLY AN ATMOSPHERIC RIVER OF DEEP MOISTURE THAT IS WRAPPING
AROUND THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE OVER THE
SOUTHEAST. THIS MOISTURE IS BEING TRANSPORTED NORTH BY A SOUTHERLY
 LOW LEVEL JET OF CLOSE TO 50 KTS AS PER AREA VWP DATA...AND THE
GLOBAL MODELS ARE SUGGESTING SOME UPTICK IN THIS JET ENERGY THIS
MORNING AS LOW PRESSURE INTENSIFIES.

STRONG FORCING AT THE SURFACE IN VICINITY OF THE FRONTAL ZONE
COUPLED WITH THE IMPROVING JET DYNAMICS/DIVERGENCE ALOFT WILL WORK
IN TANDEM TO FOCUS VERY HEAVY SHOWERS AND THUNDERSTORMS THIS
MORNING OVER PARTS OF CENTRAL AND NORTHEAST TX AND WELL UP ACROSS
EASTERN OK AND NORTHERN AR.

THE LATEST HRRR AND 00Z ARW ARE VERY WET ACROSS THIS REGION AND
SUGGEST 3 TO 5 INCH RAINFALL AMOUNTS THROUGH 15Z...WITH AN
EMPHASIS ON NORTHEAST TX/FAR SOUTHEAST OK AND WESTERN AR. THE 00Z
NMMB IS NOT AS AGGRESSIVE...BUT WITH PW ANOMALIES OF 3 TO 4 STD
DEV ABOVE NORMAL AND SUCH STRONG HEIGHT FALLS APPROACHING FROM THE
WEST...THE WETTER HRRR/ARW SOLUTIONS WILL BE PREFERRED AT THIS
TIME. THESE RAINS WILL LIKELY RESULT IN SIGNIFICANT FLASH FLOODING
AND ESPECIALLY FOR AREAS THAT HAVE ALREADY SEEN HEAVY RAINFALL
OVER THE LAST 24 HOURS.

ORRISON

ATTN...WFO...FWD...LSX...LZK...MEG...OUN...PAH...SGF...SHV...
TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...WGRFC...

LAT...LON   38009272 37969051 37258950 36528949 35799017 
            34979117 33839400 32429522 31309622 31589735 
            32159746 33049713 34149638 35709565 37179463