Flash Flood Guidance
Issued by NWS

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878
AWUS01 KWNH 282137
FFGMPD
TXZ000-OKZ000-290136-

MESOSCALE PRECIPITATION DISCUSSION 0083
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
537 PM EDT TUE MAR 28 2017

AREAS AFFECTED...WEST CENTRAL TX/FAR EASTERN TX
PANHANDLE/SOUTHWESTERN OK...

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 282136Z - 290136Z

SUMMARY...ONGOING CONVECTIVE COMPLEX CONTINUES TO CONSIST OF A
MIXTURE OF SEVERE WEATHER AND LOCALIZED HEAVY RAINFALL. FAVORABLE
UNIDIRECTIONAL FLOW WITH ADDITIONAL THUNDERSTORM DEVELOPMENT
LIKELY WILL FOSTER THE POTENTIAL FOR AREAS OF FLASH FLOODING WHERE
REPEAT CONVECTION/CELL TRAINING OCCUR.

DISCUSSION...IN ADVANCE OF A LARGE UPPER LOW SPINNING ACROSS
CENTRAL NM...AMPLE TROPOSPHERIC MOISTURE CONTINUES TO LIFT
NORTHWARD INTO THE SOUTHERN PLAINS. RECENT SATELLITE IMAGERY FROM
THE BLENDED-TPW PRODUCT SUGGESTS PRECIPITABLE WATER VALUES IN THE
1 TO 1.25 INCH RANGE. THIS IS FAIRLY ANOMALOUS GIVEN THE 12Z
SOUNDING OUT OF KAMA FEATURED DEPARTURES IN THE 2 TO 3 SIGMA ABOVE
AVERAGE RANGE. ENHANCED MOISTURE CONTENT IN CONJUNCTION WITH AMPLE
FORCING UPSTREAM AND SUFFICIENT BUOYANCY WILL HELP EXPAND THE
THUNDERSTORM COVERAGE WELL BEYOND 00Z. MUCH OF THIS ACTIVITY IS
FOCUSING ALONG AND JUST EAST OF THE ANALYZED DRY LINE AND SOUTH OF
A WARM FRONT. THIS CONVECTION IS GENERALLY ROOTED IN THE BOUNDARY
LAYER WITH HOURLY RAINFALL RATES OBSERVED IN THE 1 TO 1.25 INCH
RANGE. FURTHER NORTH...MORE OF THE INSTABILITY IS ROOTED ABOVE THE
LOW-LEVEL STABLE LAYER WITH HAIL BEING THE LARGER THREAT.

LOOKING AHEAD...ADDITIONAL ACTIVITY WAS NOTED FARTHER UPSTREAM
ACROSS SOUTHWEST TX WITH MANY OF THE CELLS ALREADY EXHIBITING
ANVIL CANOPIES PER RECENT VISIBLE IMAGERY. AS THIS ACTIVITY
ADVANCES EASTWARD...IT SHOULD STRENGTHEN AS THE 21Z RAP OBJECTIVE
ANALYSIS SHOWS AMPLE INSTABILITY REMAINING IN PLACE. THIS SHOULD
ULTIMATELY BRING A SECOND ROUND OF THUNDERSTORMS TO AREAS
CURRENTLY SEEING HEAVY DOWNPOURS/BOUTS OF SEVERE WEATHER. HIGHER
END FLASH FLOOD GUIDANCE VALUES PRECLUDE ANY LARGER SCALE THREATS
BUT SOME ISOLATED HYDROLOGIC ISSUES MAY TAKE PLACE.

REGARDING THE RECENT CAMS...MANY ARE WELL TO THE NORTH AND EAST
WHILE ALSO DEPICTING LESS SPATIAL COVERAGE. THIS IS PARTICULARLY
AN ISSUE WITH THE 12Z HRW-ARW/HRW-NMM-B SOLUTIONS. LEANED MORE
HEAVILY IN THE DIRECTION OF RECENT HRRR RUNS WHICH WERE QUITE
CONSISTENT IN SHOWING TWO ROUNDS OF CONVECTION AFFECTING THE MPD
AREA THROUGH THE NIGHT.

RUBIN-OSTER

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AMA...LUB...MAF...OUN...SJT...

ATTN...RFC...ABRFC...WGRFC...

LAT...LON   35619988 34649940 33359932 31759988 30980073
            31280197 32670140 33660120 35430110



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