MESOSCALE PRECIPITATION DISCUSSION 0820
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1154 AM EDT SAT SEP 23 2017

AREAS AFFECTED...EASTERN NM/FAR SOUTHEASTERN CO...

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

VALID 231553Z - 232008Z

SUMMARY...EARLY MORNING CONVECTION CONTINUES TO ERUPT ALONG A
SHARP MOISTURE GRADIENT ALONG THE SOUTHERN HIGH PLAINS. AMPLE
SURFACE INSTABILITY ACROSS THE REGION HAS SUPPORTED THE
MAINTENANCE OF THESE CONVECTIVE CLUSTERS. GIVEN
QUASI-UNIDIRECTIONAL FLOW...A THREAT FOR FLASH FLOODING WILL BE
POSSIBLE.

DISCUSSION...NATIONAL MOSAIC RADAR IMAGERY SHOWED A BROAD AXIS OF
CONVECTION LIFTING NORTHWARD ACROSS EAST-CENTRAL NM INTO
SOUTHEASTERN CO. UNFORTUNATELY THE PUEBLO CO RADAR IS CURRENTLY
DOWN SO REMAINED MORE RELIANT ON SATELLITE TRENDS. THE
EXPERIMENTAL GOES-16 IMAGERY DEPICTED EXTENSIVE CLOUD COVER ACROSS
MUCH OF EASTERN NM ALTHOUGH ENOUGH INSOLATION HAS FOSTERED THE
GROWTH OF NUMEROUS EMBEDDED CONVECTIVE CLUSTERS. THE 15Z RAP
OBJECTIVE ANALYSIS SUGGESTED SURFACE-BASED INSTABILITY VALUES
AROUND 1500 TO 2500 J/KG ACROSS THE MPD AREA. WHILE ON THE DRIER
SIDE OF THE MOISTURE GRADIENT...THE 12Z ABQ SOUNDING DEPICTED SOME
FEATURES OF NOTE. MODESTLY STEEP LAPSE RATES WERE EVIDENT...ON THE
ORDER OF 7.5 C/KM WITH DEEP QUASI-UNIDIRECTIONAL FLOW IN PLACE.
WHILE A 200-MB PLUS DRY SUB-CLOUD LAYER WAS VISIBLE...THIS WAS
OCCURRING WEST OF THE BETTER MOISTURE FLUXES. EXPECT NORTH/SOUTH
TRAINING TO REMAIN A POTENTIAL ISSUE AS THE ACTIVITY SHOULD BECOME
BETTER DEFINED WITHIN A HIGHLY DIFFLUENT UPPER PATTERN IN ADVANCE
OF A DEEP TROUGH ANCHORING THE SOUTHWESTERN U.S. GIVEN ONLY LITTLE
EASTWARD PROGRESSION EXPECTED IN THE LONGWAVE PATTERN...THE
FAVORABLE SETUP FOR HEAVY PRECIPITATION SHOULD REMAIN LOCKED IN
PLACE ACROSS EASTERN NM THROUGH AT LEAST THE AFTERNOON HOURS.

RECENT CONVECTIVE-ALLOWING MODEL OUTPUT SHOWS A FAIRLY DEFINED
SIGNAL OF HEAVY RAINFALL ACROSS EASTERN NM. WHILE NO ONE SOLUTION
IS PERFORMING BETTER THAN THE OTHER...GENERAL AGREEMENT EXISTS IN
ADDITIONAL UPSTREAM DEVELOPMENT STREAMING NORTHWARD THROUGH
REGIONS CURRENTLY PRECIPITATING. THE LONG DURATION OF THIS SET UP
SUPPORTS A FLASH FLOOD RISK...PARTICULARLY IN REGIONS OF COMPLEX
TERRAIN WHERE RUN-OFF MAY BE AN ISSUE.

RUBIN-OSTER

ATTN...WFO...ABQ...EPZ...MAF...PUB...

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

LAT...LON   37670347 37570304 37170299 36330311 34380349
            32620421 32810560 35260505 36230480 37080443
            37530399