Flash Flood Warning 79, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
217 PM CDT SAT SEP 20 2008

.DISCUSSION...

SHORT TERM (TONIGHT-TUE)

MAIN ISSUE OF CONCERN IN THE SHORT TERM REVOLVES AROUND CONVECTION
POTENTIAL ACROSS THE WEST TX MOUNTAINS AND SE NEW MEXICO PLAINS
TODAY/TONIGHT. 18Z OBJECTIVE SFC ANALYSIS SHOWING LEE-SIDE LOW
LOCATED ACROSS SOUTHEAST CO...WITH ASSOCIATED SOUTHWARD EXPANSION OF
A LEE TROUGH THROUGH FAR EASTERN NM/WESTERN TX PANHANDLE AND
EXTENDING SOUTHWARD INTO THE WEST TX MOUNTAINS. LATEST RADAR/SAT
TRENDS SHOWING CONVECTIVE DEVELOPMENT ACROSS THE GUADALUPE MTNS
ATTM...WITH ADDITIONAL CU DEVELOPMENT FURTHER SOUTH ACROSS THE DAVIS
MTNS. ACTIVITY LIKELY BEING AIDED BY MID-LEVEL SHORTWAVE TROUGH
ROTATING AROUND THE NE PERIPHERY OF BUILDING MID-LEVEL RIDGE ACROSS
THE DESERT SW. IT SHOULD BE NOTED THAT THE GFS/ECMWF SOLUTIONS KEEP
ALL OF FORECAST AREA DRY THIS AFTERNOON...WITH WRF OUTPUT BEING THE
ONLY GUIDANCE SUGGESTING PRECIP POTENTIAL. LATEST WATER VAPOR SHOTS
SHOWING MID-LEVEL VORT MAX APPROACHING THE AREA FROM SOUTH-CENTRAL
NM...AND BASED ON THIS...FEEL PRECIP/CONVECTIVE TRENDS WILL LIKELY
INCREASE THROUGH THE REMAINDER OF THE AFTERNOON ACROSS THE WEST TX
MOUNTAINS...AND POSSIBLY EXTENDING INTO THE SE NEW MEXICO PLAINS.
WEAK STEERING FLOW WILL LIMIT AMOUNT OF SE PROPAGATION...THUS
HAVE ONLY INCREASED POPS ACROSS THE RESPECTIVE MTNS AND IMMEDIATE
SURROUNDING LOCATIONS. H7-5 LAPSE RATES REMAIN BETWEEN 6 AND 7C/KM
WITH 0-6KM BULK SHEAR REMAINING AT OR BELOW 20KTS. THIS FEEL SEVERE
POTENTIAL REMAINS RATHER BLEAK...HOWEVER FOR FORECAST SOUNDINGS
SHOWING NEARLY DRY ADIABATIC LAPSE RATES THROUGH THE LOW
LEVELS...STRONG SUB-SEVERE WINDS AND SMALL HAIL WILL BE POSSIBLE
OWING TO FAVORABLE WET-BULB ZERO LEVELS. ACTIVITY WILL QUICKLY COME
TO AN END THIS EVENING WITH LOSS OF DAYTIME HEATING.

FAIRLY CONSISTENT FORECAST EXPECTED THROUGH THE REMAINDER OF THE
SHORT TERM WITH BUILDING RIDGE SETTING UP ACROSS THE AREA.
THUS...SIMILAR CONDITIONS ANTICIPATED THROUGH MID-WEEK...WITH VERY
MINOR DIFFERENCES IN H85 TEMPS FROM VARIOUS SHORT TERM PROGS FROM
DAY TO DAY. WELL DEFINED SFC RIDGE AXIS WILL CONTINUE EXTENDING SWWD
INTO CENTRAL TEXAS FROM THE NE...EFFECTIVELY KEEPING AREA CUT-OFF
FROM ANY MOISTURE ADVECTION FROM THE GULF. WITH FAIR NEARLY CLOUD
FREE NIGHTS AND LACK OF ANY ADDITIONAL MOISTURE...HAVE PRETTY MUCH
KEPT THE INHERITED TRENDS OF UNDERCUTTING GUIDANCE SLIGHTLY WITH
RESPECT TO OVERNIGHT LOWS. FORECAST SOUNDINGS THROUGH THE AFTERNOON
HOURS DO SUGGEST FAVORABLE MIXING POTENTIAL WITH NEARLY DRY
ADIABATIC LAPSE RATES EXPECTED THROUGH THE LOW-LEVELS. HOWEVER HAVE
APPROACHED MOS GUIDANCE WITH CAUTION DUE TO RECENT POOR PERFORMANCE
WITH RESPECT TO OVERESTIMATING DAYTIME HIGHS. GENERALLY STAYED A
DEGREE OR TWO BELOW HIGHS FOR NOW BASED ON LACK OF ANY NOTICEABLE
DIFFERENCES IN H85 TEMPS FROM DAY TO DAY.

EXTENDED (WED-SAT)

STATUS-QUO FORECAST SHAPING UP THROUGH THE EXTENDED PERIOD AS
MID-LEVEL HIGH PRESSURE CENTER TAKES SHAPE OVER THE FOUR CORNERS
REGION. WITH TIME...THIS FEATURE WILL BEGIN PUSHING EAST
TOWARDS MIDWEEK...WITH A PROLONGED PERIOD OF NORTHERLY TO
NORTHEASTERLY MID-LEVEL FLOW EXPECTED ACROSS THE REGION. CLOSER TO
THE SURFACE...WELL ESTABLISHED LEE-SIDE PRESSURE TROUGH WILL
MAINTAIN ITSELF ALONG THE CO/NM/KS/OK/TX HIGH PLAINS...WITH
SOUTHWARD EXTENSION OF FEATURE INTO NORTHERN PORTIONS OF MAF CWA.
SOUTHEASTERLY UPSLOPE LOW-LEVEL FLOW EXPECTED TO CONTINUE THROUGH
THE CONCLUSION OF THE WEEK/UPCOMING WEEKEND...HOWEVER WITH HIGH
CENTERED NEARBY FAVORING INCREASED SUBSIDENCE...SEEING VERY LITTLE
CHANCE FOR ANY ORGANIZED PRECIP THOUGH NEXT WEEKEND. ON
THURSDAY...GFS/ECMWF IN FAIRLY GOOD AGREEMENT WITH INDICATIONS
POINTING TOWARDS A SHORTWAVE TROUGH ROTATING INTO THE AREA ON
NORTHEASTERN PERIPHERY OF UPPER HIGH...HOWEVER BOTH MAINTAIN DRY
CONDITIONS ACROSS THE AREA. ONLY CONCERN WITH EXTENDED PERIOD RIGHT
NOW IS JUST HOW FAR EAST THE UPPER HIGH WILL MAKE IT AND POTENTIAL
EFFECTS ON HIGH/LOW TEMPS.

CURRENT MODEL DEPICTIONS SHOW RATHER IMPRESSIVE EASTWARD EXPANSION
OF MID-LEVEL HIGH INTO THE CENTRAL PLAINS BY THE WEEKEND AS
PREVIOUSLY MENTIONED. THIS PATTERN CLOSELY RESEMBLES A MID SUMMER
UPPER-LEVEL PATTERN...NOT TOTALLY UNTYPICAL FOR THIS TIME OF YEAR
HOWEVER. PROGRESSIVE WESTERLIES REMAIN WELL NORTH OF THE REGION
ACROSS THE US/CANADIAN BORDER...SUGGESTING THAT FURTHER EASTWARD
EXPANSION OF HIGH IS POSSIBLE AS A RESULT OF MID/UPPER LEVEL
WESTERLY MOMENTUM TO THE NORTH. UNDER A SCENARIO LIKE THIS...TEMPS
CAN BE RATHER DIFFICULT TO PIN DOWN PRECISELY WITH POTENTIAL LARGE
DIURNAL TEMP TRENDS AS A RESULT OF CLEAR SKIES OVERNIGHT. DEEP
CYCLOGENESIS IS EXPECTED BY THE CONCLUSION OF THE WEEK OFF THE
SOUTHEAST US COAST...HELPING TO MAINTAIN NORTHEASTERLY LOW-LEVEL
FLOW ACROSS THE GULF. WITH THE GULF EFFECTIVELY REMAINING
CUT-OFF...SEE VERY LITTLE CHANGE IN TEMPS THROUGH THE EXTENDED
PERIOD. WITH UPPER HIGH NEARBY AND NO SUBSTANTIAL MOISTURE ADVECTION
EXPECTED DUE TO LACK OF A GULF INFLUENCE...FEEL TEMPS WILL WARM
NICELY DURING THE DAY AND RADIATE RATHER EFFECTIVELY AT NIGHT OWING
TO LACK OF SUFFICIENT CLOUD COVER AND LOW-LEVEL MOISTURE. FOR
NOW...HAVEN/T MADE TOO MANY ADJUSTMENTS TO GOING
FORECAST...MAINTAINING PREMISE THAT OVERNIGHT LOWS ARE LIKELY BEING
OVERSHOT BY CURRENT MEX GUIDANCE.

&&

.PRELIMINARY POINT TEMPS/POPS...
BIG SPRING TX              58  86  60  87  /   0   0   0   0
CARLSBAD NM                58  88  57  88  /  20   0   0   0
DRYDEN TX                  61  87  63  87  /   0   0   0   0
FORT STOCKTON TX           60  87  61  88  /   0   0   0   0
GUADALUPE PASS TX          54  82  58  83  /  20   0   0   0
HOBBS NM                   55  86  56  87  /   0   0   0   0
MARFA TX                   49  81  48  81  /  20   0   0   0
MIDLAND INTL AIRPORT TX    57  86  60  87  /   0   0   0   0
ODESSA TX                  59  86  61  87  /   0   0   0   0
WINK TX                    59  90  61  91  /   0   0   0   0

&&

.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING
     ZONES... PRESIDIO VALLEY.

&&

32

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
213 PM CDT SAT SEP 20 2008

NMZ027>029-033-034-TXZ045>048-050>053-057>063-067>070-074-075-
079>082-258-211915-
GUADALUPE MOUNTAINS OF EDDY COUNTY-EDDY COUNTY PLAINS-
NORTHERN LEA COUNTY-CENTRAL LEA COUNTY-SOUTHERN LEA COUNTY-GAINES-
DAWSON-BORDEN-SCURRY-ANDREWS-MARTIN-HOWARD-MITCHELL-
VAN HORN AND HIGHWAY 54 CORRIDOR-REEVES COUNTY AND UPPER TRANS PECOS-
LOVING-WINKLER-ECTOR-MIDLAND-GLASSCOCK-WARD-CRANE-UPTON-REAGAN-
DAVIS/APACHE MOUNTAINS AREA-PECOS-PRESIDIO VALLEY-MARFA PLATEAU-
BIG BEND AREA-TERRELL-GUADALUPE MOUNTAINS-
213 PM CDT SAT SEP 20 2008 /113 PM MDT SAT SEP 20 2008/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST NEW
MEXICO...SOUTHWEST TEXAS AND WEST TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

WIDELY SCATTERED THUNDERSTORMS ACROSS THE GUADALUPE AND DAVIS
MOUNTAINS...AND NORTHERN PORTIONS OF SOUTHEASTERN NEW MEXICO WILL
CONTINUE INTO EARLY THIS EVENING. THE STRONGEST STORMS WILL BE
CAPABLE OF PRODUCING GUSTY WINDS NEAR 50 MPH... FREQUENT CLOUD TO
GROUND LIGHTNING STRIKES AND BRIEF HEAVY RAINFALL.

FLOODING ALONG THE RIO GRANDE RIVER CONTINUES FROM PRESIDIO TO
RIO GRANDE VILLAGE DUE TO WATER RELEASES FROM LUIS LEON RESERVOIR
IN MEXICO. SOME LOCATIONS ALONG THE RIVER REMAIN ABOVE RECORD
FLOOD STAGE...WITH LEVELS EXPECTED TO REMAIN NEARLY STEADY THROUGH
THE WEEKEND...WITH A SLOW FALL POSSIBLE INTO EARLY NEXT WEEK.
HIGHWAY 170 REMAINS CLOSED TO TRAFFIC AND THERE ARE LIKELY OTHER
COUNTY ROADS THAT ARE IMPASSABLE. TRAVELERS IN THIS AREA ARE
ADVISED TO USE CAUTION AND AVOID LOCATIONS WHERE WATER MAY BE OVER
THE ROADWAY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

RIVER FLOODING ALONG THE RIO GRANDE IS EXPECTED TO CONTINUE INTO
EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

THIS PRODUCT...ALONG WITH OTHER WATCHES...WARNINGS...ADVISORIES...
AND STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN
MIDLAND CAN BE FOUND ON THE INTERNET AT /LOWER CASE/
HTTP://WEATHER.GOV/MIDLAND