Flash Flood Warning 84, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
630 PM CDT SUN SEP 21 2008

.DISCUSSION...
SEE AVIATION SECTION BELOW.

&&

.AVIATION...
VFR CONDITIONS TO CONTINUE THROUGH THE TAF PERIOD. GUSTY AFTERNOON
WINDS WILL SUBSIDE OVERNIGHT BUT WILL INCREASE AGAIN MUCH LIKE TODAY.

HENNIG

&&

.PREV DISCUSSION... /ISSUED 210 PM CDT SUN SEP 21 2008/

DISCUSSION...

SHORT TERM (SUN-WED)

DRY CONDITIONS EXPECTED THROUGH THE SHORT TERM AS UPPER LEVEL RIDGE
AXIS CONTINUES SLOWLY MOVING EAST ACROSS FORECAST AREA. LATEST VIS
SHOTS SHOW FAIRLY EXPANSIVE FAIR WX CU DEVELOPMENT ACROSS MUCH OF
CENTRAL AND EASTERN TX...WITH TRENDS SUGGESTING WESTWARD EXPANSION
THROUGH THE REMAINDER OF THE AFTERNOON. ALONG THE SFC...18Z SFC
ANALYSIS REVEALS RATHER ILL-DEFINED SFC TROUGH AXIS EXTENDING SWD
FROM THE HIGH PLAINS OF CO...THROUGH FAR EASTERN NM/WESTERN TX
PANHANDLE. NOT EXPECTING MUCH IN THE WAY OF ANY PRECIP DEVELOPMENT
ALONG THIS FEATURE AS INCREASED SUBSIDENCE RESULTING FROM PASSING
RIDGE AXIS WILL ALL BUT SQUASH ANY PRECIP POTENTIAL AS OPPOSED TO
YESTERDAY.

MAIN FORECAST CONCERN WITH REGARDS TO SHORT TERM PERIOD REVOLVES
AROUND TEMPS. WITH MID-LEVEL HIGH PRESSURE STRENGTHENING EACH DAY
ACROSS THE DESERT SW/SOUTHERN ROCKIES...REGION WILL BECOME MORE AND
MORE INFLUENCED BY NORTHERLY TO NORTHEASTERLY FLOW ALOFT. MOST
FORECAST MODELS CONTINUE TO SHOW WELL DEFINED SFC RIDGING EXTENDING
SOUTHWESTWARD FROM PARENT HIGH LOCATED ACROSS THE NORTHEAST. AS
ELUDED TO YESTERDAY...THIS FEATURE WILL EFFECTIVELY KEEP GULF
MOISTURE CUT-OFF...LIMITING ANY SUBSTANTIAL MOISTURE ADVECTION FROM
THE SOUTHEAST. WITH LACK OF ANY RETURN FLOW AND WITH HIGH PRESSURE
LOCATED OVERHEAD...FEEL EACH AFTERNOON WILL HAVE THE POTENTIAL TO
EFFECTIVELY MIX OUT QUITE WELL...WITH VARIOUS SHORT TERM FORECAST
SOUNDINGS CONTINUING TO SHOW NEARLY DRY ADIABATIC LOW LEVEL LAPSE
RATES EACH AFTERNOON. NO SUBSTANTIAL INCREASE/DECREASE WITH REGARDS
TO FORECASTED H85 TEMPS EXPECTED...THIS FEEL INHERITED HIGH TEMP
FORECAST TRENDS APPEAR TO BE IN GOOD ORDER WITH LOW TO MID 80S
DOMINATING REGION WIDE WITH THE EXCEPTION OF THE RIO GRANDE VLY AND
HIGHER ELEVATIONS OUT WEST. PARTLY CLOUDY TO MOSTLY CLEAR SKIES
OVERNIGHT WILL ALLOW DECENT RADIATIONAL COOLING POTENTIAL CWA
WIDE...WITH MOS GUIDANCE FAILING TO CAPTURE FULL RADIATIONAL COOLING
POTENTIAL. THUS...HAVE KEPT OVERNIGHT LOWS AT OR BELOW MET/MAV
GUIDANCE WHICH CONTINUES TO BE TOO WARM...WITH VALUES POINTED
TOWARDS THE FWC MOS GUIDANCE WHICH APPEARS TO BE CAPTURING
RADIATIONAL POTENTIAL BETTER.

EXTENDED (THU-SUN)

FAIRLY TRANQUIL FORECAST ANTICIPATED THROUGH THE EXTENDED PERIOD
AS STRONG MID/UPPER LEVEL RIDGE CONTINUES SLIDING EASTWARD FROM THE
CENTRAL ROCKIES INTO THE CENTRAL PLAINS. SURPRISINGLY EXCELLENT
AGREEMENT BETWEEN GFS/ECMWF SOLUTIONS WITH BOTH SHOWING EASTWARD
EXPANSION OF MID-LEVEL FEATURE AND PROLONGED NORTHEASTERLY MID-LEVEL
FLOW ACROSS MAF CWA. ALL SIGNS CONTINUE TO POINT TOWARDS A RATHER
DRY EXTENDED PERIOD AS SFC RIDGING EMANATING FROM HIGH PRESSURE
LOCATED ACROSS THE NORTHEAST CONTINUES EXTENDING SWWD INTO  CENTRAL
TX. IN RESPONSE TO PRONOUNCED RIDGING ALOFT...VERY WEAK MID-LEVEL
FLOW EXPECTED THROUGH MUCH OF THE FORECAST PERIOD...WITH WEAK SFC
FLOW ALSO ANTICIPATED AS A RESULT OF PRONOUNCED SFC RIDGE AXIS.  H85
TEMPS REMAIN RATHER NEUTRAL THROUGH MUCH OF THE PERIOD...SUGGESTING
A PROLONGED PERIOD OF LOWER TO MIDDLE 80S FOR DAYTIME HIGHS WITH
DECENT POTENTIAL FOR EFFECTIVE RADIATIONAL COOLING AT NIGHT.
CONTRARY TO YESTERDAY/S MODELS...CURRENT TRENDS DO SUGGEST SOME
CLOUD COVER HANGING AROUND WITH MID-LEVEL MOISTURE POTENTIALLY
EMANATING NORTHWARD FROM NORTHERN MEXICO. FOR NOW...HAVE DECIDED TO
ONLY MAKE MINOR CHANGES TO FORECASTED HIGHS...WHILE KEEPING
OVERNIGHT LOWS AT OR JUST BELOW MEX GUIDANCE WITH CONCERNS FOR
RADIATIONAL COOLING AND WEAK SFC WINDS. UPPER RIDGE BEGINS TO BREAK
DOWN BY SUNDAY AS DEEP EAST COAST LOW CONTINUES SLIDING UP THE EAST
COAST AND THE NEXT UPPER-LEVEL TROUGH BEGINS DROPPING OUT OF THE
NORTHERN ROCKIES/INTERMOUNTAIN WEST.

&&

.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR THE FOLLOWING
     ZONES... PRESIDIO VALLEY.

&&

10

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
225 PM CDT SUN SEP 21 2008

NMZ027>029-033-034-TXZ045>048-050>053-057>063-067>070-074-075-
079>082-258-221930-
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-
225 PM CDT SUN SEP 21 2008 /125 PM MDT SUN SEP 21 2008/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

MODERATE TO MAJOR FLOODING CONTINUES ALONG THE RIO GRANDE RIVER
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. A SLOW FALL IS EXPECTED TO
CONTINUE THROUGH EARLY NEXT WEEK. HOWEVER...ADDITIONAL RELEASES
FROM THE LUIS LEON RESERVOIR COULD CAUSE ADDITIONAL RISES.
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...MONDAY THROUGH SATURDAY

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