FXUS64 KMAF 292344
AFDMAF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
544 PM CST SUN NOV 29 2009

.DISCUSSION...

SEE AVIATION DISCUSSION BELOW.

&&

.AVIATION...

TRICKY FORECAST FOR THE NEXT 24 HRS...W/CIGS BEING THE MAJOR 
AVIATION CONCERN.  CURRENTLY...WEAK SHORTWAVE MOVING THRU THE AREA 
IS BRINGING -RA INTO THE REGION...BUT THIS SHOULD REMAIN LIQUID FOR 
THE DURATION OF THE FORECAST PD.  MOST TERMINALS CURRENTLY MVFR 
CIGS...BUT MODEL FORECAST SOUNDINGS INDICATE CIGS IMPROVING TO VFR 
ALL TERMINALS BY 15Z MONDAY...AS SLIGHTLY DRIER AIR MOVES IN A DRIES 
OUT THE PBL A BIT.

&&

.PREV DISCUSSION... /ISSUED 246 PM CST SUN NOV 29 2009/ 

DISCUSSION...
COMPLICATED WEATHER SCENARIO ON TAP THROUGH TUESDAY NIGHT. A
SIGNIFICANT UPPER LEVEL LOW SPINNING OVER BAJA THIS AFTERNOON HAS
YET TO BEGIN SIGNIFICANT EASTWARD PROGRESS...MAKING IT DIFFICULT
TO PINPOINT THE FORECAST...PARTICULARLY WITH RESPECT TO THE
AVAILABILITY OF COLD AIR AND MOISTURE AS THIS SYSTEM PASSES. THERE
WILL CONTINUE TO BE A HIGHER DEGREE OF UNCERTAINTY IN THE FORECAST
UNTIL THE TRACK AND TIMING OF THIS UPPER LOW IS MORE DETERMINED.

NEVERTHELESS...MODELS ARE CURRENTLY IN DECENT AGREEMENT AT THIS
POINT CONCERNING BOTH TIMING AND TRACK. THE BIGGEST DIFFERENCES AT
THIS POINT APPEAR TO BE THE AMOUNT OF COLD AIR AVAILABLE WITH THIS 
SYSTEM. THE NAM MODEL ALREADY SEEMS SIGNIFICANTLY TOO WARM IN LOW
LEVELS BASED ON SNOWFALL ALREADY SEEN TODAY AT QUEEN AND TATUM NEW
MEXICO. THE WARM LAYER JUST ABOVE THE SURFACE DEPICTED IN NAM BUFR
SOUNDINGS APPARENTLY DOES NOT EXIST TO THE DEGREE SHOWN. HAVE
CONSEQUENTLY CHOSEN TO PUT MORE FAITH IN THE GFS BUFR SOUNDINGS
FOR DETERMINATION OF PRECIPITATION TYPE FOR THIS PACKAGE.

THOUGH MINOR DISTURBANCES IN FLOW AHEAD OF UPPER LEVEL LOW WILL
LIKELY PRODUCE AREAS OF LIGHT RAIN OR SHOWERS...MOST AREAS SHOULD
REMAIN DRY OVERNIGHT. AREAS FURTHER WEST WILL SEE MORE SIGNIFICANT
PRECIPITATION BEGIN TO DEVELOP OVERNIGHT AS THE UPPER LOW BEGINS TO
APPROACH. SNOW IS POSSIBLE IN THE UPPER ELEVATIONS OF THE
GUADALUPE MOUNTAINS OVERNIGHT...BUT PRECIPITATION IS EXPECTED TO
START OUT TOO LIGHT FOR SIGNIFICANT ACCUMULATIONS. HOWEVER...THE
PRESSURE GRADIENT ACROSS THE GUADALUPE PASS IS EXPECTED TO PRODUCE
HIGH WINDS THROUGH DAYBREAK MONDAY. A HIGH WIND WARNING WILL BE
EFFECT THROUGH DAYBREAK. A RAIN AND SNOW MIX IS POSSIBLE IN THE
HIGH PLAINS ADJACENT TO THE MOUNTAINS AND ALSO IN THE DAVIS
MOUNTAINS OVERNIGHT.

DURING THE DAY MONDAY...MODERATE TO OCCASIONALLY HEAVY SNOW WILL
DEVELOP IN THE MOUNTAINS. A WINTER STORM WARNING FOR HEAVY SNOW IS
IN EFFECT FOR THE GUADALUPE MOUNTAINS MONDAY THROUGH MONDAY NIGHT.
A WINTER STORM WATCH IS IN EFFECT FOR CULBERSON COUNTY...THE DAVIS
MOUNTAINS AND EDDY COUNTY WHERE TEMPERATURES MAKE THE THREAT OF
HEAVY SNOWFALL LESS CERTAIN AT PRESENT...YET A SUFFICIENT THREAT
STILL EXISTS.

THOUGH CLOUDS AND PRECIPITATION ARE LIKELY TO KEEP TEMPERATURES
SIGNIFICANTLY COLDER THAN GUIDANCE SHOWS ON MONDAY...LOW LEVEL
TEMPERATURES ARE EXPECTED TO STAY TOO WARM FOR SNOW IN THE
PLAINS THROUGH MUCH OF MONDAY NIGHT. AS THE UPPER LEVEL LOW
CONTINUES TO MOVE SLOWLY EAST...LOW LEVEL TEMPERATURES ARE
EXPECTED TO DROP ACCOMPANIED BY INCREASING PRECIPITATION RATES
INTO THE PLAINS. MODERATE TO HEAVY SNOWFALL IS POSSIBLE ACROSS
MUCH OF WEST TEXAS AND SOUTHEAST NEW MEXICO...EXCEPT NEAR THE RIO
GRANDE VALLEY WHERE TEMPERATURES WILL BE TOO WARM. PRECIPITATION
WILL WIND DOWN TUESDAY NIGHT OVER THE NORTHEAST ZONES AS THE LOW
PULLS AWAY.

THOUGH CURRENT PACKAGE DROPS FORECAST TEMPERATURES BELOW GUIDANCE
TUESDAY DUE TO CLOUDINESS...PRECIPITATION AND LIFT PROVIDED BY
UPPER LOW...TEMPERATURES WILL STILL BE MARGINAL AND WILL BE A
SIGNIFICANT FACTOR IN THE AMOUNT OF SNOWFALL THAT OCCURS ACROSS
THE AREA. FURTHER MONITORING OF THE WEATHER SITUATION WILL BE
REQUIRED...AND ADDITIONAL STATEMENTS WILL BE ISSUED AS THE SITUATION
BECOMES BETTER DEFINED.

&&

.MAF WATCHES/WARNINGS/ADVISORIES...
NM...WINTER STORM WARNING FROM 5 AM MONDAY TO 5 AM MST TUESDAY FOR 
     THE FOLLOWING ZONES... GUADALUPE MOUNTAINS OF EDDY COUNTY.

     WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE MONDAY NIGHT 
     FOR THE FOLLOWING ZONES... EDDY COUNTY PLAINS.

TX...HIGH WIND WARNING FROM 8 PM THIS EVENING TO 8 AM MST MONDAY FOR 
     THE FOLLOWING ZONES... GUADALUPE MOUNTAINS.

     WINTER STORM WARNING FROM 5 AM MONDAY TO 5 AM MST TUESDAY FOR 
     THE FOLLOWING ZONES... GUADALUPE MOUNTAINS.

     WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT 
     FOR THE FOLLOWING ZONES... DAVIS/APACHE MOUNTAINS AREA...
     VAN HORN AND HIGHWAY 54 CORRIDOR.

&&

$$

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